Paint markings in lifter valley

View previous topic View next topic Go down

Paint markings in lifter valley

Post  Trigged on December 25th 2016, 5:39 pm

I opened up my 86 block to start the rebuild and found some paint pen markings over each cylinder in the lifter valley.  Any idea what they mean? Cylinders 1-4 had 4-4-3-4 and cylinders 5-8 had 3-3-4-4 written on them.

Thanks!

Trigged

Posts : 5
Join date : 2016-12-25

View user profile

Back to top Go down

Re: Paint markings in lifter valley

Post  rmcomprandy on December 25th 2016, 8:55 pm

Trigged wrote:I opened up my 86 block to start the rebuild and found some paint pen markings over each cylinder in the lifter valley.  Any idea what they mean?  Cylinders 1-4 had 4-4-3-4 and cylinders 5-8 had 3-3-4-4 written on them.  

Thanks!

Pistons are usually sized in TEN thousandths increments for production and it seems like this is the production piston diameters used.

rmcomprandy

Posts : 4543
Join date : 2008-12-02
Location : Roseville, Michigan

View user profile http://www.rmcompetition.com

Back to top Go down

Re: Paint markings in lifter valley

Post  Trigged on December 26th 2016, 3:49 am

Not sure I follow since the pistons should be 4.360" diameter. Are you saying they should mic out to 4.363" / 4.364" or 4.330" / 4.340"?

Trigged

Posts : 5
Join date : 2016-12-25

View user profile

Back to top Go down

Re: Paint markings in lifter valley

Post  DeepRoots on December 26th 2016, 11:06 am

He said TEN thousands.

Yes the bore is 4.360, but the pistons aren't oversized, they are undersized for clearance after expansion. Expansion and subsequently clearance when cold is determined by piston material.

DeepRoots

Posts : 90
Join date : 2012-12-22

View user profile

Back to top Go down

Re: Paint markings in lifter valley

Post  Trigged on December 26th 2016, 12:58 pm

Ahhhhh! Too much eggnog clouds the brain. Thanks! That makes a lot of sense! Thanks!

Trigged

Posts : 5
Join date : 2016-12-25

View user profile

Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum