Thanks man, I'm trying to rebuild using existing parts, which are new new anyway.

 

My concern with the 383 is that it does not have that two stroke type snappy feeling....

I'm concerned that it will be more truck like in performance.

I started a thread on that.....

 

LOL, WELL I can't say what the two-stroke feel is all about. I can say that I saw alot of two-stroke motorcycles running up and down the streets of Japan when I was there but I'm not an off-roader so I can't respond to that feel. However, I assure you this.........there are ALOT of 383 Vette's on this forum, and from what I've heard no one has ever discribed the performance of them as a "truck like performance!" And I'm sure there are alot of Mustang GT's that have felt that wrath as well. Either way, goodluck in whichever way that you go!

N

 

Exactly...

Oh yeah, don't forget all the gaskets, RTV, fasteners, 200 some bucks there too...and doing it cheap again! Oh I remember my BUDGET build...

Good luck in the Z06 hunting, I'd like to hear how it works out.



Jsup, I'm confused about what you mean about that "two-stroke snappy feeling"?

A "truck motor" makes lots of torque by common use of the term, if you put it in a car with a high gear ratio and low weight, it will still be a "truck motor" but it will definitely have that snap of high gear ratio multiplication of torque. Personally I think the two biggest determinants in how fast your motor will rev are intake choice and gear ratio choice. Yes cam and lightweight components come into play, but I think a simple intake/gear change can eradicate that "truck motor" style immediately, then again so does 500lb/ft of torque.

If you are referring to the snappy feeling in terms of revving? Well no, unless you are spending serious coin your journey is ending at ~6500rpm, no matter what. To rev like a bike motor...well, lets not even get into that type of money to be hitting double digit krpms.

I have low ratio 3.07s and a 4+3. I can tap the gas and the car jumps forward violently slamming your head into the seat. It would rev faster with a different intake and 3.73s/4.10s. But it isn't like I use a kitchen timer to get through the gears!

A "truck motor" it may be, but it also runs right with C6s so I think it is ok.

 

Kind of off topic question here. What type of revs can a 377 (destroked 400) produce compared to a 383. I know the limit of my 383 is 6500, can the 377 do any higher, safely?

And if I did the 377, it would be converted to roller and use a solid roller cam.

 

377 is good to 7500, so "they" say....

 

383, the 388 will generate more heat due to less metal being in the block. also if you expect roughly 1.1hp per cubic inch you are down a whopping 5.5hp going the 383 route. personally i would trade that for the extra metal in the block. the 10:5 to 11:1 , 195cc head, 230ish @.50 cam 383 is a tried combo that many guys have made. runs hard, will take a car in the 11s and can produce decent MPG. also, this rpm business depends heavily on the parts used, how **** the motor is setup and what the intended use is. i've watched 10,000rpm 350s down at the 1/4 mile track. neat....on a trailer. rpms are an expensive way to generate HP compared to cubic inches. the human body is no different, look at some small out of shape heart with a fast pulse and high blood pressure produces versus an olympian with a big heart and low pulse rate. the olympian moves so much more blood with each beat, welcome to the large cubic inch motor family.

 

Automatic transmission is not good to 7500. Need hardened pump rings. They shatter above 6500. Plus you are going to need proper gears to use that kind of rpm. To me high rpm translates into mucho dinero. I'm going to go the 383 or 396 route myself.

 

hmm...7500 rpms, 6 cubic inches smaller than the 383, sounds perfect for that high revving twin turbo project I've been kickin' around. I'll let y'all know how its coming in about 5 years.

 

Curious. Why would you want to spin it to 7500?

What kind of rpm are u going after? My goal was 6000 and make power from idle to redline.

 

I don't want to go to 7500. Roller lifters will not support that.

Id have to go to solid lifters, and that introduces a whole other pandoras box.

I am sure of one thing, I am keeping and re using all the parts I just purchased.

I plan on keeping it 6K and under. The SR breathes enough to 6K..

 

We spin our 355 cid to 7500-8000 depending on the conditions. Once you take an engine up that high you never want to come back down!

 

having quoted that, there is NO replacement for displacement. what many have said here is true. High rpm will cost big $$ for no gains. Smaller engines usually rev higher only because they swallow more air at higher rpms and need to do that to make more power. I think Ricks 421 combo is the best street combo I've seen to date.

 

What makes it any "better" for "7500" than a 350?? Same crank, same stroke, same piston speed. I don't know of many stockish 350 short blocks that can handle 7500 RPM.

Once again, a 400, part for part, dollar for dollar will make more power than a de-stroked 400. If you spend the money on acquiring a 400 short block, USE THE 400 CRANK!!

 

I believe that spinning it higher actually allows more "driving force" at the rear wheels. I.e. if driving force factors in Torque @ RPM, RPM, transmission gear ratio, and rear end ratio. A higher RPM will allow sustained time at a higher torque multiplication and thus more "driving force."

When you use excel spreadsheets to figure out shift points, this is what you use. That said, you can't be making 10hp at 7500rpm for it to be worth it.

This could be a huge tangent though. Moral of the story, stick to a 383.

 

I don't agree with that first statement that you made. The lifters that I'm using are designed to go up to 8000 - 8500rpm and they are rollers.



Even Lingerfelter's getting in on the GM game with these!

http://www.lingenfelter.com/store/88958689.html

Noland

 

The actual lifter itself might go to 8000 but the issue you run into with hydraulic roller lifters and extreme RPM are the spring pressures involved to avoid valve float. Even with the lightest titanium valves, retainers, and locks you will not be able to shave the seat pressure enough to avoid collapsing the lifter. Hence why all engines that consistently reach 8000+ run a solid lifter set up.

 

There is no need to reinvent the wheel. 383 has been done to death.
Find someone who has a solid combo, and copy it.

 

Not for C4 LT1 / LT4! These are only for LS series Engines!

 

My 396 was three times the initial anticipated cost, and took 3 times as long for me to finish. But I've seen the light on stroker motors now.
Good God they're fun to wail on.