Smoke after gasket replacement

[Ryperd]

Firing order? Take a pic of the dizzy and sparks that I can se the layout?

Here you go:


The leads aren't long enough to make a 1342 configuration, but in any case, if it starts at 1 and rotates clockwise, it would be 1342 the way they are plugged. I used an old spark plug from my emergency spares for the no.1 cylinder, so it could be that that's a dud?

[LouisZ]

That is correct as it is.

If you pull the no1 spark lead from the sparkplug, is the engine still running like it is or do the engine sounds if it is losing rpm's?

If it is the same the wire or the sparkplug is the culprit. If it drops in rmp or stall it is fine. Do the test for all the leads.

Then take the spark plugs out too, inspect the contacts if they did not by chance got bend totally close,set the cap to to 0.8mm.

By doing this you check if it is the leads or plugs.

Then, the dizzy cap, check for cracks and also if it is 100% secured. If it is loose you get that too that the idling is like that.

What you have is a ignition problem.

[dantjie]

Ek wil nou nie n FLOTER in die drinkwater wees nie maar kyk ook of een van jou valves nie dalk vashak nie. Die blou rook is n mistery.

[Ryperd]

The terminals on the dizzy cap looked a little corroded, so I put in a spare cap from my emergency kit. No spare rotor unfortunately, but I can get one if necessary? The new cap seemed to improve things a little, but there is still no ignition on cylinders 3 and 4 (no difference if I pull out the leads, while cylinders 1 and 2 drop revs). The spark plug gap looks ok (I only have a 0.63 feeler, but the gap looked like it was close to 0.8). There was some engine oil on the thread of both spark plugs when I took them out, particularly cylinder 3. There was also a little smoke that came out of cylinder 3, but I guess that would be normal?

Danie, hoe sal ek weet as 'n valve vashak?

What next? Replace rotor? Replace leads? Put in an order for a new engine?

Photos:
1. Dizzy cap


2. Rotor


3. Spark plugs from cyl 4,3 (with oil on the thread)

[LouisZ]

Ok. Die rotor kan jy skoonskuur vir nou met fyn skuurpapier. Die olies sal daar wees op die skroefdraad, solank daar nie olie en te veel daarvan is by die sparkplug se punte.

Maak seker daar is nie petrol lekke nie.

Nou, sit alles terug. Dan op 3 en 4 terwyl die engine loop trek die lead, sit 'n Phillips skroewedraaier se punt in die lead se punt en hou naby die engine. Kyk of dit spark. As die lead foutief is sal dit nie spark, as dit wel spark is dit jou sparkplugs wat foutief is.

[Ryperd]

To be sure, I replaced the rotor, leads and plugs on cylinder 3,4 (I reckon I can keep the old ones as spares). I also took out the leads to 3 and 4 and plugged in one of the old plugs. Both got spark, so I think we can rule out electrical issues.

I took off the valve cover to check the rocker assembly again. It looks good to me, except that the second last pushrod seems to be at a slightly wider angle from the rest:


Also, the nut second from the front is sitting higher on the bolt than the one second from the back. Could be that the bolts are different lengths. I made sure to tighten them to the same torque, starting in the middle. It looks level to my eye.

I made a video of the rockers moving while I turned the crankshaft manually. I can't see anything irregular, but I don't know what to look for or if it would be visible from the rocker assembly. I also couldn't feel anything that seemed strange while I turned it. There were periods where I could feel the compression (you can hear it in the video), and then it turned easier when it went to the exhaust phase (I presume).

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View Original

So what mechanical problems could prevent two of the cylinders from firing, and how can I check?

[LouisZ]

Pm my jou adres kan kom loer ek na werk.

[Ryperd]

So Louis, amazing guy that he is , came to have a look and pretty quickly figured out what the problem was:


Luckily, it looks like that's the extent of the damage, so I'll pick up a replacement from him tomorrow and hopefully have a working engine by the end of the day.

[The Legend]

Rudi

Ek vermoed dat jy die pushrod nie reg ingesit het nie,en die oomblik toe jy die engine gestart het het hy gebuig.

[Ryperd]

Ryperd rides again!

It turned out that it wasn't quite as simple as I had anticipated to get the rocker assembly back in place. A few of the rocker arms had almost seized on the shaft and could hardly move. Eventually I resorted to securing the shaft with a vice and manipulating the arms until I could move them down the shaft again. There was some kind of metallic residue that had been deposited on the shaft under where the rockers move. I don't know if the shaft was out of alignment, or maybe there wasn't enough oil to lubricate it properly? Anyway, this is what it looked like:


After I carefully sanded it away, the rockers could move up, down and around again. It's not as smooth as it was before, and even with a fair amount of oil, I can now feel some resistance when I move the rockers around. Could this seize again, or cause some other problems down the line?

