motor problem-need input

[jon79flavette]

I am having a problem with the 350 sbc recently put into my 79. I am pushing oil out the dip stick, the dip stick is new and correct. I am also (at times) blowing the oil cap off the valve cover. The oil level is correct at 5 quarts, it is not over full. The interrior is removed and there are no gauges in the car. I could put an external oil pressure meter on it. The motor is a 70 LT-1 .30 over. a 280/520 cam. edelbrock intake with 750 cfm carb. Is it POSSIBLE that the motor is back pressured too much. This car sat for a long time. I have the stock exhust including the original cat converter. I know this is not the right exhust. It with have hooker side-pipes, but I don't have them yet. Could the exchust (restriction) and or clogged cat cause this problem??? any other suggestions. I can provide any additional info. This is getting me frustrated. Thanks Jon

 

[lytemup]

have you checked out the crankcase ventilation system (PCV)? i don't think exhaust backpressure could do anything like this...

 

[cruzer99]

It sounds like the crank case is not vented through the valve covers and either a pluged or no PVC valve. You can build up a lot of pressure in the bottom end of that engine.

 

[Jack]

;stupid I agree with both ... it's probably a crankcase ventilaton /PCV problem.
JACK:gap

 

[BB wowbagger]

If the car stood still for a couple of years,then maybe some of the pistonrings siezed up and doesnt seal properly..Do a comp test on the engine and check it..
A good way is to pour down little diesel down the cylinder and let it sit fo a night,it usually works.Some people pour Coke down and they swear by it.Just remeber to crank the engine by hand before you start it after the treatment.You do not want a bent rod...

 

[beige81]

too much (?) oil pressure

could it be some stopped-up oil return lines? wrong oil pump? Wrong crank? (some crankshafts have etchings to throw oil a certain way) it would suprise me if its the pcv. good luck:crazy

 

[jon79flavette]

Thanks for all the input. I made one of the simplest mistakes. The elite edelbrock valve covers have elite breathers in both covers. This motor was built in stages, I put them in there from the get-go and they are a real tight fit. not understanding that they are only breathers if the botton rubber gromet physically cut out. Always the simple stuff that you over look I guess. There are NO emissions, as florida became emission exempt a few years back. So the crank case should brethe normally through the valve covers---right??? Beige 81, that was and is a good point. I thought I had some severe mismatach internally. So far OK but, I have not run the motor above 3k rpm yet. Just a weird deal. I will be in Anderson S.C. ain 2 weeks if you know where that is?? Thanks again I hope this is as simple as it seems now Jon

 

[JohnZ]

If you don't have a PCV arrangement and just have breathers in both valve covers, it won't blow oil out any more, but it WILL blow hot oil mist out of the breathers; that setup isn't ventilating the crankcase - it's just a pressure relief. You should have a breather (for fresh air intake) in one valve cover (preferably from the air cleaner), and a PCV valve in the other valve cover, with a hose to the big PCV fitting in the base of the carb. The PCV system draws in fresh air, pulls it through the crankcase, and exhausts the blow-by vapors through the valve (which meters the flow) into the intake at the base of the carb. It will NOT hurt your performance (old wives' tale), and it will keep the top of your engine clean.

 

[GerryLP]

Good point JohnZ...

John79,

I am glad that is not the worse case scenario...it surelly sounded like blow-by, but if one does not test the compression, then it is hard to tell for sure.

 

[Twin_Turbo]

The PCV will mkae a huge black mess inside your manifold if you're using the vac. connection to suck out the fumes. It will probably not be legal in most states in the US but I'm running a checkvavle on the exhaust, under a 45 degree angle, and have the PCV connected to that. It gives a nice pull at the crankcase and no more black goop in the intake.

Marck