Just recently rebuilt my 73 corvette convertible stingray with 454... The engine was vat cleaned and bored .030 ... during rebuild the machine shop said the engine crank checked in tolerance and standard size main/rod inserts were used.... cam bearings were replaced... comp extreme energy cam, springs/lifter, cam gear, chain (complete kit) were used… Head numbers indicate rectagular port aluminum LS6 1970 with low profile alum intake -- 750 Holley

Problem: Idle/3000 “cold” oil pressure is 30psi (it just doesn’t move at all with RPM ) … idle “warmed up ” ~zero psi & climbs some with RPM … With warm engine at idle & no pressure (oil gauge fed with tubing , no sender unit) , the engine has no audible bearing slap or lifter chatter… ok I admit a stupid thing, the old oil pump was used but the pump pressure regulator valve was good (closed no visible trash) when I pulled it and pump tolerances checked ok (somebody put a gasket on the bottom plate and a new pump doesn’t have one.. Might be causing blow-by on bottom of gears? ) …. Plastic coupler on pump to drive shaft was broken/cracked and slipped down ... Going to replace oil pump and plastic gauge the bearings tolerances just to be sure ... will high volume pump help? A friend said that there may be oil plugs in the oil gallery to lifters, etc that could have been removed & not replaced during block vat cleaning and could be causing no oil pressure but can’t find any listed in my engine book. Pulling this engine would be no fun ... main/rod bolt torque double-checked good... You should hear this baby talk ... Anybody got any ideas on the oil pressure ??

Russ

two things...

you hear no lifter/rocker rattle..

if you start it with a racker cover off is it squirting..

i would imagine it is if you hear no rattle..

if you have top side oil pressure..

I would use an external guage to verify readings..

I agree: check the oil pressure at the fitting underneath the car where the oil pressure gauge line goes into the block, those factory oil pressure gauges are not always correct. Let us know what you find.

GOOD LUCK

Agreeded. No oil pressure would mean lifter noise, unless you have solid lifters. If you have oil to the valve train check the gauge, ususally a sending unit.

If the oil pressure is actually low, I would recommend a pump. Standard will likely do it, but for the slight difference in price I would go with the high volume.

Thx for replying and recommendations... will give pressure another look at engine block with external gauge and pull the valve cover while running ... I thought the no hydraulic lifter rattle was odd also ... pardon the pictures.... still trying to figure out the picture posting thing

Thx again
Russ

Problem was oil pump & possibly oil pickup.. Installed new high volume oil pump and pickup... pressure now a little high ... 60 lbs idle warmed up.... just glad its not the bearings

If it idles a real long time, it seems to be running hot even with a new 4 core radiator ... imagine that! temp gauge shows ok but its boiling some when I turn it off... Looks like it needs a new fan clutch ?? ... that will break the piggy bank again...

Russ

russVette said: Problem was oil pump & possibly oil pickup.. Installed new high volume oil pump and pickup... pressure now a little high ... 60 lbs idle warmed up.... just glad its not the bearings If it idles a real long time, it seems to be running hot even with a new 4 core radiator ... imagine that! temp gauge shows ok but its boiling some when I turn it off... Looks like it needs a new fan clutch ?? ... that will break the piggy bank again... Russ

its going to run a little warner than normal with a fresh rebuild..

try adding some water wetter during the break in period.

And don't baby it too much during break in. The reason for taking it easy it to allow gentle wear for rough parts and allow them to seat. The extra friction from the rough parts wearing create the extra heat.

The problem is if you take it too easy, you build up a ridge of metal at the top of the cylinder walls where the pistion rings stop their travel. Later, at heavy load and high rpm this metal ridge will actually restrict piston travel, and restrict engine operation, limiting max rpm and power.

It all depends on how much you trust your machinist work. When I assemble an engine, I run it fairly easy for the first half hour or so. Then I put it to it. But only breifly. I drive a couple of miles, and put it to it again. By the time I have 50 to 100 miles on it, there is no limit. No more babying. In fact I run it harder than normal for a while. When it forms it's ridge, it's not restricting anything.
This is a bit harsh by most standards, but when I put it together I know what I have. I trust my work, and I hammer it.

If you don't trust the builder enough, you may want to use standard breakin procedures. But don't baby it too much.

kstyer said: In fact I run it harder than normal for a while. When it forms it's ridge, it's not restricting anything. This is a bit harsh by most standards, but when I put it together I know what I have. I trust my work, and I hammer it.

I agree wholeheartedly.. break it in like youre going to drive it everyday. If youre building it for an old lady, baby it. If youre building it for yourself.... break it in with a lead foot. Besides there are few feelings better than looking back at long black marks after that first test drive.

Fun, isn't it? Love those black marks.