My Questions regarding 4.1 Junk yard stroker?

[TURBO E-BODY]

Problem 1, finding a engine Block and heads that are in good shape to Rebuild.

Problem 2, 4.1 8445 heads are different in the chambers, Just can not put a set of 3.8 champion irons on there, would have to have stock 4.1 heads reworked , ie port polish and new larger 1.775 intakes.

HEADGASKET? since the cylinder bores are now closer together with the larger bore, does that mean LESS gasket material in this area? Is the likelyhood of blowing a head gasket more so?

Problem 3 ,Pistons, although TA performane offers high dollar forged JE's in the 4.1 bore, the only budget 4.1's are the Federal mogul 471P6 Hypereutectic.

Problem 4, Stroker 3.625" crankshaft has to be internally balanced, new internal damper required, and flexplate with internal balance.

also , will piston exceed the top off the block deck @ TDC ? especially if longer connecting rods are used? Will duration/ valve lift be limited to prevent interference?

Problem 5, maximum HP/torque the block will handle, will billet steel bearing caps be a good idea? That means a line bore and special size timing chain.

Problem 6, all 4.1 cast iron production blocks are 14 bolt oil pan, one more part to hunt down,
some front covers are compatible with either 14 or 20.

problem 7,>>COST<< , is all this extra effort for 272 stoker worth it for 40 extra cubic in? Why not just stroke a 109 block to 250.58 cu. in. with .030 overbore.


Thanks, if anyone out there is building a stroker 3.8 or 4.1, please chime in.

Regards, TURBO E BODY

[87GTA-turbo]

8445 heads are the same; on a 3.8 or 4.1.
Your limited to using Felpro 1000 or Cometic gaskets. (maybe other choices but these are the most popular)
More prone to blowing? who knows....

[Orlando_87GN]

Read, read, read.....

http://www.turbobuicks.com/articles/4point1ForCheap/

[Nasty Wendy]

I got a brand new stock flexplate rebalanced to neutral for internally balanced engines from Weber Racing. Give them a call.

[TURBO E-BODY]

Originally Posted by 87GTA-turbo

8445 heads are the same; on a 3.8 or 4.1.
Your limited to using Felpro 1000 or Cometic gaskets. (maybe other choices but these are the most popular)
More prone to blowing? who knows....

3.8 8445 heads have smaller (heart shaped) combustion chamber, I do not know the effect of putting the 3.8 head on a 4.1, maybe it will just only raise the static compression ratio?

Regards, Turbo E BODY

[Orlando_87GN]

The 3.8/4.1 heads are the same. 8445 and 6293 castings. The chambers are the same. I use 8445 heads on two different 4.1's. Read the article!

[TURBO E-BODY]

Originally Posted by Nasty Wendy

I got a brand new stock flexplate rebalanced to neutral for internally balanced engines from Weber Racing. Give them a call.

I just wish the forged stroker cranks were available 4 years ago when I was having my roller cam motors built.

Heck, back then, only steel billet roller cams where avaiable, then comp came out with the ductile iron rollers just in time for my 2nd rebuild.

Turbo E BODY

[Nasty Wendy]

I'm still gathering parts but its for a 4.1 stroker.

[TURBO E-BODY]

Originally Posted by Orlando_87GN

The 3.8/4.1 heads are the same. 8445 and 6293 castings. The chambers are the same. I use 8445 heads on two different 4.1's. Read the article!

THE 4.1 head looks different, maybe it is the gasket imprint the makes it look round.


Turbo E