What occurred to you is exactly right. Just pull the tube off of the air inlet tube (the vent side of the PCV system) and pull the PCV valve out of the valve cover. The way it's smoking you shouldn't have to even drive it like this to be able to tell something. See how much blow by you have, although with your compression readings I can't believe it's much.
My gut instinct is that it's not a PCV problem but if it is, you'll clearly see the blow-by coming out the PCV and vent openings when you run it like this.
On our 3.4 that had the high oil consumption (and I know you don't want to hear this) it was a valve guide issue on the intake side. I've never seen anything like it before but the valves and guides (which had less than 20,000 miles on them) looked like they had 200,000 miles on them. The exhausts weren't quite so bad. It took new guides and valves to cure the problem. We also went through a valve stem seal replacement and like you, it helped some, but not alot.
This sucks, it makes me depressed for you just thinking about it.
John Stricker
quote
Originally posted by Will:
For the PCV, the manifold and corresponding valve cover connection were been capped. I left the other side of the PCV system hooked up. I know I need to do things differently... I'll see what I can rig up for a trap to hook both sides of the PCV system to, so that I can eliminate it as an oil path entirely.
It occurs to me that with the cam cover connection capped, blow by from un-seated rings might pressurize the crank case and blow oil out the other cam cover connection and into the throttle body, since that side of the PCV connects to the intake ducting immediately upstream of the TB.
It occurs to me that with the cam cover connection capped, blow by from un-seated rings might pressurize the crank case and blow oil out the other cam cover connection and into the throttle body, since that side of the PCV connects to the intake ducting immediately upstream of the TB.
My last Iron Duke did this. Even with the PCV running there was so much blowby it would blow oil out a similar breather on the valve cover into the air cleaner. There was enough volume to run a good size air tool.
On my new Quad 4 when I disconnect the crankcase breather (on the timing chain cover) from the oil separator suction there only a wisp coming from the crankcase. I'd think you could do the same. Plug the PCV and let the other vent go to atmosphere and see what comes out. My bet is there isn't much there given your compression numbers.
You can't run a Northstar without valve covers, for all practical purposes. The water pump drive shaft comes out the back of one of them and they seal the openings for the spark plugs, unless I misunderstood your mention of taking the valve covers off.
Personally, I'm thinking lose valve guides/valve stems that's taking out the seals, but Will should find out soon enough.
John Stricker
quote
Originally posted by The Punisher:
I am thinking either too much crankcase pressure or the valve seals are still leaking.
I say vent the pcv to atnmosphere. See what happens.
or take the valve covers back off and you might need to put all new seals in again.
Sorry if I missed this in the earlier postings but.... Did you put the plastic sleeve over the valve stems when you installed the valve seals? It is used to protect the seals from being cut by the retainer groove in the valve stem. If you didn't then you may have damaged the seals the second you installed them. Second, when you had your intake manifold off did you look to see if there was any oil in the ports? If so how far up did it go?
I have to be in Norfolk for 2 weeks for Navy stuff... Fiero's going on hold for a little while.
------------------ Turn the key and feel the engine shake the whole car with its lope; Plant the gas pedal and feel in your chest neither a shriek nor a wail but a bellowing roar; Lift and be pushed into the harness by compression braking that only comes from the biggest cylinders while listening to music of pops and gurgles. Know that you are driving and American V8. There are finer engines made, but none of them are this cool.
Luck, Fate and Destiny are words used by those who lack the courage to define their own future
Originally posted by Will: Turning the crank 7 times turns the cams 3.5 times... so the right bank and left bank would have been 180 degrees out from each other.
After thinking about it a bit, I realized that because the N* uses waste spark ignition, it probably would have run with one bank 180 degrees out from the other... It just would have run like 4 Harley's behind me all the time. With the banks our of phase like that, it would have been like a collection of 4 V-twins all the time.
