Recent content by technician8

Thank you all for your helpful advise! These oversized aftermarket studs have been out for many years with no public hardcore failures. That tells me the reduction in flow is not severe, but may have a high mileage or high RPM effect on the camshaft bearings. So I'm going to split the...

Let's say the original design oil flow was slightly reduced due to the larger passage in the block going into the smaller passage in the head which caused turbulence or something. Now I enlarge the head hole to equal the original oil flow area, but also eliminate that turbulence by having equal...

What do you mean "a requirement from a flow standpoint"? You mean equal block and head ID is a requirement? And the head ID at 11.8mm should not be a problem. The top of the head is sealed with a crush washer, and the head-to-block is sealed with an O-ring fitted for the 11.8mm ID of the block.

Hey Tom, So you don't see any significant effect on flow no longer having a a step-down from block to head ID? Thank you...

My amateur view shows me lost turbulence from eliminating the step-down, therefore the modification may overcompensate. And/or a loss of velocity in the head which may decrease flow, and the modification may undercompensate. Anyone with the correct formula?

Here's a terrible sketch showing what I'm looking at: original oil passage, after installing oversized studs, and enlarging the head hole ID to 11.8mm equaling the block hole ID. Can anyone tell me the difference in flow from original to oversized studs, with enlarged head hole to equal...

I was never good in geometry, but I was thinking taking a mm off the head ID was about right, like you confirmed. And thanks also for responding to question #2. I was thinking there must have been a reason for the Kawi engineers to make the holes 1mm larger in the block than the head. So is...

Hey Mike. I know exactly what you're saying, and I'm trying to maintain OEM oil flow. These aftermarket/oversized studs reduce flow to the top-end, I'm just looking into returning flow to what the Kawasaki engineers designed.

OK. Thanks for your help. If there are any classic Japanese muscle-bike enthusiast reading, this is a 1982 KZ1000 "J" engine. The attached picture shows the cylinder block and head. This engine delivers oil to the camshaft bearings through the space between the 4 outer mounting studs, and the...

Hi, I'm an automotive technician with a question on engine oil flow following a performance modification. Can you folks help me with that? Thank you, Alex