flathead cam choice help

hotrodderhaag

hotrodderhaag

Senior Member
i have my 37 flathead tore down and headed for the machine shop to get an overhaul.. im trying to figure out what cam i want to run. i want a very aggressive idle. Im not looking for some huge race engine build. its a mild overhaul with stock bore, aluminum heads and a valve job.
I want to run an ISKY for sure. i was interested in the FULL RACE. some say its to aggressive to drive on the street so they suggested the 400jr. .. my question is, is anyone running a full race on the street? do i need different valve springs to match the cam? what about lifters? and how about a 4oo jr? or is there other cams anyone suggest?
this is my first flathead build.. I dismantled the engine and its a bare block headed to the shop today.

thanks guy
 
I just repalced the cam in my 37 21 stud with a Jim Brierley ground cam. It is one step below the L100 which I felt had too much lift for my heads and excessive duration @ .050" for my CR/engine combo.

Specs are : .330" lift with 228 duration @ .050"

It pulls nice in my 21 stud with .050" off the iron heads in a Deuce roadster with 39 trans and 3.54 gears. Sounds cool too with the 13: glasspacks ;)

https://www.youtube.com/watch?v=tceWbVwwbWk :D

Re springs, regardless of the cam you run, check your installed height and adjust to give installed height as recommended by the cam manuf.

BFD
 
You say "aluminium heads" on a 37 engine. These stock heads? Or have you got some proper high compression heads for it? There pretty damn rare for a 37 engine, a type only used for about 18 months in the US.
Isky 88 is classed by isky as "full race" I've driven a car with one, waste of time, money, and effort in my opinion. Weak at low revs, don't really wake up at high revs. A stock cam is a good chunk better in low revs, and only a bit weaker at higher (normal use) revs.
If you go for the jnr 400, a much, much better cam. You'll have valve to head clearance problems, and a cut to clear here, would loose compression, somethin you can ill afford with a little 37 engine. Have a word with Pete on here, he grinds cams, I feel the Isky 1007b would be good for you, from what I've heard from him and OlRon. Fairly aggressive idle and good low down torque. Though it's an Isky grind, isky don't list them now, but Pete can still grind you one.
Have fun,
Martin.
 
scooder said:
You say "aluminium heads" on a 37 engine. These stock heads? Or have you got some proper high compression heads for it? There pretty damn rare for a 37 engine, a type only used for about 18 months in the US.
Isky 88 is classed by isky as "full race" I've driven a car with one, waste of time, money, and effort in my opinion. Weak at low revs, don't really wake up at high revs. A stock cam is a good chunk better in low revs, and only a bit weaker at higher (normal use) revs.
If you go for the jnr 400, a much, much better cam. You'll have valve to head clearance problems, and a cut to clear here, would loose compression, somethin you can ill afford with a little 37 engine. Have a word with Pete on here, he grinds cams, I feel the Isky 1007b would be good for you, from what I've heard from him and OlRon. Fairly aggressive idle and good low down torque. Though it's an Isky grind, isky don't list them now, but Pete can still grind you one.
Have fun,
Martin.
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i have a stock set of american aluminum heads for my engine. its more of a 36 style. it has the pumps on the heads. it was a reman engine from ford that was slapped together with whatever they had laying around. the block is a 37. domed pistons. i want the sound at an idle. im not looking for a butt load of power. i have a mcculloch supercharger on the engine also. so that helps the performance .. i have ann new stainless valves, springs and such being installed. i really didnt wanna get into head work. so whats the best suggestion now?
thanks guys
 
I think now that you have mentioned you are also running a MC supercharger, that changes the whole question about cams. I'm sure someone here will chime in with some new advice about cams and heads.
 
Seeing as ist a centrifugal blower and not roots type, I'd stay with a 1007b. If it were a roots, it would effect cam choice more, in my opinion. The thinking behind this is as follows.
A centrifugal blower has little affect at low revs. So a cam with good bottom end would be a nice combination. And you'd still have that idle you want.
I feel with a roots you can run a bigger cam, and the positive displacement from almost idle (if the blower is sized and driven for street) will calm down the big cam, due to the push from the blower not allowing reversion in the inlet ports, or atleast making reversion not as pronounced. Their is some effect of gas being blown out the exhaust in this combo. Which some blower cams are ground to lessen this, with more conservative exhaust timing.
All these words basically say, go with something along the lines of the 1007b. Fast cam lift is your friend. And this is my opinion.
There are other opinions, listen to all and make an educated choice.
Martin.
 
Scooder's comments re the 88 grind are interesting; I run one in my 37 block with 36 Eddie Meyer heads [with other mods], and love it. That little engine screams; it loves to rev. Admittedly, it lost a bit of low down torque, but any 'performance' cam will give the same result.
 
Unless you are racing, using an aftermarket cam is usually unproductive. The original Ford cams are very durable, and serve a wide range of speeds. High lift and/or long duration cams tend to have a narrow power band, making street use problematical. We install them occasionally for a customer, but warn them that some cams develop flat lobes, and most demand a high idle speed.
 
1007B with stock early steel lifters and either zephyr or Isky single springs set at 70 lb on the seat. Aluminum timing gear.

