stumped

berettajunkie1991 · Post by **berettajunkie1991** » Fri Dec 28, 2007 2:07 pm

Alright new motor in my beretta built by me Q4 all the tolerances have been met in every which manner. cylinders got bored out to .030 and got honed new pistons and rings were put in also gapped and spaced out correctly. cylinder head took it down and replaced the valve stem seals cleaned it and put it back together. Ran the motor for about 700 miles so far and then it started to smoke blue smoke-oil. So i did a compression test 150 150 165 180 dry test, wet test i came with 180 180 180 185 so pretty even across the board. i think it is the valve guides on the head and another person said that it is my oil control rings problem is there is no scoring on the walls to indicate a busted ring so i am freking stumped.

Money pit Beretta · Post by **Money pit Beretta** » Fri Dec 28, 2007 10:51 pm

I'm stumped also, it has been many years from the last time I had to think of this. All I can think of right now is the valve stem oil seals.

berettajunkie1991 · Post by **berettajunkie1991** » Sat Dec 29, 2007 1:02 am

the thing is that i replaced them but who knows at this point best thing i can do is to dissasmble the head and inspect everything i will post picture and see if it helps. The bores are as good as the day i brought the block home and assembled it the cross hatch is prestine also.

Money pit Beretta · Post by **Money pit Beretta** » Sat Dec 29, 2007 1:56 pm

I think you were right the first time (Guides). For some reason I read that you had replaced the guides not the seals. I must have been tired. I still must be, I sort of remember something about the oil control ring can only go one way or the oil will burn. The thing is I would think it would have done that from the start(not after 700miles). I say go with the guides.

1988GTU · Post by **1988GTU** » Sat Dec 29, 2007 2:05 pm

I believe it to be the guides or a seal could just not be seating right. I've seen engines come in with a valve seal problems and they had less than 20k miles on them. Turns out the rebuilder used a non OEM seal.

berettajunkie1991 · Post by **berettajunkie1991** » Sat Dec 29, 2007 8:46 pm

yea i replaced the seals what i am going to do check the head tonight and report what i find. The guy who i talked to said there is no way it should be guides even with 147000 miles and i kind of think other wise you know. i mean i am going to UTI for a major in auto and diesel tech certifications and it simply does not make sense. I understand that there should be far less wear than a pushrod motor because there is vertical and horizontal movement in a pushrod on the guide and the quad 4 is almost all vertical load. but there is still wear regardless. Also the oil control ring is a three piece and is kind of hard to mess up, and if the compression rings lined up then my cylinders would not have held compression for more than 5 to 10 seconds. rings are out the only other thing i could think of is the crank-case vent system because there was some oil in it on the timing cover side but still the all the cylinders should have had oil in them

berettajunkie1991 · Post by **berettajunkie1991** » Mon Dec 31, 2007 1:53 am

here is what i found and here is the pictures maybe you will see something suspicious
This is what the piston should look like with 700 miles

Cleaned chamber

Money pit Beretta · Post by **Money pit Beretta** » Wed Jan 02, 2008 10:18 pm

More oil was burning than I thought. How long did you drive with it doing that? It seems like too much for the guides. Yes I think also that after that many miles the guides should be done.

berettajunkie1991 · Post by **berettajunkie1991** » Thu Jan 03, 2008 6:33 am

well right now the head is at the machine shop the guy did point out that there was three cracks in the head so for in three of the chambers so but he is doing a complete inspection and replacing any necessary parts.

Money pit Beretta · Post by **Money pit Beretta** » Thu Jan 03, 2008 9:55 pm

Cracks? Not good news. Did it overheat sometime? Are you going to get a new head?

1988GTU · Post by **1988GTU** » Thu Jan 03, 2008 10:09 pm

086 heads are known for developing cracks. The that alloy material will fatigue and after a few heat soaking runs with high rpm loads it will more than likely do that. I've had a head with cracks, but it was still "usable" . It all depends on how deep the cracks are.

berettajunkie1991 · Post by **berettajunkie1991** » Fri Jan 04, 2008 12:25 am

got a new head from the machinist the head was still fixable but he just swapped out for a new head so i can get my car going. The car has not been overheated but perhaps the cracks developed when the cat backed up.

Money pit Beretta · Post by **Money pit Beretta** » Fri Jan 04, 2008 10:30 pm

So you got it all set up to go and didn't pay anything? What cams are you running? I have been talking to a new guy in the exhaust area(he has a great sounding Q4).

berettajunkie1991 · Post by **berettajunkie1991** » Fri Jan 04, 2008 11:00 pm

no i had to pay but i only had to pay labor even though it was and exchange "technically part sale" how ever i will post a start up sound when i am finished tonight.

Money pit Beretta · Post by **Money pit Beretta** » Mon Jan 07, 2008 10:22 pm

If that's all you had to pay for that's great. Can't wait to hear it run. Hey did you get time to check out sphon721's Flowmaster video clip?

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