~FLATHEADS~
1. OVERVIEW & HISTORY 7. IGNITION
2. FUEL FLOW 8. INDUCTION
3. HEADS 9. EXHAUST
4. CAMSHAFTS 10. LUBRICATION
5. CRANKSHAFT
6. RODS & PISTONS
2. FUEL FLOW 8. INDUCTION
3. HEADS 9. EXHAUST
4. CAMSHAFTS 10. LUBRICATION
5. CRANKSHAFT
6. RODS & PISTONS
CAMSHAFTS
This is my favorite subject, it’s no secret that I’m a
camaholic, I never met one I didn’t like. The stock camshaft
for the Ford and Mercury Flathead V8 is a mild unit, built
for lugging up hills, tooling around town and giving
adequate performance when required. It’s a good piece and
would probably work well in a supercharger application as
well but it’s not what we as racers are after as it is a
compromise in relation to performance. The Full Race
camshaft is another story altogether, it’s not a compromise
at all and in fact is only used to its full capacity when the
throttle is wide open and the engine is reaching its limit as
far as still remaining an engine. That’s what we’re after.
The camshaft is the heart of the engine, its job is to open
the valves at the correct time allowing fuel-air mixture to
enter the combustion chamber and do its work. The longer
the valve stays open, the more fuel that gets into the
chamber, the bigger the bang that follows. Following this
line of thought, all one had to do was make the lobes bigger
on the camshaft and you would get more performance and
that’s pretty much how it started. A fellow named Pierre
Bertrand started this practice with 4 cylinders in the 1920’s
but one of his disciples; Ed Winfield, was the first true high
performance cam grinder and his cams were copied for
decades. Ed took everything into account in his designs,
lift, duration, overlap and lobe centers, scavenging effects
and spring rates, anything that affected the overall
performance of the engine. He was genius and everyone
who has followed owes a tip of the hat to Ed.
OK, let’s get to the racing cam, there are three basic types
for the Flathead racer: One; Flat Tappet which is the most
prevalent, easiest to install and most closely resembles the
stock cam, Two; Mushroom Tappet, same basic cam as the
flat tappet with mushroom lifters which have a larger
contact area thus making the cam ‘bigger’, and three;
Radius Tappet, the widest and most cantankerous of the
bunch, the forerunner to the roller cam which we’ll throw
in with it.
Some quick basics and we’re off. Duration is the amount of
time, in crankshaft degrees, that the valve is open. Lift is
the height as which the valve is lifted off the seat. Overlap is
the amount of time that both intake and exhaust valves are
open, this is affected by the centerline of the intake versus
exhaust lobe (hence lobe center) as well as duration.
Scavenging is the affect of the exhaust charge being pushed
out and subsequently drawing intake charge in. Got it,
good. First, the Flat Tappet camshaft. Most flathead
racing cams are of this type which uses the stock type, flat
bottomed lifter. In fact most racing cams actually came from
stock cams in the first place; the grinders would just
decrease the base circle of each lobe in order to gain the
desired lift. Think of it this way, the greater the amount of
volume of the lobe (minus the base circle), the greater the
amount of fuel mixture that gets into the combustion
chamber. There are several advantages to a flat tappet
camshaft; they do not require any specialized tools for
installation, usually a hole drilled in the lifter bore and a
nail will do (if you’re using adjustable lifters). They are
usually easier on the valve train as they do not require as
much spring pressure to hold the lifter to the cam and as
such have excellent wear characteristics. They are also still
available new, or as they were more prevalent than any
other style, easily found. Ed Winfield preferred this type of
cam mainly because of the spring rates required, less
spring pressure equals less horsepower to work the valve
train and subsequently less heat. His cams had gentle
ramps, moderate lifts (in comparison to later cams) and
were the noted ‘top dog’ of the late 40’s. Other cam grinders
followed such as Clay Smith and Ed Iskendarian, they too
started with moderate lifts but soon explored higher rates.
Still, Winfield’s SU-1A was the hot cam of its day with 0.350
lift and 280 degree duration. It was the basis of many a
following racing camshaft, including Chuck Potvin’s
masterpiece; the Potvin 425 Eliminator. It was aptly named
as it often either eliminated the competition or the engine.
OK, so why the nail? Placed in a hole in the lifter bore it
holds the lifter in place while you adjust it and is a lot
easier than working with the Johnson wrenches, anyone
who has worked with either will agree. Adjustable lifters
help make up the difference removed from the base circle of
the cam and although they aren’t a must, they are easier to
work with. Or you can do it like Henry did and either grind
the valve tip or tip of your nice light non-adjustable lifter – if
you can get one with enough tip left on it to make the valve
lash. In the end, these are better as they are lighter, and
never go out of adjustment. I’ve seen plenty of adjustable
lifters with either a jam nut on them or a glob of weld to
hold the adjusting screw in place. OK, so what are some of
the best cams? The SU-1A is highly regarded, the Potvin
425 works extremely well from my experience, likes the
RPM’s and keeps pulling. I’ve tried a Giovannani 999 and
that cam worked real well, especially at Syracuse. Crane’s
353-2 was recommended by Bob Hayslett, I know that ‘Pop’
Enders used Isky 1007 LD cams and we’ve had good luck
with an Isky 1007B as well. Friends from New England
swear by Literio’s (Isky of the East) L100, we’ve also had
good luck with Racer Brown and Schneider grinds. You get
the picture, there are a lot of good cams to try and many
such as Isky’s 400Jr., Potvin’s 425, Schneider’s and
Literio's cams are still available. My recommendation as a
good rule of thumb for circle track racing is to get a
camshaft with around 0.370 total lift minimum and 270
degrees of duration, that’ll run and you won’t have to do
any carving in the valve pocket of the head. More lift equals
more work, check the depth of the heads you plan to use
first. If they have a stamping on them that says ‘400’ (and
haven’t been planed too much) then you can probably get
away with 0.400 lift. Edelbrocks usually have the
compression ratio stamped, the higher the ratio, the
shallower the valve pockets, measure first.
