11.55:1 compression and the way i've been driving it lately, it's getting pressure.

 

Dosn't GM fill all new Corvettes with Synthetic motor oil?

 

:yesnod: :yesnod: :yesnod: :yesnod:

 

The oil really doesn't matter. The hone finish and the type of rings are what's important... that link I posted is a gem. Hope somebody (other than me)gains something out of it.

 

:cool: If I can remember what brand rings I used, I would tell you.. but I can't. I know they were good ones though. I'm not sure on the hone process used for my block. I will be sure to contact my machine shop to ask. Probably not that special tool listed on that link.

 

I doubt you're going to find many automotive machine shops using the latest "cutting edge" manufacturing technology to hone cylinders. But I suppose it is possible. :)

I speak from experience. What has worked for me. The engines I have built ran trouble free until I got rid of the cars and lost track of them. The oil was never black because there was no blowby into the crankcase. I don't know of any reputable engine builder who breaks an engine in using synthetic oil.

Here is an interesting site to read. It is a motorcycle site, but it presents a different point of view.
http://www.mototuneusa.com/break_in_secrets.htm

 

Good link. I still don't know what to think of it all though :).

All I know is that I used dino oil for 1k and my oil was pretty dark when i changed it yesterday.. and it was mobil 1 synth only 2.5k miles old. I have noticed that it is using a small amount of oil, but it could be from a small leak I have. Who knows. I am running rich right now, I can tell you that ... so I'll bet that is adding to the dark oil. I'll have all my tools moved back here next weekend, so I'll do a compression test then.

 

thats a lot of reading at 1130pm!!!!!!! :D

 

Good information :yesnod:

 

Update: oil pressure still isn't holding :(

 

Did you put a mechanical gauge and verify the readings? I am beginning to think that you have a defective sending unit........And you have to take care of that over rich situation...it may be diluting your oil where it is needed most.

It sounds highly unusual for the oil pressure to be good for a little while and then go back to a low reading again. If it were a significant leak, the reading would have been constant during the whole time around the oil change. The only explanation for a fluctuating reading like you described is a faulty gauge or alot of dilution to the oil which would cause it to thin significantly. If the dilution rate is that high, you might be risking serious damage to some wear surfaces and especially to rubber seals and gaskets that are prone to deterioration from high levels of gas in the oil. But I tend to lean away from this since your oil level has not risen significantly. Does your oil wreak with the smell of gas? How about an oil analysis to see if the basic composition of the oil has changed much?


[Modified by Sharky Guam, 8:59 AM 6/3/2002]

 

yes, just tried the mechanical. i've also replace my sending unit before. The pressures are pretty accurate. It's not rich enough to smell gas in the oil. If it was that rich, I would be worried about it.


[Modified by Glock'94, 5:32 PM 6/2/2002]

 

Well, all things considered, you have some oil which is abnormally going somewhere fast. If you don't want to tear it down and recheck, I 'd advise you to go to a high volume oil pump. This will improve the pressure at idle and lower rpms and reduce the chance of doing further damage. IF you don't do this and continue to run at low oil pressure, you may not make it another 1000 miles before some sort of failure. A high volume pump will improve your low rpm oil pressure, but it may not help the high rpm side much. A leak this serious has got to be an abnormally loose cam or main bearing. It may not be enough to cause damage to the bearing until it starves and overheats. Then it will be history. What is your oil temperature like? Is it unusually high?

 

Its possible something is causing the bypass check ball in the oil pump to stick open a little. It could be debris from the engine rebuild (I would hope not, but its possible) or it could be defective from the factory. Its also possible you have a weak bypass spring. Good luck.

 

Yes, I can agree with the bypass problem. I guess it would be safe to advise you to pull the pump and at the very least do an inspection of it carefully. I have also had experience with some builders opening up some oil passages to increase oiling to critical parts. That is why they suggest a high volume pump. I would change to a high volume pump and observe what happens.

 

So you guys aren't considering the fact that at 100*C Mobil 1 loses the most viscosity of any sythetic oils? I'm going to try a different oil first.

 

It certainly does flow better! But to experience good flow one instance and then not another sounds absurd. I can agree that Mobil 1 should decrease oil pressure 2-5 psi at idle and possibly the same or a little more at high rpm. But what you seem to be experiencing is a major oiling problem at idle. You can continue to live with it and take your chances or you can try to fix it atleast temporarily and get lucky. I would atleast try to change the pump especially if you have a fair amount of money put it to this one.

 

I do, but i have no money LEFT! college student. If I had the money, I wouldn't mind taking it in to a race shop to have a big oil pan and a new pump on. but I don't have the money. All my money goes towards shool, food, and insurance.

If anything I hope that the problem is that oil pump driver thing where the distributor normally is. It sounds EXACTLY like what's happening to mine.


[Modified by Glock'94, 5:44 PM 6/2/2002]

 

I just saw your other post about the spike. Ok, more facts and the picture is getting clearer. Your pump driver under the manifold may be defective. Or somehwere in the drive for the pump, could be in the pump, the shaft or some other part has some high tolerance causing parts to jump up and down causing a leak between the mating surfaces. Hence a leak is created under certain conditions. This also explains the spike. I would pull the manifold and check the driver. Then check the pump. The shaft should not have excessive play. Perhaps a thrust washer or shim somewhere is missing.I am not sure if there is one in any part of the system. I will have to check the parts manual and see. I have to run to work now. But I will check and post later.

As for school eating funds, been there 20 years ago and done that. I also had a vette during those days. So I know how it feels to be in your shoes. Good Luck and keep up with the studies!

 

thanks sharky ... i have my service manuals here, and I've been looking around in them.

Yes, school is very stressful right now as I was on academic probation last semester and i think something bad might have happened (i'm not going into details right now, i just found out last night).