Offshoreonly.com - Ring end gaps

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Quote:

Originally Posted by adk61 (Post 4269262)

Bob what I've been doing for years to address front to rear temp differences is bleeding off the rear ports of the intake manifold thus evening out the temp from cold front hot rear... which is a common issue with BBC

Please explain how bleeding off the rear of the intake helps to equalize temp from front to back?

the clearance in siamesed cylinders could be increased (a tad) to accommodate the extra heat, but it would be minimal at best IMO

Quote:

Originally Posted by rmbuilder (Post 4269241)

Tom,

The delta between the water entrance/exit temp. The dimensional change in bore diameter on a 4.250" bore between 60º F and 210º can run from .002125" - .00425", depending on a number of factors. That can be exacerbated on a cylinder to cylinder basis based on localized temp variances in a thermally unstable block.

Bob

I see, though I'm not sure of how to drum up an answer.

Incoming water temperature being 60 degrees, I don't think I'd see anything higher than 160 degrees on the gauge... so a hundred degree difference or less. That would be my target anyway. It seems that there are a number of unknowns here especially the unknowns around the unstable block factor (how would we even know if it were stable or not?). Regarding the block itself, it is clean, passed sonic checking, did not require boring to fix anything. It is a 26-27 year old seasoned piece.

-Tom

how are you getting the hot water away from the back of the engine? it allows cooling water to hit the back side of cyl #7 & 8 where it normally gets trapped

it acts as a secondary bypass... cooling water that's furthest from the incoming water seldom cools properly without said bypass

Quote:

Originally Posted by adk61 (Post 4269268)

how are you getting the hot water away from the back of the engine? it allows cooling water to hit the back side of cyl #7 & 8 where it normally gets trapped

The water from the back of the block flows through the head and out the front of the intake.

Quote:

Originally Posted by f_inscreenname (Post 4269236)

They are good rings. Use them in all the motors I have except for those damn stroker pistons in my 496 that require a super expensive rings for some reason. :cool-smiley-011:

And that's why I picked them up from you... btw thanks again! Everything worked out well with the pistons.

Quote:

Originally Posted by TomZ (Post 4269267)

Tom,

Understood. My question was intended to determine the temperature differential, from max to min, in various areas of the block. Based on that information, running an open bore block, seeing potential 60 º min. water temp and a max bore coolant temp of 160º, I would suggest you open the gaps from .003"-.004" to compensate for the lowest internal temp.

The concept of thermal stabilization is a worthwhile conversation (for another thread), however i do not want to derail your inquiry for a viable answer to your question.

Bob

I don't run any water thermostats. My water temp coming out of my block is never more than 110*. Water going in is between 60-70 deg.

I used to run water dumps off the rear off my intakes when I had 250 blowers. When I switched to the 420 blowers I didn't drill and tap the intakes. I've been running it that way for about 100 hours now with no issues.

Quote:

Originally Posted by MILD THUNDER (Post 4269295)

no visible issues...