I just did the TA trick of putting a short allen cap screw into end of spring. I used my existing spring which gave me 65lbs at 7k. I had 50lbs at 1,5-2k cruising, hot. The allen cap now gives me 80lbs at 5k - 7k hot.. 60-65lbs at 1,5k-2k cruising Too much you think? I can grind the allen hex portion of the cap down to reduce it to 70-75lbs max. I don't want oil finding it's way out of every possible gasket.
IMHO, volume is more important than pressure. It takes HP to make the pressure & overcome the restrictions plus the more volume the better the cooling. Ask the NHRA guys what they're running for pressures. I'd suspect (I'm pretty sure actually) about ½ of what you have. Now they are willing to give up longevity for performance but in this case I'd think it's a win-win.
Curious as well. I just fired my engine up and have 60lbs at 1k. I had to replace my last distributor gear before the restart because it was chewed up and now I'm thinking too much pressure caused the added stress and stripped the gear.
80 is a little high, but for 7000, you want 70 psi minimum. If you feel 80 is high, and it is at 5000 RPM, try and adjust your shim to get 75 psi. What oil weight are you using?
Maybe on deceleration. The flat tappet cams are supposed to favor the block the way lobes are tapered & lifters are convex. I don't know how much is acceptable tho.
Boy Larry, you really want me to find some more leaks. I was thinking straight 40. I'm due for a change, maybe I'll lighten it up a bit more.
adjust the amounts of each to lower pressure I have more 10-30 than the 15-50 at 3 qts each I was at 80-85 and thought that was too much now I go with 4 of 10-30 and 2 of the 15-50 mobile one
I am hesitant to run all 10-30, or 5-30. I'm sure my hot idle will drop some. It's 20 now, pretty sure it will drop to 16 or so. This car has had 20-40 Pennzoil since 76. Changed every 3k. Great high oil pressure, according to factory gage. Motor made it to 95k before it needed valve job & chainset. All bearings & journals were pristene when torn down.
At cold start, my oil pressure is about 43 lbs and drops to 39-40 lbs at running temp. At hot idle 20 lbs. engine 350 4bbl.
I cut the allen head almost in half. Right at 73+ lbs now. That is a slick, easy trick to add high rpm oil pressure.
Cold start I run between 70-80 Hot in gear I'm right about 20 @ 700rpm (I've seen 18 but never less) Getting at least 10 per 1000rpm 10-30 Joe Gibbs Driven
because of what i run, i had the 1/4'' plate on the pump. o/p was a lot. but the down side was wearing the dist/cam gears out. this last time i took off the plate hoping to alleviate the gear wear. i bought new gears, had them hardened and polished, hoping to last longer. been 2 yrs, but little race time. o/p is a little lower now, but still higher than you guys are getting. may inspect this winter. i use plain 10-30 amsoil. and i don't have an oil filter. o/p does not drop. run only 4 qts this engine gets no relief. it turns over 6k all the time..with a blower on it. all the years running it, it only has blown 1 head gasket(felpro or whatever is on sale) and 2 intake water leaks which were my fault. i guess i'm just lucky
Me too. When I was wrenching on my wifes Tahoe, I was doing some reading on the LS oil pumps. They have 3 or 4 different versions. Standard Hi volume, low pressure Standard volume high pressure Hi volume hi pressure. They list the low volume for the Priority Main oiling blocks I got confused so I disassembled the stock pump, cleaned, inspected, reassembled, and did the shimming thing. I figured its been working for 250000 miles, its good. I WAS going to shim the relief spring using the allen bolt trick from Kenne Bell, couldn't find it, so I went with the stock set up. I have the Hi Volume pump in my GS, I removed the adjustable pressure regulator, and put the 70 psi spring in with the stock nut thingy. Im curious once I get my SRE pan installed if it solves my oil pressure dropping when I accelerate on the highway
