I just dropped in a rebuilt 302 in my Mav, the motor was bored .60 over heads were rebuilt, running a preformer RPM intake with a Edelbrock 650 cfm carb, and street cam from Edelbrock. The engine runs like a top starts right up has great oil pressure idels fine but its smoking out of both pipes. I know it may take some time for a new motor to break in but how many miles does it take? I have maybe >200 on the motor now. I did notice that my PCV valve had oil around it so I changed it out , I'm running Edelbrock signature valve covers with baffles but its seems that its still getting oil to it some how. So I don't know if the oil smoke is blow by on the new rings or coming from the pcv. Should I run the pcv to the intake or the carb as of now its on the carb. Another thing I noticed is that when the line is taken off the pcv the engine of course idels up but the smoke seems to stop ... if you plug the line smoke returns and vapor comes from the other valve covers breather .... didnt mean to be so long winded guys but I would like to get this cleared up. Thanks.
Sound like blow by past the rings...What kind of rings were used??? Did you have a machine shop do the rebuild??? Chrome rings take a long time to break in if the cyl arent prepped properly. Regular or moly rings tend to seat within the first 20 minutes/miles. Once again, as long as the cyl bores are prepped properly. 60 over is pushing the limits for a 302...You may be experiencing cyl bore distortion(extreme case) I would lean toward improper prep on the bores or riings were not properly installed/clocked on the pistons.Good luck man!!!
I bought the motor with block and pistons already assembled, it was all new the heads were still in the machine shop plastic bags so I would assume the machine shop put the rings on the pistons. The cylinders were honed as they should have been but I cant tell what kinds of rings were used.
I'm not trying to be critical here because at this point it won't make any difference...........but whenever you buy a new you need to find out everything about the motor, what kind of pistons, forged/stock.........or???What kind of rings, Moly, Cast, Chrome and what kind of bearings and what the clearances are......just ask, and if they don't know then walk away.................... A new engine........unless it has been put on an engine dyno and started and broken in........................well it's not ready to just put in the engine bay and go out and start driving. You need to break the motor in first......if it had cast rings (if they are moly they still need to broken in, just not as much as cast) then you need to take the car out for 10/15 miles and start out slow................speed up..................then let your foot off the gas and let the motor pull the car down...............do this over and over again. Here is a pretty good article on breaking in a new motor................. http://www.mototuneusa.com/break_in_secrets.htm IMHO
Thanks Olerodder, This is my first time ever getting this deep in a car but I did ask all the questions you stated save for the most important one "what rings does it have?" I will take it out after work tomorrow and try the steps as stated in the link you posted. So I guess you guys think its new ring blow by and not my pcv system ?
if thr motor has sit awhile with the new rings and pistons in it and not been started the rings will prolly never seat. seen it happen on more than one occasion.
1973Goat, OK, can you humor me, please tell me what you found out about the motor, when you put the motor in, and what you have done since starting the motor in order......................as Maverickdragger mentioned, if it has been sitting for some time you may want to try something different before you take it out on the road.
the block might have sat a month or less assembled, most all of the parts were sealed power or speed pro. the pistons are forged speed pro. the motor was built and installed with in a week then started, tuned and I have driven it 3 times. I have been told to break it in just drive it a lot and also been told to drive it hard, but I have been easy on it thus far.
1973Goat, Well, sitting for a month shouldn't pose any problem, as long as it was dry and didn't get any rust in the cylinders. I assume that you primed the oil pump before you started it up???????????????????? Opinions are like belly buttons............everyone has one. Any motor, should be broken in slowly to start with, and it needs to good and warm/hot before puting the pedal past 2500rpm.............IMHO
yeah we primed the oil pump ran it for a little while letting it get to operating temp and then drove it. I took it by the local speed shop and had the go through it today and he said he thinks it was built with chrome rings and would drive it a good 1000 miles before he would worry about it , I respect his opinion as a lot of the shops I called today said he was the SBF guy in the area. Thanks for all the help guys I'll keep you posted...
Well, a lot of "tuner types" are using chrome top rings on their turbo cars and boosting upwards of 15psi................they say chrome is the only way to go. I would say the guy that told you they will break-in in 1000 miles needs to go back to school. If the rings haven't seated in 200 miles they never will. I hope you are not using a synthetic oil to break the motor in on......especially if it has chrome rings..................use a regular oil and get it changed at least after the first 1000 miles. Keep us informed about the progress with the motor. IMHO
Years ago when I was building my Grabber, I started my freshly rebuilt 302 up to find it smoking like a freight train. I beat my head against the garage wall for days until a neighbor of mine who was a mechanic asked me when I was going to check the modulator valve on the side of the transmission. Yep with the newly rebuilt motor it was pulling more vacuum and ruptured the old modulator valve. I could also pull a vacuum line off and the smoke would quit. I don't know if your using an Auto or Stick but some one may find it helpful. Good luck, Jerry
Very interesting story. Some 40 years ago I bought a really nice 64 Chevy Impala with factory 4sp and 300Hp 327, I bought it off a car lot that specialized in muscle cars and hot rods just north of Vancouver, WA. I paid $1800 for the car and drove it off the lot. After a few days of driving as a daily driver it started to smoke................burn oil out of the number 4/6 cylinders. My dad was mechanic and my grandfather was an automotoive machinest with Baxter Auto Parts in Portland. My dad told me to take it back and get my money back...............so being a 17 year old I went back to the lot and the guy took the car to check it out. He told me what I already knew that the number 4/6 cylinders were down on compression and more than likely it was stuck rings.............so he told me he would pull the motor down and re-ring those two cylinders.....................I said well........why not pull the motor down and re-ring the whole motor................and he told me it would cost me $200/300 out of my pocket if I wanted that done or he would do the 2 cylinders for free. I told him to give me the money it would have cost him to do that and I would tear the motor down myself and fix everything the right way...............he said OK and gave me $250. I went home with the money and my Grandfather told me to run some Rislone through the motor....................I did, I don't remember how much I used but after driving the car for about 3/4 days it stopped burning oil, and was actually a pretty fast little motor..............plus I put $250 in my pocket for a new exhaust system, traction bars and some ignition work. Sometimes there is a silver linning to that black cloud!
