410 cubic inch oil burner - UPDATE... it's the guides

[471_Magnum]

Had the small block running for quite some time now. Definitely had a few teething issues, but generally speaking, it runs like a scalded dog.

On the down side, I've got a major oil consumption problem. Originally I though I had a bad stem seal, then I thought it might be an intake gasket, now I think all of the valve seals might be crap. Here's all the background from moparts if you want to get the full history:
http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=6784171&an=0&page=0#Post6784171

So now I'm wondering if the valve seals were spec'd out incorrectly. Getting ready to contact the shop that sold me the heads, but I need to get my ducks in a row.

From what I can tell, Manley valves and seals were used. The valves measure .371 on the stem. From what I can tell, it has 3/8 Manley Viton seals.

I'd be interested in getting some insight from others on the issue.

[Chryco Psycho]

when does it smoke or does it smoke enough to tell , ?
The steel body rubber liner seals are probably better then the Viton seals which are probably white nylon with a spring wrapped around

[471_Magnum]

You can see a picture of the seals on Moparts. They are blue, and I'm fairly certain that they are from Manley.

It smokes pretty much all the time, more so under load. Really not noticeable at idle though. The oil pooled on the tops of the intake valves pretty much makes the path of entry a no brainer, especially considering the lack of oil residue in the port, and the obvious compression I'm getting on the intake gaskets.

[Chryco Psycho]

it would be obvious if oil is coating the back of the intake valves . has tobe coming down the guides .
Moparts punted me as a member about 8 years ago , numerous emails & never a reply as to why, I never started any fights just answered questions as I do here  , I cannot log in but my user name is in use . I never visit anymore for any reason .

[471_Magnum]

Today I confirmed they are Manley valves and seals.

Manley tech support confirmed they should be the right combination. The only theory they presented was the possiblity that a .500" guide OD seal was used on .530" guide or vice versa. That would stretch the seal ID, or allow oil underneath for each respective condition.

The seal OD I checked last night was about .671, which is the diameter given in the Manley specs for a .530 seal.  Not sure either condition is even possible. A .500 seal over a .530 would be a lot of assmebly interference. A .530 seal on a .500 guide would leave the seal riding the valve stem (which I'm not seeing).

I'll have to pull a spring tonight to confirm those dimensions.

[Challenger340]

For anybody who has ever tried(by mistake obviously when seals get mixed up), Pretty darn tough to get a Seal designed for a .500" guide to actually GO ON a .530" diameter Guide ?Pretty much destroys them in the process...
and,
a .530" Seal would fit so loose on a .500" guide I suspect it would just flop up and down on the Valve during running ? Should be pretty easy to spot when you remove your Springs and take a 'boo....

Either way, Oil leaking by a Intake Valve Guide or Valve Seal will manifest itself most, at times of highest Engine Vacuum, typically when the throttle plates are closed, ie; Decel, Idling, or high speed cruise with the Plates just open.
Wide open Throttle, or times when you nare "loading" the Engine are LOW Vaccum, less tendency to pull Oil down through a faulty Intake Guide or Seal.   

[471_Magnum]

Just checked the seals. They look to be correct, although the fit is looser than I would have expected. I was able to press the one I checked back in place with just my finger tips.

Guide OD checked a couple thou small at .526. Since the seals have been run for a bit, as well as removed for inspection, there wasn't much interference left, but definitely some. Probably about 10 thou on the valves and to the seat.

It smokes all the time. No doubt there. I have had a guy flag me down on the highway to tell me. Embarrassing.

So... what next? I've checked everything I can think to check short of pulling the heads again to check all the valve guide clearances. If I have to go down that road I'm really going to be tempted to just chuck these things and get me a set or RHS X-heads.

[firefighter3931]

I've seen faulty PCV valves pull oil into the chamber....in one instance the engine had a vacuum port on an intake runner and the PCV was connected (incorrectly) to that port. Lots of oil fouling on that plug ! 

First i'd try running it w/o a PCV to see if that eliminates the problem.

How much guide clearance were these heads set up with ?



Ron

[471_Magnum]

I've seen faulty PCV valves pull oil into the chamber....in one instance the engine had a vacuum port on an intake runner and the PCV was connected (incorrectly) to that port.

If it were a PCV issue, I've got to believe that I'd be seeing other symptoms, like external leaks, or oil blowing out the breather.

How much guide clearance were these heads set up with ?

Dunno, but I can wiggle the stem slightly in the guide.



Ron
[/quote]

[Challenger340]

If they are Single Sealing Lip type Valve Seals, even removing them once, they are ruined.....others are more forgiving.

Like Ron says....eliminate the PCV thing, or baffling in the Valve Covers.....

