What will i gain with a 383?

[Peer81]

Hello everybody,

I'm doing a body off in my 81 vette. A friend is rebuilding the block but he came by a few things..
Stock lifters and cam are to old and will be replaced by a Comp Cam no: 12-232-3 with lifters.
The crankshaft will not hit the minimal spec's after (i think you call it) grinding, so i need another one.

I'm thinking of a 383 Eagle stroker kit (or other) or a normal 350 crankshaft. But what do i gain with the stroker kit?
The engine is original and the same heads will be on the reassembled block..
I'm not willing to put in alot of money on this engine (els i would change the heads) but i think this is my oppertunity to make a differance.
What do you think, is it a go or no go, and what will be the specs when it's a 383?

Overhere in Holland changing to another block isn't an option for me...

Groeten Peter.

 

[Ken]

In a word, and I cetainly hope you don't get offended by my choices of the word... :L

What will i gain with a 383?

Balls!

A 383 is a ballsy motor; lot's of low-end grunt, yet can still scream pretty good in the upper rpm range.

 

[Ken]

Ya know what we need around here? Someone like Hib who could take the time to really detail the answer to such a question. I honestly don't have the knowledge (Read: experience.) to tell you the best combination for the desired outcome. There are a multitude of questions that need to be answered before you can make a choice on what type of engine you want: street driven only?; race only?; street and strip?; road course; demolition derby... :L You get the idea I think.

 

[Peer81]

I didn't expect to get that answer on my question
But with a little info.
It will be a only street driven car, stock L81 outside, inside no problem.
Has a 700R4 from a 90 corvette with stock rebuild diff.
I'm not looking for a hi rev or top hp engine, just want to know the difference.

Groeten Peter.

 

[Ken]

More displacement and greater leverage means more torque -- that's the basis for a stroker motor.

Building a small-block stroker gives you something similar to having the power of a big-block, without all the weight.

 

[bossvette]

I went from a 350 to a 383 and the difference is quite noticable, the engine was built for low /mid range torque. I do have aftermarket heads and TPI which help. But I have always said "the 383 is the best engine Chevrolet never built" but guess what now it is availabe as a crate engine :cool

 

[GerryLP]

In an L81 you will gain respect . The torque increase will move it along quite nicely while the sound of tire burning (usually only noticeable on a 4-speed manual L81)will make you car a force to be reconed with.

GerryLP:cool

 

[Vette/Berlina-coupe]

-the Chevy/383cid small-block V8 is for low-rpm grunt...

FYI: -as for myself, i like the rush of winding an engine through the gears, so went the other direction and built a 352cic-V8 from a 400cid/small-block(with large-valve Alum.Heads) by installing a forged 327cid-crankshaft with 6.25"/Long-conrods(H-beam), and a Fluid-damper! This particular combination makes for a 450hp-engine that will wind all-day at 7,000-rpm, yet provide terrific fuel-mileage, owing the substantially longer dwell-time of the piston as it leaves the combustion-chamber; --plus the long-rods have greatly reduced friction as compared to the standard 5.7"-length Chevy-rods which push the piston hard against the cylinder-wall during the power-stroke. However, to most guys, a 383V8 is a big-deal, -since they like laying-rubber and feeling its low-rpm torque in the seat of the pants, and ignore the relatively lousey fuel-mileage, but have wisely avoided the relatively truck like quality of a big-block; --yet are not into the fun of skillfully using their gearbox to make-up for the lesser torque of a hi-efficiency Longrod Racing-engine....
~Bob vH :ugh
ps: -yes it does have a Comp/RollerCam w/Hyd.Roller-lifters & Comp/Roller-rockers to facilitate the easy reving capability of this fabulous engine. Moreover, coupled with the Tremec/5-speed transmission's 3.27-1stGear, it will trounce a built 383V8 every time; and out on the road, just flat walk away from same....
~B.vH

 

[Jack]

Hello everybody,

I'm doing a body off in my 81 vette. A friend is rebuilding the block but he came by a few things..
Stock lifters and cam are to old and will be replaced by a Comp Cam no: 12-232-3 with lifters.
The crankshaft will not hit the minimal spec's after (i think you call it) grinding, so i need another one.

I'm thinking of a 383 Eagle stroker kit (or other) or a normal 350 crankshaft. But what do i gain with the stroker kit?
The engine is original and the same heads will be on the reassembled block..
I'm not willing to put in alot of money on this engine (els i would change the heads) but i think this is my oppertunity to make a differance.
What do you think, is it a go or no go, and what will be the specs when it's a 383?

Overhere in Holland changing to another block isn't an option for me...

Groeten Peter.

I was once in a similar situation ... planned to simply overhaul the 350 but found the crank was not serviceable and the L48 cam was too small anyway. So I built a mild 383 (actually a 388). And I used the OE iron heads.

