recommendations for a little more hp & torque?

mumpsimus

mumpsimus

Member
My 37 could use a little more torque and hp when hauling the family around. It is a stock 21 stud, with rebuilt carb, distributor, and fuel pump. I don't want a hot rod or loud pipes, and don't want to pull the motor from the car. It idles well, is quiet and runs smooth. I'd like to keep all that, but with a touch more oomph when I step on the accelerator pedal. If it could go up from the stock 85hp to say 105hp that would be nice.

What do you guys recommend? Simply mill the heads for higher compression? Or buy aluminum heads, or instead buy dual carbs, or a cam, or something else?

Is any modification recommended over the others?

thanks in advance,
Pete
 
Last edited:
Might want to look at JWLs book, it addresses this very topic. He goes through a series of bolt-on modifications and then more in-depth mods and shows the dyno results with each.
 

Attachments

  • Book%20Cover1.jpg
    Book%20Cover1.jpg
    63.5 KB · Views: 75
Really, the best thing you could do is increase the stroke, but that involves a different crank and pistons. Not sure the bolt on stuff will get you to the HP level you want.
Good luck!
 
I don't want to bother with stroking it. But how much power would the bolt-ons add? If not 20hp, will they just give 5-10hp then? That doesn't seem like much, but I guess it might be worth the effort and cost.
 
Cheapest route to more HP is to raise the compression and with a flathead headers and
dual exhaust are a good idea......quiet mufflers if you wish. Take a comp test first.....
if you see some cylinders under 85 pounds you'll be wasting $$$$ to do any mods.
Charlie ny
 
A very basic question would be- What is the actual condition of your motor that you are saying is "stock"? Do you have experience with a properly built stock motor that is really tuned up and running healthy? The reason I say this is there is a very wide range of performance difference between a weak ,poorly tuned motor and a well tuned healthy one. Both of them may run quiet, smooth and not make smoke, but actual performance may vary widely. Since we are not dealing with a lot of horsepower with these old flatheads, a minor horsepower increase from tuning can make a big difference in seat of the pants performance.
If the iginition system is really setup correctly, the carb is truly correct, the rings are tight , the piston to head clearance is set to Ol'Ron's specs , compression is good and even ,cam not worn out, valves adjusted and sealing properly, etc then the engine will perform as a strong, nimble and tight power plant, especially with the light Ford bodies (21 stud era). I would say that 75 percent of the engines out there running today are nowhere near the state of optimum tune. This is shown in the numerous complaints of poor milage, hard starting, overheating, etc. Find a friend that has a really good healthy stock 21 stud motor and compare how his performs before you go into tearing into and changing yours. My 21 stud LB motor, newly done, really performs with spirit when pulling around a light 32.
My opinion
 
Charlie ny said:
Cheapest route to more HP is to raise the compression and with a flathead headers and
dual exhaust are a good idea......quiet mufflers if you wish. Take a comp test first.....
if you see some cylinders under 85 pounds you'll be wasting $$$$ to do any mods.
Charlie ny
Click to expand...



Thanks for the reply. Good tips. I’ll double check compression in all 8 before going further. Milling the stock heads seems like a simple route. Not sure if finding 21 stud aluminum heads is any better than milled iron heads.


Sent from my iPhone using Tapatalk
 
Floyd said:
A very basic question would be- What is the actual condition of your motor that you are saying is "stock"? Do you have experience with a properly built stock motor that is really tuned up and running healthy? The reason I say this is there is a very wide range of performance difference between a weak ,poorly tuned motor and a well tuned healthy one. Both of them may run quiet, smooth and not make smoke, but actual performance may vary widely. Since we are not dealing with a lot of horsepower with these old flatheads, a minor horsepower increase from tuning can make a big difference in seat of the pants performance.
If the iginition system is really setup correctly, the carb is truly correct, the rings are tight , the piston to head clearance is set to Ol'Ron's specs , compression is good and even ,cam not worn out, valves adjusted and sealing properly, etc then the engine will perform as a strong, nimble and tight power plant, especially with the light Ford bodies (21 stud era). I would say that 75 percent of the engines out there running today are nowhere near the state of optimum tune. This is shown in the numerous complaints of poor milage, hard starting, overheating, etc. Find a friend that has a really good healthy stock 21 stud motor and compare how his performs before you go into tearing into and changing yours. My 21 stud LB motor, newly done, really performs with spirit when pulling around a light 32.
My opinion
Click to expand...



