Posted: Mar 15, 2005 1:29 PM
So, I have a rebuilt bottom end I bought last fall. It was a complete engine that the original buyer backed out on and I just needed the bottom end.
Basics: balanced, 94mm 10:1 forged pistons, etc. Builder is local, has good reputation and alledgedly worked for Metric Mechanics years ago.
I broke it in easy, a week or so around town, jaunt from Seattle to SD for 'fest and still haven't tracked it or run it too hard. It has +/- 10k miles now.
He said he shimmed the oil pump for more pressure. I get >90# at 5000 on a warm engine, reaches 100# at 6000 and it's climbing. Could be seeing 120# at redline.
My mechanical gauge pick up is on the filter housing. We (builder and I) tested at the head and saw 50-75# with a test gauge. Same gauge showed the 90-100+ at the housing. He thought I should run lighter oil.
I replaced the housing with a non-cooler housing also tapped for p/u and readings are the same.
Fresh filter, Kendall 20-50. Same situation w/ straight 30w. Haven't tried w/ synthetic.
My old motor had a real MM oil pump and never saw >80-85#.
Is it agreed that 100# hot is too much?
Is there a pop off in the pump that may be stuck?
Should I swap that pump back in, and how much of a pain is pump R/R with the motor in?
Walt
Basics: balanced, 94mm 10:1 forged pistons, etc. Builder is local, has good reputation and alledgedly worked for Metric Mechanics years ago.
I broke it in easy, a week or so around town, jaunt from Seattle to SD for 'fest and still haven't tracked it or run it too hard. It has +/- 10k miles now.
He said he shimmed the oil pump for more pressure. I get >90# at 5000 on a warm engine, reaches 100# at 6000 and it's climbing. Could be seeing 120# at redline.
My mechanical gauge pick up is on the filter housing. We (builder and I) tested at the head and saw 50-75# with a test gauge. Same gauge showed the 90-100+ at the housing. He thought I should run lighter oil.
I replaced the housing with a non-cooler housing also tapped for p/u and readings are the same.
Fresh filter, Kendall 20-50. Same situation w/ straight 30w. Haven't tried w/ synthetic.
My old motor had a real MM oil pump and never saw >80-85#.
Is it agreed that 100# hot is too much?
Is there a pop off in the pump that may be stuck?
Should I swap that pump back in, and how much of a pain is pump R/R with the motor in?
Walt