383 stroker?

Question

I have a 350 bored 0.60 over with a comp cam I am looking to turn it into a 383 stroker by puttin in a 400 crank I have decided not to put the shorter pistons because I dont want top end.............my question is this I know I will have to get the crank turned to fit in a 350 will i still need to know the stroke and size of connector rods or can I just buy new rods????? any information you have would be greatly appreciated

Answer 1

You have got some mixed up info from somewhere man.

I don't understand the "decided not to put the shorter pistons because I dont want top end"

Piston height has nothing to do where power is made.. The stroke lenght, cid of engine, cam and heads sets your power band..

There's 2 ways of doing a 383 stroker...
The old school, out dated, not near as good way..
350 block, punched out (.030") but .060" will work too, std. 350 pistons (to fit bore size), 400 short 5.565" rods, 400 crank and have it turned down to fit 350's 2.45" mains, then use a 400's extranal balanced flexplate and damper..

Or the much better, stronger, and last longer way..
350 block punched out (.030") .060" over will work too, std. 350 5.7" rods, "383" stroker pistons made to work with the bore you have, and the 3.75" stroke, then one of the many drop in 3.75" stroke cranks... Scat makes thier 9000 cast crank (stronger than GM forged, plus lighter) for right at $200 in the 2.45" main journal size with a 3.75" stroke.. It will drop right into the 350 block.
The longer 5.7" rods will cause less side thrust, side loading on the cyl walls, piston, and ring package..
The right pistons will have a shorter compression height (wrist pin to top of piston) due to the diff in 3.48" and 3.75" stroke.. That also means piston will be alittle lighter and help with rate of accel. That combo will work with a std 350 internal balanced flexplate/damper.

Now what your over looking is clearance prob..
On ALL 383 stroker builds you will have to clearance (grind) a few things.
If std. rods are used, the shoulders of the rod bolts will need to be ground down.. Or you can buy $300 aftermarket rods already stroker clearanced.

Depending on the cam you use, if its a big size, you may have to go with a small base circle.. When this is done, std. lenght push rods won't work most of the times.

Next, the 3.75" stroke crank's counter weights will hit the bottom of some of the cyl bores and you must mark, and grind the bottom of bores for needed clearance.

Also You may have to grind the block's oil pan rails for clearance of the crank throws too.

Next, is oil pan clearance.. Alot of the stock pans will not clear.. Even a good bit of the aftermarket pans won't clear the 3.75" stroke in a 350.. ASo be sure to check that

Answer 2

383 Stroker Pistons

Answer 3

Actually you can use the 400 rods and leave the standard piston pin locations where they are. Or, have the crank turned and use your present 350 - 5.7" rods and have the crank turned.
Personally I'd like to see you use the 400 large journal 5.7" rods rods because of the strength in the larger big end of the rod. If you opt. for longer rods the piston pin location will need to be raised in your new pistons and really their is no need for that in a low rpm torque engine. Since the 400 or in your case 383 motor your looking for torque under 5000 RPM. Motor builders increase rod length when an increased RPM power band is anticipated.
When that happens low end torque is decreased.
In any case you'll need to do some grinding at the bottom of the cylinder sleeve area so that the big ends of the rods have adequate clearance as the crank spins. Please pick your camshaft accordingly. Crane, Crower and Comp. Cams have great resource answer lines. If you have a 350 block that has roller lifters already in it you have a distinct advantage when it comes time for a cam selection. The new acemetrical ramp designs will open the valves quicker so that the valve is off the seat in a faster rate of lift without needing to stuff in a lot of duration in the cam. 383's and 400's like a lot of lift .500 - .530 works well in the street.

I'd like to "lobby" for a new set of Vortec cast iron cylinder heads for your project they come in two versions: #25534421 has 185 cc intake runners and 65 cc exhausts. #25534431 has 215 cc intake runners and 84cc exhausts. Both have 66 cc combustion chambers which would put your compression ratio awefully close to 10.1. Both of these sets of heads are cast to accept .530" valve lift with no modifications. GM claims an added 35 - 45 horsepower with a set of these heads un-touched off the shelf.
From reading your description above I think you meant your plan to bore the block .060 not .600. To be dead nuts on your displacement you will wind up with 382.452 cubic inches.
If you ever want to figure your own motor size the formula is: pi = 3.14 x r = radius squared ( radius times itself) x stroke length x number of cylinders.

Have fun with your project.

Answer 4

for one chevy hot rod'ers came up with the 383 to stay up with mopar simple as takeing the 400 crank an turning it down to fit the 350 main's an all of you are right so stop the bitching lol stock 350 pull the crank drop 400 crank in an short rod's an whoopy a 383 stroker ... yes you can buy a creat 383 for about 5500 to 8500$$$$ any body got that cash hell no so guess what get a 70's 350 block a 60's or 70's 400 crank dont cost much to turn down diffently if u know shop's own'ers an why they did this is becuse 400 small blocks had head over heating issues becuse of the water ports wasnt drilled out in the heads so to get the same compression an performance on a buck they mild down the 400 to fit the 350 ....

Answer 5

too late as the 383 only has a .030 overbore!

Consult a Machine shop to get your parts shopping list. Generally they will sell a full stroker kit and you just pick your options with the sales rep.

ASE Cert Auto Tech, 331 stroker(from a 305)

Answer 6

Q: What happens to the compression ratio when you stroke a motor?

A: Stroking usually involves increasing the cubic inches. The compression ratio will go up. Compression ratio is the ratio of the cylinder and head volume with the piston at Top Dead Center (TDC) to the total volume at Bottom Dead Center (BDC). Since the piston is moving down further at BDC, but returning to the same position at TDC, the swept cylinder volume increases while the volume at TDC remains the same. Hence, the compression ratio increases.

Answer 7

The block needs to be machined inside to clear the crank. Summit, or PAW , plus others sell a stroker kit comes with every thing you need.

Answer 8

Be cheaper to buy a crate motor. All the hard work is done...and done right. Think about it.