383 stroker?

[Pa Goose]

My nephew has a 78 monte carlo and he keeps telling me I should convert my 81 Vette to a 383 stroker. What exactly is a 383 stroker, what would I have to change and how much of a difference would there be in HP MPG roar?

 

[Crimson Thunder]

A 383 is when you replace your 3.48in stroke crank in your 350 with a 3.75in stroke crank from a 400.Of course nowadays you can buy a complete balanced rotating assembly for a very reasonable price.

 

[TMPJoe]

along with increasing the stroke, the cylinder will be bored out .030 and that coupled wit the longer stroke will make the engine displace 383 cubic inches as opposed to 350 cubic inches in stock form. (If you have a 1981, you could have a 305 Cubic Inch engine also. )

The longer stroke of the engine helps to produce more torque than the 350 inch motor and torque is what moves the car intially... so that "strokers" are an easy way to get a lot more acceleration for the money....

how much power depends on a the cam, heads, pistons etc.. ..

Crate engines are available and most of them run between 350-425HP depending on how much you spend...

stock 1981 corvettes are not terribly powerful so switching to this kind of motor would be quite a difference.

however, it requires relatively major work..... which from the sounds of it you would have to trust to others to do....

you are looking at engine, transmission exhaust rear end gearing... if you do not do any of the work it can run $7,500 to $10,000 to do it right and take advantage of that new power....Certainly not less that $6,000 in any case...

 

[Evolution1980]

you are looking at engine, transmission exhaust rear end gearing... if you do not do any of the work it can run $7,500 to $10,000 to do it right and take advantage of that new power....Certainly not less that $6,000 in any case...

I think those numbers sound a bit high. If he didn't do anything except the engine and had someone else do the work, I think he could get by for about $2000. However, as you stated, to get close to the FULL POTENTIAL of the engine, you're gonna want to make other mods, such as exhaust right off the bat. And being an L81 setup, I'm not sure what kind of computer/carb mods would have to be made. You may have problems with the stock transmission handling the increased torque if you find your foot getting heavy when the stoplight turns green.

It is something you can do in parts though. A little bit here and there.
In the long run, if you aren't turning the wrench yourself, sometimes it's just better to save your pennies and buy a 383 crate engine, then you just drop it in rather than work over an older engine. There are threads-galore on this topic. Just do a forum search for "crate engine" in the C3 forum here and you'll find tons of threads.

 

[SIXFOOTER]

Well, a few things I have learned dealing with my 81, the carb is a 750 cfm rochester quadrajet, the primarys happen to be computer controlled, the secondaries are just like the older ones. The CCC WILL keep up with a seriously modified motor
Dual Exhaust and hy flo cats are a minimum for ANY HP mods
Just about any heads out there make more HP that the stock units, Dart Iron Eagle, Pro Comp, AFR180, AFR195.....
There a whole list of cams to use, either flat tappet or roller
The stock 81 intake is the Edlebrock 2101, a pretty respectable unit
A 383 stroker might be fun, but it requires way more work that I personally think its worth. My recepie is: Comp Roller Cam kit, AFR180 heads, stock carb and dizzy, 2004r tranny I built to stage 2, stock gears, 2 1/2 duals, no cats Bourla Pro XS Mufflers.
I am in the middle of this, but I expect 350+ hp and a driveable well mannered car that will get 20+mpg (as long as I keep my foot out of it)
The problem as I see it with a 383 stroker, is that it is running out there on the edge of what the motor can do, requireing more attention to tuning than I want to do. When I get my car done I will have 2 yrs and $15K in it. I will want to drive it more than work on it at that point.

My Humble .02


Oh by the way, that $15k is a full on frame off resto mod, paint and body included

 

[Art Jett]

My 383 ended up costing about $5500.00. With the 700R-4 and exhaust it came up to around $9000.00. I have a custom TPI setup though. As far as messing with it after getting it running, I haven't had to do much of anything. It runs like a scalded a** ape and gets 19MPG. It would get better but I can't seem to keep my foot out of it, it sounds and runs too good. I checked my plugs the other day and they almost look like new after 1500 miles. Art

 

[TMPJoe]

all cool ideas... i included in my cost estimate what you need to do to a stock suspension on a 25 year old car to make that power useable without breaking things...

new carbon fiber spring, polyurethane bushings, decent struts, refurbished control arms and drive axles... etc... I mean I guess you could bubba that but I think there is a thread about this somewhere.... not the best idea if you take the horsepower up 50-200% with modifications...

the other issue is if you are asking what a 383 stroker is then you sure are not going to be doing any wrenching....

