318 help

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Lil Demon

Lil Demon

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New to the forum and already have questions. I just bought a 71 Demon with no engine/trans. I currently have a 230 hp 318 2bbl sitting in my 70 'Cuda with the 904 or is it 727 (?) which I plan to swap into the Demon. I plan on installing a Edelbrock air-gap intake, Holley or Demon 4bbl, and headers. From what I have read this motor is supposed to have 9.2:1 compression. Is this true? How can I tell. If so what is the best all around cam (268 or purple+) or others with maybe a small stall converter. The car has a 3.23 rear gear. Just want a good torquey rev happy little setup while I eventulally build up a 340 motor I have. Really just want something fun/cheap to drive while I finish other projects. I plan on using the intake/carb/header setup for the eventual 340.
 
are you talking about an early 90's pre magnum roller cam "302" casting head's, 9.0:1 comp motor?
 
Welcome aboard.

Lets take it a step at a time.

Is that 318 the OE engine of the Cuda's?

The advertised comp. ratio is a little generous. It is probably lower, but that isn't a big issue ethier.

A comp cams 268 is a little large, but not a bad cam. I myself would use the next smaller one down, the 262. It will work well with the cars weight and gear ratio. Been there done that.

If you do a slight head work, (IDK if that is in the cards with this 318,) you can run in the 14's easy.
 
Thanks for the reply. Yes oe 318. 14's huh? that sux!! Now this is with the 4bbl, headers, right? Would milling the heads do anything? high 13's at least?
 
Head porting/bowl work, 1.88 int./1.60 exhaust, dumped into headers and 2-1/2 exhaust. I think that would do it.

Why bother? Save time money effort and build that 340
 
I hear you, Thanks for the info rumblefish. I take it the same thing goes for the X heads on the 340? may as well go with Edelbrocks?
 
IDK about that, IMO, some basic bowl porting on the X head is just about all you'll need for most street strip efforts. The 340 head flow approx. 200+ cfm. Bowl porting and a good vave job is cheaper than E-brock heads and will flow enuff for good power. You may not be able to run a high lift cam, but then again, you don't need to do so unless you want to do so.

Let me get a link to someone who dyno tested a few engines. I had a talk with him on his stuff. He was most helpful and forth coming. For certainly a good guy alert to him.

Allthough these are 360 engines, the 340 should make the same HP numbers, just at a higher RPM with alittle less torque.

Click this---> http://www.mopar1.us/dyno.html
 
I did 13.92 with a 318, 1966 273 heads cut .030(measured 57CC's) with 1.88, 1.6 valves no other head work, compression calculated out to 9.2 actual, Edelbrock performer intake(NOT an RPM), 3310 Holley, an old Crane Blazer cam(this is larger than the Comp268), Thorley "D" Dart headers, 3.55 gears, 215/70x14 tires, 904 with an MP 166K converter in a 65 Barracuda. Point is you don't need 3.91's; try a shorter rear tire, don't need an RPM intake unless you've already got one laying around, I wouldn't put 340/360 heads on unless you mill the livein' day lights out of them, 302 castings or early 66/67 273 heads can get you there.

Good luck.
 
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