What will i gain with a 383?

[Jack]

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

If ... IF one ONLY changed L81's bore & stroke to attain 383. OE Cam, carb, heads etc.

Simply a guess: Expect a small increase in TQ. Expect HP might suffer. Expect power band to shift lower. Expect a smoother idle. Expect car's vacuum system would work better than before. But convinced one would be sorely disappointed.

My Edelbrock experience is primarily with intakes. All good. One indication of their QC is this fact: Some of NASCAR's 2 barrel touring series rules dictate the ONLY aftermarket intake permitted for sbc is a recent production, completely unmolested Performer P/N 2101. Probably thousands of USA racers are directly affected by the 2101 rule. Edelbrock's control of process & quality results in very little performance deviation amongst recent 2101 intakes.
JACK:gap

 

[SPANISHVETTS]

If ... IF one ONLY changed L81's bore & stroke to attain 383. OE Cam, carb, heads etc.

Why?:confused
A butt kicking, tire burning, Porsche eating, Audi spitting, BMW farting, 160++MPH 383 like the one I have in Thunder is so cheep and eaisy to build why would you build an anemic SBC into a more anemic SBC?

On second thought go ahead and do it and tell every German car driver you know that you are running a Vette with a 383. That way I can pass through Holland on my way to England for my MOT next year and have some fun with your Beamer – Porsche friends… for cash of course… At a 100€ a go I should be able to pay all of the French tolls and the Ferry in less than an hour.


All joking aside a 400+ HP 383 is cheep and easy. The most expensive part is the machine work and the rotating stock. Looking at the pics of your Shark you have plenty of time. If you watch eBay you can pick up the bits you need for Poco Dinero! :bash



It is so much fun to watch a guy that dropped $150000+ on a piece of Euro-trash with a hi-revving 3.5 ltr engine shifting like a maniac – trying to figure out why that OLD Vette just ate his lunch that you have to give it a shot. It is even more fun when I do it in the S10 but that is a different story.

 

[Edmond]

How much will he gain with the stock heads and intake? Weren't those nearing the end of the emissions clampdown from the late 70's?

 

[Peer81]

Oke here is what i'm willing to spend on the 383 materials. Between $1400 and $1750-.
This is only for the crankshaft, connecting rods, pistons with rings, harmonic damper, other camshaft with lifters, bearings and flywheel (i don't know why i shoot change the flywheel, mine is oke..)
The intake, heads, carb and exhaustmanifolds stay OEM. All the EGR stuff is still on it (and will be) but only for the looks and not to pas the emissions. My ECM thing is also working but i don't know if this will effect changing it to a 383? The ECM also stays.

Can this give me something nice to raise the output figures of my engine and where will it be?
My friend said changing it to a 383 wouldn't make that big a difference so i wanna know where i'll be standing after putting that money in it.

Of course i have plenty of time, 1 or 2 years till she's back on the road so i'm not in a hurry. But in 1 month i'll begin my masters study so i need to keep an eye on my money!

Greetings Peter.

 

[Jack]

correction

Oke here is what i'm willing to spend on the 383 materials. Between $1400 and $1750-.
This is only for the crankshaft, connecting rods, pistons with rings, harmonic damper, other camshaft with lifters, bearings and flywheel (i don't know why i shoot change the flywheel, mine is oke..) The intake, heads, carb and exhaustmanifolds stay OEM. All the EGR stuff is still on it (and will be) but only for the looks and not to pas the emissions. My ECM thing is also working but i don't know if this will effect changing it to a 383? The ECM also stays.Greetings Peter.

I can't estimate shipping/taxes so don't include them in purchase of parts ONLY. IN USA, $1600 will easily get you iron EXTERNAL balance 383 crank, 6" rods, good pistons & rings, good cam & lifters, good valve springs, good pushrods, good timing set, oil pump & shaft, all bearings & gaskets, and a new HEI distributor that has BOTH vacuum and mechanical advances. Machine shop services are additional. Properly chosen parts and careful assembly should easily yield a reliable 400+ HP on high octane pump gas (you still haven't told us what octane you'll usually run ... nor have you told us what the new deck height is and how much if any has been milled from heads).