------------------ Turn the key and feel the engine shake the whole car with its lope; Plant the gas pedal and feel in your chest neither a shriek nor a wail but a bellowing roar; Lift and be pushed into the harness by compression braking that only comes from the biggest cylinders while listening to music of pops and gurgles. Know that you are driving and American V8. There are finer engines made, but none of them are this cool.
Luck, Fate and Destiny are words used by those who lack the courage to define their own future
When warm the car doesn't smoke on heavy throttle, smokes somewhat on coast down/high vacuum conditions and blows LOTS of smoke at light throttle/tip in from coast down/blipping throttle from idle...
Allen Cline thinks that the oil rings are not working correctly. He says that there's enough reversion in the intake port at light throttle to throw oil up into the intake runners where it flows back down and pools on the intake valves after I shut the engine down.
This generally jives with what I see... as the times when it's smoking worst are the times when the rings are unloaded, rather than high demand on the valve stem seals.
My dad remembers reading an article in a recent car magazine that didn't have much faith in Total Seal oil rings... He's looking for it now.
I will also shortly be put in touch with a guy in the Miata community who's done 3 or 4 engine builds with TS rings and they all smoked... I'm going to compare signs and symptoms with him to see what we can decide is up.
So if my suspicions are confirmed, I may end up tearing the engine back down, ditching the TS oil rings and replacing them with GM oil rings, while keeping the TS top and 2nd rings...
------------------ Turn the key and feel the engine shake the whole car with its lope; Plant the gas pedal and feel in your chest neither a shriek nor a wail but a bellowing roar; Lift and be pushed into the harness by compression braking that only comes from the biggest cylinders while listening to music of pops and gurgles. Know that you are driving an American V8. There are finer engines made, but none of them are this cool.
Luck, Fate and Destiny are words used by those who lack the courage to define their own future
The manual calls for 140-170 psi cranking pressure and my engine has 190-200.... I think the gapless ring concept works... just needs some ironing out.
Allen Cline is of the opinion that there's enough reversion at part throttle to lift oil into the intake ports, where it would pool on top of the valves at shut down. This is what I was experiencing. I tried shutting the engine down at WOT once and after pulling the intake found no oil on the valves, however after a shut down from idle the valves would have half a teaspoon or so of oil on the back of EACH one.
Talked with Total Seal and the machine shop who originally honed my block... The block was honed with 400 grit stones, almost certainly silicon carbide. This does not work well with the Northstar as the hard silicon carbide stone against the hard cylinder liner produces a very shallow pattern. TS recommended an aluminum oxide stone not finer than 280 grit.
In an amusing note, the Haynes manual for overhauling Chevies said to hone the block to 400 grit for cast or moly rings, but not finer than 280 for chrome faced rings. The TS rings are chrome faced. So even Haynes says it's wrong... <chuckle>
The plant where my dad works has a profilometer which we can use to measure the cylider finish on the bores. That way I will have hard data to use in working with TS to get this engine to seal.
I'll be pulling the engine and tearing it back down in the next couple of weeks.
------------------ Turn the key and feel the engine shake the whole car with its lope; Plant the gas pedal and feel in your chest neither a shriek nor a wail but a bellowing roar; Lift and be pushed into the harness by compression braking that only comes from the biggest cylinders while listening to music of pops and gurgles. Know that you are driving an American V8. There are finer engines made, but none of them are this cool.
Luck, Fate and Destiny are words used by those who lack the courage to define their own future
Jstricker: what TSB's will I need to properly overhaul a '95 engine?
Thoughts?
i have a question for you.. is this a VIN 9 or a VIN Y ? if its a VIN Y, i have a set of VIN 9 heads and camshafts for sale, i'll sell them to you dirt cheap, as i need to get them out of my garage to make room for some 4.9L heads to work on for my 4.9L caddy. they are out of a 2000 seville STS, and only have 16K miles on them.
[This message has been edited by aaronrus (edited 10-14-2004).]
