Breaking in engine, which oil?

[navyflyer72]

I am breaking in my sbc (327 bored .060). I HAD Mobile 1 Synthetic 10W-30, but after 300 miles, a broke push rod on the #2 cylinder exhaust and a rounded cam lobe on the #2 intake, I have found replaced the cam, lifters and pushrods. On startup I have a small rear main seal leak (more like an intermittent drip) and I have a lot of blow-by through the breather. The pcv is working great, but I still have a lot of crank case pressure. I have heard that I should not use synthetic oil for break in, that I should use a 10W-30 with detergent (and also high zinc) for at about the first 1000 miles to get the rings to seat. Any one have input on this? Also is there anything else can I do to decrease crankcase pressure? I am hoping that by seating the rings and decreasing the crankcase pressure that clears up the drip from the rear main also... Thanks for any advice

-George

[Matt@RFR]

Man, this is a persistent misunderstanding. With today's rings and cylinder honing techniques, it is NOT necessary to "seat the rings". The first time the engine reaches operating temp, that's it.

Once again, for example: A new engine on an engine dyno, if it has a roller cam, they will light it, time it, and let it warm up at just past idle...then immediately run it up to it's shift point, and then some.

The break-in oil debate will never go away. I use dyno oil for the first couple hundred miles simply because it's cheap, and you need to change the oil and filter 2-3 times to get all the lint/dust/blood/small fury animals out of the engine.

If your rings aren't sealing now, and it sounds like that may be the case, then you might as well start tearing it apart.

Have you done a compression test?

[navyflyer72]

I have not done a compression test yet, but that is my next step. I think that will tell me what I am fearing may be the case. I am just trying to put off the inevitable because this is my daily driver right now (believe it or not). 60K into her and I am driving her to and from training... Who needs a garage queen? Gotta love it.

-George

[Zee]

I broke my motor in on Valvoline VR1 racing oil and Crane's break in lube. So far, so good.

[tbair]

I agree with Matt to a point.on your engine 327 has to be a 60s motor.I dont know what your start up procedure is ,but if you lost a cam lobe it wasnt right. You need to prime the oiling system before start up pull both vavle covers and prime the motor with a hand held drill and primming shaft.until you get oil all the way up to one head then turn the motor over by hand 180 until you get oil to the other head. put it back together. prime the carb. start it up dont let it idle below 2000 for the first 15 min. that how you lost a lobe.the old motors with a flat tappet cam still need break in.synthetic oil is not what you want for start up.after that its your call.I think its worth every penny you pay for the synthetic oil.One more point on the pre 85 small blocks is they have a 2 piece rear main seal and its hard to keep it from leaking with the better oils on the market today.Tim

[critter]

Use the Valvoline Racing Oil or Rotella oil for diesel engines. Both still have ZDP in them. Other oils have had that removed due to new EPA standards. Roller cams are not as prone to failure by design but the flat tappet cams are not faring well since they pulled the ZDP. Throw in a bottle of EOS (engine oil supplement) from GM for the break in as a safety measure.

Pick up the June issue of High Peformance Pontiac magazine for an in depth article written by my friend Rocky Rotella (no relation to the oil company) regarding this.

[justanova]

fwiw on the cam issue according to crowers website they do not recommend synthetic oil on flat tappet cams.

And a cyl. leakdown test would tell you more than a compression test as to wether or not the rings are sealing.

[ProStreet R/T]

I agree on doing initial breaking in with dino oil purely because of cost even on a roller motor. Throw in a bottle of lucas oil stabilizer just for good measure and let it go.

Sounds like you have some more serious issues though. Are you using single or dual valve springs?

Did you double check to be sure the lifters were spinning in the bores?

[navyflyer72]

We did prime the pump and got oil up into both heads prior to lighting her off the first time, we also ensured the first 20 minutes were at 2500 rpm, I had synthetic oil in though for the breakin. Now that the cam, lifters and pushrods have all been replaced and she has been broken in with dino oil, the only major problem I have is the blow-by. I just made the 250 mile trip from Virginia Beach to Annapolis, MD with no audible problems, (this is right after the 2nd break-in), ran at about 2500-3200 rpm most of the way. When I got here, found the bottom of the engine covered in oil and about 1/4 pint of oil sitting under the carb on the intake (Edelbrock air gap). I am pretty sure the oil is all blow-by, but who knows just yet. With the way labor is adding up I am seriously contemplating a crate motor, but I would rather keep the original motor. plus I have a slight cooling problem, as described in the cooling section. Thanks for all the input, keep it coming. I have to drive her back to Va Beach tomorrow so hoping to sort some of this out before then...maybe.

-George