View Full Version : low compression 440 build up
05-19-2001, 02:02 AM
I have a 74 roadrunner that i plan put a 75 440 in it. I would like to run in the mid to high 13s so i can beat the new mustang gts and some z-28s . I was thinking of using preformer rpm intake and heddman hedders and a comp cam extreme energy cam with 268 intake duration.i would like to stick with my 3.55 gears but i could go with3.91 or 4.10 . any suggestions would be helpful
05-19-2001, 02:33 AM
DAN-THE-MAN, I have run a 75 440 at the level you want. I used headman headers, performer, a 3310 carb and an MSD ignition. The rest of the motor was stock. (heads, cam, 8.2:1 comp.) I'm not to familar with Comp Cams cam you want to use. I used the stock 440 HP grind. (268/284 duration, .458 lift) You should pick a cam close to those specs as it will work good with the low compression. I also used 3.55's. They are a great duel purpose choice. 3.91's and 4.10's are not as streetable but they offer better performance at the track.
As for other suggestions, put on a windage tray and an electronic ignition. You might also consider 2.5 inch exhaust pipes if you don't already have them. Also, the performer rpm is a great upgrade over the standard performer. Good luck.
05-19-2001, 10:24 PM
Dan, it is easy to get a low compression motor to work well. I have a performance shop and just did one for our local Chrysler dealer. He runs it in a Duster it was all steel except for the glass hood and ran 10:80 1/4 mile times. It is a stock 71 short block with a set of 452 heads I ported and a flat tappet cam,the car is very consistent. If you would like to talk to him I can give you his number. If you have any questions contact me. at Tothperformance@csonline.net
05-20-2001, 01:35 AM
I almost bought a '68 Charger w/ a '74 440 in it. Thought about what I could do to the motor. Thats pretty much what I was thinking. do a cold air induction as well.
05-20-2001, 02:41 AM
I've running a '68 440 set up with the following:
Cast Silv-O-Lite pistons (.110" piston to deck height), moly rings
Stock 906 cylinder heads (88cc chambers), 933 Hemi springs
MP Street Hemi cam (280/.474")
Edelbrock Torker II intake
Holley 750 mechanical secondary carb
MSD 6AL ignition and Billet distributor
Hedman 1-3/4" to 3" headers, 3" exhaust w/Flowmaster muffs, crossover tube
The above motor yields an 8.32:1 compression ratio, with a warm cranking compression reading of 155 psi @ approx. 900 ft. altitude. My '68 Charger weighs in at about 3,750-3,800 lbs. and has a 3.23 open diff rear. Best E.T. has been a 13.42 on street radials, best MPH of about 104.
05-20-2001, 03:06 AM
alright, i spent a lot of time analyzing the dyno readings for these mid to late 70's 440s, because thats what is in my cuda
what i figured out is, because these motors had to make huge amounts of torque, but not a lot of power, they didn't have to rev.
so, in reality, make it rev and you will get the power back...right?
my cuda has a STOCK 1977 440 out of a new yorker, bought the entire setup for 300 dollars, the stock tranny with the stock torque converter, stock motor with the stock carter AFB and stock internals.
i had the valve covers off once : to change the valve springs.
that is these engine's severe weakpoint...the reason they don't rev is almost completely due to the valve springs.
with headers, through the dual 2.5" exhaust and street radials on lightweight wheels (these are a must with these 'newer' 440s...the lighter the wheels, the faster the motor can get into the torque band) with 3.55:1 posi gears this car will do 13.70 at 102 at 2800 ft altitude here in canada.
thats a low LOW 13 second pass at sea level...just with proper tuning and a motor that i got lucky with.
hope that helped answer your question
05-20-2001, 05:45 AM
thanks alot guys that answered my question great i like the time slips
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