Very interesting Will. Dang... a profilometer, now that's blingin' measurement equipment! This is definitely one hell of a troubleshooting session you've been through so far, good research and good contacts!
i have a question for you.. is this a VIN 9 or a VIN Y ? if its a VIN Y, i have a set of VIN 9 heads and camshafts for sale, i'll sell them to you dirt cheap, as i need to get them out of my garage to make room for some 4.9L heads to work on for my 4.9L caddy. they are out of a 2000 seville STS, and only have 16K miles on them.
Are you still trying to sell those heads? I'll stick with the flat tappet valvetrain until I can get my hands on a VVT engine...
No work was done on the Fiero since Friday 22 OCT, as I was on a brief float with the Kearsarge last week. However, today I got the engine down on the ground and will tear it down tomorrow and get the cylinder surface finish checked and maybe get it rehoned by the weekend...
<mental note: call Total Seal and get the P/N of that stone you it can be ordered tomorrow> <mental note 2: find out about reusing N* head bolts with time serts wrt difference between $50 each GM gaskets with bolts and $30 fel pro gaskets without> <mental note 3: order said gaskets in addition to new front and rear main seals and new w/p gasket which was missing last time> <mental note 4: order more Loctite 518 (anaerobic goo for case half seal)>
------------------ Turn the key and feel the engine shake the whole car with its lope; Plant the gas pedal and feel in your chest neither a shriek nor a wail but a bellowing roar; Lift and be pushed into the harness by compression braking that only comes from the biggest cylinders while listening to music of pops and gurgles. Know that you are driving an American V8. There are finer engines made, but none of them are this cool.
Luck, Fate and Destiny are words used by those who lack the courage to define their own future
Originally posted by Will: <mental note 2: find out about reusing N* head bolts with time serts wrt difference between $50 each GM gaskets with bolts and $30 fel pro gaskets without>
The N* head bolts need to be replaced if the head(s) are ever removed. That's why GM includes them in their gasket kits. Is saving $20 worth having do do this yet again?
GM cautions to not reuse the head bolts because they have a sealant on them that keeps the coolant out of the thread interface. This extends the life of the aluminum head bolt threads in the block. However, my block has time-serts in all 20 head bolt holes. There are no longer aluminum threads to worry about. Is the sealant still necessary?
From a fatigue standpoint, the head bolts are reuseable. The reason GM says to not reuse them is only a function of the thread sealant.
Or maybe I'll just not worry about it an spend an extra $200 on ARP head studs...
------------------ Turn the key and feel the engine shake the whole car with its lope; Plant the gas pedal and feel in your chest neither a shriek nor a wail but a bellowing roar; Lift and be pushed into the harness by compression braking that only comes from the biggest cylinders while listening to music of pops and gurgles. Know that you are driving an American V8. There are finer engines made, but none of them are this cool.
Luck, Fate and Destiny are words used by those who lack the courage to define their own future
[This message has been edited by Will (edited 11-02-2004).]
Got the engine apart last night. I've heard that you should be able to feel a good hone pattern by running your fingernail over it, more so in the way up than down. I didn't feel much of anything, but I still have oil on my cylinder walls.
Should be able to get ahold of the profilometer in the next couple of days. Anyone know of a GOOD machine shop anywhere in VA or even MD or southern PA that would be willing to work with me extensively to get my block honed correctly? I'd supply the stones I'd want them to use, and I'd double check their work directly with a profilometer.
didn't realize you were so close to home.. i can't really recommend a machine shop - it usually depends on the specific employee of the shop for the service..
on a side note - you gonna make it to MIR sunday? "baltimore area fieros" trying to get a good showing of fiero people - lildevil and soulcrusher will be there.
Had no plans to go. Going to a Fiero event without a Fiero is just going to give me Fiero jones in addition to my current V8 jones and stick-shift jones.
