Chevrolet 383 Stroker Build - Junkyard Heap To 383 Neat, Part 1 Of 2

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From the July, 2011 issue of Classic Trucks / By Wes Drelleshak
When I set out to build a Chevy 383 stroker motor there was one thing that I found very important and that was resources. Horsepower numbers and timeslips don’t mean anything to you or me when the parts that you ordered online don’t fit the motor right. One of the toughest things I have found in the past is getting the right part that fits without searching all over to find it. Lucky for me I happened to stumble across the Summit Racing website and began looking around for the much needed parts for a 383 build. I was originally going to rebuild a mild Chevy 350 using a standard junkyard motor, but then I thought why not build a 383 out of the same block and get some more torque and horsepower. Besides, the 350 rebuild would have been just that--a rebuild with lackluster dyno numbers, and who wants to read about that? Plus, almost all of the same rules for rebuilding a 350 apply to the 383.

I have installed tons of aftermarket parts on 350 platforms, but I have never jumped into a complete build from a junkyard motor. My plan is not to show how to completely build a 383 motor, but rather to provide a parts guide and insight into some of the mysteries of a 383 stroker. So I did some research before looking for the right donor block. The Chevy 350 small-block was introduced in 1968 from GM and is still one of the most readily available motors in junkyards, dealerships, and parts houses.

Over the years there have been several differences in the motors, like two- or one-piece rear main seals and two- or four-bolt main bearing caps. The ’67-85 350 came with two- or four-bolt mains and two-piece rear main seals that tend to leak if not installed correctly. The ’86-95 pre-Vortec motors had a one-piece rear main seal that didn’t tend to leak like the two-piece seal and also came in two- or four-bolt mains. So what year 350 did I chose and why? With any 350 you want to find the one with a four-bolt main, and I like the idea of having a one-piece rear main seal, because if GM liked the one-piece seal enough to put it on modern cars then so do I. I went with a ’88 Chevy 350 that was equipped with a factory hydraulic roller cam, a cam thrust plate, and a one-piece rear main seal. I could have used an older two-bolt main 350 that was lying in my garage, but there is just something about those extra bolts holding the crank down when stepping on the gas.
So what did I learn from building a 383 bottom end from scratch?

For starters it is very important that the machine work is done correctly and that the engine builder knows what he or she is doing with the motor. Things like vehicle weight, transmission, towing, drag racing, autocross, or daily driver all come into play when selecting parts.
You need to look at the overall picture, like what heads you are going to use and piston dish. The heads can easily be changed while in the motor but the pistons cannot, so first figuring out the compression ratio that will suit your needs is ideal before putting the motor together. Pistons that are domed will usually cause increased compression; dished inward will decrease the compression ratio. Cylinder heads have what is called combustion chamber. This is the space on the underside of the head around the valve area and usually measured by the manufacture or engine builder.

Depending on what piston you have is a factor that determines the compression ratio compared to the combustion chamber on the heads. If the cylinder head chamber is 64 cc and you have a dished-style piston of 16 cc you will have a lower compression ratio, about 8.5:1 to 9.6:1 depending on other variables. If you had a domed piston with that same 64cc head your compression will be higher, 11:1 and up depending on other variables. The same domed piston and a larger combustion chamber head of 74 cc will lower the compression ratio. I could have used a slightly smaller D-dishedtype piston to increase the compression, but with a set of RHS 64cc heads (PN 12053-02) and other things considered that should bring me up to a 9.6:1 compression ratio. Also when using aluminum heads a rule of thumb is that you can get higher compression without the worry of detonation. I am going to play it on the safe side when pushing the compression envelope. Look into building the motor you already have; that way it is built for your needs and can handle the type of driving you put it through. CT

Parts List

Junkyard block: ’88 Chevy 350
Eagle Specialties 383 kit: PN B13052L030
COMP Cams Extreme Energy Camshaft: PN 08-432-8
COMP Cams timing set: PN 2136
COMP Cams lifter hardware w/thrust plate: PN 08-1000
COMP Cams 10W-30 oil: PN 1594
COMP Cams two-piece cover: PN 210
TCI Crankshaft Balancer Rattler: PN 870001
Summit Racing water pump: PN SUM-312449
Summit Racing fuel pump: PN SUM-250000-1
Summit Racing fuel pump push rod: PN 134-8701
ARP engine bolt kit: PN 534-9802
ARP four-bolt main bolts: PN 134-3701
ARP crankshaft bolt: PN 134-2501
Milodon oil pump: PN 18755
Milodon oil pump pickup: PN 18311

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