I can't say I've ever had this happen before. Started my new engine and if I hadn't done it myself I'd swear it was built by a team of retarded Chimpanzees. Comically low oil pressure, I mean we're talking under 5 psi at idle with straight 30 wt oil and just over 10 at 2000rpm. Lots of smoke out of the even numbered cylinder bank too. TBH I began to suspect when I prelubed the engine by spinning the pump. Didn't see the pressure I was expecting and as I had the valve covers off I was watching the rockers for oil and I wasn't seeing much at the rear rocker. Then when I went to the other side the head was overflowing onto the ground and made about a 3 ft puddle. I think something may be off with my lifters. Could be a little low on oil too so I'll top that off and try again. All taken together that's a bit discouraging considering what I went through to build this engine. Possibly the rings can still seat. Possibly new lifters from TA will also help (kinda expensive but if it fixes the oil pressure then OK). Pulling the intake back off wouldn't be fun but easier than swapping to the 340. Not really the result I was looking for. Other than that it seems pretty solid though so I guess that's a plus.
Jim
I would be real surprised if it is the lifters. Where are you measuring the oil pressure?
Check your bypass valve.
Nope, all the oil is going up into the even numbered valve cover, flooding the umbrella seals on the exhaust valves and starving the odd numbered bank. Turns out the SBC lifters offer very little restriction to oil flow whereas the Buick ones use a completely different metering method which greatly restricts flow by comparison. I think G is right about that. I can't order the right lifters until Monday. Johnson is the brand and they are costly. I can't think of any other scenario that explains everything.
Jim
Let's see if you guys have ever heard of this one. According to G the SBC lifters use a disc type flow regulator to control how much oil goes up the pushrods and since it's a low pressure/high flow system it isn't very restrictive, whereas the Buick lifter uses a pin type flow regulator which allows much less oil to pass. Anyone heard of this one? Honestly I don't recall seeing anything you could call a pin inside one myself. Could be another example of AI silliness but the fact remains that I have far too much oil on the top end and the lifters are the only thing that I can think of that would cause that. It would also account for the blue smoke on the off side. I should have a Buick lifter I can disassemble to look at. Might have to tell G he's wrong again. I do that quite often.
The 300 does have an oil hole for shaft oiling in each side of the block. But I'm pretty sure the TA heads don't have that hole and my head gaskets don't either. That is definitely something I looked at and decided it would not be an issue. BTW the pressure relief is installed correctly and the bypass just bypasses the filter and that wouldn't match the symptoms either. If I hadn't seen what it was doing when I pre-oiled it due to having the valve covers off I would really be scratching my head at this point. Using my stock dual gage for oil pressure and it is working as normal, tied into the block side sender port so it's reading pressure right off the pump.
Jim
Would pulling the intake and watching what's going on in the lifter valley when you pressurize the oiling system give you any new information?
Got it. As it turns out, Chevy relies on lifter bore clearance to meter oil to the lifters by putting the oil hole where it is blocked off from the oil galley. Buick relies on internal lifter clearance between the body and the top piston. Without that internal restriction, oil floods the top end. Actually a reasonably well known issue. The practical solution is a set of small orifice pushrods with a .020" hole in the top end. So, I'll be calling Smith Bros tomorrow. A much more elegant solution than tearing down the engine and swapping out lifters I think. Once again, G was of great assistance in figuring this out and was the one to actually suggest the pushrod remedy.
Jim
Back in the day, restrictors were used in lifter oil galleries for race engines with solid lifter cams.
IIRC weren't those mostly Chevy race engines? Saw this video, an engine builder was comparing lifter swaps, mostly Chevy and Mopar and they were roller lifters but the Chevy ones had the oil hole located on the side that faced the solid wall rather than the oil gallery, which is offset from center. There was no groove around the lifter or maybe just a small one well below the hole and the tie bars kept them oriented that way. So that meant the oil from the gallery had to seep around the lifter to get to the hole and snug as lifters are, it limited the oil to the same approximate flow as something like a .0012" orifice but is less susceptible to clogging. Apparently orifice restricted pushrods have been a thing for some time now, we just didn't know about them.
If you look at the Comp Cams Endure-X Sportsman series lifters there is a hole above the groove for the pushrod oiling. The more expensive ones also have a hole below the groove to oil the roller bearings. Somewhere in this site is a picture but so far I haven't found it, showing a relief cut I ground in the lifter body in an excess of caution to ensure it got adequate oil. Well I guess that wasn't the issue. It would not have made any difference because the hole was in the oil gallery anyway except at full lift. If you compare the SBC and SBB lifter oil galleries you find a curious thing. On the SBC tho hole runs almost dead center through the lifters or is offest to the inside a bit. On the Buick it is very much offset to the outside. This means that any oil hole in the outside of the lifter is very likely to get full oil flow where on the SBC it would be restricted. So absent any further restriction in the lifter itself you'd have full flow through about a 3/32 hole to the pushrod. 16 of those make for a very big leak.
Apparently on the race engines the lifter to bore restriction still wasn't enough to keep from flooding the valve covers so they started restricting oil to the galleries. These restricter orifices apparently ran in the range of 1/32 to 1/16" typically and that was for 8 lifters. So it's increasingly clear why I would have a problem.
G recommends a .020" pushrod orifice even after I explained the Buick system's reliance on leak containment, due to concerns about orifice clogging. With clean oil it seems to me that if you had that problem you'd also have far larger bearing issues. I'll be calling Smith Bros and relying on their expertise in selection of an orifice size I think. .020" strikes me as just a little big. At 65psi that would spew quite a bit of oil I think. Certainly more than what is required to lubricate the roller rockers. Just how much of a concern is cooling the springs? Anyone have a clue about that one?
Jim
Valve springs get hot. They need that oil shower.
See the 2nd post:
https://garage.grumpysperformance.com/index.php?threads/valve-spring-cooling-via-engine-oil.6491/#post-20681