Like the title said, my intake likes oil and from what I found playing with the ''search'' option I'm not alone.

https://www.thirdgen.org/techbb2/sho...=oil+in+plenum

https://www.thirdgen.org/techbb2/sho...=oil+in+plenum

https://www.thirdgen.org/techbb2/sho...ram+intake+oil

I'll try to make the story short.

- First when I got my engine running for the first time I did it on an engine stand with a carb intake and had no leaks around the intake ports when I removed the intake.

- My oil consumption started when I installed the HSR intake (1 quart every 300-400 miles). I had my PCV installed and I could see the inside of the plenum coated with oil.

- I then installed a catch can inline with the PCV. It did it's job but the plenum was still coated with oil.

- I removed the intake for the first time and found out that the contact pattern impressions of the intake was not good and that the first 1/3 of the bottom of the gasket was wet around the ports. The gasket was only slightly crushed on the bottom. After some measurement I found a gap of 0.008'' at the bottom of the port between the intake and heads.
After comparing the angle of the intake with an other SBC intake I concluded that my engine set up and not the intake was the problem.
I then had my machinist removed 0.018'' of materiel from the TOP of the manifold so I now had 0.010'' more meat at the bottom to crush the gasket properly.

- The gasket I'm using is (Fel-Pro 1205) and this time I used it with some RTV on both side of it around the port. Torqued the intake at 35 ft-lbs.

- Still had oil in the plenum. I then got rid of the PCV system and installed a breather.

- Still had oil in the plenum. Oil consumption was down to around a quart for every 600-700 miles. I then decided to change the intake valves seals.

- Still had oil in the plenum. I did remove the intake manifold again. I checked the torque on the bolts and it was down to around 23 ft-lbs. Sure enough 1/3 of the gasket was wet and the RTV didn't stick to the intake side of the gasket.
But the contact pattern impressions of the intake was good this time.

- I installed a new gasket with no RTV this time around the port. I went for a short ride of 30 miles. Came back removed the plenum and sure enough it was coated with oil (intake port as well).

- I even had an engine builder with more than 25 years of experiance installed my intake manifold with the same result.


So if your still reading this, is there some strange thing happening with that intake when it goes thrue some heat cycle. (expension, contraction).

Or the intake manifold gasket in this case FEL-PRO 1205 is not up to the task.

Or I just don't know how to install an intake properly ????

Thanks

PAT

 

I was having the same problem.....Holley didnt do anything for me after 12 calls so I had to take it to the next level. I ordered a new one from Summit and cleaned up my old base real well...boxed it up and kept the new one. Told summit that it looked like it was used and I wanted a refund....got my money back no questions asked. I installed the new base and it is leak and oil free. The new base was a different casting with more material on the rear china wall and the correct intake gasket angle. Sorry to say sometimes when you get screwed you need to turn to drastic measures!!!

 

ok im not positive but i know on other aftermarket heads the rocker stud holes go thru to the intake ports, if your do thats most likely where the oil is getting in from.

 

LOL

Not the AFR heads I have and like I said the intake gaskets were wet when I remove them.


PAT

 

hmm good to know that. are you using the rubber gaskets onthe ends of the block or silicone? just wondering since i had an issue with those dam things once that wouldnt let the intake seal before.

 

I'm using silicone (Right Stuff) with good results there.

PAT

 

Ditto. I went though a quart every 500 miles because I didnt put anything on my rocker studs.

 

For those interested in knowing where I am right now with that problem follow this link.

http://web.camaross.com/forums/showt...96#post3221596

PAT

 

Do you have any sort of breathing setup on the engine at this point? If you have removed the PCV then you need to have a breather type oil fill cap on the engine or something like that. Otherwise, when you hit the gas it's going to leak oil somewhere. It will blow the dipstick tube out and leak there, an intake manifold gasket will leak, or you may make valve seals/rings leak by....... Depending on what you have for an engine you may need more breathing rather than less......... That's why race cars always have at least two breather type oil caps on the valve covers. (One each side or two on one side) Just a thought.....

Another thought is this, what type of baffling do you have in the valve covers where the PCV is located? IF you have none at all, like most aftermarket stuff, you may be sucking oil into the intake from either the PCV or the line that goes to the TB.......

