FX Holden Race Car Project

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Re: FX Holden Race Car Project

Postby Holden202T » Thu Sep 01, 2022 9:55 am

Macca97 wrote:202s are still readily available, that poor block is just a conversation piece now. if you red low on blocks sam, ive got probably 10 red ones

Thanks man, still got a few in the stash!

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Re: FX Holden Race Car Project

Postby vlad01 » Mon Sep 19, 2022 5:13 pm

Bit of a hijack, but after thinking about how the V6 is cam fed first I decided to have a closer look. I noticed on both the oil starved bad block (blocked oil pick up) and a really good spare block which I took a perfect crank from for my red car years ago and the big ends and mains were in great shape. Both these blocks showed cam bearing wear, totally stuffed on the oil staved one vs the big ends which were damaged but nowhere near as bad. The good block had the bottom of the cam bearings showing copper even though the cam journals looked really good and that had near perfect bottom end bearings.


You'd think it would be the other way around but clearly not, seems like it's not as simple as one might think.


The path actually goes from filter/pump to driver side lifter gallery/first cam bearing. From the lifter gallery they go to he mains past the cam by intersecting drillings. The rear and first cam bearings have a groove cut all the way around the outside in the block, this feeds another 2nd hole in those cam bearings but more importantly it supplies a limited amount of oil to the passenger side lifter gallery around the outside of the bearings.

This explains why the first cam bearing has a massive 11mm drilling going to the mains, it has to supply majority of the other lifters.

The rear cam bearing has also a bigger drilling than the middle 2 for the same reason. Middle 2 have no such cross over groove.

This might explain why some people get spun center cam bearings once they drill out the 2 middle main galleries, it might be bleeding off pressure to the mains quicker than it can supply the cam. I heard all kinds of dodgy remedies like epoxy the cam bearings and drilling down through the valley to pin the 2 middle bearings.

As for spinning them in stock engines (which I never had happen to me), the cam bearings are of a split design and probably can move/not hold as tight as the solid once piece cam bearings.

it's probably a fine balance between cam and mains by drilling size and position. I think it can go either way, as evident by early ecotecs with the drillings too close to the cam bearings, effectively starving the mains and big ends.

Perhaps the mains can be drilled out bigger and then restrictions installed to the mains to have finer control between the 2.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.

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Re: FX Holden Race Car Project

Postby The1 » Thu Sep 22, 2022 3:19 pm

It's probably an oil problem to, 50w as used on earlier engines was prob to thick, I think 30w is fine and would feed more volume. Especially the earlier engines with 50w would be non synthetic as well and anyone that doesn't do regular oil changes wouldn't leave much room for error.

I've also seen it on my own engines using 20 or 30w oil even after sitting for weeks lifters are quiet straight off the bat and oil pressure is still good. 40 or 50w they sit there clacking away for upto a minute. Both on my fresh VT L67 my VX S2 and vs S1 engines

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Re: FX Holden Race Car Project

Postby vlad01 » Thu Sep 22, 2022 3:46 pm

The1 wrote:It's probably an oil problem to, 50w as used on earlier engines was prob to thick, I think 30w is fine and would feed more volume. Especially the earlier engines with 50w would be non synthetic as well and anyone that doesn't do regular oil changes wouldn't leave much room for error.

I've also seen it on my own engines using 20 or 30w oil even after sitting for weeks lifters are quiet straight off the bat and oil pressure is still good. 40 or 50w they sit there clacking away for upto a minute. Both on my fresh VT L67 my VX S2 and vs S1 engines



I see the exact same issue when using 20w50 and try to use 15W40 where I can, the lifters don't like too thick oil and the newer gen replacements (genuine LS lifters) hate thick oil and tend to rattle on cold start up with 20w50 but are fine with 10W or 15W.

The V6 have always ran tight tolerances unlike other GM or ford engines so it's a bit odd they specified such thick oil, but to be fair, that's all they had back then, now thin syn oils are the standard.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.

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