Rev3 Cylinder Head Gasket "blow By"?

[eugenevd]

Hi trialistas,

In my continued hunt to find the reason why my engine running so hot ( http://www.trialscen...it-05-rev3-270/ and http://www.trialscen...ns-a-beta3-270/ ) I've starting taking apart the bike again to see if I have blockage somewhere because everything else seems fine.

When I took off the cylinder head I found these strange combustion/burn patterns (underside of head) and what looks to me like some sort of "blow by" past the head gasket. Now, when I last assembled the head I used a brand new gasket and I torqued the bolts to the specs given by the Beta manuals.

Can anyone explain these?

Does it have a correlation to my hot running engine?

Thanks

Album with more photos:

[0007]

Can you explain what you mean by your engine is running hot?

What you have here is the hardest question in the mechanical world, Is this a cause or is it a result

No one on the Internet can give you this answer

1) if your engine was overheated one or more times you could have distortion to the cylinder and or head

2) if your head gasket was not sealing it would not be overheating, it would be putting compression into the cooling system, this would over pressurize the system and blow coolant out the overflow

I have found that often physical evidence is less likely to answer a question than using the symptoms as a diagnostic tool

At this point you have the engine in pieces and you do not know the cause of the problem

Kinda like a doctor cutting you open and putting your colon on the bench to try and look at why you are constipated

First test would have been a pressure test of the cooling system (at full operating temp) to see if there is a pressure leak, coraborating evidence is that there would be combustion debris in the coolant (oily dirty greasy goop)

Also temp gun the cylinder and rad to compare to a known good runner, (same location, same day, side by side riding) IE: if you are blowing coolant, and your engine is cooler than the other bike, it is not an overheating problem

At this point all you can do is surface plane the cylinder and head to flatten them and reassemble the engine with fresh gaskets

Then you can start the diagnostic process

[0007]

Oh, I took the time to read your other posts and my comment is

The temperature of exhaust exiting the exhaust port is somewhere between 1000 and 1300 degrees F

The human pain point is roughly 120 degrees F

It's just not possible to use seat of the pants or touch to tell if an engine is at a reasonable operating temp, for example, my pipe has marks from my pants melting onto it in several places, I would assume this happens at several hundred degrees above my pain point

You also mention that you don't blow coolant, you cannot overheat without blowing coolant

I hope this helps, engines run wicked hot under normal conditions

Cheers

[jfc]

You have had problems with your coolant impeller (as you mentioned in earlier posts) so you may have cooked the gasket first time out after your rebuild, may be if you ensure your coolant circulation is correct and you did not get the bike too hot! You may be lucky and a new gasket will sort it out!

Good luck.

PS was your fan working?

Edited February 22, 2013 by jfc