Do you not know there was a defective batch of those springs when the manufacturer was changed to save Comp money? Lots of people lost complete engines because of the springs. Saying 918s are a "great proven spring" is not at all completely accurate. Maybe you are slightly out of the loop.

 

Sounds like you bent/marred/killed a valve and have no compression in one or more cylinders. Could have happened because of the valvetrain not being installed correctly, faulty springs, and the whole rev limiter thing. If that is the problem it will most likely have been from a mix of those.

I would do a compression test ASAP on every cylinder.

 

I am aware, but I wouldn't assume right away that he has a broken spring without at least looking at it first. His symptoms point to a leaky valve, or bad valve adjustment, IMO.

We could tally up all the 12 second LT1/LS1's running beehives. There are many. So I think it is accurate to say it is a great spring. Bad batch aside.

 

I never assumed he had valvespring problems.

 

Okay here's the deal. I did a compression check on the 4 driver's side cylinders and on the first two passenger side cylinders. It was a royal pain in the *** I'll just leave it at that. The last two plugs on the passenger side must be accessed by removing the starter from the bottom, which I did, but for the life of me I could not get the damn compression checker started. I tried and tried until my forearms were so beat that I couldn't turn it any more. I can't believe they don't have a short compression tester that's easy to screw in for overhead valve engines. Anyway, the six cylinders I did all had between 200-210 psi. The plugs from the last two cylinders looked identical to the rest, and although that doesn't completely rule out the possibility of a dead cylinder, it's pretty conclusive. The only thing that erks me is that the cylinder which had a broken valve spring was the last one on the passenger side, the one that I couldn't get the compression tester started in. I would have liked to get numbers for that cylinder too so I guess I'll attempt another try tomorrow when my arms recover.

I pulled the driver's side valve cover and I saw no damage whatsoever to anything under there. I looked very closely with a flashlight up against the springs and I couldn't see even the finest hairline. Also, I bought my 918's a while back, they have a blue stripe on them, and I'm pretty sure they are the non-mexican ones.

One interesting thing that I noticed was that a couple of the plugs had dielectric grease on the tip where it contacts the plug wire. Comments on that? Would it completely shut the spark out, or make it weak, or would it make no difference? This bothers me because the time I replaced the opti and all of my other ignition parts, I was in such a bad mood that I just slapped it together with no grease or antiseize and then I was blown away by how fast the car was when I was done.

Rob, is there such a thing as a weak valve spring? As in, the spring works, but it can't maintain proper seat pressure even at lower rpm's? I doubt it but it doesn't hurt to ask.

 

Dielectric grease is fine as long as you have metal to metal contact from your plug wire terminal to the plug terminal end.

 

That's the thing, the grease was on the plug terminal end... I'll clean em, it's a long shot but who knows.

 

Your plug wire should always "snap" onto the plug. So that should mean it makes good contact.

 

I finished the compression test. I have good compression on all cylinders.

I will check the passenger side valve cover later but I don't expect to find any broken springs. Since that incident where my boss smacked the rev limiter, I have changed the springs to 918s so the springs in the car right now did not endure that stress.

Anybody else see anything I should look at?

 

have you verified the timing chain did not jump a tooth? TDC on #1 cylinder compression stroke = #1 in the opti?

Yes - weak walve springs will functionally close the valve but not maintain correct seat pressure or close fast enough to keep up with the cam lobes.

The kicker is you lost oil pressure at the same time.
Have you verified the pressure with a mechanical guage?

i'm just spouting things - it sounds like he hurt you motor - in a few ways potentially.

 

How can the motor be hurt? I mean what part could be hurt? I figured it was just the oil pump but what else could be damaged by high revs and cause low oil pressure?

Is there any easy way to check the timing chain without pulling the timing cover? The chain is a Cloyes True (Double) Roller by the way.

 

"just the oil pump" is no small matter.
Sudden oil pressure drops I've seen were caused by faulty gauge reading, oil pump gear damage, oil pump pick up tube falling off, spun rod/main bearing, an internal oil passage plug coming out, or?
Either cause should be confirmed and corrected before much run time - or complete failure may occur.
It may be something simple - but good pressure one minute, lost the next would have me on edge.
Timing chain position can be checked by verifying TDC on #1 cylinder compression stroke = rotor on #1 plug in the opti. That's the only way I can think of.
I'm not claiming any of these things happened - just process of elimination.

 

Would any of those things cause a loss in power and hesitation?

The oil pressure is weird, when the car is cold or driven easy it is normal. If I hit the gas even for just one single gear pull the pressure will be low and stay low until I let the car cool down and start it up again.

I will see if I can check the timing chain to make sure its still lined up. I wish there were a way to do it without taking the front apart. Nobody makes a two piece LT1 timing cover?

I have seen an oil galley plug and the pickup fall off and the oil pressure was VERY low. Mine is not as bad as the instances where I have seen those things happen. I am leaning towards bearing damage or oil pump gear damage. At this point I don't really care if the motor explode because I'm planning a stroker and new heads soon. I just don't want to build the motor and spend all that money to have the car still run ****ty.