OK gang, heres the deal. I decided that the 383 thats been in the Camaro is not built the way I want it. Mainly, I didnt expect to make any "real" power and I never planned on spraying it, its a street & strip car & will stay that way. It also has hyper pistons & compression has been dropped to 11.3:1 by slapping a fat head gasket on & giving it too much quench. Ends up I'm making better power that I figured & I would up addicted to nitrous http://www.nastyz28.com/ubb/wink.gif What I have now is a 383 with bottom end parts that I dont feel safe with. They have lasted, but I'm afraid to push it. Not to mention I still want more street manners out of it so I can drive it more next year (compression).

I was thinking of dropping it back to a 355, lowering compression to 9.5:1, adding forged pistons & better rods and spray it more to make up the difference.

Running some numbers through a engine analazer, I lose about 50TQ, 15HP, and a average of 30TQ/16HP across the whole RPM range.

How bad is this going to kill it at the track? I should gain a ton a streetabilty with the 355 combo right? Someone please reassure me that going down in CI will be worth it! Money has become a huge issue so I just cant afford to be wrong anymore http://www.nastyz28.com/ubb/wink.gif

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11.74@118mph in full street trim, driven to the track every time! Trailers are for boats..

If money is a huge issue, then don't do anything to it, until it breaks. Then, just buy another motor.

Why not buy the better rods and dished pistons for your 383? If you're lucky the block will hone and you will be out little more than the parts and balance job over a normal refresh. Drop the compression to 10:1, give up nothing. http://www.nastyz28.com/ubb/wink.gif

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Custom Auto, your source for quality machine work, cores and new parts at competetive pricing right here in British Columbia 1-888-563-4050
A Canadian, EH? (with a 10 second street car)

Well IMO there are a couple easier things to do besides going to a different crank and pistons.

If you are interested in running pump gas you could get some heads with 76cc chambers. AFR's come that way or even a set of 882's or similar stock head. You would definately give up some power with big chamber stockers though.

The other option is more cam. I run 11.3:1 in my 383 with pump gas but you have to have enough cam to bleed off cylinder pressure. I'd suggest something like the Comp Magnum 294s -- its a little rough on the street but definately doable. Idles 850-900 in gear and sounds pretty mean.

Also, if you are running a flat top piston and a thick head gasket I doubt you are at 11.3:1. Probably down to more like 11.0:1. I am 11.3 with a 4.060" bore, 64cc heads, flat top piston and a tight .034" quench.

PS. dished pistons might be a good idea too like rust suggested. Especially if you block is fairly fresh then a quick dingleberry hone should be enough to get the rings to seat.

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Mid 11's on pump gas, all motor . . . and no trailer.

[This message has been edited by Eric68 (edited December 03, 2004).]

[This message has been edited by Eric68 (edited December 03, 2004).]

if you are going to replace the pistons spend some money on forged units with the thermal coating on them. they will actually disapate excess heat and allow for a larger shot of nitrous if you want it. I would suggest saving an extra $2500 so when you reabuild the lower end you have some extra for a blower. Then next time you get hungry for more power all you will have to do is decrease the pulley size on the blower and adjust the waste gate and you will have tons of extra power. I would not suggest losing the stroker kit though. The engine analyer is way off and the torque fiqures it gives you as an average loss are more realisticly aroun 80 - 100 ft pounds especially going for 11.1 to 9.0 to one...

Man, I was kind of all over on that post http://www.nastyz28.com/ubb/confused.gif Too much work & no sleep do strange things!

My thoughts were to yank the 383 rotating assembly & either sell it, hand down to a buddy, shelf it or do something stupid like stroke a 305 later on http://www.nastyz28.com/ubb/wink.gif I have forged cranks galore, 3.48 & 3.25 strokes. The current 383 block should be fine. If I were to just sell the 383 assy that would buy some nice forged pistons for a 355, all I gotta do is buy some nice rods & I got a stout bottom end cheap- not to mention being a lot more nitrous friendly than the 383 is now. I'm determined to use the 200 pill!

My main reason for not wanting the 383 anymore is the small base cam deal. I change parts & plans so often its a royal pain to have to get a custom cam every time. If I had a aftermarket block with the raised cam journals it wouldnt be a issue, but it would be a lot bigger than a 383 then http://www.nastyz28.com/ubb/wink.gif

I dont hate the 383, I just built it with different goals than I have now. I dropped down to a 244/254 at .050 cam with 63* overlap and that helped a ton with tuning issues but I can only band aid it so much.

Thanks for the ideas gang!


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11.74@118mph in full street trim, driven to the track every time! Trailers are for boats..

If the rods are clearanced properly or you buy the appropriate rods then cam clearance is NOT an issue. Choose your rods and pistons correctly and you may not even have to rebalance the crank.

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Custom Auto, your source for quality machine work, cores and new parts at competetive pricing right here in British Columbia 1-888-563-4050
A Canadian, EH? (with a 10 second street car)

And you do not necessarily need a small base circle cam in a 383 . . .

I ran a Comp Magnum 294s (294* advertised, 250* @ 050, .525" lift) in mine with a standard base circle cam and had plenty of clearance.

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Mid 11's on pump gas, all motor . . . and no trailer.

Yup, can't do anything but DITTO that. Had to clearance the stock GM rod bolt shoulders a little (and I do mean 'little', nothing uncomfortable) and am running a crane standard diameter base hydraulic roller with 234/242, .539/.558 lift. If you wanted an 'end all wories' for the rods you could go to a set of the Eagle ESP H-beams and never worry about cam clearance in anything less than a 4" stroke.

I'll probably be flamed for this, but I think you will be sorely dissapointed with stepping down to a 350. EA told you that you'd loose 50# of torque, and you gotta remember TORQUE is what accelerates the car. More average torque in the usable range of your driving is the ONLY thing you feel in the seat of your pants, and the only thing that makes ET.

If your totally uncomfortable with the rotating assembly, well then changes are your decision. BUT... I'm going to 1000% agree with Eric here. Don't remember what head your running now, but get a set of DECENT heads with larger chambers seems to be the perfect solution here. Not only do you increase performance over what you have, but lowers compression to a pump fuel tolerable range. You won't give up nearly as much torque dropping compression 1 to 1.5 points as you will giving up 30 cubic inches. Later as funds come available, a better rotating assembly will add the confidence in the motor that matches the performance. It just seems like the logical thing to do, but that's just me.

i thought he was running dart i/e 215's 64cc.