68 z/28 302 question
 

My uncle owns a 68 z/28.It is all stock he said he had it dyno'd and it was 453 horsepower. Is this possible? I havent seen the dyno sheet. just asking opinions

Re: 68 z/28 302 question
 

All stock, no.


Jason

Re: 68 z/28 302 question
 

IMHO it depends on who built the engine. If the General built the engine, the answer would be "No".

Re: 68 z/28 302 question
 

In factory-delivered "stock" trim, no.

Built to NHRA "stock eliminator" specs, those #'s are attainable.

Re: 68 z/28 302 question
 

DITTO what Eric said! Ask Jerry MacNeish, he may tell you his dyno numbers! I know he has em. https://www.yenko.net/ubbthreads/imag...ins/3gears.gif

Re: 68 z/28 302 question
 

TRACO blueprinted a 302 engine, added an off road cam and an X-Ram to get that kind of flywheel horsepower.

Re: 68 z/28 302 question
 

I bet Jerry will not reveal his dyno numbers, but his times are in the very low 10.70s, which would take every bit of 453hp at the wheels.

Re: 68 z/28 302 question
 

Is your uncle Jerry McNeish? https://www.yenko.net/ubbthreads/imag...mlins/grin.gif

Re: 68 z/28 302 question
 

Jerrys new 67 Z28 went at 475 HP according to his web site on the new car.

Re: 68 z/28 302 question
 

no my uncle isnt jerry. he has a 68 z28 4spd with 4.56gears. i believe his car has dealer ordered headers and intake manifold and i want to say a cam also. im not possitive. he had kept it hidden for a long time until last spring. he finally got it out and started messing with it and said he had it dyno'd and that 453 was what the dyno read

Re: 68 z/28 302 question
 

Among the very interesting Chevrolet engineering letters that were sent around for the Z was one from June of 1967 where a service pack engine was stated to be capable of 448hp under test conditions. In the letter it stated that the engine would produce closer to an estimated 403hp in full vehicle trim. This engine was decked out pretty well and had some notable work done to it and parts added like cowl plenum, headers, transistor ignition, etc. I would say based on that the numbers even for a 302 built back in the day was capable of some real good numbers but it is unlikely this one did unless it had some major work done either at the dealer or after. Depending on the cam the dealer added with the parts you are mentioning and with some other work it just may have produced those kinds of numbers. If the work done is more modern then who knows what it is capable of, if you have the money and knowledge you can build some pretty wild stuff. Gerry though I am sure has a plethora of knowledge including the insider tricks on the 68 Z's as others have noted having owned, raced and researched them for a long time.

Is the car a crossram car?

06/05/67 Z28 Service Pack Engineering Letter

Re: 68 z/28 302 question
 

...calling all my uncles now to see if they are hiding cars too!! https://www.yenko.net/ubbthreads/imag...iggthumpup.gif

Re: 68 z/28 302 question
 

Those stock eliminator engines are FAR from stock as we know that term! https://www.yenko.net/ubbthreads/imag...ins/3gears.gif

Re: 68 z/28 302 question
 

i'll have to see if my uncle Bill has any pics i can scan. i'll post them if i get any