Funny but you can spend a lot more than $6000 on just parts for your motor depending on how wild you go... trust me... its not hard to do!

the 700R4 route makes a nice cruiser.... especially with either the original 3.07 rear or a 3.42.... I have toyed with the idea of a gear vendor unit for mine... but I have other projects to use those funds on....

to me this is what the fun of a forum like this is all about.. different "strokes" for different folks

what a pun!

 

[Evolution1980]

..different "strokes" for different folks

what a pun!

Baaaah!!! Very punny, Joe! :eyerole:L

 

[Art Jett]

TMPJoe is right. I replaced all my suspension bushings, added a 7/8" rear sway bar, new springs, I rebuilt the trailing arms and put in Bilstiens and all new U-joints, rotors and rebuilt O-ring calipers w/braided SS hoses, master cyl and booster. The money adds up before you know what's happening!

 

[grumpyvette]

read thru this ,thread ,it will give answers to most questions

http://www.chevytalk.org/fusionbb/showtopic.php?tid/131229/

 

[Pa Goose]

Wow. Thanks for all the info. This Vette is only the second GM product I have ever owned, the first was my 1st car a 57 Bel Air 2 door hardtop. Sounds like a 383 stroker is the way to go. Don't have the automatic to worry about though. Mine is a 4 speed. Getting ready to put a new clutch in next weekend.
Again thanks for all the information.
John

 

[ratflinger]

383 bah! Everyone has one, be different build a 396 or 408 from your 350. Cost is about the same.

 

[black_81_vette]

The 408 runs good thats what im running

 

[Jack]

Pa Goose:
I like a street 383 ... lotsa bang for the $. Suggest you scrounge up a good used bare 350 block w/ bores that'll clean up at 0.030" over ... build it up as 383 ... most '86-up 350 blocks either have OE Roller Cam or are ready to fit OE RC ... lots more cheaper piston choices for 383 than for 396/408 ... usually less clearancing needed for 383 too. Keep your OE motor OE & stow it when you swap. If you can find a decent sbc400 block without spending lotsa $ ... that'd be great choice too ... a thirty-over sbc400 = ~ 406" ... but sbc400 Not produced since about 1980 & None have OE Roller Cam & None are ready to fit OE RC.

350 blocks are cheap & plentiful ... 383 builds/parts can be relatively cheap, simple & reliable ... all why 383 so popular. FYI ... a 400 crank will not simply drop in a 350 block ... 400 crank's main bearing journals must first be machined to fit 350 main bearing saddles... hence popularity of relatively inexpensive aftermarket 383 cranks that fit 350 main bearing saddles.

TIP: Pay attention when choosing pistons/heads ... Do Not build street motor w/ too much compression ... you may have trouble finding easy access to adequate octane ... now or in future. Here's a handy, accurate static compression calculator from Federal Mogul-SealedPower-SpeedPro aka TRW:
http://www.21cgt.com/FMWebCatalog/frmConversion4.aspx

 

[ratflinger]

Cheaper if you go cast - yes, not if you go forged. I wouldn't build a cast engine anymore, but if you don't want to spend $5-6k, then get a nice core, have it cleaned, magnafluxed, decked, align bored/honed, & punched .030 over. Get a nice Eagle rotating kit (balanced from Eagle) & aim for a CR of 10:1 @ 64cc. Heres where you put your money - AFR 180 Street heads, a nice cam, Air Gap or Air Strike Stealth intake, 650 Demon. You'll have a nice 355 that will make a lot of 383s show you some respect.

 

[tshera388]

I built a 383 stroker with an 8.5:1 compression ratio and added a Wieand street charger 142. I used a cast crank, 400 rods, stock heads with 1.96/1.5 valves, external balance, and pretty much standard parts. The weak link in the whole system was the 700-R4 tranny. I kept slagging the front drum. Most fun I ever had in a car with my clothes on. I'm building another for my 'Vette, the only big difference is that I will be using Dart Iron Eagle heads and a bit tougher crankshaft.