Next up, the Mushroom Tappet cam. Another basic
brainchild of Winfield’s and again, used subsequently by
Clay Smith and Ed Iskendarian. These cams look just like
the flat tappet offerings but used a larger based lifter which
immediately made the cam ‘bigger’ in that the opening and
closing rates were accelerated by the larger surface area the
lifters provided. This obviously increased what I call lift at
duration and got more air in the engine over the same
amount of time the valve is open. A Real Good Deal. Also,
since it’s still a flat tappet cam, wear characteristics are still
great (even better than a flat tappet cam), spring rates are
still tolerable and the lifter still spins in the bore with even
less side thrust than the 1 inch flat tappet. Think of this
combination as ‘mechanical advantage’ much in the same
way that an OHV engine can gain lift at duration by using a
different ratio rocker. Obviously, Flatheads don’t have
rockers but by using the larger based lifter (the mushroom
tappet has a 1.182 inch base versus the standard 0.999
inch base of the flat tappet), the ‘volume’ of the lobe is
increased so to speak. The only drawback is installation
which requires the use of a back cutter to spot face the
bottom of the lifter bore and provides clearance for the
lifters larger base. You’ll also need a set of bronze bushings
with the lifters, if you can find them. The lifters used came
on Studebaker Champs, which were 6 cylinders so you’ll
need to find two of them. They were also made by
Whitteman in the 50’s and can still probably be had at Egge
or similar restoration parts manufacturers. The one I have is
a Clay Smith X-270 grind that Little Joe Lawrence
bestowed me with (it actually says ‘Potvin 60’ on it – just
another decoy often used by racers and cam grinders who
didn’t want their competitors seeing what grind they were
running when they took the front mount ignition off). He
related it worked real well with a supercharger which I’d
like to try out someday. Joe and his driver, D.D. ‘Rebel’
Harris sure did well with the set-up they had in the early
1960’s at the eastern NY tracks and it should be noted that
Barney Navarro has always favored this setup although from
what I gathered he did it with a Winfield SU-1A. Bottom line
in my opinion is that this is a fine set-up.
Last up is the Radius Tappet camshaft, this is the one most
of the top Flathead racers used. This cam had extremely
high lift rates and lots of lift, although usually less duration
(to build compression) than the flat tappet offerings. They
were easily the most radical cams and the forerunner to the
roller. When Fred Offenhauser bought out Henry Miller and
wanted to go into business he consulted with Ed Winfield
about the cams, Ed said make everything bigger (like the
mushroom tappet) but Fred couldn’t afford it so they came
up with the radius (cup) cam instead, so that’s where these
types of cams originated. Due to their radical design, they
usually exhibited greater wear then a flat or mushroom
tappet but who cared, once worn out it was going to just be
replaced by another and it gave the greatest performance
on a short track, at the drags, and often the dry lakes as
well. The lobes of a radius camshaft ramp up quickly, often
with no clearance ramp, flatten off at the top and then come
back down to the base circle just as quickly. They are the
limit as far as ‘volume’ of the lobe and since they can return
the valve to its seat so quickly, they also help the engine
build compression. With the lobe ground as it is, the lifter
had to have clearance and thus was radiused on the
bottom, in one plane only. This meant that the lifter had to
be held in that plane to stay aligned with the cam lobe and
again, special tooling was required for installation. There
are two different types of lifters: The Weber 1 inch radius
and the Isky or Crane type 2 inch radius. Each used a
different type of aligning mechanism, both worked well if
installed properly. The Weber has the retaining key in the
lifter itself and then a slot has to cut in the inside of the
lifter bore in the block with a broach. Weber made the tool
and it should be noted that the new Crower roller liters
(with a 1 inch roller ball) use the same approach. The only
tool I know of like this resides in Michigan at Mark Kirby’s
Motor City Flathead shop but he’ll let you borrow it if
needed, at least he let me borrow it. The lifter is then
aligned to the camshaft (in this case a Weber F-7 Giant) and
the setup works perfectly. More common was the
Iskendarian or Crane set up which used a 2 inch radius
lifter with the key placed on the inside of the lifter bore,
and then the lifter itself is slotted to hold it in alignment
with the cam lobe. This requires the use of a jig to drill the
lifter bore from the oil valley side of the block, a ‘flattening’
tool to jam the key in place and then bending over the ends
of the ‘key’ on the outside of the bore to hold them
securely. It requires a lot of patience, a file to ensure the
lifter doesn’t hang up and maintenance. If that lifter gets
out of the key it’ll wipe a lobe off the cam pronto. Also, don’t
use a block that has been previously drilled for lifter
adjustment via the previously mentioned nail method, the
holes have to be perfect to hold the key in place. OK, so
that's the tough stuff, now for the good part, these cams
were used by nearly all of the top racers in Central NY that
I know of and they won a lot of checkered flags. I honestly