I say go for the stroker ... but plan for it carefully. First, do not order any cam or stroker stuff until after the block has been closely checked and expertly measured ... same for the heads ... if you have to machine any surfaces it will affect compression ratio ... so you need to know final measurements before you order piston type or cam profile. If you order a stroker kit make certain it has rods that are "3D profiled for stroker" or are "stroker clearanced" ... otherwise the rods might come too close to or hit the cam lobes. FYI: Rods that have small capscrews instead of bolts are usually profiled & clearanced for stroker. And if you're going to get new rods, might as well opt for longer 6" rods as they're no more expensive than same rod in 5.7" (OE) length ... do ensure you have proper piston depending on 6" or 5.7" rods. After you've settled on rod length and piston dome/flat/dish ... calculate compression ratio ... then ask Comp cams which cam for YOUR combo. FYI: all the cheaper 383 kits I've seen with a cast crank are "external balance cranks" and REQUIRE a different harmonic balancer/damper than your 350 ... same for flexplate or flywheel.

BTW, Comp's catalog recommends 12-232-3 cam for a Ski-Boat ... your vette IS fibreglass, but that's a car motor in front ... not a Marine engine. That cam runs out of breath about 5K rpm and it has less duration than you'll probably want for a stroker. It might work for a mild 350 car but I strongly suggest you ask Comp to recommend a cam that's right for YOUR combo.

What octane fuel do you plan to use most of the time???? That's important when planning the compression ratio and cam.

So, have your block and heads checked and measured by a machinist. Then decide on how much your pocketbook$ can stand. Come back with your machinist's findings and a realistic budget (in USD) ... there'll be plenty of folks here to assist you.
JACK:gap

 

[Ken]

... yet are not into the fun of skillfully using their gearbox to make-up for the lesser torque of a hi-efficiency Longrod Racing-engine.

What??? What you talkin' 'bout Willis? :L

Seriously though, I hear ya!

 

[SPANISHVETTS]

Here is what a well built 383 gives me :L each and every time I push the happy button.

All of Stephen Batchelors record breaking SBCs are 383 beast that live happily at 7000 RPMs but most folks cain´t build a engine like Batch...My animial redlines a 6200 but with the intake we are running it runs out of breath shortly after 5000.

I get 26+ MPG on the Motorway at 90-100MPH and 16+ in town. At the track we just connect a long hose from the tanker to Thunder so I can complete a lap.
A good 383 will also put your local Tire Dealer´s children through Med School.

 

[goingballistic]

As is already stated, low end torque ( grunt as it's affectionately referred to).

Make sure you know WHAT you want before you start buying parts. That CAM is not ideal for what you trying to do, look at the 12-250 cam, that's the cam I went with for my 383. Decide if you want internal or external balance, I chose internal but AFTER I purchased an external balanced crank ( still have it if you want it PM me) Also have a 12-250 CAM with a cut base circle of 1"
Go with 6" rods and was said make sure the rods you buy are cut for clearance for the cam and you also MUST check the clearance of the rod shoulders and the block as the rotating assembly completes full revolutions. When I first did mine I had issues with the rod shoulders contacting the block and had to grind areas of the block and rod shoulders to ensure nothing contacted the block.
Strip the block and get to a good shop, have the block checked to make sure nothing is wrong. Have the deck checked for flatness maybe shaved to true it. Bore it 30 over ( obviously). I opted for zero deck and AFR heads, this gives me about 10.7:1 CR ( calculated, bored 60 over), solid lifters, dished pistons, RPM airgap manifold etc etc etc.
If you are just going for street driven, cheap, stay external balanced, look into a lower profile cam that won't be so lopy ( vacuum problems if too lopy at low idle), I would strongly recommend forged pistons....strength ( others will disagree and recommend HE pistons), kind of becomes a pocket book question, certainly new bearings and freeze plugs in the block. Toss the old oil pump and put in a new one ( for the price it's worth it ).
I had the shop put in my rotating assembly for me, $170........it was well worth the investment in time and money.

Good luck.

 

[SPANISHVETTS]

Peer81,

I just noticed that you are in Euro-land. Frankie can give you a lot of advice and has a great inventory but with the Euro to $ rate today you could not find a better time to buy in the USA. Even with the shipping charges you will still save 50% over the European prices.

Unless you are going to Drag Race at a strip keep your stock rear end. My American brothers do not understand how really fast we drive over here. I have a tall rear end in the S10 that I am going to change for a 2.73:1...6 MPG and 4200RPMs on the Autopista just does not make sense.

 

[Peer81]

Thanks everybody for the advice so far, is more then i was expecting.
And yes also a Eurolander overhere

The Comp Cam was for the original 350 i didn't know this would make a big difference for a 383... Or that it was for a skiboat :L .. the only thing i know are the basic engine things and that's it! I have one Summit catalog beside's me and that's it. I wasn't planning to go to deep into the details but if i could learn something i would be nice of course.

