Harts56

Hi all,

Just got a 70 Challenger Convt with a 440! Not original 440 car, started out as 318. Any way looks like the 440 is a 1970, low compression motor with stock cam for a 1974 motor. Car is NOT very peppy. Engine has Edlebrock 750 and Performer manifold, dual exhaust.

I'm thinking heads and a cam would wake up the 440, any thoughts?

What were the combustion chamber sizes in 1970 vs 1974?

From what I've read 1970 compression was about 10.2 vs 1974 compression on 8.2. I have no problem using premium gas as it is only driven to shows and for pleasure.

Thanks for you help!

1 Bad Mirada

im not sure of a few things here...

the engine, is it a 1970 440, or 1974 440? and if its a 1974 440, is it a truck motor?

Harts56

It is a 1974 440. Not sure if pass or truck at this point. I'm out of town till Wed eve, I'll check and let you know then.

Thanks

1 Bad Mirada

hmm...i know that by 1974, the 440 was long gone from the challenger, but the charger still offered in it 74...it was a bit watered down, to 280 hp, but it is still a buildable 440...any 440 is a good place to start, but finding out what it came from will tell you how potent it was stock...for instance, the 440 found in trucks in 1974 would have only been 235hp

Harts56

Here is more info on the 440:
Ø Block #’s 4006630-440-10 dated 2/75
Ø Heads 4006452 believe them to be 81.5cc combustion chamber 2.08 intake/1.74 exhaust
Ø Cam Duration 260, Overlap 34, lift .430, Centerline 110 degrees. I believe this is a very mild cam for my desires.

I am looking to get more pep out of this engine without having to pull it and start over. Heads and cam are a can do, just need to make sure I get the right stuff! Think I need heads with combustion chamber of around 73.5 to raise the compression from 8.2 to around 10.5.

Anyone got ideas?

Thanks

1 Bad Mirada

well, you can make anything strong with enough money...without touching the bottom end.

first off, before you do this, have you done a compression check?

Harts56

No, compression gauge is shot. I'll see a buddy tomorrow and borrow one.

The guy I got the car from owned a Dodge dealership and he told me he had gotten it from Dodge a number of years ago. When I pulled the valve cover it was clean, like new. The camshaft is a Dodge P4286675. From what I have seen I would imagine that the engine is dead stock.

I'll check compression and let you know.

Thanks!

Harts56

Just ran compression check, 120/125 all cylinders. Also borrowed a scope and checked the pistons: flat top, all are clean with minimal carbon. Compression would be about 8.0ish I would imagine.

Guy I got car from said engine was just rebuilt and from pulling the valve cover and looking into the cylinders I believe it. He does not know any of the specs; just “had it done and it ran good” was what he says.

Any thoughts?

1 Bad Mirada

well, seeing as how im making around 460hp with a 340 pulling around 8.5 to 1, there is definately power to be made with the low compression pistons. the key would be in the head and intake work,and the cam. i will admit that i have ONLY ever dealt with small blocks, but the way that we got my compression up a bit (it was originally around 8 to 1, if not lower [&o] ) was to have a machine shop mill the heads and intake to decrease the combustion chamber size in the heads. find yourself a little healthier cam, and a set of headers, an upgraded ignition (perhaps MSD, etc) and it should liven up that motor a bit. i do not know what "the good low buck intake" is for the big blocks. the good ones for the small blocks are the edelbrock air gap and LD340, as well as the mopar M1.

Harts56

Sounds like I am on the right track. I'm looking for a set of Chrysler 906 heads with 73.5CC combustion chambers. This would be 10.0cc less than I currently am running, and hopefully should increase compression by 1 to 1.5 points. Am also looking into cams to pep it up.

I am running headers/dual exhaust and a performer manifold. Can't go much taller with the intake due to hood clearance. Rear gears are 3.23. Will also be looking at at torque converter for a little help.

Thanks for you input!

John



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