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Discussion Starter · #1 ·
I hoping I can get some advice to fix an on going oil issue.

It's a LONGGGG story. I'll try to keep it as short as possible.

I was running a single turbo SBF (3.4 stroke/5.4 rod) 100% street car for about 10 years. I decided to freshen it up and switch to twin turbo.

In the past 3 years the engine/s have been rebuilt with different parts with the same outcome 5 times (yes FIVE times), oil on top of the pistons and intake ports.

First 4 were built by a competent builder. 2 of the 5 builds were ran and broken in on the dyno in NA carb form with no oil on the top of the pistons. The last build I assembled. All 5 ended up with the same result.

Builds have used 2 different blocks (R block and currently Dart Iron Eagle). 2 different cranks (Eagle now currently Callies Magnum). 2 different 9:1 pistons (Gibtec and currently JE).
2 different oil pans (Canton Pro Drag pan and currently Moroso). 2 Victor carb/FI intakes (brand new intake just installed). All builds used Melling HV oil pump. Twin turbos were brand new Precision-not the cause of the oil-both turbo cold sides are bone dry as is all the cold piping right up to the TB.

Each build had a different set of rings tried-all Total Seal. Gibtec piston used thin rings- I will have to check the paper work but around .040-.043 from memory and from memory 2mm oil. (My memory and wallet is shot from all of this). Oil rings were 12lb than 15lb. Thin rings were AP top. Builder has profilometer and stated all the numbers were spot on. After the 2nd build I questioned the thin rings and requested the JE pistons with 1/16 and 3/16 rings. The JE's were the exact piston I was running with no issues for 10 years, other than being .010 larger. I also requested moly coated top for the 3rd build as that had worked in the past. New oil rings were 18lbs, than went to 21-22lbs on the 4th build. I took it apart and had it honed a local shop and installed 22lb oil rings this lat try. Same out come. Massive oil. Excessive amount of smoke coming out of the tail pipes, especially after I made a quick pull. I believe it is vacuum related, that's why it never smoked on the dyno.

I have showed all the parts to many good people. No one could find anything wrong.

The TW heads had no issues on the previous build. They were gone thru but a top guy in the field and spring pockets were milled down to make room for taller springs to match the new solid roller going in the new build. All the original guides were good, as were the intake valves. New inconel exhaust valves were installed. They were dissembled MANY times during all the builds, with new blue Viton seals installed each time. No one could find any issues with the heads. The intake rocker hold down bolts were removed and resealed about 8 times between the builds and me checking everything.

Intake gasket has good crush, even went as far as buying new intake to take that out of the mix. No change.

Car is fuel injected. I did not wash the cylinders down ever. Tune is closely monitored. Even went as far as installing 8 EGTs. Engines all ran great, but was afraid of breaking something from detonation, a lot of oil. I never really ran it hard.

Just before I pulled the engine I took the intake off. I cleaned the intake ports on the head and intake. Reinstalled intake and ran it for 6 miles total. Pulled the intake elbow and seen oil in all the head intake ports. Center of intake under carb pad was dry, so not reversion.

I went as far as installing a GZ vacuum pump to hopefully band aid the oil so I could at least enjoy it. The visible smoke from the tailpipes disappeared, but similar amount of oil on top of piston.

I don't know how it is even possible, but I feel the oil is getting past the rings. There is way to much oil to be coming from the guides. Intake gasket has good crush. Even went as far as pulling 30" of vac in the intake with the intake rockers off. It took about 30 minutes to slowly go down to 0. Did the same with 30psi of air pressure.

I'm sure there will be a ton of questions. I didn't want to make the post to long to start with.

Here are a few pictures from the last tear down 2 weeks ago when the engine had 500 miles on
it: Just a note on the intake gasket picture: head ports are larger than intake ports. I believe the oil was getting wicked up from reversion.

I'm hoping something jumps out for someone.

Thanks in advance for any help!!!!

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Discussion Starter · #3 ·
How short is that piston?
Piston is 2 1/8". At BDC sticks out .370" at lowest point. I just measured the original JE pistons from 13 years ago, the same 2 1/8"

The coated piston is the Gibtec from first 2 builds
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X2 on the rocker arm stud going into the intake port.
 

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Hone looks terrible. Profilometer is no guarantee the hone is good.
Might be a little suspicious about the spring pads being cut. You said you vac/pressure checked the intake but in a static condition they might seal up. If they broke through, even slightly, or are cracked, might be a different story when running with springs dancing around. Just thinking out loud...
Napier oil ring?
 

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You've answered your own question really, the only thing that hasn't been changed are the heads- I would look there . I would get the heads pressure tested hot, cracks can often be sealed until the heads heat right up. I had an iron block that was fine up 'til 190f, but as soon as it got to 200f water started to spray from two cracks just under the heads. I had pressure tested it a couple of times but only when cold..
Pic 4 looks like a crack in the runner floor , maybe just a scratch.
 

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my 2 cents,, are the pistons suppose to have a buttons when the oil ring is exposed to the piston pin bore ? Sounds as if the prob begin when you went to TT. Are the turbo's mounted low in the car? and where did you run the turbo oil drain back lines to?
 

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The oil ring has the support rail on it , you should plug the PVC valve and see if that fixes the oil problem
 

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I would get someone to double check the valve guides. Earlier TW heads were already known to have guide problems.

Its also possible that they could have been damaged when the spring seats were enlarged.
 

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I've chased a similar problem - only to find it was the PCV valve.
 

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I don't know what that hone is, but I doubt it had a profilometer on it....

Also... twin turbo? Take the pins out and look at the pin bores. Those are not twin turbo pins and that piston is oil-canning guaranteed. Probably still not the oil issues however but your ring seal is junk with those pins.

Also I know they are telling you the rocker bolts are sealed up but it would be nice to see some residue for proof.... look pretty dry to me other than the oil in the threads....
 

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Discussion Starter · #20 ·
Does the rocker bolt go trough to the intake runner?
Yes intake rocker bolts go thru into intake port. 5 builds with rockers removed and reseal many times on top of that. Tried all different types of sealers. This is gray rtv. Last try just before disassembly I went as far as wrapping the bolts with gray megatape AND generous gray rtv on the threads in the head and the bolt also.

Also the hold downs sit flat on the pads. Put a bit of rtv under the head of the bolt last go around. Every time I remove valve covers the oil will be sitting on the bolt head/hold downs like in picture
.

I do wonder if it can be the oil getting past the bolts??? I'm not sure if I didn't put any sealer on the bolts, there would be that much oil getting past??

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