"Reco" heads - blowing smoke on startup

[gerg 10,871]

G'day guys just wondering what you all thought of those "umbrella" type valve stem seals and how well they work on a Clevo. My engine's only 30,000 km old but uses a litre of oil every thousand. Gives a big puff of smoke on hot startup and you can smell the oil in the exhaust at idle. I've got 2V irons with what looked like hardened seats. Could the head reco place have used old worn-out valves and guides? How do the umbrella seals work when they rely on gravity and the oil falling downwards around them yet the valves sit nearly sideways (like on a Clevo)? It's like standing out in the rain with your umbrella tilted at 45 deg.

[Butcha 111]

I've run them and never had an issue with that. I have found the umbrella seals go hard with some synthetic oils. Worn out guides maybe but glazed bores and a blocked pcv not letting blowby out will cause the same thing. Tbh I dont think oil consumption is due to oil getting past the valves.

[gerg 10,871]

Thanks Butcha. Good advice about the synthetic oils... I only use mineral in old gear. Pulled the oil cap while idling, not much blow by at all, PCV works fine, passes the usual test. Engine runs great, revs nicely, plenty of oil pressure. If it is rings, I'll be even more shitty about it than if it's the heads.

[revhead 1,392]

don't forget broken top rings will do the same thing ,

[hendrixhc 10,921]

My Clevo in the  Xc leaks about a litre of oil every thousand km's!

[gerg 10,871]

My Clevo in the  Xc leaks about a litre of oil every thousand km's!

 

Luckily mine's as dry as an arab's fart all over so I've got a good one obviously

[hendrixhc 10,921]

I wanna take mine out and clean up the bay and reseal the main seal and sump BUT we all know how that ends up.

[slydog 7,873]

Chrome in your case and lots of it

[bear351c 10,271]

Ha Ha Ha Ha..^^^^^

[bear351c 10,271]

My guess would be worn valve guides. Are your plugs oily.?

[gerg 10,871]

I don't think so, might pull some later and look. Definitely not fouled (car goes great). Worn exhaust valve guides won't foul plugs as the oil goes straight out the exhaust.

[Butcha 111]

Oil can be drawn in on intake due to vacume at idle and part throttle... oil getting through exhaust usually only leaves a puff of smoke on startup. 1 liter of oil every 1000km is heaps though pour 1 litre on the ground and see. That sort of consumption I would have yhought comes from the rings. Plugs would be very gummed up either way

[gerg 10,871]

Fuck I hope it's not rings. I hate doing jobs twice

[gerg 10,871]

I do tend to drive short trips, as it's only 8 km to work. The big Clevo is barely lukewarm by the time I get there. This means the consumption might be higher than if I was doing a lot of motorway or country cruising. I don't have a problem tipping a slurp in now and then as I get it for shit but I just don't want it to get out of hand. It's a bit embarrassing starting my "old clunker" in car car park full of Hondas and Camrys and getting looks because of the big puff of blue smoke coming out the back

[Butcha 111]

I guess grab a compression tester or leakdown tester an do a dry vs wet test (squirt a bit of oil down the hole) and go from there. maybe get a camera and have a looke at the back of the valves and see if they are gummed up.

[bear351c 10,271]

Good idea. If the valve seals and/or guides are worn, the oil will drip down during the day and sit on the piston, only burning on start up. Rings generally burn oil all the time, or under load. I've used the rubber umbrellas before without issue, although my engine head guy, suggested I machine the valve guides to accept the Chev ones, (metal cap with a rubber seal and a small spring around them). Just couldn't put anything with a "C" in it on my Ford..

[ando76 4,354]

I have seen those umbrella type valve stem seals get 'picked' up by the inner spring or damper in some application and this allows oil to get past and can cause this issue. 

 

I'm not sure of the size of the valve guide boss on a clevo but if it is the same as crossflow and I'm tipping it would be, you can use the stem seals off an eb-ed or late EFI X FLOW as they are steel body with a rubber seal and spring as described by Bear above. 

 

Those umbrella seals just look way too agricultural for me in that they have no way of keeping the seal around the valve tight like the spring ones.  once they are worn they just slop all over the place. 

 

If its only smoking on start up and there is no evidence on the plugs or exhaust of oil deposits then I'd be tipping valve stem seals, perhaps a poor/ old batch.

[gerg 10,871]

Yeah cheers Ando, I found what you described on my old XB motor which has the valve covers off and half of those shitty seals were riding up the valve and the other half were still attached to the guide. Good info on the e-series stem seals too, cheers for that

[ando76 4,354]

I can also get the old style seals that use to come in the ACL race series gaskets sets for X-FLOWS.  They are a great seal and a bit easier to fit compared to the late xf efi/eb seal.

[Ando81 2,949]

I cannot explain why but a mate of mine bought a v8 a while ago secondhand. He put castrol magnatec in it before ever starting it. He put a litre in it before a 2500km service and thought he had bought a dud. Changed to penrite oil and didn't use a drop since. I didn't believe it myself but he swore that it was just a different oil that apparently the engine didn't like. He hadn't changed anything else, just brand of oil.

[BBS XE 160]

I don't touch Magnatec after opening up an engine that had been run with it for years, sludgy coating on everything, blocked up lifters. I'd agree with if it's smoking on start up only it would be stem seals, if it was rings it'd be either all the time or when you nail the throttle in my experience. 

[gerg 10,871]

Yeah that's what lead me to believe it was valve seals/guides in the first place. Maybe I can switch oils next service and see what happens. Last lot was Penrite HPR30 which is 20W60. Lasted allright but when gradually topped up with (I think) Castrol 15W40 or similar it chewed through it much more quickly. I've tried a few different brews, even a mono grade 50 meant for Detroit Diesels. Not a good choice in winter.... It flows like diff oil when cold.

[gerg 10,871]

Having a sticking relief valve in my oil pump made the pressure high all the time and maybe worked the oil too hard, breaking it down very quickly. After replacing that, I'll see if my oil lasts longer.

[Ando81 2,949]

Penrite hpr30 is oil of choice for my crossflow and it loves it

[ando76 4,354]

Having a sticking relief valve in my oil pump made the pressure high all the time and maybe worked the oil too hard, breaking it down very quickly. After replacing that, I'll see if my oil lasts longer.

I doubt high oil pressure would work the oil too hard.  In my experience with these oil pumps the higher the relief, and therefor pressure, the better.  If the relief was stuck low I would say that the oil would have been stressed (and aerated) because the pump would have been relieving internally all the time. 

 

With the relief set higher the oil does not bypass internally and simply leaks out through the engine because of bearing clearances etc.  Whilst the engine is consuming the pressure there would be no internal relieving in the pump and therefor less aeration.

 

If the oil pressure was above 75psi with standard clearances then yes I would say if could stress the oil to a degree and would not be very brilliant for the bearings either. 

 

With a clevo and high pressure, you could have been pumping all the oil to the top end - leaving not enough in the sump and therefor creating a stress issue in the oil.  Without knowing what you have for a sump (more capacity) or whether you have enlarged the factory drain holes in the valley it is hard to say.