Nice catch.

GC - What changed that would influence the pressure or pressure numbers?

with RPM, my gut is telling me oil pump clearences.

After this season its gonna get gone through again.

Gae, when you dyno'ed what filter was used and was the bypass in the block?

I just got off the phone with Joe. If you look at coolant temps they are alot cooler on the first dyno. Cooler temps will give you higher pressures......on the same note the pressures shown on the second dyno sheet do make me a bit weary but Joe assured me that if there was an issue he would have caught it and that if I was running this way before most likely nothing has changed on the bottom end. Especially after 23 pulls with consistent readings and power.
T-Hill will be the ultimate test on this motor this weekend as weather has been forecasted for 100 plus temperatures.

Cant remember brand of filter and yes the bypass was in.

Makes sense on both counts. :thumbsup:

Did you change pushrods, pan, p/u and lifters? I too think that 45 psi is a little low on a road race eng @ that RPM, just remember


"Oil pressure and oil volume are 2 different things. As long as the oil supply gets where it needs to go at a given pressure, more pressure is just more strain on components"

I changed pushrods and pan. Pan was the same one as I had last time so I didn't change p/u.

I'm going to run the temps up as soon as it dries up outside and see how the pressures look.

Don't forget that gauges can read differently too + you can't read volume on a gauge.. Just keep an eye on it. A lot of people like to pull the pan after a dyno and read the bearings, I know it's a pain, but you may want to take a look at the bearings that will tell you a lot. , your dyno guy knows his stuff, I'd say you're safe.

I know you know...change the filter it's easy and cheap. Hope it's not a FRAM We had a lot of problems with those after that Co took Fram over. Switch brands if it is I like K&N or Wixs or get a reuesable filter like a systems 1 or?? I had an oberg I liked it, I took it apart and had a look all the time

Running a System One adapter and remote filter system with 12 an lines. I agree.....pressures look low and they even seem lower on the gauge than before. Theres only one thing I can think of right now that would have changed that and it would be pan to p/u clearance. Not sure why that would have changed though.
I'm just going to have to take it easy on the track the first couple of sessions and just watch the oil pressure gauge. I'm going to ask Dave to let me run in a slower group for the first couple of sessions.

So how did Joe try total timing at on your latest dyno session? How high did he go before reverting back to 32.5?

That is a huge difference to go from 37 to 32.5 for a 23* head. Timing is largely based on the efficiency of the head's combustion chamber, but you did not change heads, so I am confused.

I don't think I've seen a 23* head with such low total timing.