I have a few mods on the 1921 Engine.
-Model A crank.
What do you think ?
Mine is close to that and the dynamometer hit someplace around 36 HP. I question it a bit because sitting in the car with the throttle wide open scared me a bit and I had my foot on the brakes a little.
Were you afraid about the high rpm of the wheels and engine rpm?
The distributor adds no power.
The Model A crank helps a bit, maybe 3 - 4 horsepower.
The aluminum pistons are good for a couple horsepower.
The Z head is likely good for 2 - 3 horsepower. The open exhaust is noisy but probably adds nothing.
So you might have 26 - 28 horsepower which is a lot.
Thanks all for replying.
I just figured with the distributor would add with the coil a more efficient spark/burn?
You Fella's are so great.
Royce is in the wheel house, Type of cam will also
add or take away HP.
I've been very curious of the same!
- Rajo 4 valve head
- Stipe 280 cam
- Aluminum domed pistons .030" oversize
- Dual intake manifold and dual Zenith S4BF carbs
- Dual exhaust manifold and pipes
- 351W exhaust valves (marginal difference maybe)
- DU-4 magneto (probably doesn't matter except maybe accurate spark at high RPM)
There's a dyno right by my house I'm gonna visit and I'll share once I find out. I do know this, 60 mph is EASY and I have gobs of throttle left. No telling how fast she'd really go. I'm also curious how much HP I lose through the Warford transmission.
(Message edited by Wreckrod9 on July 02, 2016)
Share it please.
Seth I would guess you are somewhere around 40 - 45 HP.
Pruss 8 to 1 aluminum head, nasty Model A Ford reground cam, stock flat pistons, stromburg 97 downdraft carburetor, tubular intake manifold with carburetor at 90 degrees. Tubular exhaust header, chopped and balanced flywheel, Bosch ignition 009, correct heat range spark plugs for each cylinder, no fan pulley so electric fan, splash oil system with old faithful and flywheel slingers to directional port on hog's head, 12 volt generator, oversized radiator with 7 pound pressure cap. see chart made when the block and valve seats were cracked and the crank shaft web was cracked half way through as well as the triple gear bushings broken. Bill shut it off before he reached the maximum r.p.m's because of the noise from the triple gears thus the strange spike on the chart. Now it makes more horsepower after we replaced the block and crank and re-fit all of the trick parts.
The chart below shows 1/4 mile results 23 years ago for the same car when it was first in a competition. Not too shabby for a T crank with a Pruss cylinder head in 1993. #22 had a better cam grind and more compression shown as right lane 179.
Sorry wrong cylinder head on my post above. During the the posted dyno test we were running a Reader head. We recently changed to a better combustion chamber and more compression with a Pruss cylinder head. That's what I get for typing too fast, sorry. Frank
If I remember correctly, when the cars at an MTFCI tour were tested on a dyno the results ranged from around 10 HP to over 40 HP.
Would like the experts opinions on my engine. I have assumed I got no more than a couple of HP extra. But here is what I have:
- bored 30 over, aluminum pistons
- Chaffin .270 grind cam
- Stainless valves. What the vendors sell. Slightly larger than original. I got them from Langs I think. we set the lash at .010 across the board.
- stock head with about .090 shaved off of it.
- SCAT counter balanced crank.
- running on stock coil and magneto system
what type of ignition are you using ?
See last bullet Frank.
Sorry, then you are handicapped. With a distributor and a downdraft carburetor you should be at about 38 horsepower. As you are I would guess you are at 30 horsepower. The cam is the most important and compression is number two, in my honest opinion. Then comes carburetion, remove the fan, remove the magneto and reduce the weight, match and enlarge and relieve the ports in the block, and get the correct heat range spark plugs.
This thread is funny.
My lawn tractor and generator has more HP than my T.
Thanks Frank. that's a lot more than I'd of guessed. If I have 30HP I am thrilled.
You probably have less than you think. I just rechecked the dyno results on the the MTFCI site. At the Minnesota tour they tested 83 cars and only 15 had over 20 horsepower, 6 over 30. The Kanab tour tested 63 with 15 at 20 horsepower or more, 3 above 30. Probably a pretty good cross section of our hobby. Note: this is rear wheel horsepower.
We have done some dyno testing in Tulsa too. In two separate tests we got a 40 to 45% improvement with a Z head. I did one comparison test with a distributor and got a 10 to 15% improvement. However, I believe that a perfectly tuned timer and coils may be as good as a distributor. I would guess overbore and Model A crank would be roughly proportional to the increase in displacement, but somewhat more due to compression increase.
I have come to believe the drive train friction losses in a Model T are about 20 to 25%, which is somewhat higher than a modern car. A good running stock T engine seems to make about 15 to 16 HP on a chassis dyno. I would guess you are looking at maybe 25hp at the rear wheels.
25 HP is more in line with what I was thinking. Not that "what I was thinking" has any foundation to it. I failed to mention I am running a stock Kingston L4. I suppose an aftermarket carb would add more power.
I was actually responding to the original post. You can't get very much from shaving a stock head. If you take off 0.125 it bumps the compression ratio from 3.8 to only 4.2, but you're still stuck with a poor design. Also, despite what Glen tells you, you'll probably lose some low end with the reground cam. Check out all our cam testing.