Thanks Floyd. I’m pulling a heavy load: woodie body, 5-6 passengers and sometimes a light trailer and one or two c1915 motorcycles. A bit more mass than a light 32. :) The motor was rebuilt to stock specs by the previous owner 5k miles ago. I’ve done the dizzy, carb, HT leads, etc this summer. Assuming (big assumption, I know) that the motor was running as well as it was designed to do, would you recommend a cam swap or aftermarket heads? Or is milling stock heads recommended? I’m not convinced that additional carbs are beneficial unless other changes are done first. But I’m open to suggestions.

This is my first Ford V8, but I’ve built and tuned a lot of 1-2 cylinder bike motors from 1910-WWII. Small changes are very beneficial in those 5-20hp motors! But it is much easier to port them, valve jobs, etc than on a V8 that is still in the car. I don’t want to pull it out, hence my questions about simple bolt-ons. Thanks again.


Sent from my iPhone using Tapatalk
 
mumpsimus said:
Thanks for the reply. Good tips. I’ll double check compression in all 8 before going further. Milling the stock heads seems like a simple route. Not sure if finding 21 stud aluminum heads is any better than milled iron heads.

==========================================================



Before checking the compression, run the engine for 10 minuets or so,
and then pull all the spark plugs out, and open the carb throttle
plates wide open so the cylinders can suck in plenty of air as you're
checking compression.






.
Click to expand...
 
Forget about changing the cam. That would make your car into a 'hot rod'! You would lose power at normal, everyday RPM. Same with dual carbs. Only good at full throttle at high RPM.
How about a McCullough supercharger? They came out in 1937 to solve your exact problem. One of these would give the needed power and would be period correct, to boot!
 
As much as I love 21 stud engines, in all honesty, the easiest and cheapest method to achieve what you desire, would be to drop in a 39-48 239 cu in engine. Bolt in deal!!
 
Brian said:
As much as I love 21 stud engines, in all honesty, the easiest and cheapest method to achieve what you desire, would be to drop in a 39-48 239 cu in engine. Bolt in deal!!
Click to expand...
That bolt in deal takes a lot of money...lol
Will be cheaper to punch out the engine to 3 3/16 and raising the compression then finding a new engine that you know is good.
 
In our 33 fordor , we tow a caravan ,with the 221 babbit engine it was Ok and will do a 5000klm trip no worries,but if you got caught out rubbernecking at something and never saw a hill coming it was drone along and wait.
I had built up a 99a engine with a 4in crank ,stock cast iron heads ,stock 33 manifold and 97 crab,and fitted it this is a way nicer engine.
Not cheap but sure nicer to drive,
If we never did towing,but just touring in the 33 I would have left the 221 babbit engine in as they are so nice ,
Lawrie
 
Just "milling the heads" for more compression is an oversimplification. You want to end up with .040-.060" squish in the combustion chambers for the greatest efficiency. This entails removing the heads and checking the existing clearance with clay or aluminum foil balls. Once you know where you're starting from, you can determine how much to mill. I always take a liiiitle bit more off than I should and use a die grinder to remove any remaining areas of interference. You can do this with stock heads as well as aftermarket aluminum heads. As to aftermarket heads : good luck in finding some, and if you do find them, they most likely will have been worked over, probably several times. Don't assume that just bolting them on will result in a satisfactory situation. Any heads you use will need to be massaged. I would also suggest going with a larger 2 BBL carburetor, either a Ford 2100 series or maybe even a Rochester 2GC.

Unless you are into pulling the engine and getting serious with internal modifications, this is about all that you can do. I am assuming here that the stock ignition is "up to snuff".
 
You must log in or register to reply here.
Back
Top