dont know what to do...

[outdoordan]

Hi everyone.

I could really do with your help... The bottom end of the engine I just fitted went to VM Specialists and had new piston rings, 1 new liner and new seals fitted. They also cleaned it all up, checked the timing gears and oil pump.

It came back to me and I swapped all ancillaries including injector pump before getting it running.

It ran 3 times

1st for 3-4 minutes a bit rough. alternator belt was too loose and screaming. shut it down, tightened belt. general smokiness all around vehicle.

2nd for about 20 minutes. Bled cooling system. ran more smoothly but guessed the injector pump timing could be tweaked. fiddling with cold start advance had no effect on running. At first I thought it was blowing smoke out of the exhaust manifold but on further inspection smoking quite heavily from crank breather ports on nos 2 & 3 rocker boxes. I hadnt yet fitted the hoses that carry the gases down under the engine.

3rd for about 5 minutes after re-torquing head bolts and fitting hoses to crank breathers. no smoke in engine compartment at all. blowing smoke from crank breather hose. blew nan injector out and that was that.

The question I have is what could be causing the smoke from crank case?

There was "steam train" chuffing from oil filler cap when removed and dipstick hole.

I need to make a decision about whether I invest in new or recon cylinder head(s) if the bottom end is worth saving, or whether I bodge a repair to get me back on the road until I can fit a 2H.

I mean no disrespect whatsoever to George... he has been brilliant. Friendly, and extremely helpful... but is it possible that something has failed?

I may well be wrong (I often am) but I thought that the only way the crank case could become pressurised and blow smoke was if gasses were leaking past piston rings.

What should I do?

To be honest, the sooner I get a 3B or 2H in this thing the better.

Thanks in advance for your help.

OD

 

[Iwan]

That's bad luck there Dan. Sorry to hear this! From a previous post on the VM.. Is it true that your gearbox has 10 course spline? Because it sounds like it's the same input shaft as the 60 series 2H. Just change the bell housing (I have one here) and modify the mounts and drop in a 2H.. there has to be a few around?? The 2h is a lovely motor that wount give much greif.

The vm may have blown the head gasket and the pressure is going down the oil return to the sump... not sure!

 

[outdoordan]

Hi bud. Yup. Def got 10 spline input shaft... didn't measure length when lump was out though.

 

[Iwan]

So if you went for a 3B then the input shaft would be incorrect.

I suppose it wouldn't hurt to take the offending cylinder head off but like you say to buy new cylinder heads, but then your getting further money wise with no guarantee of it behaving itself!

I read a long time ago that the VM engines are hard to get going right after failing... tricky situation!

 

[clivehorridge]

I may be speaking out of turn here because I know nothing about the VM engine, but regarding causes of excess crankcase pressure, leaking valve guides are often a contributing factor.

Most valve guides from new are a tight(ish) or a close fit to the valve stems and the very slight chance of pressure leaking between stem and guide is eliminated by a valve stem seal of various types, such as an “O” ring or equivalent seal.

After ageing, the wear between guide and stem causes pressure leaks which are excessive for the seals to operate efficiently, or the seals themselves have deteriorated (hardened/worn compound material) and this results in pressure escaping into the crankcase down from the rocker covers which are open vented to the crankcase.

I maybe wrong, or on the wrong track, but worn valve guides are certainly a contributing factor to excess crankcase pressure as well as blow-by at the piston rings.

Just an idea....

 

[outdoordan]

thanks clive. its a possibility. the heads are 25 years old with 270,000km on them. there are no valve stem seals on these. just a steel guide about 30mm long.

 

[clivehorridge]

thanks clive. its a possibility. the heads are 25 years old with 270,000km on them. there are no valve stem seals on these. just a steel guide about 30mm long.

I’m not saying that the wear you have is enough to cause the extent of the problem you have, but I’ve seen the effects for myself on other engines.

However, on re-reading your posts, it seems the exhaust may be running clear, and usually valve guide wear also causes oil burn in the exhaust, so on second thoughts I may be off track with this idea.

 

[StarCruiser]

Dan, you mentioned you re-torqued the head bolts. This is not usually needed as the head bolts should normally be tightened in the suggested sequence to the required torque and or an extra amount of rotation and then left. I don’t know the VM engine but if you had to re-torque it it sounds like it wasn’t tight enough in the first place. Did you have the head(s) skimmed flat? Did you use New head bolts if recommended? This has all the hallmarks of a head gasket problem.

 

[Shayne]

I may well be wrong (I often am) but I thought that the only way the crank case could become pressurised and blow smoke was if gasses were leaking past piston rings.

This is way out of my depth but even if rings don't leak the pistons will pressurize the crank - that's why it has to have a breather , a vacuum in the cylinders will resist the piston coming up and having to compress air to go down would do the same .

Obviously the breather is not entirely blocked but might it be partially blocked ?

 

[outdoordan]

thx for help guys. i'm going to re-do cylinder heads to get on the road... failed gasket looks like the cause of the problem as everyone pointed out. George reckons worn valve guides wouldnt cause it.

i'll be fitting a 2H as soon as I can. may already have found one. loads of little issues to be resolved there... its coming out of a 24v HJ60/61, and the BJ is 12v, the exhaust manifold is on the opposite side to the VM so looks like a substantially different exhaust set up and a different radiator or some radical reworking of hoses. thats just at first glance.

going to try and go see it on my way back from scotland

 

[outdoordan]

right... so i bought set of these:

cylinder head by Dan, on Flickr

and a set of these:

injector by Dan, on Flickr

should be waiting when i get home.

the original heads have drop in injectors held in place by cantilever clamps... these heads have screw in injectors... fingers crossed