Bad Valve Seals or Piston Blow By?

[MustangBillJr]

Hey guys... I recently installed a set of AFR 165 heads on a 89 5.0 with around 42k org. miles on the motor. With 1.72 D.S.S roller rockers, edlebrock performer intake, BBK longtubes ect....

Anyway around mid summer I noticed that I was starting to burn oil. At first I though it was nothing because it was hardly noticable. Then near the end of the summer it started to get worse, smoking noticably when I'd sit there idling, when I would go to back up, and it was the worst when I would drive it then park it for a few minutes and start it up once again.(all after it was fulled warmed).
I've done a few things thinking that they might be might problem. I've changed the pcv valve a couple times, and then I put the breather filter on the filler neck of the valve cover and another breather filter in the pcv hole since oil was being sucked up from both spots.
Mid fall I had to put the converters on to take it to emissions, which it barely passed and then changed the header gaskets since they sprung a leak, with a pair of percy gaskets. Upon pulling the header off I noticed and a few(not all) exhaust ports there were little puddles of oil in the port. Not a significant amount but maybe about a spoon full.

What do you guys think my problem is? My dads heard around the internet that AFR sent out a batch of bad heads but IDK if I received a pair of them. The car had about 40k miles when I put the heads on and now I've got about 42 not even. Also it never burnt oil before doing the head swap. I'm hoping the valve seals are the porblem since thats cheaper and easier then pulling the motor to get it rebuilt.... Any help would be appreciated, Bill

 

[Rick 91GT]

Do or have a leakdown test down, it will tell you if it is the rings or the valve seals.... If it is valve seals it is a easy fix..

 

[jtfairlane]

With worn piston rings you will typically see blue smoke on hard acceleration.

With worn valve guides, you will typically see blue smoke on deceleration/braking.

I would reinstall your PCV valve and filler neck to throttle body hose. You have no way of eliminating harmful corrosive crankcase vapors right now with your changes. If you are worried about oil consumption, put a PCV Oil-Air separator

in line between your PCV valve and the upper intake manifold, that will collect some of the oil that will naturally travel along with the crankcase gases. Also, your PCV valve requires a little mesh filter

underneath it in that hole in the lower intake to keep excessive amounts of oil from traveling through the pcv and into the upper intake. Many people lose these/throw them away, and then wonder why their motor is taking in so much oil.

If your rings are bad, that's a shame, since it is a low mile motor.

If you are having an issue with valve guides/valve stem seals, than I would be more inclined to believe that is an issue resulting from poor valvetrain geometry and improper pushrod length than from a fault at the factory. Did you use a pushrod length checker when setting up your motor? Did you color in the valve tip with a marker and check to make sure the witness mark was thin and centered?

 

[MustangBillJr]

Well the heads are brand new 165 AFR heads. I've had them on the car for about a year now with no more then a few thousand miles. When I setup the valve train everything was centered and set the way me and my father have always set up a valve train, and weve never had any problems until now. I didn't use a pushrod length checker but used the same pushrods my father used in an old setup with the same mods, and he never had any problems.
If you'd actually read my post then you would have seen the fact that I said how susposably AFR send out a bad batch of heads. And i'd be more inlinced to believe the heads were faulty since I set the valve train like we've set everything other valve train on the numerous other mustangs and motors we've worked on. Plus I never had any problems before putting the heads on.
Also I still have the filter in the PCV hole under neath the filter I put there, I'm not that stupid, plus I have extras so I wont be losing anything. And again if youd read my post I said that it burn oil in the same way I explained, before taking out the pcv and putting a filter on the valve cover. It sucked up oil through both spots even with the filter under the pcv before taking them off. Its not so much that I dont like it sucking oil, I dont like paying for 14 hundred doller heads that are screwed up after not even a season of use.

And I'll explain again just incase you missed it, the car burns oil when its sitting still and idling, or after the cars been warmed and I turn it off for a while and then get back in to drive it, thats when its the worst. It seems to me that once the car is turned off oil puddles up in my exhaust ports, because upon changing header gaskets months back I noticed oil puddled in a few off the ports, thats when I figured my heads were screwed and not anything I did or piston blow by. I assume that if I didn't set the valve train right more then just 2 or 3 exhaust ports would have problems.
Again, the motor has only 40k on it with a completly untouched short block. Afr 165 heads, 1.72 D.S.S roller rockers, edlebrock intake, BBk Long Tubes ect.

 

[Rick 91GT]

The leakdown test will tell you what is going on, while you are at it I would do a wet and dry compression test...

As far as using the same pushrod as another combo, EVERY motor is different. The deck heights vary a good bit from the factory the only ture way to ensure proper valvetrain geometry is with an adjustable pushrod checker. How wide was the contact patch on top of the valve, when the motor was rotated?