 

Right now I have one breather (2 totals) per valve covers.

I have Proform valve covers with stock style baffles under each of my breathers. I can't be sucking oil from the PCV or any other lines cause there is none.

PAT

 

A few more suggestions:

1. Take the manifold to a machine shop and have them check it for straightness.

2. Have them seal all the openings and pressure up the manifold to see if there are leaks somewhere. I'm not sure that magnifluxing it would work in this case.

3. Look at the edges of the manifold. If they are perfectly smooth, you may want to rough them up just a little with some 200 grit sandpaper. (Not a normal thing to do!!!!!) The old chrome thermostat housings used to leak , no matter how much silicone/Permatex we used, unless we sanded the chrome off of the mating surface.

4. Use Permatex #2 on the intake manifold gaskets instead of silicone (Keep the silicone for the ends). Much harder to clean off when you remove the intake, but it will seal way better.

5. Find a different machinist if he only took metal off the top edge of the intake..... If you have shaved your heads enough to require any machining on the intake you will have to take metal off all surfaces! The sides that mate to the heads and the ends where it mates to the block. If you don't take metal off the ends, it still sits too high and would actually make your leaks worse.....

 

Oil and Fuel problems with the HSR are not uncommon. I was one of the first people to have problems with the HSR and the HSR fuel rails.

This is a great thread talking about many problems with the HSR intake manifold:

http://www.stealthram.com/phpBB2/vie...r=asc&start=30

There are many tricks, read the thread and try some.

 

Update,

Short story of where I am with my oil problem.

Full story here :http://web.camaross.com/forums/showt...=383551&page=1

-With a Fel Pro gasket # 1245 and Permatex (the right stuff) on both side of the gasket I did managed to get a perfect seal. But I still had problem.

-I am running the engine with a carb set up and still having the same problem.

-The problem basicaly comes down to oil passing the valve seals (I can't think of anything else), and this is probably cause by problem with oil return from the heads (oil level higher than the seals).
I think that my my high volume/high pressure oil pump has something to do with that.

PAT

 

Pushrods too long or short causing them to push down the valve at a slight angle?

 

Would it happen only with worn valve guides or there is enough play when they are new ????

But the length of my pushrods were chosen by my engine builders they look fine to me.

PAT

 

What kind of RPM are you running? How tight/loose was the fit of the bearings? If you are only running 6000-6500 I don't see the need for a high pressure pump. In fact, it's probably not needed unless you are runnng a remote oil filter setup.

Unless you have loose fit bearing for high RPM (7000+) i don't think you would need high volume. A 7 vane standard pressure pump like a Mellings (Badger is their generic) should work fine. It already has about 10# more pressure than a standard 5 vane pump, put out more flow and has a smoother pulse so it affects the distributor less..... Just a thought, go with your engine builder's recommendation.....

Another thought, can you open up the drain back holes a little? Grind off casting flash, remove metal screens on drain holes, etc.?

 

you have a part number for the 7vane?

 

I'm shifting in the 6400-6600 zone.

My bearings clearance is 0.0028. And I'm using Moroso oil pump part # 22112.

I talked to him about that and he said that we should probably try an MEM-55 and see how it goes from there. It's gonna be a trial an error process

By looking at the drain back holes there is not much restriction there, the only thing I can think of is the position of my AFR rev-kit bar that can restrict the flow somehow. (Will look into it when I will lift the intake again). I really don't like the idea of lifting the heads so I can grind the block.

I do have oil restrictor plugs in the lifter valley and screens at each end of the block but I don't see how the oil level can be high enough to interfer with the oil that drains back from the heads.

PAT

 

Did the roocker arm stud threads (into the head) have sealant applied to them during asembly. Many of the aftermarket heads have the stud holes open into the tops of the intake runners.

RBob.

 

I have AFR 190 heads and there is no opening in the intake ports.

Beside that the oil can come from only 4 places that I know of.

-The intake gasket. I finally had a good seal with a Fel-Pro 1245 gasket.

-From the PCV valve. (I don't have it anymore)

-From the cylinder during overlap at idle ??? (I did a compression test and everything looks fine with the rings)

-From the intake valve seals. (they were changed for an other brand with no luck) but it looks like the oil is coming from there.

