[tbird88tbo]

Ok people, im at my wits end. Ive had this engine to the machine shop twice and they cant seem to see anything wrong with it. Here is the story.

New manly forged rods and pistons, new cobra crank, new clevite bearings, new total seal rings, .020 over on the cylinders, all balanced and blue printed. On the heads, new exhaust guides and all new seals. Both heads and block decked. Felpro performance head gsks, arp main studs, arp head studs, melling high vol oil pump with billet gears. New lifters, new timing chains, gears, and tensioners.

Ok, before i rebuilt everything the engine ran ok and didnt smoke, but i was planning on more power so i wanted to beef up the bottom end. Now that everything has been rebuilt im burning 1 quart of oil in less then 100 miles. SMOKING BIG TIME. Ive already checked the obvious ( pcv, vent tube, supercharger) I cant see where oil would come in from the top end. The pcv and vent tube are both breather caps and the intake manifold has no oil passages. Intake valve guides have been checked for clearence, exhaust guides replaced and new seals. All supercharger disscharge tubing is dry as a bone along with t-body and manifold. Rings were checked to make sure none were installed up side down.

If anyone has been through this on a rebuilt dohc 4.6l any recomended checks will be greatful. I dont want to have to take this thing apart a third time.


HELP PLEASE!

[majorownage]

run it without the PCV system hooked up for a while; look at the ex-duser side of the supercharger is there oil? Look in the intake...is there oil?

[tbird88tbo]

i already did that, read the last three sentences of the second paragraph. no offence. im just at my wits end.

[majorownage]

just get some boost and seat the rings w/ lots of timing pulled

['97'Cobra]

shot in the dark. Did you stagger the rings? I have seen brand new motors put togethor and then smoke badly because the rings were never in the right positions.

[CobraStang161]

you sure the rings are gapped right?

[tbird88tbo]

I did stagger the rings and on top of that i had it back to the machine shop and they double checked the rings and said everything looked fine.

[tbird88tbo]

my gut feeling is that it is something to do with the rings but i dont know how to prove it.

Has anyone ever heard of too much oil pressure causing this?

[roybrown45]

have you checked the cylinder bore roundness? i've heard these motors have to be plate honed to prevent warpage of the cylinder bores. did they deck the block first or bore the cylinders first? i wonder if the order of those two processes would affect the bore roundness? have you checked the flatness of the deck faces of both block and heads?

[C MY 4D]

What rings are you running?

[CobraStang161]

Originally Posted by tbird88tbo I did stagger the rings and on top of that i had it back to the machine shop and they double checked the rings and said everything looked fine.

You sure they were done right? After cutting the rings your suppose to file down the ends due to beveling from the ring cutter, if you don't do that the rings won't seat right.

[Ruffellbaker]

Were the pistons installed at the machine shop or did you install them? Because it wouldnt take much for the rings to shift around if they werent installed right after you set them up. Also are you sure the rings were installed facing the right way? Most rings have a dot or some kind of indicator that shows which way is up. But just a hunch, did you maybe forget your valve stem seals? They are really easy to forget, Ive almost done it myself.

[tbird88tbo]

Still havent settled this issue yet, just dont seem to have the time. On top of that my new toy (yzf r6 sport bike) has been occupying most of my free time. I did do some more research that makes me even more positive that it is the rings. Ok, let me answer some of the questions from the last posts. Yes cylinder bore roundness was checked. The cylinders were bored .020" over and honed using only the best equipment. The machine shop i used came hightly rated and the owner did most of the work and hes been in buisness for problay 30 plus years building mostly race motors. Im not saying hes impervious to mistakes but i did take it back for him to check. The ring package is the total seal rings with the moly gapless top and ductile second. This is where my major clue is. I did a google search on the problem im having, specifically with Total Seal rings and found a TON of hits for an aray of different vehicals using these rings. In conclusion what i belive happened is due to a combination of factors. Total seal recomends using not only a specific honing stone, but also a specific machine to hone the cylinders. I dont know if he used the proper setup but i would exspect he did because hes a total seal dealer and his shop isnt some back yard shop, it top notch. This is where i think the problem came in, i lubed the rings. Ive always lubed the pistions and rings apon installation and never had any trouble. Makes sence right? Thats just how i learned to do it. Apparently total seal recomends installing the rings dry for break in purposes. I guess i can see that, but as soon as you start the engine oil will be at the rings almost instantaniously. So anyways, the test is going to be getting a new set of rings and problay will rehone the cyls. I may try to just drive it with some plane motor oil instead of the break in oil for a few thousand miles and see if it breaks in that way, but if not ill have to tear it down...again. And honestly, i really have no desire to do that. Oh well.

[Mod Mustang Racing]

Lubing the rings is one of the biggest mistakes and can prevent a ring from properly seating and cause the problems you are having.

If you like you are welcome to send us the engine and we can figure it our for you, let us know if we can help!

MMR