Bearing failure

[scir16v]

Does the bearing failure have to do with the oil passages in the crank, or the sump itself?

[Mettler]

Popular theory is tight factory bearing clearances.

[karay24O]

I believe it's a similar problem as the RB's--all the oil gets stuck in the head, and nothing left in the sump. (maybe not nothing, but obviously not enough).

I've been meaning to post pictures, but I chopped up a spare vh head to follow the intersection of oil passages. It's a maze! There's so much flow to the head there's no wonder the block runs out of oil. I guess it's obvious. . . each head has to supply enough oil to lubricate two cams, pressurize 16 hydraulic pivots (double SR20 per head), and supply enough oil for the VTC to work properly

My guess is, if you Modify/convert the hydraulic pivots (lifters) to aftermarket and plug the oil supply to those passages going to all 32 of them, the oiling problem should be kept in check.

The only problem w/ this is, as far as I know, no one makes cams for solid pivots (lifters), and could cause premature wear on those dainty looking roller rockers as the ramp on the hydraulic cams tend to be more aggressive.

Anyone else waste a weekend or two thinking about this problem? lol.

[Q45tech]

Just do like NASCAR and have an 16-18 quart capacity. ORObviously changing oil and filter FREQUENTLY alleviates much of the problem.20.2 years and 326,000 miles so far on oem systems ~~ 82 oil changes so far.

[kingkilburn]

Changing the oil more frequently would have no effect on the pump pumping all the oil into the heads faster than it drains back down(all under heavy load\high rpm).

[Mettler]

Run an accusump and have a warning light on the dash when the accusump kicks in.

[ultrapulse]

Apparently the small std filter and housing may be a restriction under hard duty..

[darinz]

I ran a bigger filter with no luck.I'm building a bigger sump and will up the capacity (and drop the level) to about 12 litres, so about a 50% increase. Also will be opening bearing clearances up so hopefully that will solve most of the problem accept for the big nut behind the wheel!

[piranhamatt]

So I'm putting a VH45 in my car shortly, and am a little worried about bearing failure.

I plan on enlarging the sump to run parallel with the crossmember, in hopes that this will help alleviate these issues.

Would this mod alone be enough to help protect my motor?

[kingkilburn]

It will go a long way but it still doesn't address the oil drain back issue.

Does any one have pictures of the modifications done by the Aussies and Kiwis to fix the drain back issue? I know I had seen something done with new oil return lines.

[piranhamatt]

Thanks for that.

I'm all for making modifications necessary for oil drain back from the head. Pictures or even describing what was done would be tremendous. I'd rather copy someone's work than experiment and potentially learn from my own mistakes in this instance.

Also, I know it's an old thread, but what are thoughts on this?

zer...36245

It seems the thread died after that post, and it seems intriguing to me. A drain at the back of each valve cover and a larger sump seems like it might be a good solution.
Modified by piranhamatt at 1:02 PM 3/25/2010

[Guishnu]

Mill out the return galleries to the edge of the gasket

Fit oil drain to the rear of the head and link onto the sump to equilise the pressure between the head and the crankcase + provide an additional route for oil to return to the sump (make sure you connect pipes to the correct side of the sump)

Enlarge stock sump/pickup/fit trapdoor baffels

Fit oil restrictors to the feed galleries in the block to reduce the amount of oil flowing to the head under high rpm. I think the standard are 2mm so i would probably reduce to 1.2 for an engine that's spending a lot of time high in the rpm band.

[scir16v]

What about thinner oil than the manual states? Would that work?

[gs14racer]

if you get a good motor to begin with, you shouldnt have a problem. i got my motor with 100k miles and a meticulous maintenece history, currently 10k miles plus of 400+whp and banging it off the rev limiter in 3rd 4th and 5th gear and crushing the oil pan on rumble strips at the track and still running.


knock on wood of course lol.