What make the most sense is that the oil level probably gets above the seals somehow and then they can't do there job properly. This is due to the drain back holes not up to the task, and it is probably amplified by my high volume pump.

I can't think of anything else.

PAT

 

Are you sure you have enough vacuum to get the oil rings to seal properly?

 

You mean vacuum in the block or in the intake..... I know I idle in the 60-65 kpa range.
And with the PCV installed it was sucking oil true it so it was even worst.
The more I think about it and the more I have a hard time believing that if I have a problem with my rings, I don't think that during overlap there is enough time for this amount of oil to go back in the intake.

The engine is burning a 1/4 of a quart for every 140 miles.

PAT

 

I was referring to vacuum in the block that would aid the rings in sealing properly against the cylinder walls. You seem to be having an issue with oil control and the oil ring is one of the prime suspects for oil in the intake if your P.C.V. system is up to the task.

 

I used to have a PCV set up and at first I tought that it was the reason I had oil in the intake.
I installed a Greddy catch can inline and still had oil so I removed everything and I'm now using 2 breathers instead. (I did had oil in the catch can so it kinda worked)

Like I said before I used to have total seal gapless top ring and had that problem, and now same thing with speed pro rings.

2 things I will do soon, a leak test and at the same time I will install some Perfect Circle valve seals and will see from there how it goes.

PAT

 

IRACE87,

I'm having very similar problems that you are. Fresh engine, that uses way to much oil, high volume oil pump, replaced rings to no avail, oil all over intake, working pcv, valve seals seem to look fine. My head gaskets seem to block the oil drainback holes in the head a litte, but not much. So i'm curious to see what solves your problem. Of course i'll let you know if i figure anything out. I've been seriously thinking about replace the oil pump with a stock unit. Maybe i'll get around to it tomorrow, if i can do it without completely removing the engine.

Keep us updated.

Thanks
John

 

If you don't have a windage tray like me it's not to hard to remove the pan with the engine inside the car.
Let me know how it goes.



PAT

 

I have all the new pump parts in front of me! Well I have a stock pan, if i remember correctly they don't have a tray. I can't get a hold of a hoist until later this week, so unless i can jack it up from underneath i won't be getting it done today. I'll let you know though.

 

Well i have the old high volume pump off. I probably won't get it running tonight, but i'll get the bottom end together. I still have some valve springs to put back together and some other stuff. Should have it going this week. I sure hope this does the trick, i've been dealing with subpar performace for too long, and i'm sure you have too.

 

I can't wait to find out if it does the trick for you. If it does I will be changing mine also before next week end.

I know how you feel, this is my second racing season I'm missing and all that time I've spent under the hood could have been spent on something else. And I'm not even talking about $$$$.

PAT

 

I do not think that you answered Rbob's question:
"Did you use a sealant or tape on the threads of the rocker arm studs?"

If you really think that you are having sealing problems at the intake manifold than you need to try a Fel-Pro #1286. It is .120" thick rather than the 1204-6's .060"thick.

If you are still having a problem you need to try the sin and arc sin of the HSR in comparison of a good manifold.

You do not need a high volume or pressure pump unless you are running RPM's in the average of 5,000-9,000 range or ar running exessive clearences. They can also suck a 5 qt. pan dry.

PCV only needs 2-3" of vacuum, not full vacuum by the way.

 

Have you ever run the engine with the VC's off? Seems you would be able to get a pretty good idea if too much oil was pooling in the heads.

 

Good idea, but its really not that easy to just "pull a valve cover" if you have the factory a/c intact, as i do. Any way we should find out soon. The only thing holding me back from trying my new pump is a busted oil cooler hose. Should have it going tonight.

 

No, like I said earlier I have AFR heads and there is no opening in the intake ports from the rocker arm stud threads .

I used a Fel-Pro #1245, that is .120'' thick also and got a really good seal. So that is not my problem anymore.

How do you set it up to get 2-3'' of vacuum, I had mine set up like the factory plus a catch can inline.

That is exactly what I'm gonna do tomorrow since I will be changing the valve seals anyway. That should be interesting.

