I wondered if anyone is running a 383 (Chevy...not Mopar) engine that is set up for max performance. As in 12-1 or 13-1 compression ratio and a solid lifter or solid roller cam. What RPM are you taking it up to for shift points? Will this size mouse survive at 7000+ RPM like it's short-stroke versions?

Dep

 

Guy at the local track ran 11.50s at 115+ (spanked me GOOD one evening.....) with a 383 SBC, with an 8" converter, 29" slicks and 4.56 gears:
I figure he is trapping about 6700-6800, easy, with no-problems at all.

 

Why not?

These are the pistons to a friends off road only, road racing 383 ci. I think these JE popups were 12.8 or so compression with 64 cc heads. This motor uses an 8000 rpm red line. Every year that it has been raced it's never had a failure. Same crank, rods, and pistons. It just gets new ring, bearings, and mod's every year to make it work better.


second picture off to the right.

 

Well the compression isn't quite that high at 10.7:1, but I shift my solid roller 406 small block at 7300rpm. Track results and details are in my sig. I am only trapping around 5000rpm with these gears so I'm leaving some ET on the table. I run 91 octane unleaded, 10" converter, TH400.

Why do you ask?

 

Thanks guys!!! I haven't seen much about full blast 383s, and these reports are encouraging. I saw the specs on the crate motor 383 from GM and it was okay, but I wondered how it would respond to being warmed up a lot more.

I wonder if anyone is running 377CI engines any more (destroked 400)?
I guess they fell out of favor when the 383 became popular.

Anyways, thanks for the excellent responses.

Dep

 

I'm running a 388 which is a destroked 400 (4.125 bore with 3.625 stroke). I'm still working out some bugs, but ran a 12.8 at 115mph last year the one time I took it out. The engine is coming out to take car of some issues I had last year. Should be much better when it goes back in and the DP carb versus the vac sec I had last year. Oh 11:1 compression on pump gas too

 

Here is an article on the HT383, GM also offers it with their fast burn heads calling it a ZZ383 with 425hp.

http://www.hotrod.com/techarticles/66278/index.html

 

Smoked: yikes!!! 11-1 on pump gas!!! You must have some very hot pump gas in your area!!
I'm thinking racing fuel on anything above 10.5-1. Are you still using the stock rear end and stick or auto?

Fevre: Yep...saw that website. But I am looking more for info on full blast strip-only 383s or 377s. Actually, the 377 was used in the Cheetah cars.

Dep

 

Dep - What parameters are you realy looking for? The 12.8 pistoned 383 is making something like 660 hp @ 7400 rpm. He is using T&D shaft rockers on some odd named heads.

The only limitations on motors these days is air flow and will the valve train hold together. Once you get into good bottom end parts the old idea of feet per minute of the pistons doesn't really come into play on sub 8000 rpm motors with sub 3.800 or less stroker cranks.

Anybody that has to use anything above 92 octane in 11:1 or less CR motors has not done their homework

The other thing if your going to run race gas why stop at 12.5 CR Why not go ahead and just build 15:1 or 17 to 1 with methanol

 

mine is 10.something to 1. Olivier said AR told him keep it under 6300. I shift at 5800 and with my stupid 3.36's, I'm no where near redline at the stripe. It has a survived 60 something passes with Olivier, 25 1/4 mile passes and 12 18ths with me. Not to mention almost 3000 ,miles since I installed it in December 04.

 

Well gas in my area is pretty crappy (Chicago=Oxygenated junk).
I'm not worried about pump gas as I plan on racing fuel no matter what engine I use. I haven't seen engines UNDER 11-1 compression being used in any serious competition (NHRA and NASCAR). 13.5-1 is about the limit in practicality for compression ratio. I'm not running John Force's car you know

Considering NASCAR is using a 358 motor and getting over 700 HP, and Dave Strickler was getting 456@7700RPM out of a 302 (using STOCK valve train), I would hope that a substantial horsepower increase could be reached with a hotter 383 without going too exotic or breaking the bank.

