Billet Main Caps

[1UZ-HZ]

I've been thinking again, and has anyone here have the ability to machine up a full set of steel main bearing caps? I think some nice fat ones should ensure block integrity with high boost, high HP and high RPM insight for a few people on this forum. I guess if we go that far a stud girdle would be a good idea too.

 

[Peewee]

From pics I have seen the block gives way not the caps.

 

[Peewee]

Whether thats a direct result of a cap slightly giving way directly beforehand I don't know.

 

[Zuffen]

One major drawback of having billet caps made and fitted is the need to linebore the block after.

Whilst lineboring is old hat the implications are often overlooked.

If you remove 10thou, that's 1/4 of 1mm of material to do the linebore (which would be pretty normal) you can run into problems with deck height.

One area most peope would never think about is the relationship between the cranks new centreline and the transmission centreline. 10thou isn't much but thats the toerance you are playing with in getting things lined up.

You can buy offset dowells for most American engines to overcome the problem. Minimum offset (that I know about) available is 7thou which means the manufacturers see this as critical.

Lastly whilst it may be minimal you will have an impact on cam timing.

 

[1youZee]

I would agree here. all of the time and money to get it right could be put toward something more productive... like boost.

 

[ballo]

i wasnt aware the the 1uz's had a problem with the main caps, or is the breakages due to more then standard rpm?

 

[Miles B]

I'd leave them alone unless you are trying for 1500hp or something...

 

[Red Supra]

Stop trying to re-invent the wheel. I've never heard of anyone breaking a factory 1uz main cap, nor have i heard of anyone stretching a 1uz main stud.

As said before, the bottom end is solid! The induction is where most of the money should be spent on.