think that a Mushroom Tappet cam is the best setup but
they were not as prevalent as the Radius cams. There’s
nothing wrong with a Flat Tappet cam either, they also won
a lot and were easier to maintain but if you talked to the
top racers at Waterloo, Watertown, Midstate or the NYS
Fairgrounds, nearly all had a radius type cam. OK, onto
some of the best, obviously the Iskendarian 404A Track was
the most famous of the bunch and won a ton, Crane’s
offerings of the 425, and the 425-2 were also excellent and
since they were offered by Bill Beamon of B&M Speedshop
in Rochester, were often used by racers at Waterloo. Clay
Smith’s 4-54 is a good cam in a big engine, as is Weber’s
F-7 Giant. Bob Hayslett sold me an F-7 that I’m using now
and it’s super, he related that I should try the 2 inch lifters
on it (instead of the 1 inch Webers), as Woody Van Order
did. I thought about it but went with it as engineered
instead, where you gonna find another one if you ruin this
one? It works real well on the 1 inch radius and although I
understood what Bob was getting at – faster action – in the
end I didn’t want to chance it. Lastly is that cam that only
one guy I’ve talked to here in NY knew about and that’s
John Schoolers offerings from Jacksonville, Florida. Cliff
Kotary won 5 of his 6 NYS Fair Races with Schooler cams,
Willy Wust would’ve had to pay plenty of peso’s for that
information. While many of the cams were ‘single pattern’
(the Isky 404, Potvin 425, Crane 425, etc.) a few were of
‘dual pattern’ design such as the Crane 425-2 and
Schoolers. Harvey Crane went to the dual pattern cam later
with his 425-2, using the same intake lobe as the 425 but a
355 exhaust lobe and it worked extremely well with less lift
on the exhaust. I’ve run the one Bob Hayslett had in his
original B29 and it cooks, excellent cam. Schoolers
approach was different though, he felt than in order to get
fuel into the engine, you had to get the exhaust out first
and ground his cams accordingly with higher lift on the
exhaust lobe. This thought goes hand in hand with the
philosophies of the Racer Rocket and Al Sharp’s heads. I
was fortunate to find a Schooler a few years back and must
try it out. One would have to note that Cliff did pretty
darned good with his equipment and has always related to
me that the Schooler cams were the best he ever ran.
Bottom line, if you can find a good radius tappet camshaft
for your Flathead race engine and have the means of
getting it installed, then use it. All of them turn up fast and
hard so plan accordingly. I prefer the chilled cast iron
lifters, they’re a little heavier but wear much better than
the lightweight steel lifters from Isky, remember these
lifter’s don’t turn so wear is an issue. Pay attention to your
spring rates, Isky requires 195 lb. open so test your springs
at open height and shim accordingly. I use the Isky 185-G
springs as they’re available and much easier to work with
than the dual spring setup although those work well also. If
you can’t find a radius or mushroom tappet cam then there
are several other flat tappet options that also work
extremely well. The Potvin 425, the Howard M-16, Isky 431
(the later Isky 433 is good too, blew one of Dad’s engines
into the weeds), the Literio L-100 (which John Flach uses
and is available through Cam Techniques in Florida) and
Schneider will grind you anything you want. Plenty of
choices. The thing to do is to take everything you want to do
into account, what do I have for engine size, what will my
budget allow, the heads that I have and what do I want the
engine to do? Do the research and then plan your engine
around your camshaft. Properly applied, any of the
camshafts mentioned here will give satisfactory results, but
again, that’s only one piece, although the most important
piece, of the puzzle.
Other pieces of the valve train puzzle include the guides,
valves and springs. Guides are simple, find a set that isn’t
heavily worn and use them. I have had guides reamed and
lined with knurled bronze inserts for greater lubrication
and less wear but have noticed no difference over stock
guides. My recommendation is to use guides with 0.0005
clearance minimum and make sure that the valve slips in
and out of them easily. That’s it, you can use Permatex #1
to glue them in place if you wish to keep any fuels out of
the oil but this generally isn’t a problem with new o-ring
gaskets. I put them in place in the block when I do the
porting to contour them as I wish. For springs there are a
couple of choices; Reds Headers sells a Lincoln Zephyr
spring which works very well and is affordable, so does
Iskendarian, part # 185-G which is what I generally use. I
wouldn’t hesitate to use either. If you have used springs
just be sure to test them before installation, over time they
deteriorate and used springs aren’t always good. For the
185-G springs on a radius camshaft I use an installed
height of 1.950 inch which equals 100# on the seat. Check
your installed height as assembled as many factors such as
valve length and lock groove placement may vary from valve
to valve. Usually, two 0.060 shims will work on a stock valve
set-up. I don’t generally use the Isky dual springs just
because they have to be disassembled and re-assembled in
the block which is more difficult and I have found that the
185-G gives the same performance. The 185-G can be taken
out of the block with the guide and valve as an assembly
which is easier to work with. Not that the dual springs
aren’t a fine piece, they are, just tougher to work with.
