kod99

I did a leakdown test. The engine was cold and no oil was put into the cylinders before the test. Here are the results:

#1 : 9%
#2 : 15%
#3 : 9%
#4 : 21%
#5 : 6%
#6 : 16%
#7 : 8%
#8 : 8%

The test was conducted using 100 psi and was repeated twice with pretty much the same results.

I plan on warming the engine up and repeating the leakdown test on warm engine.

zipper06

That's a lot of difference from the left bank to the right. Do you have file fit rings or Z gaps. If they are file fit it will decrease on the leak down when warm, but it's the big difference that concerns me. Maybe 6 to 8% with file fit COLD, should be the limit, unless you're running a blown/ supercharged engine.

JMO

Zip.

kod99

The rings are file fit and the engine is natural aspirated.
It was the bank with the least leakdown that blued the headers. Could the two facts be connected?
I have a feeling that this new engine is going to have to be opened up again. Now I have to find a good BBC guy in my area. Crap!!

zipper06

Before you pull it down do a cold compression check, then a hot compression check, it could be a lot of factors, too much piston to wall clearance, rings not properly file fit. I'm thinking that the rings may be wiped out and possible cylinders scored from way too rich. A well sealed cylinder will definately run hotter than a cylinder with a lot of blow by.

JMO

Zip.

kod99

Thanks Zipper.
I will run another cold test and a couple of hot ones tomorrow and post the results. I am concerned that the overly rich conditins may have washed oil off the cylinder walls and lead to some scoring or ring damage.
When the engine was fresh and run on the dyno, without the vacuum pump, there seemed to be a lot of pressure in the crankcase. I had leaks from the pan gasket, rear seal and intake gaskets.
Your statement about the tighter cylinders running hotter makes a lot of sense.
BTW, all cylinders seemed to be leaking to the crankcase only. I couldn't detect any intake, exhaust or head gasket leaks.

kod99

Hot leakdown test was even worse. Pulled engine and sent it the engine builder to be checked out.

zipper06

Smart move, before you ran it again.

JMO

Zip.

kod99

I do learn....it just takes me a while.
I'm gonna put on a 0 1/2 pump, 80 pill and 39 nozzles and tune from there.

hammertime

:wink:

bbchevy

I Can HOOK you up with ALL of those PARTS,INCLUDING a Nice T-2 Terminator and a Primer +.Just Posted the Whole System,in the Classifieds.
Hope things are NOT to bad,and maybe a Finish Hone and a set of Rings.....?
Later
G