6 bolt thrust bearing size

[halestorm]

I have 96 tsi awd with a 1990 6 bolt swapped into it. A rod bearing was spun so I obtained all new Eagle forged rods, and had a stock crank machined to replace the marred one. I am about to order bearings, but am somewhat unfamiliar with the thrust bearing. If I'm not mistaken there is only one, it sits in the center of the block and comes with any 6 bolt bearing kit. I am buying ACL race bearings, and a reputable machine shop machined my mains and rod journals on the crank to .010 (.25mm) under spec, however he said that the thrust is standard. This is where i get confused. If i buy .010 under bearings, will the thrust bearing fit without machining of the thrust surface on the crank or should I have him machine the thrust surface on the crank to .010 under as well? Any help is greatly appreciated.

 

[BogusSVO]

The .25mm mains will have STD thrust size.

In some brands, you can get the .25mm mains with a a OS thrust.

Why the ACL race bearings?

 

[halestorm]

I only drive the car 2000-3000 miles a year, but when I do I like to get on it and I plan on making a moderate power level (350-400hp). It seems to me race bearings would be better suited for this. I have an N/A block (no oil squirters) and balance shaft delete so i don't foresee any oiling issues, plus a disabled clutch switch for added insurance on startups. Race bearings sounded like a suitable choice for what I'm using it for, but if you have any suggestions or experience with either I'm all ears. I could use some input. Thanks for the reply.

Jeff

 

[JacksonAuto]

The Race series of bearings from ACL are designed for high RPM and racing applications. They have more eccentricity which provides oiling at high RPM. They also have less embedability which is bad for street use. If a piece of crud finds it's way between the journal and the bearing, it sit on top of the bearing and scratch the crank. With the AlumaGlide bearings, that piece of crud would become embedded below the surface where it can't damage the crank.

We only like to use the Race bearings on engines that either see a tremendously high load or in race engines that will be freshened up after a season or two.

 

[halestorm]

I realize that while ACL Race bearing provide less embedibility than Aluglides, like you said they provide more eccentricity at high RPMs. ACL's website lists the Aluglides as a reccomendation for stock replacement. So I want to thoroughly weigh the pros and cons of each so I make the right choice for my application. Its kind of a trade of between the tendency to bite the crank, or a possiblity of bearing deformation. I realize my power goals aren't extreme by any means but if I choose the Aluglides I want to make sure it is a strong enough material for my application. Thanks for the input.

Jeff

 

[BogusSVO]

Many of engines have been built with the Aluglides, Clevites, and King bearings at the power level you have set.

Unless you want to change the oil about every other week, to keep the debris out of the oil, pick a more "street" friendly bearing.