Crank question

[Razor]

The TTA crank has cross drilled mains. Was the casting number used still 877 but with the mains cross drilled? Everytime i've had my oil pan off.. I forget to look..

Anyone have a TTA motor apart that can verify? I kniow the rod bolts have SPS on them. And the rods are the two dot..

 

[Pace 1989]

Crank

Aren't you still using my old crank as a paperweight?

Ken

 

[Razor]

It was a nice door stop, But I sent it to Ivan in Chicago a year ago since he had a home for it.. 20/20 in a stocker. So have had the opportunity, just have never capitalized on it.

 

[junkbrick]

Ours is currently at the Machine shop...I will call and get the numbers in the a.m., need to see where they are at on our work anyway.

Reed

 

[junkbrick]

just checked on our crank and it is in fact the 877 casting number, and is cross drilled... hope this helps out.

Reed

 

[Razor]

Well what I thoughts pan'ed out. Thanks for taking the time.

 

[junkbrick]

I have never checked on the TTA crank PN, but is it different than the GN??? (same casting, just PN'd different for the application?cross drilling?) Also heard the pistons were different for the CC's on the head (compression ratio), but also heard that Pontiac took all of buicks leftover GN stock to build the TTA...would they have taken already finised GN cranks and then cross drilled) any light or reference to this??? I have also gone through countless GN motors (84-87) and have seen no consistant rods in either year (two dimple or three dimple, or SPS bolts or not)...do you think they just used what they had or??? Our TTA has the 3 dimple rods and SPS bolts, but the pistons measure the same as other stock GN stuff. Wierd.

 

[Razor]

Well the pistons have a deeper dish.

My understanding was they started making a replacement crank after the GN left the assembly, it was a cross drilled crank, and every crank that was bought after 1989 was suppossedly a cross drilled crank. I've heard of stories that GM short blocks for GN's that were available after 89 came with GN pistons but cross-drilled crank.

The rods to be turbo rods are suppossed to be the 2 dot rods. Tho what I found was interesting is my TTA motor the rod bolts say SPS on the heads. Yet I have rod/pistons out of a GN motor that the bolts dont say SPS and the rods are two dot.

Some say the blocks are different as well, meaning that all 109 blocks are not the same. This I dont believe. Tho the SG2 thing is something to look at.