Smoke at start up

[olmate]

The engine in my 2A was rebuilt just over 18 months ago and now runs on unleaded. Runs very well, smooth, quiet and clean out the back. However, regardless of starting clean in the morning, she will start with a puff of smoke in the afternoon. This is only a very quick puff of smoke that seems to occur as she initially cranks and comes to life. She starts very well so it is not much at all, but it is annoying.

I have been told a few things:

1. I need to wait for her to run-in.
2. The rubber seals on the valve ends may be buggered.
3. The oil drainpipe at the rear of the head may be blocked.

Considering that she is over 18 months old and runs well I would have though that she would be over any running-in period. But saying that, I am open to any suggestions or advice as this situation is annoying to say the least.

[vnx205]

On my Series III, it was always the valve stem seals that gave me exactly the symptoms you describe- a puff of smoke at startup but low oil consumption.

The seals seemed to harden and need replacing every couple of years.

[olmate]

That is what I have tended to think the problem is. But as they were not that old I thought it couldn't be and must be something else.
Could it possibly be that the seals are not of good quality and I should look elsewhere for a set? or is this that common that I should just live with it ?

[Rangier Rover]

The engine in my 2A was rebuilt just over 18 months ago and now runs on unleaded. Runs very well, smooth, quiet and clean out the back. However, regardless of starting clean in the morning, she will start with a puff of smoke in the afternoon. This is only a very quick puff of smoke that seems to occur as she initially cranks and comes to life. She starts very well so it is not much at all, but it is annoying.

I have been told a few things:

1. I need to wait for her to run-in.
2. The rubber seals on the valve ends may be buggered.
3. The oil drainpipe at the rear of the head may be blocked.

Considering that she is over 18 months old and runs well I would have though that she would be over any running-in period. But saying that, I am open to any suggestions or advice as this situation is annoying to say the least.
I have a few series still going here and all have done the same. Some times I've found the valve seal part way up the valve :eek: They do go hard quick. I don't worry about mine doing it here anymore as they don't seem to consume much oil.
If your head hasn't got hardend guides they may not be as durable on ulp with no flash lube.
Tony

[JDNSW]

If it is blue smoke it is almost certainly valve stem seals.

John

[olmate]

Thanks Tony / John,
I think that I shall have to learn to live with it also. The head has been done up properly for the ulp conversion so I suspect that the seals have done as you suggest.

[Rangier Rover]

[QUOTE=olmate;847041]Thanks Tony, I think that I shall have to learn to live with it also. The head has been done up properly for the ulp conversion so I suspect that the seals have done as you suggest.

Warning.... Can be a bit embarasing in a car park of near a pub:blush::D
Tony

[olmate]

Warning.... Can be a bit embarasing in a car park of near a pub:blush::D
Tony

I know Exactly what you mean :eek::(

[Aaron IIA]

I will address each numbered point.

1. How many miles has the engine done since the rebuild? Were the valve stem seals replaced? Were the valves replaced? Were the valve guides replaced?

2. When I rebuilt my 2.25L, I could see daylight between the valve stem seals and the valve stems. The engine was not consuming more oil than normal. The valves were a good fit in the valve guides.

3. The oil pipe at the back of the head is actually the pressurised oil feed to the head. The oil drains from the head throught the channels for the pushrods.

I would not be worried about a puff of smoke at start up. If it puffs every time after idling for a while, such as when taking off from the traffic lights, it may get a bit annoying and warrant investigation. If your engine has the later style valve stem seals, the version that are like little cups that slip over the valve guides, they can be changed without removing the head. If your engine has the early style valve stem seals, the O-ring version that sits inside the valve guides, you need to remove the valve, and hence the head to change the seals.

Aaron.

[Rangier Rover]

I will address each numbered point.

1. How many miles has the engine done since the rebuild? Were the valve stem seals replaced? Were the valves replaced? Were the valve guides replaced?

2. When I rebuilt my 2.25L, I could see daylight between the valve stem seals and the valve stems. The engine was not consuming more oil than normal. The valves were a good fit in the valve guides.

3. The oil pipe at the back of the head is actually the pressurised oil feed to the head. The oil drains from the head throught the channels for the pushrods.