FYI: Your L81's 350 has an INTERNAL (aka neutral) balanced rotating assembly. The cheapest 383 cranks are based on a 400 rotating assembly and they're both EXTERNAL balanced. There are crucial differences between flywheels, flexplates and dampers that MUST NOT be dismissed. An external crank must use external flywheel/flexplate and damper. An internal crank must use internal flywheel/flexplate and damper. Your L81 has an automatic 700R4 transmission, therefore it uses a flexplate (not a flywheel). A new 400 type (External) flexplate can be had in USA for under $40 ... or a "balance plate" to convert existing internal flexplate can be had for under $20. A new external damper is under $50. As far as I know, balance plates are not used to convert flywheels ... but I'm not certain of that. Regardless whether Internal or External, regardless what type of flywheel/flexplate/damper, the stroker rotating assembly MUST still be balanced by an automotive machine shop. Also, a new vac-mech advance HEI distributor will render your ECM impotent. If your damper is 20+ years old it probably needs replacing anyway ... when they fail they cause big problems ... and older ones routinely fail.
JACK:gap

 

[Peer81]

Sorry i forgot, i'm running 95 ron fuel, but i don't know if the european ron number is the same as the american!?
I don't know the new deck height and is the heads have been milled, but when i know i'll post it here!

The estimate is purchase parts only so that's no problem

Groeten Peter.

 

[Peer81]

A little update,

The block is in premo condition, the heads have never been decked and just need a little milling (how much is still open).
To ballance all the stuff will cost me around 5 to 600 euro's. So with the current euro > dollar. I think its better for me to buy a compleetly balanced kit (with flexplate and damper) in the states and send it to europe. But compleetly balanced kit's are difficult to find with a 2 piece rear seal (i heard a 1 piece rear seal is no good for my block) Does anybody know some other kit's then the one's on ebay?

Groeten Peter.

 

[AUSSIEVETTEMAN]

...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....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....

Peer,
I have just done a rebuild on the stock 350 in my 81. Just so you get an idea, we decked the block, bored it 20 thou over, balanced the crank, new lighter pistons, just over stock cam, pump up lifters, standard push rods and a set of Yella Terra roller rockers, oiled by a high volume oil pump. A bit of inlet and exhaust valve work and LT1 Corvette valves springs. On top is a Edelbrock inlet manifold (the stock one had water jacket issues) and a new Elelbrock QJet 795cfm carb. On the dyno, with a high auto diff 2.87:1 she pulls 210 rear wheel hp and 330 lbs/ft of torque @ 3200 rpm. The dyno test only went to 4200 rpm as it was a tune test for the carb.
This donk is basically stock!

Cheers

Tony

 

[bossvette]

try Waynes Engine Supply
(909) 781-2191
been a while since I've used them but they sell complete balanced assemblies.
You want a pre 87 version

 

[Jack]

A little update, The block is in premo condition, the heads have never been decked and just need a little milling (how much is still open). To ballance all the stuff will cost me around 5 to 600 euro's. So with the current euro > dollar. I think its better for me to buy a compleetly balanced kit (with flexplate and damper) in the states and send it to europe. But compleetly balanced kit's are difficult to find with a 2 piece rear seal (i heard a 1 piece rear seal is no good for my block) Does anybody know some other kit's then the one's on ebay?Groeten Peter.

I've tried to not get into exchange rates ... but just for today 28 JAN 05 ... One (1) Euro equals about 1.355 USD ... so 500 euro is about $678 ... 600 euro about $813 USD.

Balancing SBC in USA roughly averages about $200-$225 now. So, (Based solely on Peter's balance quote) it would seem to appear that machine shop work in Netherlands costs at least TRIPLE (3X) the price in USA. I do not have much faith in the accuracy of the balancing of those cheaper completely balanced stroker kits ... I believe it's best to have it balanced at a machine shop. Also, I find it more likely that a 24 year old vette that needs a body off will also need its motor bored. Based on the likely need for boring and balancing etc ... and Peter's relatively high associated machining costs; I suggest that it might be cheaper for Peter to simply order a mild stroker short block assembly from USA.
JACK:gap

 

[Peer81]

I suggest that it might be cheaper for Peter to simply order a mild stroker short block assembly from USA.

You're right about that one Jack. But then i'm only one step away for buying a compleet crate engine. I can also look at it like this when i take a "cheapy" stoker kit (something like $1000,-.) and balance it here in NL for 500 to 600 euro's. I could also buy a balanced strokerkit in the states for $1650 to $1800,-. I don't know if i'll have a cheap or normal to good balanced strokerkit for that money. But i'll try to call Waynes next week and find out The search is still on.

@Jack, you don't wanna know what we pay for normal corvette / v8 parts overhere. In a shop its between 1.8 to 3.0 time's catalog pricing..

Greetings Peter.

