How do you build a 383 SBC ? looking for input

[Guest Anonymous]

I would like to get some technical input and opinions on building a SBC "Stroker" out of a 350 block and 400 crank. To start: 1.Which rods are best ( 5.565, 5.7, or 6.0) 2. Internal or external balance../balancing plates and flex plates (153 or 168 tooth)?. 3 What type pistons (dome/flattop)? 4. Any block modifications requiring machining? 5.What cylinder heads and combustion chamber size/ compression ratio ?..6. Suitable damper size?

[Guest Anonymous]

It depends on your budget and intended use. A low budget, mild rpm setup is the 400V8 crank/400V8 5.565" rods/350V8 piston setup, but the rods are only good for 5500 rpm due to the recess around the bolt heads. Going to the stronger 5.7" rods requires a non-stock comp. ht. piston but gives a better rod:stroke ratio and a higher rpm limit. The 6" rod setup is the ultimate, but you're looking at a tight ring package and even more expense. Both the 5.7" rod and 6" rod setup should be checked for clearance between the cam lobes and rod bolts. If you internal balance the engine, then any SBC flywheel/flexplate and balancer can be used, otherwise you have to use 400V8 specific parts. Piston type and heads are very subjective on intended use; but flat-tops give an unobstructed flame front for cleaner burning.

[Guest Anonymous]

Quantrex, What do you mean by the " a tight ring package with the 6 inch rod' ?

[Guest Anonymous]

It's usual practice on stroker pistons that, as the piston pin is moved upward, the ring grooves are closer together and/or closer to the top of the piston. The "tighter" the ring spacing, the more easily the rings can develop blow-by due to piston rock as the mileage accumulates. The closer you run the top ring to the piston crown the more end-gap you have to use due to the heat and more end-gap means more blow-by as well. (You might also go to www.kb-silvolite.com and read why they use an "accumulator groove" on the K-B pistons.) The other options used in some stroker engines is to run the piston pin into the oil ring groove or using thinner rings.

[grumpyvette]

the tight ring package refered to is because that 6" rods while a very good choice require the lower oil ring scraper ring to pass through the upper area of the piston pin hole.

heres some more 383 info.

 

http://www.bracketmasters.com/small_block_stroker_383_cu.htm

 

http://www.findarticles.com/cf_0/m1185/n8_v32/21148174/p1/ar ticle.jhtml?term=chevy+%2Bcombustion+%2Bchamber+design

 

http://www.greenbaypartsworld.com/g383a.htm

 

http://www.speedomotive.com/chevy_383_street.htm

 

http://www.speedomotive.com/chevy_383_sportsman.htm

 

http://www.dumpit.org/grimreaper/reaper_engine.htm

 

http://www.diabolicalperformance.com/diabolical383.html

 

http://www.kb-silvolite.com/page32.htm

 

http://www.kb-silvolite.com/page33.htm

 

http://www.kb-silvolite.com/page05.htm

[Guest Anonymous]

thanks grump

[Guest Anonymous]

I have found that using 202 heads (2.02 intake and 1.50 exaust)helps the flow of intake and exaust. I have also found that Comp brand camshafts have a very good reputation on the track, and I have found that they provide a substancial gain in hp's on the street.

 

Also if you are novice to stroking engines a 383 stroker requires a bore of .030 oversize cilinders in order to achieve that exact displacement. and the 400 crank has 2.65" main bearing journals while the 350 has 2.45" journals.

[Guest Anonymous]

I am still reading Mr. Grump's info. Thanx! (but I am not finished yet). It seems that no parts can be selected until a cylinder head combustion chamber size is arrived at.