I would not be worried about a puff of smoke at start up. If it puffs every time after idling for a while, such as when taking off from the traffic lights, it may get a bit annoying and warrant investigation. If your engine has the later style valve stem seals, the version that are like little cups that slip over the valve guides, they can be changed without removing the head. If your engine has the early style valve stem seals, the O-ring version that sits inside the valve guides, you need to remove the valve, and hence the head to change the seals.

Aaron. Just thinking my 69 11A had the feed line block and stuffed all the rocker gear completely. Had a bit of a rattle at 1st. It gave a heap of warning. But well I kept driving it:angel: We sometimes learn the hard way:wasntme:
Tony

[vnx205]

[quote=olmate;847041]Thanks Tony, I think that I shall have to learn to live with it also. The head has been done up properly for the ulp conversion so I suspect that the seals have done as you suggest.

Warning.... Can be a bit embarrassing in a car park of near a pub:blush::D
Tony
Probably no more embarrassing than starting up a 300TDi and from what I can make out, they are actually designed to blow a small cloud of black smoke on startup.:p

[rovercare]

If it is blue smoke it is almost certainly valve stem seals.

John

^^^That:cool:

Easy repair, just need a fitting to fit the plug hole and add compressed air, then a tool to compress the valve springs, swap the seal and all is well:)

[Aaron IIA]

^^^That:cool:

Easy repair, just need a fitting to fit the plug hole and add compressed air, then a tool to compress the valve springs, swap the seal and all is well:)

Correct if it is the cup seals. It also helps if when working on the cylinder in question, the piston is at top dead centre. If the vehicle is diesel, the compressed air is not needed. If it is the O-ring seals, the head must come off.

Aaron.

[dandlandyman]

I think I have the same problem. I have a new set of valve stem seals waiting for me in Katherine when I get around to it. I seem to recall that they're the same as Ferguson tractor ones.

My smoking, though, only occurs when starting the engine hot. I find it takes quite a bit of cranking to get it started, and then it sends out a short thick belch of smoke. I did find a way around it, but it's completely impractical for everyday use - lift the air cleaner hose off the carby before starting. It seems to percolate fuel in the carby when hot and not running, and the Zenith doesn't have an atmosphere vent like the Holden Stromberg. I'm thinking it saturates the air in the hose with fuel vapour and this makes it hard to start hot. Starting from cold is just fine.

My engine is also about 18 months old, but has always done it. It's on its second set of valve stem seals, the first set shattered like glass when I tried to get them off. Hopefully, the set of MF seals my mate has for me will be heat resistant. I have found out that PBRs black plastic seals (eg. wheel bearing, transmission, timing case) are not heat resistant. Maybe some of these valve stem seals are made cheaply as well.

Dan.
69 2A 88" pet4, 74 3 109" pet4, 68 2B FC pet6.

[olmate]

I will address each numbered point.

1. How many miles has the engine done since the rebuild? Were the valve stem seals replaced? Were the valves replaced? Were the valve guides replaced?
She has done under 8500 miles and in that - only a couple of longer trips as I drive her these days to / from work. Although I haven't looked, I did pay to have all these thing replaced and (fingers crossed) that is what happened.

2. When I rebuilt my 2.25L, I could see daylight between the valve stem seals and the valve stems. The engine was not consuming more oil than normal. The valves were a good fit in the valve guides.
This engine doesn't consume any more oil than normal (although it could do with a change soon). When the head was done - the report back was a positive one.

3. The oil pipe at the back of the head is actually the pressurised oil feed to the head. The oil drains from the head throught the channels for the pushrods.
Thanks mate - this stops that line of thought that I had.;)

I would not be worried about a puff of smoke at start up. If it puffs every time after idling for a while, such as when taking off from the traffic lights, it may get a bit annoying and warrant investigation. If your engine has the later style valve stem seals, the version that are like little cups that slip over the valve guides, they can be changed without removing the head. If your engine has the early style valve stem seals, the O-ring version that sits inside the valve guides, you need to remove the valve, and hence the head to change the seals.

Aaron.

Thanks Aaron for the help. My smoke is only at start up and only a small puff out the back. Nothing a traffic lights etc. I reckon that I shall investigate some new seals to instal over the christmas break.

[olmate]

Thanks all again.