Valve seats: in the block I have used both 45 and 30 degree
seats, I now use 30 degree seats on the intake and 45 on
the exhaust. On the valve faces themselves I use 44 degrees
on the intake valve and 29 degrees on the exhaust valve,
this gives an interference between the seats and I lap them
in lightly to ensure the seal. It also moves the seal to the
outmost section of the valve face which offers more surface
area for better sealing and cooling. I check the seal by
placing the block on the stand with the valve flat, click it
shut and spray carb cleaner on it to create a puddle. If the
valve will hold carb cleaner you have a good seal. For valves I
have used several types, SI for oversize valves, of course
stock valves and Manley ‘Race Flow’ as well. Stock valves
work fine, they are 1.500 inch diameter and with a little
work can actually flow quite well. Don’t use the one with
the big stop on them that butts up against the guide, not
the hot set-up. We used a carbide cutter on an engine lathe
to rid ourselves of that lump and these valves worked great,
and still do. The oversize 1.600 – 1.625 inch valves require
ample porting and seat reaming work to really make a
difference, not to mention the extra work in the heads to
get the flow around them. I have used them and they have
run well in engines but at this point I don’t see a great
advantage over my first choice which is Manley small block
Chevy (ok, so it’s not the valves fault, they don’t know
they’re for a chevy) ‘Race Flow” valves P/N 11521, 1.500
inch diameter, with 11/32 stem. These are just beautiful
valves, undercut below the valve tulip in the area of port
flow, swirl polished, stainless, light, stellite tipped for great
wear characteristics and they’ve also 0.060 inch longer (add
a shim) than stock valves which means you can now use
that stock adjustable lifter (versus the heavier ‘race cam’
adjustable lifter which has a thicker head on the adjusting
screw, and is consequently heavier). Great set-up. Now, get
some retainers from Flathead Jack and the corresponding
hardened 7 degree valve locks and you have a kick ass set-
up that will last for years. Ok, now let’s get to the bottom
end and look at the crankshaft.
camaholic, I never met one I didn’t like. The stock camshaft
for the Ford and Mercury Flathead V8 is a mild unit, built
for lugging up hills, tooling around town and giving
adequate performance when required. It’s a good piece and
would probably work well in a supercharger application as
well but it’s not what we as racers are after as it is a
compromise in relation to performance. The Full Race
camshaft is another story altogether, it’s not a compromise
at all and in fact is only used to its full capacity when the
throttle is wide open and the engine is reaching its limit as
far as still remaining an engine. That’s what we’re after.
The camshaft is the heart of the engine, its job is to open
the valves at the correct time allowing fuel-air mixture to
enter the combustion chamber and do its work. The longer
the valve stays open, the more fuel that gets into the
chamber, the bigger the bang that follows. Following this
line of thought, all one had to do was make the lobes bigger
on the camshaft and you would get more performance and
that’s pretty much how it started. A fellow named Pierre
Bertrand started this practice with 4 cylinders in the 1920’s
but one of his disciples; Ed Winfield, was the first true high
performance cam grinder and his cams were copied for
decades. Ed took everything into account in his designs,
lift, duration, overlap and lobe centers, scavenging effects
and spring rates, anything that affected the overall
performance of the engine. He was genius and everyone
who has followed owes a tip of the hat to Ed.
OK, let’s get to the racing cam, there are three basic types
for the Flathead racer: One; Flat Tappet which is the most
prevalent, easiest to install and most closely resembles the
stock cam, Two; Mushroom Tappet, same basic cam as the
flat tappet with mushroom lifters which have a larger
contact area thus making the cam ‘bigger’, and three;
Radius Tappet, the widest and most cantankerous of the
bunch, the forerunner to the roller cam which we’ll throw
in with it.
Some quick basics and we’re off. Duration is the amount of
time, in crankshaft degrees, that the valve is open. Lift is
the height as which the valve is lifted off the seat. Overlap is
the amount of time that both intake and exhaust valves are
open, this is affected by the centerline of the intake versus
exhaust lobe (hence lobe center) as well as duration.
Scavenging is the affect of the exhaust charge being pushed
out and subsequently drawing intake charge in. Got it,
good. First, the Flat Tappet camshaft. Most flathead
racing cams are of this type which uses the stock type, flat
bottomed lifter. In fact most racing cams actually came from
stock cams in the first place; the grinders would just
decrease the base circle of each lobe in order to gain the
desired lift. Think of it this way, the greater the amount of
volume of the lobe (minus the base circle), the greater the
amount of fuel mixture that gets into the combustion
chamber. There are several advantages to a flat tappet
camshaft; they do not require any specialized tools for
installation, usually a hole drilled in the lifter bore and a
nail will do (if you’re using adjustable lifters). They are
usually easier on the valve train as they do not require as
much spring pressure to hold the lifter to the cam and as
such have excellent wear characteristics. They are also still
available new, or as they were more prevalent than any
other style, easily found. Ed Winfield preferred this type of
cam mainly because of the spring rates required, less
spring pressure equals less horsepower to work the valve
train and subsequently less heat. His cams had gentle
ramps, moderate lifts (in comparison to later cams) and
were the noted ‘top dog’ of the late 40’s. Other cam grinders
followed such as Clay Smith and Ed Iskendarian, they too
started with moderate lifts but soon explored higher rates.
Still, Winfield’s SU-1A was the hot cam of its day with 0.350
lift and 280 degree duration. It was the basis of many a
following racing camshaft, including Chuck Potvin’s
masterpiece; the Potvin 425 Eliminator. It was aptly named
as it often either eliminated the competition or the engine.