"Been in the cam business 60 years"
 
I agree with Pete, erxcept for the spring pressure, unless you you plan on Very high revs 50 would work just as well and have less were and tare on the valve train. At least that where I've been running them. As for the supercharger. Be interesting how much boost you get out of it? But in my experience they don't do much below 4K and not much after. But they look great.
 
hotrodderhaag said:
i have a stock set of american aluminum heads for my engine. its more of a 36 style. it has the pumps on the heads. it was a reman engine from ford that was slapped together with whatever they had laying around. the block is a 37. domed pistons. i want the sound at an idle. im not looking for a butt load of power. i have a mcculloch supercharger on the engine also. so that helps the performance .. i have ann new stainless valves, springs and such being installed. i really didnt wanna get into head work. so whats the best suggestion now?
thanks guys
Click to expand...
Hi hotrodderhaag; If the block is not cast for water pumps it's not a 37, anyway the 221 cu. in. may be disappointing in performance for the money you'll invest in it. Good luck and I hope you post more about your build.
 
gents,
my engine is cast for the block mount pumps. as i stated before this is a dealer installed reman engine from 1940. so it looks to be built from spare parts honestly. it has the block of plates for the lower pumps, and it has pumps in the head.. As far as money invested for the power... thats debate is irritating. thats why you see chevy engines in cars today. cheap and powerful.. oh and also WRONG... im not concerned with what it costs. its a flathead with a supercharger on it.. nothing about that statement is cheap.. but is cool as cool gets.

the little McCulloch supercharger makes a world of difference at 1800-2000 rpms. it pulls like a freight train at 2.5 -3 lbs of boost.. I will say this, my brother and i both run 221ci engines in both of out cars and for as light as they model a's are. they scream right along no problem. could be happier. I tore my engine down and the cam that is in it was reground to match a winfeild semi race. 295/295 and 111 lobe angle. My car has dual stainless exhaust with no mufflers and it always idled like a harley.. choppy and but not aggressive. and it would rev untill you didnt have any more room to shove pedal down. i would continue to use this cam if it wasnt wore out..

i had planned on running an isky cam and the matching adjustable lifters. also i switched the engine over to the straight stem valves. But what i need to know the most is whats the largest lift cam i can run and not hit stock heads.? since my aluminum heads are chambered stock. i did not really want to have to fly cut the heads at all but i can if needed.
thanks guys
 
hotrodderhaag said:
gents,
my engine is cast for the block mount pumps. as i stated before this is a dealer installed reman engine from 1940. so it looks to be built from spare parts honestly. it has the block of plates for the lower pumps, and it has pumps in the head.. As far as money invested for the power... thats debate is irritating. thats why you see chevy engines in cars today. cheap and powerful.. oh and also WRONG... im not concerned with what it costs. its a flathead with a supercharger on it.. nothing about that statement is cheap.. but is cool as cool gets.

the little McCulloch supercharger makes a world of difference at 1800-2000 rpms. it pulls like a freight train at 2.5 -3 lbs of boost.. I will say this, my brother and i both run 221ci engines in both of out cars and for as light as they model a's are. they scream right along no problem. could be happier. I tore my engine down and the cam that is in it was reground to match a winfeild semi race. 295/295 and 111 lobe angle. My car has dual stainless exhaust with no mufflers and it always idled like a harley.. choppy and but not aggressive. and it would rev untill you didnt have any more room to shove pedal down. i would continue to use this cam if it wasnt wore out..

i had planned on running an isky cam and the matching adjustable lifters. also i switched the engine over to the straight stem valves. But what i need to know the most is whats the largest lift cam i can run and not hit stock heads.? since my aluminum heads are chambered stock. i did not really want to have to fly cut the heads at all but i can if needed.
thanks guys
Click to expand...
Hi hotrodderhaag; I didn't intend to sound critical and do hope you post more about your build. Good luck, Craig.
 
Craig CT said:
Hi hotrodderhaag; I didn't intend to sound critical and do hope you post more about your build. Good luck, Craig.
Click to expand...

sorry craig,
that wasn't intended to sound that way. IVe herd that alot. mainly from machine shops i called to get work done :) I always hearm " why dont you build an 8ba" im a big fan of my little 21 stud. in fact i have 3 of them and a 59a. the 59a just sits on a running stand and doesnt do much.
 
Haag you would be best to mock up your valve& guide without springs put on heads with gaskets & measure how much you can move valves until they hit heads & then you will know max valve lift for your engine . Then subtract clearance you want to the head & that will be your max cam lift . Keep in mind you will still have valve clearance up your sleeve. Hope this helps .
I may have a specific "FLATHEAD BLOWER CAM " in the future , but it is too early to give specs or details yet.
Cheers
Tony
 
Craig CT said:
Hi hotrodderhaag; If the block is not cast for water pumps it's not a 37, anyway the 221 cu. in. may be disappointing in performance for the money you'll invest in it. Good luck and I hope you post more about your build.
Click to expand...
Don't diss the 21 stud, Brian on here has a 21 stud that will blow most flatheads (and a bunch of OHVs) into the weeds.
 
i called delta cams and ordered a isky 1007b grind on a stock core. This will be perfect and has been highly recommended by many people. it has .355 of lift which will clear my stock heads. it purchased some johnson adjustable lifters, 8ba straight stem valves, guides, springs and keepers.... i had the crank mains ground to .020 and the rods i left at .010. they were like new. this little engine otta roll the model a around a little better than before
 
sidevalve8ba said:
Okay, wondering out loud here. If the 1007B cam grind is so well liked I wonder why Isky discontinued it? :confused:
Click to expand...

i often wonder that also.. its also like why did ford discontinue the 300 straight six, or why did doge discontinue using the 12v diesel that got 24 mpg.. why did ford discontinue using the ranger truck that car lots couldn't keep on stock..

all perfectly good things that are no longer available.
 
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