After putting it back together, I let it idle for about half an hour and didn't hear anything too strange. The smoke seems to be pretty much sorted (though I'll only really know tomorrow in the light). There was a small amount of condensation coming from the exhaust. I never know if that's normal, or if it's a sign that there's coolant leaking into the cylinders?

Tomorrow I'll take Ryperd for a bit of a drive to see if anything shakes loose. Thanks for all your help, I think I'll go crack that beer!!!

[Mud Dog]

That 'metal residue' you show on the rocker shaft is a result of heat seizure .... the rockers get lubed through the push-rods and splash. Oil splash in the top of the motor is sparse, it's not enough at all .... wonder if the holes at each end of the rods are open (not gummed up) or even that you have enough oil pressure. An old motor looses oil pressure through worn bearings as well as the fact that the oil pump itself gets a bit tired. Might be an idea to have the oil pressure checked.

[LouisZ]

Nice!! The condensation is good.

Start the engine, let it run for 3 minutes. Turn off the engine.

To be sure just take the tappet cover off. Look if the arms and rockers are oily. There should be quite enough.

Then oil all over the rocker arm assembly. turn by hand and see if all the rockers are moving up and down. Remember, some will be loose on the pushrods, some not. For the ones that is tight see if you can get the smallest feeler gauge in between the valve stem top and the rocker point, if you cant then it is fine. If the gauge go in, the rocker do not move as it should.

Turn the engine clockwise and work through till you know you tested all.

[Ryperd]

Andy, if the tappet cover is not sealing properly on the cylinder head, would that affect the oil pressure, or just cause a bit of leakage? Before I opened up the rocker assembly yesterday after checking the electrics, I noticed that the gasket was a little bit off the side of the cylinder head and may not have been sealing properly.

Louis, thanks for the tips, I'll work through it tomorrow morning.

[Mud Dog]

Andy, if the tappet cover is not sealing properly on the cylinder head, would that affect the oil pressure, or just cause a bit of leakage? Before I opened up the rocker assembly yesterday after checking the electrics, I noticed that the gasket was a little bit off the side of the cylinder head and may not have been sealing properly.

Louis, thanks for the tips, I'll work through it tomorrow morning.

No that won't affect oil pressure (unless it all leaks out there and there's no oil left to pump ). Just check the gasket before putting the cover back (when you check the rockers Louis suggested) ... make sure that it hasn't been 'hurt' and that it seated flat into the groove all around the edges of the cover.

[Ryperd]

The rocker assembly had a good amount of oil when I checked it, and it was tight on the valve stems. I loosened the rocker shaft a little so that I could move the rockers more easily. They could move easily enough on the shaft. When I went for a bit of a drive, the car performed well, but there was a scratchy sound coming from the engine, which I think could come from the rockers, so I'm thinking of replacing it for peace of mind. Does anyone know where in Pretoria I can get a replacement rocker assembly and what it should cost?

[dantjie]

More Rudi eks bly dat jou trokkie nou weer aan die gang is, ek sien altyd as mens sukel met iets as n (learning curve) n mens leer altyd iets nuuts leker dag daar hoop jy kom verder reg sterkte.

[Ryperd]

Dankie Danie, alles het nie heeltemal glad geloop nie, maar so leer 'n mens! Ek is bly dat ek dit self aangepak het, en volgende keer sal dit baie makliker wees. Lekker dag vir jou ook.

[Ryperd]

I can get a replacement shaft and rockers from Alert Engine Parts for R372 (I can take the springs from my current assembly). No idea about quality though - is this something I should get OEM, or are grey parts likely to be okay?

[Mud Dog]

I think those spares are aimed at the taxi industry, but that doesn't mean they're no good - so not sure about the quality, but might well be better than the damaged one you have in there. Also, the old rockers wear hollow over time on the valve-stem side so new ones would be better from that point of view as well. (You can always keep the old one as spare just in case.)

[Mars]

AS ek jy was het ek hulle probeer. Ek het nog nooit gemors spares by Alert gekoop nie.

[Ryperd]

Eventually I got the parts from Naskar in Silverton (Alert had only inlet / exhaust, not both rockers) and the engine is now quieter than it's been in ages. There is also no smoke from the exhaust, which is great! I still need to take it to Silverton Radiators to check for carbon monoxide in the coolant in case there is still an issue with the gasket. Radiator test came back negative for carbon monoxide. After a reasonably long drive (40km or so), the temperature was sitting on 1/3 on the gauge except for the last couple of kilometres, where it was pushing up towards half, which has me mildly worried that there might still be something that needs to be addressed.

Andy, how would I check the oil pressure? I'm not convinced I know why the last rocker assembly seized, so I'd rather make sure it doesn't happen again. I did check that the pushrods were not blocked when I fitted the new parts.