OK, so why the nail? Placed in a hole in the lifter bore it
holds the lifter in place while you adjust it and is a lot
easier than working with the Johnson wrenches, anyone
who has worked with either will agree. Adjustable lifters
help make up the difference removed from the base circle of
the cam and although they aren’t a must, they are easier to
work with. Or you can do it like Henry did and either grind
the valve tip or tip of your nice light non-adjustable lifter – if
you can get one with enough tip left on it to make the valve
lash. In the end, these are better as they are lighter, and
never go out of adjustment. I’ve seen plenty of adjustable
lifters with either a jam nut on them or a glob of weld to
hold the adjusting screw in place. OK, so what are some of
the best cams? The SU-1A is highly regarded, the Potvin
425 works extremely well from my experience, likes the
RPM’s and keeps pulling. I’ve tried a Giovannani 999 and
that cam worked real well, especially at Syracuse. Crane’s
353-2 was recommended by Bob Hayslett, I know that ‘Pop’
Enders used Isky 1007 LD cams and we’ve had good luck
with an Isky 1007B as well. Friends from New England
swear by Literio’s (Isky of the East) L100, we’ve also had
good luck with Racer Brown and Schneider grinds. You get
the picture, there are a lot of good cams to try and many
such as Isky’s 400Jr., Potvin’s 425, Schneider’s and
Literio's cams are still available. My recommendation as a
good rule of thumb for circle track racing is to get a
camshaft with around 0.370 total lift minimum and 270
degrees of duration, that’ll run and you won’t have to do
any carving in the valve pocket of the head. More lift equals
more work, check the depth of the heads you plan to use
first. If they have a stamping on them that says ‘400’ (and
haven’t been planed too much) then you can probably get
away with 0.400 lift. Edelbrocks usually have the
compression ratio stamped, the higher the ratio, the
shallower the valve pockets, measure first.
Next up, the Mushroom Tappet cam. Another basic
brainchild of Winfield’s and again, used subsequently by
Clay Smith and Ed Iskendarian. These cams look just like
the flat tappet offerings but used a larger based lifter which
immediately made the cam ‘bigger’ in that the opening and
closing rates were accelerated by the larger surface area the
lifters provided. This obviously increased what I call lift at
duration and got more air in the engine over the same
amount of time the valve is open. A Real Good Deal. Also,
since it’s still a flat tappet cam, wear characteristics are still
great (even better than a flat tappet cam), spring rates are
still tolerable and the lifter still spins in the bore with even
less side thrust than the 1 inch flat tappet. Think of this
combination as ‘mechanical advantage’ much in the same
way that an OHV engine can gain lift at duration by using a
different ratio rocker. Obviously, Flatheads don’t have
rockers but by using the larger based lifter (the mushroom
tappet has a 1.182 inch base versus the standard 0.999
inch base of the flat tappet), the ‘volume’ of the lobe is
increased so to speak. The only drawback is installation
which requires the use of a back cutter to spot face the
bottom of the lifter bore and provides clearance for the
lifters larger base. You’ll also need a set of bronze bushings
with the lifters, if you can find them. The lifters used came
on Studebaker Champs, which were 6 cylinders so you’ll
need to find two of them. They were also made by
Whitteman in the 50’s and can still probably be had at Egge
or similar restoration parts manufacturers. The one I have is
a Clay Smith X-270 grind that Little Joe Lawrence
bestowed me with (it actually says ‘Potvin 60’ on it – just
another decoy often used by racers and cam grinders who
didn’t want their competitors seeing what grind they were
running when they took the front mount ignition off). He
related it worked real well with a supercharger which I’d
like to try out someday. Joe and his driver, D.D. ‘Rebel’
Harris sure did well with the set-up they had in the early
1960’s at the eastern NY tracks and it should be noted that
Barney Navarro has always favored this setup although from
what I gathered he did it with a Winfield SU-1A. Bottom line
in my opinion is that this is a fine set-up.
Last up is the Radius Tappet camshaft, this is the one most
of the top Flathead racers used. This cam had extremely
high lift rates and lots of lift, although usually less duration
(to build compression) than the flat tappet offerings. They
were easily the most radical cams and the forerunner to the
roller. When Fred Offenhauser bought out Henry Miller and
wanted to go into business he consulted with Ed Winfield
about the cams, Ed said make everything bigger (like the
mushroom tappet) but Fred couldn’t afford it so they came
up with the radius (cup) cam instead, so that’s where these
types of cams originated. Due to their radical design, they
usually exhibited greater wear then a flat or mushroom
tappet but who cared, once worn out it was going to just be
replaced by another and it gave the greatest performance
on a short track, at the drags, and often the dry lakes as
well. The lobes of a radius camshaft ramp up quickly, often
with no clearance ramp, flatten off at the top and then come
back down to the base circle just as quickly. They are the
limit as far as ‘volume’ of the lobe and since they can return
the valve to its seat so quickly, they also help the engine
build compression. With the lobe ground as it is, the lifter
had to have clearance and thus was radiused on the
bottom, in one plane only. This meant that the lifter had to
be held in that plane to stay aligned with the cam lobe and
again, special tooling was required for installation. There
are two different types of lifters: The Weber 1 inch radius
and the Isky or Crane type 2 inch radius. Each used a
different type of aligning mechanism, both worked well if
installed properly. The Weber has the retaining key in the
lifter itself and then a slot has to cut in the inside of the
lifter bore in the block with a broach. Weber made the tool
and it should be noted that the new Crower roller liters
(with a 1 inch roller ball) use the same approach. The only
tool I know of like this resides in Michigan at Mark Kirby’s
Motor City Flathead shop but he’ll let you borrow it if
needed, at least he let me borrow it. The lifter is then
aligned to the camshaft (in this case a Weber F-7 Giant) and
the setup works perfectly. More common was the
