SanDiegoPaul

My boss tells me that MAYBE I shoulda thunk differently about the heads I used on the 383. I put it together with OEM 1.94 Chevy heads. The engine has a Crane Cam (http://dab7.cranecams.com/SpecCard/D....asp?PN=113942) with Crane 1.6 roller rockers and a 10:1 compression ratio forged stroker kit.

He's afraid I'll have to run aviation fuel to keep it from pinging! I doubt it will be that severe a problem ... but I'd like some feedback here.

SLICKMAN

That cam is just about the same as a stock L82 cam.. :yesnod: I think you will be fine with 10.1 compression..

SanDiegoPaul

That cam is just about the same as a stock L82 cam.. I think you will be fine with 10.1 compression..


I HOPE SO!! If that is all that cam really IS .... then add 10:1 plus 1.6 rockers then I'll have plenty of power. I'm targeting 300-315HP at the wheels. I'm using an Edlebrock Performer Q-Jet 795CFM and the matching manifold. :cheers:

MotorHead

That cam will not get you 300HP at the wheels you have ot move up a notch ot two

SanDiegoPaul

No? I figure it should make at least one HP per cubic inch - or about 385HP. That would put me close to or at 300HP at the wheels.

HOPE?? :flag

Blues77

how does that cam compare to the 268H compcam, with the stock L-82. Can someone put up some numbers(specs) of all 3? For us cam impared.

Jvette73

Im running flat top stock pistons with 64cc heads milled .012" so im sure im well over 10:1. I run the CC XE262 cam and have no problem with detonation or ping on 93 octane pump gas. Full agressive ignition timing and curve and still no ping. If yur cam has equal or greater duration then I would suspect you will not have a problem on pump gas. :cheers:

SanDiegoPaul

Here is the cam's spec page on mine:

http://dab7.cranecams.com/SpecCard/D....asp?PN=113942


[Modified by SanDiegoPaul, 7:29 PM 12/25/2002]

Smokehouse69

DD2000 estimation (since I'm not sure what heads you're using) is 389hp at 5000rpm 440lbft of torque at 3500 rpm. Figuring a 20% loss you should be around 311 hp at rear wheels.
Remember this is a guestamation from incomplete data in a program that can only be considered ballpark accurate. Your mileage may differ. :D

jackson

Here's approximate L82 cam specs ... in some respects it's less cam than the Crane 272.

These specs for SpeedPro L82 clone (SP pn CS1095R): adv dur= 291/287. Duration @ 0.050= 224/224, lift @ 0.050=.450/.460, lcl=114

Paul:
Where did you get 10:1CR? What is deck height? ... What are head CC? Most flattops have a neg vol ... what are piston cc?

69 N.O.X. RATT

I have to agree with Motor head, that combo will probably not make 300 at the wheels. The cam is way to small and the heads do not flow very well. Most of the factory Chevy heads flow around 200 cfm at .500 lift. That flow would be the minumum to make 380 ish hp if you had enough cam. Your cam is out of steam at 5,000 rpms. The motor should have very good throttle responce though, it just won't want to rev. To be honest a good pick up truck combination.

Give it a try on the dyno and see what happens. If it does not make enough power, up grade the cam to something in the 230 ish at .050 and over .500 lift. There are some very good small block heads that are not much money. A little work on the heads you have may help also, depends on thier casting #.

What intake are you using?

MotorHead

Just reread my post sorry for being so negative, just that I saw a few small blocks on a chassis dyno this past summer and none hit the 300RWHP mark, most didn't even come close. The engine combos there were running much more cam with better heads etc. including 2 ZZ4's. I might add mine came the closest but still off by about 10HP. We are all a little optomistic when it comes to this sort of thing but the proof is pudding so to speak.

If I was you I would move the cam up a litttle and see about getting some aftermarket heads if you are serious about 300RWHP. :D

SanDiegoPaul

If I was you I would move the cam up a litttle and see about getting some aftermarket heads if you are serious about 300RWHP.

My Desktop Dyno results are the same as the other post above. Of course, software is only an estimation ... and a guide. As for the cam, it will have to do for another couple of years 'till I don't need to smog it any more. As for the heads having low flow, they have been ported and polished too. Everything on the motor right now, as I type is smog legal in CA and I have the numbers to prove it. :rolleyes: I am prepared as I can be.

Now, back to fuel. What is the best 91 octane to use??? :cheers: Here in SD the choices are Texaco, Shell, and Chevron. Nothing higher than 91 or 92.


[Modified by SanDiegoPaul, 6:40 AM 12/26/2002]

fauxrs

Like I mentioned in my e-mail - I'm not sure if you are really running 10:1 CR. Flattop pistons are often advertised as 10:1 pistons however they achieve that often using the smallest chamber heads available - and like I mentioned in my e-mail alot depends on the gasket thickness (compressed) and how far "in the hole" the piston is at TDC.

That cam is very similar to the L-82 cam with a shorter intake duration, slightly longer exhaust and more lift. In fact your exhaust lift will be well over .50" with 1.6 rockers. This may help but some iron heads simply wont flow as well even with the higher lift.

Ported and polished is good to do to oem heads however sometimes the actual benefits only bring you up to the level of non ported aftermarket heads. For anyone to be able to make an educated guess we would need to know which heads you installed (ie. casting numbers). It is also important to understand that any combustion chamber work done to the heads, removes material and therfore reduces compression ratio.

I think what you are going to find is that motor is going to have a lot of "grunt" on the bottom end and will be an excellent "stoplight grand prix" car. However I expect it will run out of breath on the high end.

That may not be a bad thing - depending on what your goals are. Frankly i like a good low rpm street motor. Building for the dragstrip is fun too of course but not always the best solution on the street YMMV


[Modified by fauxrs, 7:35 AM 12/26/2002]

69 N.O.X. RATT

The porting and 1.6 rockers will help a lot. Good luck. I have no idea what fuel to use. If you run into detonation problem post it and I will give you the address to a place Mountainmotor told me to call regarding octane boost. I tried the stuff and it worked great for me. I was having a little detonation problems with approx 10.3 to 1 with a high lift solid roller. It is approx 100.00 bucks for 12 32 oz containers. I bump this 91 California crap up to 93 for a buck or two a tank.