Proposed 3.8 bearing roll justification.

[MightyMouse]

Sorry to be the bearer of bad news .... but the stroker crank is a stock one reqround with offset journals, so IMO strength is going to be significantly reduced.

My major goal is to try and suppress the tendency the 3.8 has to knock by trying to clean up the gasflow.

Its a bit strange really... its got a massive intake valve and not a badly sized exhaust, a reasonably normal bathtub combustion chamber and the cam events are pretty traditional yet it knocks easily.

My bet is the spark plug location and angle.... by normal combustion chamber design its tilted the wrong way towards the exhaust valve not the inlet. Also sort of explains why they are super sensitive to plug design and multi electrode designs don't work well due to electrode shrouding.

As it seems to have been done to provide clearance for other components... wont be an easy one to fix.

Never mind....... what would life be like without a challenge ?

[Wazza D]

Yeah, that's why I commented on the quality of the crankshaft to be re profiled.
Speaking of profiles, where are you getting the combustion chamber and porting profiles for your heads from, or is this a MM research and development project?

[MightyMouse]

The engine is remarkably similar to a dunnydore motor... so whilst there's an element of suck it and see i'm basing as much as possible on what works for them.

Also bathtub combustion chambers are VERY common on this general type of engine so there's a lot to be learned by studying others.

Having a flowbench helps as well

[Wazza D]

Pity the doughy old 3.8 didn't bang like a Dunnydore!
Anyhow, I'll keep researching. Keep in mind that I am just trying to improve a product without compromising reliability, not build a hot rod.
So if you hear noises in your workshop in the middle of the night MM, it will probably be me carrying out a covert operation.

[MightyMouse]

If it ain't broke don't fix it.

If you want to do something really positive, do some research into oil consumption issues / oil suitability for the EGH engine........ makes for interesting reading and viewing.

[Wazza D]

Which brings us back to the original post.
I don't have any concerns regarding oil consumption. I have only had to top up slightly a couple of times prior to a long trip when the service is not quite due.
The point is, I would rather have the engine removed due to high oil consumption than a bearing failure which occurred in the middle of nowhere .
When it comes to fixing it when it is broken, I would much prefer it to be in the distant future rather than sooner.
Oil consumption control is one of my favourite subjects though.