oil pressure high enough to break oil filter
Turbo Mini Forums

Hi

I am putting an SPI engine in a car for a friend over here. It is an engine that has been rebuilt by a "professional" engine builder.

I finally got the car started after getting oil pressure on the starter yesterday. Within 10 secs after it started there was a loud bang, and there was oil everywhere. The seal between the oil filter and oil filter head had blown out. This happened twice, so was not something wrong with the filter.

I have checked the plunger for the oil pressure, and that is loose.

both ends of the gallery have threaded plugs, and there is also a threaded bolt in the small brass plug below the oil pressure spring/plunger.

There could be the possibility that the gallery plugs are too long, but there is plenty of oil in the plunger hole, and there is as said oil pressure in the gallery.

What could this be??

You suspicions. May be correct! And or. . .there may be remnants left of the old brass plugs in the oil drain back to sump at the back of the cross drilling ? What pressure did it reach? If you don't know repeat it again and let us know.

yikes, not an experienced builder or anything but im with benross sounds like a blockage not allowing it to release pressure to the sump
they didn't plug the pressure return hole did they? the one closest to the crank looking at the block upside down should be open i believe

I think that is the likely cause as others have said. There is also the possability that the wrong hole has been plugged and now the open hole is actually plugged by the gearbox/gasket.

Edited by Sprocket on 12th Apr, 2014.

as above, you may need a strip down to sort this .............. please keep us posted

Thanks for your suggestions. It ended up with the owner of the car complaining to the engine builder. I tok the engine out and its now at the builders place. He will sort out his mistake whatever it is. I will probably get to know what it was, and will report back.

I have now heard back on this. No problem was found, and the return was not blocked.

The theory is that the oil seal on top of the filter is a little bit to tall, and together with cold 20w50 oil and new street engine with tight tolerances the pressure could be a little too high. I still dont understand how this could happen, but should of course have measured the oil pressure properly. i am not sure what to think, and would hate to put an SPI engine in just to find the same thing happening again...

While not a perfect test.

You could hook up an air compressor into the oil lines, say at the oil pressure switch or something.

Then feed air into the oil galleries in the engine ( make sure the rocker cover or oil cap is off )

This should also pressurise the filter to at least test it to say 100psi to see if anything blows apart.

Then prime the system with oil, and crank the engine over ( plugs out ) to see if it makes decent oil pressure at cranking speeds and see how things perform like that before actually trying to start the engine.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Just a thought....... Ball or bullet?

Make sure the ball uses the shorter spring.

I built an spi engine and the owner fitted the ball and spring along with one of those adjuster nuts. We couldnt get the oil pressure low enought to read on the right side of the guage, it was 100psi or greater.

Bullet, which is not stuck. Its the same parts as was in the engine before the rebuild.

very strange,

maybe spin the cam up with a drill befor putting the chain on?