1SIKZ31

iTrader: (5)

Hmm.. This is weird.

I have an LS1 Miata with a TSP 228R cam in it, hardened pushrods, and Patriot Gold Extreme Springs on PRC Stage 2.5 5.3 Heads. Melling Standard volume oil pump, and built bottom end.

Anyway... with the 228R cam, my oil pressure was 20psi HOT idle, 30-35psi COLD idle... 40psi ANY other rpm past idle for the most part... even 6,000 rpm would read maybe 40-46psi on my aftermarket pro-sport oil pressure gauge which is tapped in to the oil pan fitting with the 2 bolts near the oil filter.

I just changed my 228R cam to a Comp custom .597/.609 234/244 custom grind on a 112LSA... I did NOT change the timing chain or touch the oil pump.. I simply removed the timing cover, removed the sprocket, slid out the cam and reinstalled the new cam, torqued all parts back to specified torque specs, and reinstalled everything. Oil pump or anything else oil related was never touched!

Anyway, since the new cam install... oil pressure is now 30-35psi HOT idle, 50psi COLD idle... 4k rpm's is now 70psi!... 5k is 80+psi...

What the hell? How did I gain 40+psi from a cam install?


Now heres the kicker with the old cam (the 228R in it before...)
The cam was installed in my old motor, which spun 7 rod bearings, and had metal shavings ALL in the motor, all the cam bearings got ruined but the motor was only ran maybe 200 miles with this cam!... When removed, the 228R cam was absolutely VISUALLY perfect. NO scarring of any kind, no pitting, nothing abnormally. All surfaces looked polished looking still, not even a single sign of wear.

If I could take a guess maybe the old 228R cam was pitted/scarred or something past what the naked eye could see? ... I could maybe see a 10psi change in oil pressure in a situation like that but not freaking 40+psi difference?!

Any opinions? Thanks!

ls1 1990 VN

Your oil pressure in the old engine was never right, nor was your pump working right in that when you increased revs the oil pressure was not increasing as it should've.
At least now it's doing what it's meant to.

Chevycrew

iTrader: (1)

Have you meausred the diameter of the cam where it rides in the bearing? It could have worn down. Or was it something with pulling the balancer?

mark21742

You might not have had a good seal on your cam retainer plate before letting oil seep strait out the lifter bore oil ports....when you put the new cam in you probably got it to seal right

farmington

iTrader: (14)

Cam bearing surfaces might have been ground small and allowed a lot of leagage.

DONAIMIAN

iTrader: (18)

Your old pressure scares me. The new pressure is about the norm.