Cam & transmission question

3739ford

3739ford

Senior Member
My 1942 Ford GPW :D is all original and love it, but....

I have built a 49-53 1CM, with 4" stroke crankshaft, stock EAB cam, milled heads to .045 clearance, and 2GC Rochester carb, chevy distributor modified for flathead with AOD transmission. I'm putting this into 39 ford pickup that will be on the road soon I hope. I have dual exhaust with Red's headers.

I'm considering going to a cam something other than stock (wife and daughter love sound of engine with hot cam) and wanted some opinions/feed back from those that are running an automatic transmission with more than a stock cam. I do parades from time to time, very slow, lot of stopping; along with city driving. By the time I finish a parade with the GPW I can hardly walk and looking for something fun, with sound that is the same day after day cranking and driving.

Just asking before I jump off the cliff.

Thanks for all comments.
 
Probably a Nax #1 would keep most of the low end torque. However an EAB cam could use your stock lifters ans save sime money. Chancing a cam in a stock street engine is a VERY expensive move.
 
You won't be happy with any cam other than stock for what the planned use is.
If you need a lumpy idle, just pull the choke out a bit.
 
Thank you very much.

If I removed the glass pack mufflers and ran straight pipes from headers out the back maybe that would give me more cam thump sound.

Anyone got a sound video of stock engine and straight pipes?
 
I vote for straight prpes. With the headers and 1 and 3/4 inch pipes. You save money on cam and mufflers and, the ladies ought to be happy.
 
Forty years ago, I walked up to a cute Model A coupe at a swap meet that sounded like it was just sittin' there with the stock engine idling. Looked inside the open window and the guy had a tape recorder sitting on the seat, playing the A-Bone song at top volume. It would even rev-up every fifteen seconds or so. Put a smile on my phizog! DD
 
JayChicago said:
What’s the “A-Bone song”? Did a google search, nothing turned up.
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It's just the happy sound of a Model A engine caught idling on a tape recorder, with intermittent periods of revving-up to break the monotony. I don't believe "Google" has yet discovered this particularly-delightful acoustic! DD
 
3739ford said:
My 1942 Ford GPW :D is all original and love it, but....

I have built a 49-53 1CM, with 4" stroke crankshaft, stock EAB cam, milled heads to .045 clearance, and 2GC Rochester carb, chevy distributor modified for flathead with AOD transmission. I'm putting this into 39 ford pickup that will be on the road soon I hope. I have dual exhaust with Red's headers.

I'm considering going to a cam something other than stock (wife and daughter love sound of engine with hot cam) and wanted some opinions/feed back from those that are running an automatic transmission with more than a stock cam. I do parades from time to time, very slow, lot of stopping; along with city driving. By the time I finish a parade with the GPW I can hardly walk and looking for something fun, with sound that is the same day after day cranking and driving.

Just asking before I jump off the cliff.

Thanks for all comments.
Click to expand...

Well, no matter what you do to the exhaust, a stock cam will still sound like a stock cam. Even straight pipes will be pretty quiet at idle. Your girls will not be happy!
I think you can make a hot cam work with a couple of modifications. First, do you have EAB heads (from a Ford, not Merc)? The Mercury heads (0CM, 1CM, EAC) have larger chambers than Ford (8BA, EAB) so using Ford heads and milling them gives more compression, which helps with a hot cam. Also more ignition timing at idle will get some torque back. So recurve the distributor to keep total advance the same but have more initial timing and have the advance start sooner. The added compression and timing will make it bark a little better, too. Check out Comp Cams Thumpr series. They're supposed to give a "drive-in" idle with decent drivability.
Next, go to a higher stall torque converter. This will lessen the 'drag' on the engine at idle and let the engine rev a little higher when taking off to get further into the powerband. You don't need a race converter, just one with a little higher stall speed. Call one of the converter companies. A nice thing about the AOD converter is that it has partial lockup in 3rd and full lockup in 4th (overdrive) so fuel mileage and drivability on the highway are not affected, and the pipes will play sweet music.
Finally, just make sure you have a good trans cooler for those parades, where extended running just above idle can make a lot of heat.
 
One thing about a cam change is cost. Bottom line is about $500 +/- Then you have to completely dissesemmble the valve train. All for Rump, Rump??? The choke trick was my favorite!!
 
Ol' Ron said:
One thing about a cam change is cost. Bottom line is about $500 +/- Then you have to completely dissesemmble the valve train. All for Rump, Rump??? The choke trick was my favorite!!
Click to expand...




The problem with the choke trick is that you are washing down the cylinders with raw gas, diluting the oil, and fouling spark plugs. That's engine abuse:)
 
I do have EAB heads, and bored to 3 5/16. Distributor already set up for flathead. I really appreciate all the opinions and comments they will help me determine what route I take. The auto trans is new to me and how it will perform behind the flathead. I have always been told the only stupid question is the one you don't ask.
 
My avatar has a stock engine with electronic distributor and 2 2s running progressively. I have 2.25” straight pipes, no mufflers, and MANY GUYS have thought I was running a hot cam and/or the engine was hopped up in some way. Stock cam, stock bore, 3 3/4” crank, stock intake with Y adapter for the 2 94s. Exhaust exits before the rear wheels ....
 
Well . . . I can't help myself . . . I will always run a hot cam and 'Yes' it will reduce the torque/HP at low speed. But - I build HotRods, not stock engines . . . just the way I prefer them.

I think the suggestion of a mild stall in the converter is good and I think you can still get away with a somewhat lumpy cam - like a 1007B, which Pete can grind for you. It is always a trade-off, if you want a cam that makes horsepower at higher RPM, has that "lumpy rumpity rump" sound, then it is taking HP/Torque away at lower RPMs. Bigger cubic inches help the situation and having higher compression helps the situation (low speed driveability).

But Hey - a high-performance flathead is supposed to have that "drive in" sound if you ask me! ;)
 
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