Ok guys, we know what my motor problem is, but we can't find the reason for the problems.

My issues with running that I"ve been chasing for 2+ years now is definitely a continual failure of the intake manifold gaskets. Oil and oil vapors are getting sucked into the runners, and subsequently burned, throwing everything to hell. Massive internal vacuum leak causing high fuel pressure, oil and vapors throwing VE off and causing detonation, car WAY down on power, and a ridiculous low end stumble, not to mention fouling plugs in the blink of an eye.

So, here's the setup: Decked block, actual amount unknown. According to Chad Golen (Golen Engine Service) it can be no more than .020" for a zero deck height. Heads were verified to be .015" decked as measured by the 52CC combustion chambers. Intake manifold was cut to properly seal to heads by Chad as mocked up on a decked block at Golen Engine Service. He verified that I should be getting an outstanding seal at the manifold to head.

Yet I keep showing up with intake manifold gaksets that are letting oil by. These pics were taken after maybe 30 sporadic minutes of run time for some idle tuning. http://community.webshots.com/album/460272038haJSmQ You can see how the runners are just wet with oil, and the inside of the intake manifold is the same way. Even the TB gasket was saturated, and a film of oil coated the back of the TB.

I checked the PCV system, and it's dry as a bone, and the PCV valve seems ok as it rattles when shaken. The intake manifold lines up perfectly with the bolt holes in the manifold, and the gaskets show an incredible pinch pattern from the manifold and heads.

Yet I still end up with gaskets looking like the above pics after 1-2 minutes on a brand new install. This seems to be the ONLY issue plaguing the car. It's also chased me from the stock shortblock to the new shortblock, which REALLY leads me to believe that it's the heads/intake combo, but with such a good pinch pattern showing on the gaskets, why again is it failing.

Chad stepped outside the box today and made mention of "what if it's excessive crankcase pressure forcing oil by the gaskets?" In that case though, wouldn't I be pissing oil out of every external seal?? And wouldn't my PCV system be saturated too??

I really need some help here guys, I know that there are several engine builders lurking around and making valuable posts here, and if you guys could offer any ideas or insight, I'd be most appreciative. If you need any more info or specs, don't hesitate to ask. I can't access the site from work, but I'm always lurking around in the evening.

TIA from a guy about to give up.

 

#1. Are you sure there are good valve seals on there.
#2. Is the heat cover on the bottom of the intake manifold?

Bret

 

The heads were thoroughly checked over after this problem caused me the teardown of the original shortblock, and were verified to be just fine. A new valvejob was performed was performed at that time is the only change. New seals were installed also, and I get no smoke at initial startup.

The heat cover is on the bottom of the manifold.

Thanks!!

 

Try getting rid of the PVC and putting breathers in the valve covers. Another thing, Do not use RTV on the intake ports. The gasket should fit fine without added RTV. Did you do a compression check? Maybe some oil vapors getting past the rings? Did you measure the angles on the intake vs the heads and make sure they are flat against each other when seated? My intake ports look new on my engine and I attribute that to not having the PVC valve and EGR valve hooked up. Hopefully, you will figure out the problem.

Good Luck

Matt

 

What would be the best way to bypass the PCV valve???

 

Stop using silicone at the intake ports...get some high quality SCE gaskets and apply a light bead of weatherstrip adhesive to the gasket and manifold, then set the gasket in place, put the manifold in place and lightly torque, let sit over night, then cut excess adhesive out, seal it up and see what it does.

I have heard about a lot of people having problems with those felpro printoseal gaskets, I have only used them a few times with no problems, but I use SCE's on everything and never have intake leaks.

 

Put some clay around the intake ports, and lightly torque it down, verify that it is hitting all the way around equally.

 

If the Fel-Pro 1284 the Printoseal you were mentioning??? I just picked up an additional set of intake manifold gaskets from Advance Auto, a set of gm styled Fel-Pro's. The metal style.......which shouldn't wick up any oil either.

You can obviously tell the gaskets are getting pinched all the way around just by looking at them when they come out of the car. OBVIOUS pinch patterns, which is why this is so confusing.

I'm going to use that newer Fel-Pro gasket set I got (the metal gm style gasket) and the weatherstrip adhesive around the ports and see what I come up with. Also going to try the valve cover breather at the same time.

Manifold is going back on in a matter of a half hour.

 

The black gaskets with raised blue rubber are the printoseal felpro's, The harder stock gaskets that come in kits are called permatorque.

That pinching is why I wanted you to measure with clay the difference in compression around the ports.

The weatherstrip stuff only works with the high density cellulose gaskets like SCE accuseals.

 

Just plug off the hole in the valve cover and on the throttle body and on the intake manifold and put in a breather on the valve cover. I would get one for each side.

 

If using the stock gaskets, they should need no sealer, but I do put a very light coat of RTV on mine. Glue will not stick to the graphite coating of stock gaskets anyway. If they are getting proper crush, any gasket should work sufficiently.

As for "kit" gaskets, the Felpro LT1's come with stock type graphite/steel gaskets. Permatorques are generally found in regular small block kits.

Bret mentioned the heat/oil baffle on the intake. This shields oil from the PCV. If it is there, did you check under it for the pipe plugs which seal off the IAC ports. If one of these is missing, you will definitely suck up some oil. The idle should be high as well. Check this before putting the intake
back on.

 

Yeah I wonder about the IAC ports in the intake as well, something is sucking oil from the bottom end to the rest of the motor causing this oil issue if the valve seals are perfect.

Bret

 

If a plug was left out it would idle like crap and be way down on power.
Ya think he would have noticed?

 

I seem to remember......

........


........


I want to say they were on there......but thinking about it, I'm not 100% on that. That's something that NEVER donned on me to make sure was there.

I put the manifold back on two days ago, and was running the car today. And now, thinking about it..........I may just pull the manifold to be sure. I was running and driving today, and while better, it just wasn't all the way there. Felt strong, but not nearly as strong as it should have.

 

Ok, after tuning it a little for idle tonight, it's still not pulling much vacuum at idle (6-10 but MUCH more steady) and with 40% VE it was idling nice and smooth. Pulled plugs 1,3, and 4 and all were showing lean white. For the first time ever.

However, the low vacuum still concerns me as I had 34* advance at closed TPS idle.

I think you guys just may be on to something. If those IAC holes didn't have the plug, and were sucking oil in, it would be getting in the runners. Even if I had a good seal with the head to manifold, given that I was using paper gaskets (FP 1284's) the oil could have seeped through, right? I'm trying to figure if it's worth me pulling the manifold right now for a look.