Iskendarian or Crane set up which used a 2 inch radius
lifter with the key placed on the inside of the lifter bore,
and then the lifter itself is slotted to hold it in alignment
with the cam lobe. This requires the use of a jig to drill the
lifter bore from the oil valley side of the block, a ‘flattening’
tool to jam the key in place and then bending over the ends
of the ‘key’ on the outside of the bore to hold them
securely. It requires a lot of patience, a file to ensure the
lifter doesn’t hang up and maintenance. If that lifter gets
out of the key it’ll wipe a lobe off the cam pronto. Also, don’t
use a block that has been previously drilled for lifter
adjustment via the previously mentioned nail method, the
holes have to be perfect to hold the key in place. OK, so
that's the tough stuff, now for the good part, these cams
were used by nearly all of the top racers in Central NY that
I know of and they won a lot of checkered flags. I honestly
think that a Mushroom Tappet cam is the best setup but
they were not as prevalent as the Radius cams. There’s
nothing wrong with a Flat Tappet cam either, they also won
a lot and were easier to maintain but if you talked to the
top racers at Waterloo, Watertown, Midstate or the NYS
Fairgrounds, nearly all had a radius type cam. OK, onto
some of the best, obviously the Iskendarian 404A Track was
the most famous of the bunch and won a ton, Crane’s
offerings of the 425, and the 425-2 were also excellent and
since they were offered by Bill Beamon of B&M Speedshop
in Rochester, were often used by racers at Waterloo. Clay
Smith’s 4-54 is a good cam in a big engine, as is Weber’s
F-7 Giant. Bob Hayslett sold me an F-7 that I’m using now
and it’s super, he related that I should try the 2 inch lifters
on it (instead of the 1 inch Webers), as Woody Van Order
did. I thought about it but went with it as engineered
instead, where you gonna find another one if you ruin this
one? It works real well on the 1 inch radius and although I
understood what Bob was getting at – faster action – in the
end I didn’t want to chance it. Lastly is that cam that only
one guy I’ve talked to here in NY knew about and that’s
John Schoolers offerings from Jacksonville, Florida. Cliff
Kotary won 5 of his 6 NYS Fair Races with Schooler cams,
Willy Wust would’ve had to pay plenty of peso’s for that
information. While many of the cams were ‘single pattern’
(the Isky 404, Potvin 425, Crane 425, etc.) a few were of
‘dual pattern’ design such as the Crane 425-2 and
Schoolers. Harvey Crane went to the dual pattern cam later
with his 425-2, using the same intake lobe as the 425 but a
355 exhaust lobe and it worked extremely well with less lift
on the exhaust. I’ve run the one Bob Hayslett had in his
original B29 and it cooks, excellent cam. Schoolers
approach was different though, he felt than in order to get
fuel into the engine, you had to get the exhaust out first
and ground his cams accordingly with higher lift on the
exhaust lobe. This thought goes hand in hand with the
philosophies of the Racer Rocket and Al Sharp’s heads. I
was fortunate to find a Schooler a few years back and must
try it out. One would have to note that Cliff did pretty
darned good with his equipment and has always related to
me that the Schooler cams were the best he ever ran.
Bottom line, if you can find a good radius tappet camshaft
for your Flathead race engine and have the means of
getting it installed, then use it. All of them turn up fast and
hard so plan accordingly. I prefer the chilled cast iron
lifters, they’re a little heavier but wear much better than
the lightweight steel lifters from Isky, remember these
lifter’s don’t turn so wear is an issue. Pay attention to your
spring rates, Isky requires 195 lb. open so test your springs
at open height and shim accordingly. I use the Isky 185-G
springs as they’re available and much easier to work with
than the dual spring setup although those work well also. If
you can’t find a radius or mushroom tappet cam then there
are several other flat tappet options that also work
extremely well. The Potvin 425, the Howard M-16, Isky 431
(the later Isky 433 is good too, blew one of Dad’s engines
into the weeds), the Literio L-100 (which John Flach uses
and is available through Cam Techniques in Florida) and
Schneider will grind you anything you want. Plenty of
choices. The thing to do is to take everything you want to do
into account, what do I have for engine size, what will my
budget allow, the heads that I have and what do I want the
engine to do? Do the research and then plan your engine
around your camshaft. Properly applied, any of the
camshafts mentioned here will give satisfactory results, but
again, that’s only one piece, although the most important
piece, of the puzzle.
Other pieces of the valve train puzzle include the guides,
valves and springs. Guides are simple, find a set that isn’t
heavily worn and use them. I have had guides reamed and
lined with knurled bronze inserts for greater lubrication
and less wear but have noticed no difference over stock
guides. My recommendation is to use guides with 0.0005
clearance minimum and make sure that the valve slips in
and out of them easily. That’s it, you can use Permatex #1
to glue them in place if you wish to keep any fuels out of
the oil but this generally isn’t a problem with new o-ring
gaskets. I put them in place in the block when I do the
porting to contour them as I wish. For springs there are a
couple of choices; Reds Headers sells a Lincoln Zephyr
spring which works very well and is affordable, so does
Iskendarian, part # 185-G which is what I generally use. I
wouldn’t hesitate to use either. If you have used springs
just be sure to test them before installation, over time they
deteriorate and used springs aren’t always good. For the
185-G springs on a radius camshaft I use an installed
height of 1.950 inch which equals 100# on the seat. Check
your installed height as assembled as many factors such as
valve length and lock groove placement may vary from valve
to valve. Usually, two 0.060 shims will work on a stock valve
set-up. I don’t generally use the Isky dual springs just
because they have to be disassembled and re-assembled in
the block which is more difficult and I have found that the
185-G gives the same performance. The 185-G can be taken
out of the block with the guide and valve as an assembly
which is easier to work with. Not that the dual springs
aren’t a fine piece, they are, just tougher to work with.