Try to nail down WHEN, it burns Oil the WORST as a condition,
then,
Relate that to HIGHEST ENGINE Vacuum, as to when it is SUCKING the Oil into the Combustion Chamber and you are seeing the blue !

Wide Open Throttle...LOW Engine Vaccum....probably NOT Guides or Seals but more probably RINGS.

Throttle Plates closed at IDLE....HIGH Engine Vacuum......will suck Oil through anywhere it can...Guides, Seals, Intake Gasket, etc., etc., but may not be BURNING much blue due to Cam reversion.

Light Part Throttle Cruise......HIGH Engine Vacuum.....will suck Oil in and BURN it due to rpm present

Big Camshafts compromise diagnostics due to lower vacuums present...but still determinable if you watch.

[471_Magnum]

I'll replace the seals before I put it all back together.

I've got stock VCs and PCV system. If I were getting too much crankcase pressure, I'd have oil coming out elsewhere. This motor has NO external leaks. Ironically seems to be the tightest motor I've ever built.

It does most of it's oil burning cruising down the highway, so high vacuum. Not noticeable at idle.

[mauve66]

get a set of them clear valve covers and then you can watch what its doing while in action

[Musicman]

If I were getting too much crankcase pressure, I'd have oil coming out elsewhere.

I believe what they are saying is that engine vacuum may be "pulling" this oil out of the crankcase and into the manifold via a faulty PVC valve or system. Removing the pvc setup and replacing it with a breather on each valve cover will answer this question.

[471_Magnum]

Manifold is dry. The oil is running down the valve stems. The oil I see pooling is getting their AFTER the motor has shut off. Think about it. If it's a PCV issue or intake issue, it's only going to leak while running and that oil will get sucked straight into the combustion chamber. Wouldn't have a chance to pool on top of the valves.

Gotta be the guides/seals.

[471_Magnum]

Pulled the heads. Checked the clearance on the #5 intake which seems to be the worst offender.

Found 12 thou of slop in the guide and visible wear on the stem.

Rocker tip wear pattern is dead nuts on, so that's not the problem. Those guides must have been loose from day 1.

[Chryco Psycho]

.012 is just a little excessive !!
.003 -.004 on the exhaust guides which require extra clearance for the heat would be closer

[Challenger340]

What type of Guides, Cast Iron, Silicon Bronze, Bronze Liner ?

[471_Magnum]

Bronze.

[471_Magnum]

So the heads when back to the shop that I bought them from shortly after my last post on this thread. Six weeks later I got them back with pretty much new everything.

Put them back on the car and drove the car as much as I could these last couple weeks. Not very much really. Less than a tank of gas.

It's burning some oil with smoke under heavy acceleration, has a valve "tic", and an intermittant "pop" through the exhaust at idle. Pretty much same shit, different day.

Pulled a valve cover today for a closer look. Removed the rocker shafts to reveal a wear pattern on the tips that indicates no valve rotation. The #2 exhaust valve is actually starting to gall on the tip. Plenty of oil up there though, and no significant wear on the shafts.

Looks like the valve guide clearance was fucked up again. I'm sure dis-assembly will reveal wear on the stems. Probably won't get into that until next week.

So needless to say, I'm done doing business with these guys. I'll be calling them Monday to see how they want to handle it from here, but I'll be satisfied with nothing less than a refund. Considering how much time and money I've put into R&Ring these heads, and the downtime associated with it, that's pretty generous. Whether or not I get restitution in any form remains to be seen.

Stay tuned.

[elacruze]

oil smoke under load usually means poor ring seal and high crankcase pressure, pushing oil into the PCV or past the rings into the combustion chamber. If your piston tops are clean around the edges but black in the center, that's one indication of oil passing the cylinder wall.
Poor oil control at the valves usually presents as smoke at start-up and while idling, and when first throttling away from idle.

Have you had any significant detonation? Detonation blows the lubrication off the cylinders/rings and can scuff the walls ruining ring seal and pressurizing the crankcase. Oil in the combustion chamber reduces mixture octane, making detonation more likely too.

[471_Magnum]

It'll be the guides.

I had oil pooled on top of the intake valves previously. I'm sure I'll find the same once I pull the intake again.

[elacruze]

It'll be the guides.

I had oil pooled on top of the intake valves previously. I'm sure I'll find the same once I pull the intake again.

Haven't thought about it in a long time, but improperly installed guides in Harley-Davidsons would pull oil between the guides and head; there's a lot more oil to pull, too, at the base of the spring. After cleaning, maybe use duct tape and a shop vac to check it. Maybe the shop's prep wasn't too good.