Dep

 

Dep, I'm incredibly suprised. I was under the impression that you had a strong aversion to all small blocks but the 302. In fact, you inspired me to build the 496 that's going in my Nova. What changed your mind?

 

If Dave strickler was using all the same parts and just increased his ci to 383 he would still only have @456 hp max. But it would probably be at less than 6000 rpm.

Ci within a class range. Like 350 through 427 ci with all the same parts and compression. Would all make the same HP within a small %.

Like my 383 and 427 are very simular. MY 383 is a radical thurough bred compared to my TQ monster 427 small block.

 

The GMPP Crate Motor 383 wasn't that impressive...but a great upgrade from a ZZ4. I shift my 383 at 6500-6600 rpm, with 10.2:1 flattop pistons, and with a nice bottom end, the long stroke motors can last...of course Dep, you know that.
As for 13.1 or more CR on 383s..that would be awesome, but I never see any for some reason. Most high CR motors that I have been around were Big Blocks.

 

In a word...and everyone has heard this before...MONEY.
You can get an amazing "bang-fer-yer-buck" with a mousemotor as compared to a big block. I still have the utmost respect for the 302 Z-28 engine and I have NOT ruled out going with that cubic inch for my engine choice. Consider...I can get a VERY nice SET of smallblock complete heads for what I pay for ONE big block head. I can almost stroll down the street and pick up smallblock parts laying around
I can buy a COMPLETE smallblock for what they are selling a short block big block for.

Don't get me wrong...I still think the ratmotor is the ULTIMATE in performance for the Chevy line. No amount of boring and stroking can turn a mousemotor into a ratmotor equal. But if I drop in a killer big block into my Vette (and I wouldn't even bother with any of the mild crate ratmotors Chevy offers), I have no doubt that the rear end and u-joints will immediately become shrapnel. I'm not running an auto, and when I come off the line, it will be slipping my foot off the clutch. I have ZERO confidence that the Vette drivetrain can take a lot of those type of launches with the power and torque a big block puts out. A smallblock offers a much better chance of the rear end surviving. Until someone comes up with an inexpensive way of installing a Ford rear end in a Vette without back halfing the car and cutting the crap out of things, I think I'll be stuck squeaking with a mouse

Dep

 

For the money, I think I could do better. $3895 for a long block. Their article on GETTING IT RUNNING mentioned no dollar amount that I could see.

When they finaly get done blathering, you have a build up, using their numbers, of $5300 for 380 HP and 474 ft. lbs. of torque.

Mine ain't done and running yet, but I have less than $3700 in the engine alone, and, according to DD, 387 HP and 435 ft. lbs of torque. My dollar figure is based upon the cost of new parts vs the used parts I am taking from my 350. Their big bump is a roller cam, my numbers are for a flat tappet.

No wonder people are starting to say WTF is with the magazines? I have receipts for all my parts, if anyone is interested. No secret on how to get performance on a budget, just don't listen to the mags.

Hey, I am not proud, if anyone wants to know what I did and how I did it, E-Mail me. Don't forget, my numbers came from DD. Will chassis dyno this spring when everything is together.

 

Some people are on a time budget and dropping in a crate eng fits their budget better assuming they have the $ to spend.

 

Check out this reading on "the 350 engine chevrolet should have built" by Hotrod magazine. It kinda tough to read and Hotrod's website doesn't seem to be working to well right now for me. This was interesting reading when I built my 388
http://purplesagetradingpost.com/sum...%20engine.html

 

Smoked: Interesting read is right!!!!

Dep

 

My old 383 wasn't that high reving, but it had a lot of torque.. My shift points were usually at 5800 RPM and that was also my trap RPM.. My 1/4 mile mph was around 120 mph (running mid 11's on slicks and skinnies with a 5-speed)