Valve seats: in the block I have used both 45 and 30 degree
seats, I now use 30 degree seats on the intake and 45 on
the exhaust. On the valve faces themselves I use 44 degrees
on the intake valve and 29 degrees on the exhaust valve,
this gives an interference between the seats and I lap them
in lightly to ensure the seal. It also moves the seal to the
outmost section of the valve face which offers more surface
area for better sealing and cooling. I check the seal by
placing the block on the stand with the valve flat, click it
shut and spray carb cleaner on it to create a puddle. If the
valve will hold carb cleaner you have a good seal. For valves I
have used several types, SI for oversize valves, of course
stock valves and Manley ‘Race Flow’ as well. Stock valves
work fine, they are 1.500 inch diameter and with a little
work can actually flow quite well. Don’t use the one with
the big stop on them that butts up against the guide, not
the hot set-up. We used a carbide cutter on an engine lathe
to rid ourselves of that lump and these valves worked great,
and still do. The oversize 1.600 – 1.625 inch valves require
ample porting and seat reaming work to really make a
difference, not to mention the extra work in the heads to
get the flow around them. I have used them and they have
run well in engines but at this point I don’t see a great
advantage over my first choice which is Manley small block
Chevy (ok, so it’s not the valves fault, they don’t know
they’re for a chevy) ‘Race Flow” valves P/N 11521, 1.500
inch diameter, with 11/32 stem. These are just beautiful
valves, undercut below the valve tulip in the area of port
flow, swirl polished, stainless, light, stellite tipped for great
wear characteristics and they’ve also 0.060 inch longer (add
a shim) than stock valves which means you can now use
that stock adjustable lifter (versus the heavier ‘race cam’
adjustable lifter which has a thicker head on the adjusting
screw, and is consequently heavier). Great set-up. Now, get
some retainers from Flathead Jack and the corresponding
hardened 7 degree valve locks and you have a kick ass set-
up that will last for years. Ok, now let’s get to the bottom
end and look at the crankshaft.
Stock cams were often ground
for quicker opening and
closing times, giving
additional duration.
for quicker opening and
closing times, giving
additional duration.
Stock, 3/4, and Mushroom
Tappet Camshaft lift rates.
Tappet Camshaft lift rates.
One ratty sounding camshaft.
Radius and Flat Tappet cams,
both ground from stock cores.
both ground from stock cores.
The full gamut of lifters, stock
lightweight, stock adjustable,
race adjustable, mushroom with
bushing, 2 inch radius Isky type
and 1 inch radius Weber.
lightweight, stock adjustable,
race adjustable, mushroom with
bushing, 2 inch radius Isky type
and 1 inch radius Weber.
Radius tappet cam left and flat
tappet, note the difference in
lobes.
tappet, note the difference in
lobes.
Whitteman tappets, flat and
mushroom.
mushroom.
Flat tappet 0.999 in. dia. vs.
Mushroom @ 1.182 in. dia.
Mushroom @ 1.182 in. dia.
Mushroom tappet & cutter.
Spotface lifter bore.
Clay Smith X-270.
Weber 1 inch radius lifter, key
in lifter, slot in bore.
in lifter, slot in bore.
Isky instructions for installing
radius lifters.
radius lifters.
Installation tools and key.
Drill jig in bore.
Key holes drilled in lifter bore.
Finished installation.
Weber F7RS Giant timing card.
Clay Smith 4-54 Timing card.
Harvey J. Crane's 425-2 timing
card. Harvey ground these
himself on a '32 steel billet.
card. Harvey ground these
himself on a '32 steel billet.
Isky dual spring rates.
Stock, Tuliped, and Tuliped
and Undercut valves.
and Undercut valves.
Grind 'em slowly and carefully.
Update 11/2/08
Through the years I've been fortunate enough to have talked with several former racers
as well as the men who made the racing equipment. They all answer their own phone
and it's just a metter of picking it up and calling them. Barney Navarro gave me good tips
on blower applications, Ed Iskendarian sent me some Olds valve springs for my Ardun,
Mickey George sent several sets of radius lifter wires he had made as well as pictures and
a diagram of his jig so I could make my own. All very nice people, all into flatheads and
willing to share their knowledge. I was pleasantly surprised to recieve this letter in the
mail recently.
as well as the men who made the racing equipment. They all answer their own phone
and it's just a metter of picking it up and calling them. Barney Navarro gave me good tips
on blower applications, Ed Iskendarian sent me some Olds valve springs for my Ardun,
Mickey George sent several sets of radius lifter wires he had made as well as pictures and
a diagram of his jig so I could make my own. All very nice people, all into flatheads and
willing to share their knowledge. I was pleasantly surprised to recieve this letter in the
mail recently.