My friend said a Edelbrock cam was best for my engine (goals) but i don't want any Edelbrock in my engine..
Well i already know what i get and that's torque
For most part this engine will be used for street only! Just cruising on the hiways to go to meetings with now and then a stoplight battle. Above 5k rpm is nothing for me and i realy don't need a gas guzzler because fuel here tripple the american price's.. So if a 383 is pumping fuel like a big block its nothing for me!

The only thing i don't like on the normale L81 is that when you're used to it (we only have 4 cilinder engine's overhere) the L81 make's a nice sound but no power for 5.7 liters. When i'm beside's a BMW at the stoplight and i have to know if it's a 3 or 5 serie's if i could beat him or not then i don't know what my 5.7 liters are doing.. If i could get 0 to 60 around or in the lower 5 sec with a 383 with a 700R4 that's perfect for me! Of course on our hiway's our speeds are legaly 75mph but i'm not attending to go over the 145mph. The engine has to idle very stable and that's about is.

If the crank was oke it still be a 190hp 350ci L81 just to cruise around, but now i could have something more v8

I first wait untill the block is back, it had to be decked and the cilinders had to be polished so i'm open to suggestions. The original oilpump will be replaced for a high volume pump. Could i go with the original 2 bolt registers of do i need the (i think you call it) splayed one's?

Damn long store this is... Could somebody give me a raw increase in torque and hp, so i could get an idea what where talking about?
My corvette was on a DynoJet two years ago doing 179,4hp and 258lb/ft
I'll get back on you with how much money i have to spend! I'm looking for a "cheap" but good quality 383 setup.

These are some photos of the current state of the body and chassis so you know i need to some more money to make it a Corvette again..

Groeten Peter.

 

[Jack]

small base circle cam sources

BTW ... Howards Cams will recommend a proper profile & can grind a hydraulic flat tappet cam on small base circle for about $150 USD. Howards also has a lot of other stuff like cranks, pistons, direct lube lifters, stroker kits etc ... and unlike Summit or Jeg's ... their staff are experienced racers and builders. Contact John Steely jsteely@howardscams.com www.howardscams.com

Also highly qualified are CamCraft Cams. Contact Charles Reichard charles@camcraftcams.com www.camcraftcams.com

FYI, I run one of these folks' cams and the other's lifters in late model circle track sbc motor ... VERY pleased ... others are too. Both enterprises are much smaller and lesser known than Comp ... but I find quality and service superior.
JACK:gap

 

[dfw81shark]

The only thing i don't like on the normale L81 is that when you're used to it (we only have 4 cilinder engine's overhere) the L81 make's a nice sound but no power for 5.7 liters. When i'm beside's a BMW at the stoplight and i have to know if it's a 3 or 5 serie's if i could beat him or not then i don't know what my 5.7 liters are doing.. If i could get 0 to 60 around or in the lower 5 sec with a 383 with a 700R4 that's perfect for me! Of course on our hiway's our speeds are legaly 75mph but i'm not attending to go over the 145mph. The engine has to idle very stable and that's about is.

If you don't require emissions, my emissions-less L81 with Hooker Headers makes 0-60 in 6.2ish seconds. I have the TH350, 3.54 rear, and with your 700R4's 1st gear, I bet you could get the low 5's with the emission-less L81. Overdrive and 3.54 should get you decent gas mileage too. With that said, any well-put together 383 (high or low CR) should get you where you need to go..

 

[Edmond]

I'm curious as to why you don't want any Edelbrock stuff in your car. They make good stuff. Their intakes, carbs and heads are good stuff. My neighbor swears by their intakes.

 

[Ken]

I have friends who work at Edelbrock's Torrance facilities, and I can attest to the fact that they are very strict with their quality control. Nothing leaves that plant if it's not 100% right.

And as far as I know they're very helpful on the Help desk, as well as doing all they can to satisfy the customer if there's a problem.

 

[SPANISHVETTS]

I have friends who work at Edelbrock's Torrance facilities, and I can attest to the fact that they are very strict with their quality control. Nothing leaves that plant if it's not 100% right.

And as far as I know they're very helpful on the Help desk, as well as doing all they can to satisfy the customer if there's a problem.

:BOW Elderbrock products have always been spot on for me. Never had a leakly intake or a badly machined part. Their off the shelf kits kick out lots of power for the $ and require very little thinking but this is just MYHO.

 

[Peer81]

I didn't mean to change the subject...
It's just a principle of me to take (when i have the change) parts from companies that focus on only a few product that a hole productrange from A to Z.
So i don't have any bad experience with Edelbrock stuff! It's just personaly the way i think

Anybody willing to take a gues at a stock L81 with 383 displacement, torque numbers and hp?

Groeten Peter.