[harvs]

[Scrawny]

There won't be any issues changing to qld rego.

[stocker]

Let the rings bed in a little longer

[foolsp33d]

what colour smoke?
how much of a rebuild did you do?
valve stem seals get replaced when you done the rebuild?

[harvs]

I'm not about to rip it appart just yet, I've got a wheelin expedition comin up in 2 weeks that I need it running for.

what colour smoke? - Blue, it's oil...
how much of a rebuild did you do? - Pretty much everything, wasn't bored out though, just a hone.
valve stem seals get replaced when you done the rebuild? - Yes, was done by the cylinder head joint though that machined the head (I was lazy and couldn't be bothered assembling myself.)

I'm just thinking, if the stem seals were nicked or something, then surely it would blow smoke on start? (has always done that to me on other cars.)

If it was the rings not beded in yet, wouldn't it smoke at least a little bit at idle?

Good to hear about the rego, I was kind of worried about that.

[Rusho]

What grade oil are you using?

[mnemonix]

A lot of new engines will smoke on decel until they're bedded in. They can be completely smoke free at idle and during accelleration.
The engine vacuum while decelerating causes oil to pass by the rings.

How long it will last depends on how coarse the honing was, and how hard the rings/cylinders are.

If the engine appears otherwise OK and the oil use isn't excessive, I'd carry on driving with 500-1000km oil changes for the short term.
Then reassess if things have improved or deteriorated.

[foolsp33d]

have you stuck a compression tester on the cylinders since the rebuild to see if there is a drop in a particular cylinder?

Have you contacted the place that redone the head to inform them its blowing smoke? is its possibly that a guide was nicked reinstalling and is leaking oil into the exhaust manifold?

[Scrawny]

Can you stick a trailer on with a load or just load up the cargo area? That would give you extended WOT which may help bed the rings in. Who did the head rebuild?

[Shansh]

im gonna ask a stupid question, not being a smart arse either but did you make sure that the gaps in the rings were staggered when you put the pistons in?

[harvs]

Few questions there:

Oil grade - 10W30 - it's what Suzuki recommed for this engine in this climate.

Just did a compression test then, they're all looking pretty good and within 5psi of each other. However there is a difference in the amount of plug fouling between the cylinders. 2 the worst, 3 the best, 1&4 somewhere inbetween. However it's obvious the oil is getting into the cylinders, not just into the exhaust ports.

Yes, I certainly staggered the rings. Had to file them to get them to the minimum allowable gap as per the FSM. So they should be right.

mnemonix - I like your suggestion I guess I'll just see how it goes over the next 1000kms. The compressions definatly have increased over the last 1000, so I guess it's just bedding in. Going down through the gears leading up to a round about then accelerating is enough to cover the road in thick smoke. Not so good.

Nar I don't really have a trailer. But I do have a beach drop it in 4 LR and its pretty close to WOT. Did a fair bit of that yesterday.

[Shansh]

2nd stupid question, whats WOT stand for?

[Scrawny]

Shansh wrote:

2nd stupid question, whats WOT stand for?

Wide Open Throttle

[Shansh]

of course, its obvious now, cheers...............

[harvs]

I've heard a lot stupider questions in my life...

[Scrawny]

I still think its too soon to be worrying about it.

[harvs]

^^^ Cool, I thought a 1000kms was a fair while. I'll give it a few more then and see what happens.

[FullyZooked]

Scrawn wrote:

I still think its too soon to be worrying about it.

Hmmmm. I too would be worried.

For the engine to be pulling that much oil to produce that much smoke even after 1000km's I would also think issues. Takes breath...

First issue I see here(given there is indeed shitloads of smoke on deccel) is oil on cylinder walls vs rings trying to seat. But you say you have good compresson. What sort of PSI are we talking? Hot or cold, wet or dry?
I find it hard to believe the rings are the culprit being that the car runs well and does not produce smoke even when under load and light cruising.

I would be more inclined to say valve stem seals for the win.
Valve stem seals in alot of cases won't rear there ugly heads until under decceleration. The seal is tight enough at idle and shut off but as soon negative pressure is present they will pull oil past and give some pretty healthy smoke out the arse end.

Keep us updated. I am keen to see what you find.

[royce]

I am not going to type that the oil rings play not part in compression and the compression rings play not part in oil control again cause its on my list of things I am sick of saying


You say you honed it only, didn't you have this problem before you rebuilt it? how round did you measure the bores as? what was the cylinder to piston clearance like?

[stocker]

It could also be a sign of incorrect timing...

Could try sticking at timing light on it.

[harvs]

Timings is setup. No drama's there.

Compressions are about 170 cold and dry. I haven't had the chance to do it properly yet. But given 170 is the minimum when hot, I'd say it's only going to be better when the engine is warm.

No I didn't have the smoke problem before. I really tore it down to fix the copious oil leaks more than anything, that and the compressions were a bit low.

Piston to bore clearance - to be honest, my gauges were struggling to measure it because it was so tight. But considering the pistons that were taken out had only the slightest scuffing on them and the bores weren't even marked (orginal honing marks still clearly visable), I figured it couldn't hurt to replace the pistons with the same size (I did measure), new rings and give it a quick hone. I didn't get over excited with the hone, just enough to give a consistent cross-hatch pattern over the bores. It's never failed on me before, and I stuggle to see how it could fail this boldly this time.

[zooky08]

Doesnt matter if the bores still showed the crosshatching. The bores could still been oval shaped. I assume you checked for oval shaped bores right?

[harvs]

yeah as much as I could, as I said, my gauge wasnt having the best of times with this engine. And it didn't burn oil before...

[Scrawny]

Oval bores would show up at other times too

[harvs]

I guess at the end of the day, it doesn't really matter. I'll give it a while, and either it'll clear up or I'll have to rip the engine out and start investigating.

There's no chance of changing valve stem seal in the engine with this casting, and to take the head off you may as well pull the engine out.

[royce]

did the head shop test the head?

its not something stupid like the master cylinder spitting it and filling the booster?

[harvs]

They tested it for cracks if that's what you're talking about.

Gees now that is out of the box thinking. However I can't fathom how a split master cylinder (brakes?) could end up with engine oil in the combustion camber? Brake fluid level is fine if that's what you're talking about being sucked in?

[royce]

master cyl dies, leaks fluid into booster

booster is connected to inlet manifold, sucks fluid in and gets burnt

[atari4x4]

brake fluid makes a wicked smoke screen.

[harvs]

Thought that was what you're talking about. But 1000kms and the brake fluid level is still spot on.