I responded with a letter including a few timing cards I had received from Bob
Hayslett and after a couple of phone calls sent my 353-2 to Harvey for his analysis.
An interesting fellow, Harvey started modifying flathead heads at the age of 13 and
continues his work at age 77. Obviously, as one would expect, he's way over my head
in camshaft design, I just use them, he designs them and his work has been used by
many to great success on the track. He's sending some more info on the 353-2 cam
this week and has also opened other doors for me by simply dropping a few numbers
my way. One number he dropped was of a man named Speedy Spiers who worked
with John 'Pop' Schooler (and still has his first cam grinding machine, a small unit
used for making Indian 45 cubic inch cams), which held records for years. Interesting
fellow, he went on to work for Bill Fish at Fish Carburetor and was a mechanic on the
Fish cars, driven by Glenn 'Fireball' Roberts. Later he wrenched cars for Tiny Lund.
When I talk to fellows like these, I take notes - more to follow - for now here's a link to
Harvey's Website which many may find interesting - (to be continued).
Hayslett and after a couple of phone calls sent my 353-2 to Harvey for his analysis.
An interesting fellow, Harvey started modifying flathead heads at the age of 13 and
continues his work at age 77. Obviously, as one would expect, he's way over my head
in camshaft design, I just use them, he designs them and his work has been used by
many to great success on the track. He's sending some more info on the 353-2 cam
this week and has also opened other doors for me by simply dropping a few numbers
my way. One number he dropped was of a man named Speedy Spiers who worked
with John 'Pop' Schooler (and still has his first cam grinding machine, a small unit
used for making Indian 45 cubic inch cams), which held records for years. Interesting
fellow, he went on to work for Bill Fish at Fish Carburetor and was a mechanic on the
Fish cars, driven by Glenn 'Fireball' Roberts. Later he wrenched cars for Tiny Lund.
When I talk to fellows like these, I take notes - more to follow - for now here's a link to
Harvey's Website which many may find interesting - (to be continued).
Update 11/9/08
Harvey's analysis of the 353-2 is done and the cam is on it's way back, along
with a couple from Speedy which will make my Monday (they're at the post office
ready for pickup) seem a lot like Christmas.. Harvey sent along a few notes on
Flathead cams in general that I've attached here, these guys are fun to talk to
although I have to think through what they talk of as I related before, they're
over my head a bit, and talk so 'matter of factly' about what they have found ,
that it takes a bit of time for me to digest it. Much more to learn..
with a couple from Speedy which will make my Monday (they're at the post office
ready for pickup) seem a lot like Christmas.. Harvey sent along a few notes on
Flathead cams in general that I've attached here, these guys are fun to talk to
although I have to think through what they talk of as I related before, they're
over my head a bit, and talk so 'matter of factly' about what they have found ,
that it takes a bit of time for me to digest it. Much more to learn..
Update 7/5/09
Received a nice package from Speedy Spiers this week who still likes to twirl the
wrenches. He sent along a picture of his beautiful coupe which is a replica of the
one he raced in 1960-1961. The car has a 439 Checy small block pumping 868 HP @
7900 RPM according to his notes. That's more than I could handle.. Speedy has a
dyno in his shop and obviously likes to make horsepower. As a co-worked with John
Schooler (Speedy still has John's first cam grinder) and later at Fish carburetor, he
got to know the ins and outs of NASCAR racing in it's infancy. His drivers thrugh the
years included Glenn 'Fireball' Roberts and Tiny Lund. Together they raced for a
living so I doubt you'd be able to bring up much new to Speedy. His latest flathead
employs a Iskendarian Mushroom grind, flat top pistons, 4 1/4 inch crank, and 305
cubes. As he called it 'A little one'. That's a big one to me. The head volume is 31cc
and the pistons pop up 0.012, for a compression ratio approacing 15:1. With 1.630
exhausts and 1.812 intakes, this is a breather as well - and on the edge I'd say. But
the real secret here is the manifold which in our conversations he relates 'Frosts up'
- that's good. He related acheiveing 307 H.P. @ 6300 RPM and 303 Ft. Lbs. of Torque
at 5900 RPM. 300 HP Flatheads are not a myth in Speedy's world.
wrenches. He sent along a picture of his beautiful coupe which is a replica of the
one he raced in 1960-1961. The car has a 439 Checy small block pumping 868 HP @
7900 RPM according to his notes. That's more than I could handle.. Speedy has a
dyno in his shop and obviously likes to make horsepower. As a co-worked with John
Schooler (Speedy still has John's first cam grinder) and later at Fish carburetor, he
got to know the ins and outs of NASCAR racing in it's infancy. His drivers thrugh the
years included Glenn 'Fireball' Roberts and Tiny Lund. Together they raced for a
living so I doubt you'd be able to bring up much new to Speedy. His latest flathead
employs a Iskendarian Mushroom grind, flat top pistons, 4 1/4 inch crank, and 305
cubes. As he called it 'A little one'. That's a big one to me. The head volume is 31cc
and the pistons pop up 0.012, for a compression ratio approacing 15:1. With 1.630
exhausts and 1.812 intakes, this is a breather as well - and on the edge I'd say. But
the real secret here is the manifold which in our conversations he relates 'Frosts up'
- that's good. He related acheiveing 307 H.P. @ 6300 RPM and 303 Ft. Lbs. of Torque
at 5900 RPM. 300 HP Flatheads are not a myth in Speedy's world.