Dan - when you get a chance can you pm me the detail re these seals you speak of and i shall investigate them from this end as well ;):D

[JDNSW]

........
My smoking, though, only occurs when starting the engine hot. I find it takes quite a bit of cranking to get it started, and then it sends out a short thick belch of smoke. I did find a way around it, but it's completely impractical for everyday use - lift the air cleaner hose off the carby before starting. It seems to percolate fuel in the carby when hot and not running, and the Zenith doesn't have an atmosphere vent like the Holden Stromberg. I'm thinking it saturates the air in the hose with fuel vapour and this makes it hard to start hot. Starting from cold is just fine.
..........

I think your problem with starting is probably excessively rich mixture for a hot start, and removing the hose gives a slightly weaker mixture. The rich mixture could have the mechanism you suggest, but I think it unlikely. Another possibility is a partly blocked aircleaner, or incorrect float level, but again, I think these are unlikely. The most likely cause is that the top cover of the Zenith is warped, preventing a good seal on the gasket and O-ring, or the O-ring is not good. I have also had burrs on the screws holding the emulsion block to the top cover prevent the top cover from seating properly.

John

[olmate]

Here we go again folks .... :( And reading what I have previously said I realise that I have been very lazy when it comes to addressing this issue with olmate :o

I replaced my valve seals over the weekend, the head is good and clean now and all has been cleaned up. Well - as the motor was rebuilt just over 2 yrs ago, it should still look like new inside it I reckon.

All adjusted fine and she goes very well up the road BUT still puffs smoke at start-up in the afternoon :mad::mad::mad: Who reckons I am frustrated now:o

So what's next - she starts well in the am, goes like a treat to work and then (when I start her in the arvo to come home) I get a puff of blue smoke before she idles nicely. What to do?? There is no smoke whilst driving or at lights etc its just at the one time in the aro when I start her up :(

Any thoughts out there ?

[Rangier Rover]

Is it a bit cranky when hot or warm? Fuel smoke?

I've given up worrying about it with mine.
They are worse when warm. Seems like fuel smoke. Maybe a trait with Zenith carbys with that notorious warpage on top plate when warm.:(
Mine has the O ring fitted as well.

Tony

[olmate]

Tony,

She is fine; not cranky at all - starts and runs well (less the puff of smoke of course).
I do have a holden carby on it tho, using a paper filter. Running nice and lean without a hitch.

[UncleHo]

G'day Olmate :)

One of the reasons for this is that since these engines were designed 1950's the oil qualitly has greatly improved, and the oils are now generally thinner, 20w-40w, so when hot starting (after use) there will be a small amount of oil that has by-passed the valve stem seals, this is and always has been a design problem with this motor,the original "O"ring was not a success and the umbrella was not a lot better, if it only puffs blue smoke for about 1/4-1/2 sec on startup don't worry, my motor has done this for the last 140,000miles :) I run Penrite 20w-40w everday driving oil, it holds it's viscousity well and gives good oil pressure when hot,and I have had no lube problems, but change it regularly.

Puff of smoke on start up= oil lube to rockers OK :D

[JDNSW]

Tony,

She is fine; not cranky at all - starts and runs well (less the puff of smoke of course).
I do have a holden carby on it tho, using a paper filter. Running nice and lean without a hitch.

What do you have in the way of a crankcase ventilation system? Is it possible you are getting a drop of oil from the crankcase into the inlet manifold on startup that way?

John

[olmate]

Problem fixed....

And I expect to hear the laughter very loud and clear :)

Simple matter of changing the oil (got rid of the flash synthetic stuff) I put the mineral based oil in her and she is as good as gold :D:D:D:D

Thanks Ivan - I thought that I was doing the right thing by using a good quality oil. She is a different car now ;)

[Rangier Rover]

Problem fixed....

And I expect to hear the laughter very loud and clear :)

Simple matter of changing the oil (got rid of the flash synthetic stuff) I put the mineral based oil in her and she is as good as gold :D:D:D:D

Thanks Ivan - I thought that I was doing the right thing by using a good quality oil. She is a different car now ;)

You will save a fortune:D So it has cleared the smoke on a warm start up?
If so you have done very well:D

So you now run a 20/50? I run 20/50 in all my Rangies and Series with no dramas.

Tony