Got a "maybe"... Talked to a guy who does two ring Miata engines with TS rings... he said that 4.6 Ford mod-motors will exhibit oil consumption similar to mine if the engine is not honed with a torque plate. Since we can make a torque plate here, there's no real reason not to try that. I'll talk to AJ about it...
Since we can make a torque plate here, there's no real reason not to try that.
Profilometers...and torque plates...and hone stones, oh my! It's pretty obvious you're not screwing around. I'll be interested to see what comes out of all this, thanks for documenting so much of your leg work, it'll come in handy to many of us in the future.
I talked to Alan Johnson and he said that the torque plate wasn't necessary, but that it couldn't hurt. The first shop he had hone his blocks used a torque plate, but had a tendency of stripping head bolt threads and not telling him about it. The next shop he got to hone things doesn't use a torque plate and he hasn't had problems.
Originally posted by Will: There are no longer aluminum threads to worry about. Is the sealant still necessary?
I have no idea. Everyone I've talked to has said to get the headgasket/bolt set from GM, no matter what... And (of course) to use timeserts. In summary, I have no idea what the f*** I'm talking about... but if I were rebuilding it, I'd use the new bolts that come in the GM kit.
Since I asked that, I've been in touch with Allen Cline, and he says that the sealer is a Loctite product with two purposes... high pressure lubricant to lubricate threads as the bolt is being torqued and thread locker to prevent the bolts from backing out. Apparently aluminum blocks (or maybe just threads, don't know which) can spontaneously back out, which is why the lube/locker stuff is there. The head bolt cavities are sealed by the head gasket, so there shouldn't be any coolant in them anyway.
Finally made sense of something I had been noticing every now and then... shoulda looked harder at it a long time ago.
My bores are patchy. I had been dismissing it as a trick of the light until recently. Anyway, the bores have bright and dark patches. The dark patches are were the cylinders have been burnished... that's partially burnished... So the shop that honed it really screwed the pooch, only I didn't know what to look for until some time later. Upon closer inspection, catching the light on the bores showed me that the dark patches are much smoother/shinier than the bright patches.
Now that I have a concrete image of what's wrong, fixing it is much easier. This is why the profilometer was giving inconsistent results. The surface finish actually is that inconsistent.
Also put in a drawing for a torque plate. That should be lasered out next week, after which I'll have to drill the head bolt holes and surface grind it flat. This particular laser is somewhat old and can't do a good job cutting a hole smaller than the thickness of the material it's cutting, which will be 3/4" in this case.
So once the torque plate is done, I'll take it to a shop that's been recommended to me by multiple friends and get them to hone it with the stones I bought.
Once that's done, the block will have enough clearance for forged pistons, so I'll have to make a decision. That decision will be partially based on the outcome of my interview with Sunoco next week.
When warm the car doesn't smoke on heavy throttle, smokes somewhat on coast down/high vacuum conditions and blows LOTS of smoke at light throttle/tip in from coast down/blipping throttle from idle...
Allen Cline thinks that the oil rings are not working correctly. He says that there's enough reversion in the intake port at light throttle to throw oil up into the intake runners where it flows back down and pools on the intake valves after I shut the engine down...
I’ve heard of something like this before. I remember reading about Corvette owners that were complaining of high oil consumption. After some investigation it was found that at high rpm under light throttle conditions oil was seeping past the rings and getting burned. If I recall correctly there was a replacement ring designed (or found) to fix the problem.
From reading your posts it doesn’t seem likely that this was exclusively your problem but it may be something to double check. I can’t remember where I read the article, but I did find this, that collaborates my story.
Yes, I remember that. Under conditions of high ring loading (heavy throttle or engine braking), the rings were fine, but at high RPM, light load conditions when there wasn't much ring loading, the rings would flutter and allow oil past. GM didn't pick that up because no sane person drives in such a way as to spend a lot of time at high RPM light load conditions...
I'm pretty sure my problem was all in my bores. I'll try to get a picture of what I am talking about later this week. It may not show up well in a picture, though.
