Im curious to hear how big the clearances got. I got down to measuring mine to find i have misplaced my 0-1" micrometer to measure bearing thickness so i'm without my own info as far as bearing clearance for now.

Once i get another one, i will post up some info on my old HMO h22a. Had about 90k miles on it and was beaten on pretty bad.....and revved to 8500. Ran on Mobil1 most of its life. Changed to Royal purple towards the end before i swapped in the 23.

Please specify engine / bearing type / mileage / engine use / max RPM seen while racing / Oil used

My cylinder bores and pistons were still in great shape. #4 was right at the max limit tho at .0011 PTW but still not too bad. That piston also had a good bit more oil passing through the rings based on the looks of the outside of the ringlands. The rest of the cylinder PTW were .0006, .0008, .0008.

hopefully we can get some interesting discussions.

 

dissasembled a 94 gsr block, 210K miles, rod bearing clearence was at .0022", main bearing clearence .0020"... not too bad imo.

 

how did you like the royal purple compared to mobil ! .. i still have my bearings from my gsr that had 121k on it never measured them tho

 

RP is superior to the typical Mobile 1 that's used by people.

 

hate to turn this into another oil thread, but in what way is it superior? just zinc content, or other areas as well?

 

i've been using rp 5w30
put mobile1 10w30
motor didnt like it
so going back to rp 5w30 next oil change

 

Every motor that I've tuned, and built including my own. I've used mobil1.. and when i've had to disassemble or do something the motor has been completely Clean.. its not all gunked up with the brown gravy or copper look like you get with other oils..

I'm not going to argue which oil is better, cause there's a big olll thread about it.. but i do have a opinion.

 

because it doesn't have the API starburst on it's label meaning it doesn't have to fit (be limited by) a narrow set of requirements for the oil to meet API standards. Typically this means that oils like Royal Purple and Redline are made from better base stock oils to begin with and have a higher zinc content in their oil because they're not regulated. They would generally exceed most API standards but be excluded form others because of high zinc content.

It's kind of like race gas vs pump gas....it's not that one is way better than another, it's that one isn't limited like the other and can therefore make more power with less limiting factors, which on a performance engine can mean a big difference over a simple grocery getter.

 

thanks for the explanation.

i personally have always used Mobil 1 with zero issues or excessive wear...

 

Cam/rocker arm wear is the main area most of us have problems with the newer oils. If you have a car that uses newer roller followers/rockers, the newer oil is less of an issue.

 

I know of a particular F20C the goes through (burns) quite a bit of Royal Purple. After seeing this I won't run it. Maybe it's the engine build (2.7L InlinePro kit), but I still won't run it.

 

how would an engine build that burns oil be the oils fault?

 

Never burned oil until RP was run in it.

 

...doubt the oil caused this ....think u have another issue