My 72 Europa SS

[Certified Lotus]

Glad to hear it all worked out. We were all rooting for you Sofa King!

[Sofa King]

Good news! I made a local car show.....
Bad news.... my oil pressure isn’t better! Engine has to come out again.

3 Lotuses (Loti?) at the show!

[jbcollier]

Can you drop the pan?  If so, use an oil cooler adapter plate to pressurize the oil system and see where the problem is.

[BDA]

  Did you compare the oil pressure from spinning the starter before the fix and after? Did it show higher pressure after the fix? If so, it seems that it should follow that your running oil pressure would be at least better than before the fix.

At least it doesn't take long to pull the motor.

Good luck!

[Sofa King]

My oil pressure cold went from 20psi to 35psi. On my electric gauge.  The 20 was with 20w50 and the 35 is with 5w30, so it’s definitely better. But when warmed up I’m showing 0 at idle and barely any at 2000 rpm when warm. (Engine water temp only gets to about 175!) the mechanical gauge read about 10 psi higher than the electric. I didn’t have the mechanical on it tonight. But I’m guessing that 20 psi is the cushion that got me home!

JBC: Interesting idea! I’m not sure I can do it though, the oil filter on the LS motors attaches to the oil pan, so if I drop the pan I loose that attachment point and I’d have a big leak if I pressurized it from somewhere else. Any ideas on how to do that?

[JohnMcL]

Hi SK.  Sorry to hear about your problems but depending on the shape of your sump (no big wings) there may be a way into the oil system to check pressure or pressurise the system without major disassembly.  On LS engines, just behind the filter, there is an internal passage to connect the main oil gallery to the top of the motor.  You can see external evidence of this oilway in a rounded shape up the side of the block.  The bottom of this oilway is closed by a threaded plug with a recessed hex shape in its face.  Just take out this plug and you’re in.  Unfortunately, only good for initial diagnostics.  Sounds like the fix will still need engine out.

[EuropaTC]

Hmm, that's not good news. I can see the pressure has increased but that might be due to the higher pressure pump and not entirely down to the seal you found ?

I know nothing about the engine series you've got there so I'm struggling with ideas because you seem to have nailed a lot of possibilities. 

You've got 2 gauges, electric & mechanical, so my first thoughts are "where are the sensor and mech. feed taken from", are they directly after the pump or part way around the circulation path ? The only idea I have is to look at the engine for what's between the new (and assumed perfect) pump and the take off points for the gauges.

One weird idea that came was if there's a problem in the pickup/feed to the pump. It works ok with thick oil but once hot it no longer seals properly and you're trying to circulate a mixture of oil & air or a reduced oil flow.

It's a tough one. I've got to admit that after cross checking the gauge with a known good one and replacing the pump/relief valve (as you've done) then I'm afraid I'd just give up and tear the engine down to check bearings/seals and even mike up the crank in the faint hope that I'd got a reground crank with the wrong shells in !   A lot of work but at least it's going to work out in the end.

Brian

[Sofa King]

Thanks guys! The problem has to be the cam bearings. It’s the only thing that I haven’t replaced or verified. I was a little lazy last week when I had the engine out! I was convinced that the cam cover was the problem, and I was putting pressure on myself to make the Power Tour.(which I wimped out on anyway!) I’ll pull it again and dig deeper, but it probably won’t be for a week or two, I need to get away from it for a bit.
Brian: your idea of a leak on the pick up is actually a pretty common problem with these engines. Unfortunately, I’ve “been there...done that”! 

[EuropaTC]

Brian: your idea of a leak on the pick up is actually a pretty common problem with these engines. Unfortunately, I’ve “been there...done that”! 

I'm amazed, I thought it was such a daft idea that I hesitated in posting.   What's the history on the engine, did you buy it as fully overhauled with new bearings/etc,  rebuild it yourself or was it bought as a "running engine" with little history ? 

But whatever the outcome this is an odd one, I hope you're going to post up the culprit after all this head scratching !

[Sofa King]

This is definitely a “Franken-engine”! I bought the short block for $200, because I needed 1 piston for another project. Later, I bought a complete set of pistons from a guy in an Autozone parking lot for $80. Then I bought a complete LS6 engine for $500, that had a “slight” bottom end noise. That noise turned out to be two broken connecting rods and a piston jammed at a 45degree angle in the bore. But it did provide a good set of heads. I had the heads redone, the crank and connecting rods just needed fresh bearings, assembled everything and it sounded great. Unfortunately I never ran it long enough to detect the oil issue until I put the body on the chassis, and could drive it around.

Now that I’m trying to do the detective work to see where my mass of junk parts went wrong, I vaguely remember the guy that I bought the block from telling me that it had a spun bearing! I took that to mean crank bearing, but when I took the crank to have it redone my machinist assured me that it was fine. The previous owner must have meant cam bearing, but i never made that connection and on visual inspection they looked good.

[BDA]

A spun cam bearing! I've never heard of that which doesn't mean much. I have heard of scraping a cam bearing while installing the cam on a V8. That might be something to check.

[Sofa King]

I agree, I’ve never heard of a “spun” cam bearing , which is why it didn’t occur to me at the time. I think “walking” might be more appropriate, but I  told that bad cam bearings can create a problem like mine, and other than a crack in the block, there isn’t much left that it could be. If I’m not completely certain that I have the problem fixed, this motor won’t go back in!
The frustrating part, is that if I ignore the gauge, it drives great!

[jbcollier]

I have.  Wish I hadn't.  Have seen spun main bearings too.  Not pretty either.

[Sofa King]

Ignored it to get home... don’t plan on continuing thepractice! I have also spun a main bearing and bought another LS with one and replaced it. Neither engine had low oil pressure before or after.

[jbcollier]

It all depends which bearing spins as one usually controls the oil feed up to the top end as well.