Stroking a stock 3.8 block

[434nova]

When you stroke a 3.8 does the block need to be clearance ? Do the pan rails need to be grinded or the bottom of the bores? Also what is the biggest stroke you can put in a 109 block? Thanks

 

[Kip]

When you stroke a 3.8 does the block need to be clearance ? Do the pan rails need to be grinded or the bottom of the bores? Also what is the biggest stroke you can put in a 109 block? Thanks

These days a common stroker crank is a 3.625. No on the pan rails. Maybe on the bottom of the bores, depends on how the assembler chooses to skin the cat and what parts are used.

 

[pacecarta]

you have to clearance the oil pickup galley by # 1 rod (usually needs a sleeve driven in from front of block)
depending on rod you may need some clearancing on top of rod at big end or even shave the rod bolt head a little
you have to be carefull that none of the rods come into contact with anything in particular the cam. the timing chain needs to be in and set where it will be run , then rotate and make sure nothing hits ..

 

[Jay J]

All I had to do on mine was some grinding on the oil pickup galley, to clear number one as referenced above. Did not have a template, so it was a pain due to having to grind, disassemble, test fit, and repeat until enough was removed.
I did not grind through the galley wall, so no sleeve was needed. This is something you can do yourself...

 

[Ttype6]

One of the heads of the number 1 connecting rod bolts will contact the outside wall of the main oil gallery. You will find that the block has a relief machined in this area from the factory. You'll need to remove more material from the factory machined relief with a die grinder.

One side of the large ends of each connecting rod will need some material removed to insure that the cam lobes and rods don't come in contact with each other. The rod bolts on that side of the rods can be replaced with ones that are conical shaped or pointed at the threaded ends of the bolts. These two modifications increase the clearance between the cam and rods. Weber provides this service for the rods.

 

[pacecarta]

if you buy a stroker kit from a vendor like weber you can order the rods to be clearanced by them before they ship

 

[434nova]

Does stroking the motor make the block weaker ? I am used to small block chevy stuff. New to the buick stuff. When stroking the motor do I need a small base circle cam? Thanks

Posted from the TurboBuick.Com mobile app

 

[Turbo6inKY]

Does stroking the motor make the block weaker ? I am used to small block chevy stuff. New to the buick stuff. When stroking the motor do I need a small base circle cam? Thanks

Posted from the TurboBuick.Com mobile app

Old thread revival. Just because your question wasn't answered and I'm fighting this now.

I'm stroking a 3.8. I used the Molnar rods and had the machine shop mock up and clearance the block at the oil galley. I also had to use a small base circle cam.