 

[Peer81]

After some research i'll just stay with my 350.
When im going to change stuff i just want to change to much to optimise everything and the original intake and carb are to little for real power. So it will be optimising the original 350 with another camshaft.
Thanks for al the advice!

Greetings Peter.

 

[BlackVette66]

Lots-o-Hosrepower-Lots-o-Torque

March 2005 issue of Hot Rod magazine has an article about a 383
they built with a complete list of parts and part numbers they
used to build the motor.

500 + horse power
500 + lbs/ft of torque

This would put you on par horsepower/torque wise with
the new Z06

 

[dfw81shark]

Check these out:

new 383 complete for $3682:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33615&item=7951608820&rd=1&ssPageName=WDVW

new 350 complete for $2977:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33615&item=7951756047&rd=1&ssPageName=WDVW

Free shipping, free 2yr unlimited mile warranty

I don't think I could put the 350 together for cheaper than that, especially with the power it makes. Anybody have any issues or concerns ordering one of these from an ebay store with over 300 feedback? I'm considering it. Phoenix isn't too far if I have to lay some smackdown.

Here's another almost-complete stroker with Trick Flow heads:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=7950363487&rd=1&sspagename=STRK%3AMEWA%3AIT

How do they sell these so cheap? Are some of the parts hot, or are there severe markups in Summit-type catalogs? I've got a friend who works for a small hotrod shop and most of the stuff they get from the manufacturer is nearly the same price as Summit.

 

[SPANISHVETTS]

Look at that torque curve! Almost flat and 350 ftlbs. from 2000 to 6000 RPMs. This lump stuck in front of a 700R4 will more than make up for the tall 2nd gear and keep your Vette well in front of the Euro-Trash and your tire dealer will love you.

How do they sell these so cheap? Are some of the parts hot, or are there severe markups in Summit-type catalogs? I've got a friend who works for a small hotrod shop and most of the stuff they get from the manufacturer is nearly the same price as Summit.

Volume buying! We buy our kart tires by the container...you would not believe how far any Mfg will drop his pants for a high volume order.

 

[Edmond]

Those eBay crate motors look pretty good. A long block for $3600! Just need the exhaust system. They said at the bottom that exhaust manifolds would bring the HP down to 358! The dyno they did was with large tube headers and an open exhaust.

Only qualm I'd have is that the heads could be cast iron and not aluminum. But they do have performance sized valves!

They also invite you down to the shop to take a look but why are the auctions only open to preapproved bidders?:confused

 

[GerryLP]

... Anybody have any issues or concerns ordering one of these from an ebay store with over 300 feedback? ...

Yes! I do!

Buying an engine that has not been put through an actual dyno run is not very conforting or re-assuring about its performance, quality and reliability. I'll tell ya'll, I know a little about this. Even today, no matter how confident I feel about an engine that I or my guys have put together, I'll never bet my house payment on it.

My shop puts helicopter engines together. Now, you all will say that "Well heck! A helicopter engine! That's not the same!", but I'll tell you that it is the same. Helicopter engines thrive on torque, and without a dyno run, there is no way one can guarantee that it will produce "X" number of Shafthorsepower or Torque. We have assembled engines that are all new (new components throughout) except for the engine data plate, and they performed marginally at best (that's just a few horsepower above minimum requirements after spending days of troubleshooting).

And what good is "X" horsepower if it's vibrating or leaks, or because it runs like a dog because one did not have the correct rear ratio, stall converter or exhaust?

Sorry to play the Grim Reaper here, but its best to go after a tested engine. I just removed the engine and tranny out the Vette last weekend, and would hate to do that because I would need to return the "rotten piece of cr@% ad engine I bought without a dyno test run. Perhaps you'll get lucky, but chances are that the odds are against you.

GerryLP:cool

 

[dfw81shark]

Sorry to play the Grim Reaper here, but its best to go after a tested engine. I just removed the engine and tranny out the Vette last weekend, and would hate to do that because I would need to return the "rotten piece of cr@% ad engine I bought without a dyno test run. Perhaps you'll get lucky, but chances are that the odds are against you.

GerryLP:cool

"In addition the Full Dyno Report is included with every package, with all Horse Power and Torque ratings verified by Dyno2000® on every engine package*."

Wow. If you read the * and didn't realize that Dyno2000 was a software package, you might be surprised. Thank you for that insight. Makes it sound like it is physically tested though unless you read the fine print at the bottom. I wonder if GM crates are each dyno tested?

On a personal note, I was convincing myself to buy complete to not have problems, now it makes me want to build it.. Thanks for being my devils advocate. I needed that..