How not to built an L67

[shane_3800]

Crank support? When are these engines breaking the snouts off the cranks?

People have already fitted whipple blowers on these motors.

No one's been pulling on the crank hard enough yet then ☺
It's not about snapping cranks it's about wearing the front bearing. You can run more clearance on the front main with a crank support which also helps with bearing wear.

 

[Immortality]

It seems you are looking for problems that doesn't exist.

The V6 uses a different bearing style than most other engines and require different bearing clearances. using Chev 350 type bearing clearances in a V6 isn't recommended.

 

[shane_3800]

It seems you are looking for problems that doesn't exist.

The V6 uses a different bearing style than most other engines and require different bearing clearances. using Chev 350 type bearing clearances in a V6 isn't recommended.

I hear what you're saying, but the more HP you sap from the engine via the blower the worse the stresses are.
You start pushing into very heavy boost numbers the more everything will flex.

 

[Immortality]

This is true but I've not seen or heard of an L67 crank failure at the snout, there are bigger oiling issues I'd be worried about before that.

In a way the crank snout is already supported because the oil pump is in the timing cover and the pump would absorb some movement.

Check out @Decicrate my ride thread, make over 500rwhp with an L67.

 

[shane_3800]

This is true but I've not seen or heard of an L67 crank failure at the snout, there are bigger oiling issues I'd be worried about before that.

In a way the crank snout is already supported because the oil pump is in the timing cover and the pump would absorb some movement.

Check out @Decicrate my ride thread, make over 500rwhp with an L67.

The only part of an oil pump that would add support is the outer casing which would actually dig into the crank if that much flex was happening.

It's not to do with oiling issues it's to do with flexing at center making the crank journal slightly off line from the main. The way you overcome this is by tightening the bearing clearance up which limits bearing life.
No matter what you do you will get bearing to crank contact it's just how hard and how long for that determines the wear.

Also the pump would not really add much support as it's only bolted on with not very strong bolts.
Again if a billet timing cover was made it could have the pump incorporated adding strength like a girdle.

If you're going to push an engine more strength is needed otherwise block grouting and crank girdles wouldn't exist.

 

[gtrboyy]

Dunno the donor vehicle looked fairly rough & trashed to hell so possible it or something else would have failed even if left stock.

Weirdly thought you'd bend pushrods with cam/spring change as I'm guilty of putting stock pushrods back in hipo engines to get them running...then bent most of them while waiting for proper item lol.

Ecotec don't snap crank snouts or walk caps usually holden v8 issue if too greedy with blowers

 

[shane_3800]

Ecotec don't snap crank snouts or walk caps usually holden v8 issue if too greedy with blowers

I just don't think anyone has really put that much blower through a V6 tbh.

I'll check out immortality's link though.

 

[EYY]

I saw one of the old YT test engines in person a couple of years back and no crank support from memory. Had very serious work done to it apparently and made some serious power.

 

[shane_3800]

I saw one of the old YT test engines in person a couple of years back and no crank support from memory. Had very serious work done to it apparently and made some serious power.

I've also seen many chev V8 engines without crank supports making 800hp+. Like I said it's not about snapping cranks but more about keeping the front main healthy.
The V6 has a much weaker main web than the Holden V8 or the Chev V8 so I would conjecture it would have to be beneficial to run a crank support.

 

[Immortality]

And yet you don't see V6 blocks blowing out, the serious guys fit mains girdles from MACE

Cranks flex, it's a fact of life. Don't create solutions for problems that don't exist. If V6 motors where blowing out the mains then sure, but they aren't so why waste big $$$ on a solution for a non existent problem?

There are a couple of whipple charged V6 motors, 4.2 strokers

There is also a 513rwkw turbo 4.2 ecotec in the Mace forum, check it out. Those little blocks are quiet sturdy.