Ask me what I did with my oil cooler


PAT

 

Well I got it running tonight. Its still blowing oil under hard acceleration, but I'm hoping thats just residual oil in the intake and heads. I seemed as though each full throttle run produced less oil smoke. I'm not really sure though, as its dark out. I'll give it 100 or so miles to make a conclusion. Also I'm gettting much less pinging, although i'm not sure if that is from new, unclogged plugs or less oil in the mixture. Also the oil pressure looks nicer now without the high volume pump.

I look forward to seeing how the vc test goes.

Good Luck
John

 

Well, if you swapped pumps, you may have eliminated the need to pull the VC's...if it's aPIA for you, then I'd suggest run it and monitor...the HV/HP pump may have very well been your problem.

Yes, the reduced pinging is most likely due to less/no oil in the A/F mixture.

Seems like yo're heading down the home stretch

 

Update,

First I removed my valve covers to see how high the oil level would at idle. The oil level is fine, the seals that gets the most amount of oil (#7 cylinders of course ) and gets oil to about half of it's total height.

I then replaced all the valve seals with Victor Reinz seals on the intake (they really looks like the Fel-Pro I had) and crane cams teflon seals on the exhaust valves.

One thing I noticed is that there was oil under each seal I removed (worst with the exhaust ones) I don't think I should see oil there, should I ????

So I think the theory is that I'ma having the seals slobbering in oil. The oil gets probably above the seals at higher RPM but not from a restriction in the block.
What I think is that the drain back holes in the heads were machined to high because with the valve cover removed and the engine off (looking at #7 cylinder, lowest point in the head) with the oil level being at the lowest point of the drain back hole there is already oil to half the height of the valve seal.

It would be easy to have oil above the seals if the oil level gets higher than that.

Does it make any sense, and how high is the lowest point of the drain back hole compare to the valve seals in a production SBC ??? I have AFR 190 heads and don't have anything else for comparison.

I even put some teflon tape on the rocker stud just in case, and after a 20 miles drive it was still smoking like usual.

PAT

 

I went to see a friend of mine that has lots of SBC heads, and sure enough looking at 3 different brand of heads all of there drain back holes are machined at the lowest point in the heads and it's well below the valve seals.
That is not the case with my AFR 190.

See this link

http://forums.corvetteforum.com/show...afr&forum_id=7

I will be contacting that guy at AFR next week and will probably send him those heads.

It appears that the oil problem with the AFR 190 head is common. They didn't design the drainback holes properly.

PAT

 

What were they thinking?

 

Hey IRACE87, Could you give us an update?

I have the same oil problem with my AFR190 heads. I wanted to machine the heads as seen in these pics from the corvette forums:

http://forums.corvetteforum.com/show....php?t=1118974

here is a before and after pic:

 

Didn't have time to do much I was away from home for awhile.
The heads are still one my work bench but I did have a chance to get them to the machinist.
Basicaly what I did is to cut about a 1/2" wide slot that was centered over the lower bottom corner of the spring pocket. It was cut using a ball nose end mill and he stayed about 0.040" shy of the depth of the spring pocket for the whole lenght of the heads. (looks like the pics on your link)
I did port the drain back holes, I got them around 0.100'' lower than original.
The other thing I'm gonna do is to change my high pressure high volume oil pump to a high pressure normal volume pump, it sure won't hurt.

So I won't find out before april-may if it's gonna fix my problem (I won't try the car in the snow).

I did contact someone at AFR about that problem twice and by reading between the lines I know that they know about that problem but the only thing they are willing to do is to look at my heads, clean them and install new guides.
They did also offer me a rebate on their new series of heads that are due to come out sometimes over the winter.

Hope this help.

PAT

 

Would you consider reversing the oil pump description. I would use a high volume, normal pressure pump.

 

I'm using a Moroso # 22112 Blueprinted Racing Oil Pump. (high volume, high pressure)

And I will be changing it to a # 22100 Standard Volume Racing Pump.

This will limit the amount of oil (volume) that have a hard time draining back from the heads.

PAT

 

Well Thanks for the update. I just worry about cuting too close to the water jackets on the heads

Keep us posted when on your project next spring.

 

Hey just as an update, the std oil pump never stopped my oil consumption. My next step is to take apart the shortblock, again.