PaulRainbow
Well-known member
I don't want to fill the chambers, i want to fill the ports and see if the diesel pisses past into the chambers.
VP MD202B - No compression
- Thread starter Jokani
- Start date
I don't want to fill the chambers, i want to fill the ports and see if the diesel pisses past into the chambers.
drydog
Member
I get the logic, however, it will be an inconclusive test to fill the induction or exhaust ports because some of the valves will be naturally open due to the camshaft (correctly or incorrectly) opening them.
PaulRainbow
Well-known member
I get the logic, however, it will be an inconclusive test to fill the induction or exhaust ports because some of the valves will be naturally open due to the camshaft (correctly or incorrectly) opening them.
Blimey, does no-one read what's said ?
That's why i said
drydog
Member
I'm not going delve any deeper over this point suffice to say, the valves could just as easily be open in a normal non combustion position because the cam has opened them. Not damaged them. How do you determine which state they are in if the timing cannot be confirmed?
PaulRainbow
Well-known member
If you cannot work out when a valve should be closed, you didn't ought to be posting in this thread.
VicS
Well-known member
Yu take the top cover off and look at the rockers. When the valve is closed a small gap ... will open up between the the inverted bucket or tappet and the rocker ( the gap you adjust when "doing the tappets")
As a valve opens you will see the push rod rise and the rocker push the valve down.
drydog
Member
PR, ok, I get it now. you are going to pour some fuel into the induction or exhaust port whichever is convenient or do both if you wish..
All the fuel disappears and you shout eurika!! the valves bent - and you could be wrong @66% of the time. (3cylinder engine)
What hasn't been identified is whether the camshaft is keeping the said valves open allowing the fuel past or if the feindish valves actually are bent.
Hopefully you haven't ever used this system to 'diagnose' engine issues in the past, because, psssst, you were wrong.
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drydog
Member
Ahh so identifiying which one is TCD or closed, then you pour into that port. Got you. Well I never.
It's all becoming clear now. Hopefully anyone not having done this before will realise it's not just a matter of pouring stuff into manifolds.
PaulRainbow
Well-known member
Let's pretend we're going to adjust the valve clearances. We'll follow the VP manual for that, save any unnecessary instructions from me. When you get to the point where it tells you to measure the clearance with some feeler gauges you do so and if a clearance exists you tip the diesel into the port for that valve, none of the others, just that one. It clearly should be closed and sealed, because the cam is in the appropriate place and you verified a gap with your feeler gauges. If the diesel stays put the valve is sealing, if it disappears, it's not sealing.
This is a basic test that has been around since the dawn of internal combustion engines. It is something that zillions of mechanics will have done zillions of times and they weren't all wrong. Some of us can mend an engine without a laptop.
PaulRainbow
Well-known member
Ahh so identifiying which one is TCD or closed, then you pour into that port. Got you. Well I never.
It's all becoming clear now. Hopefully anyone not having done this before will realise it's not just a matter of pouring stuff into manifolds.
I suspect it was only you that thought that
drydog
Member
PR not all of us are mechanics. See my reply to Vic.
PaulRainbow
Well-known member
drydog
Member
anoccasionalyachtsman
Well-known member
....anyway, I still reckon the timings out.
As do I!
What Paul is saying would work well, but he's imagining doing it with the manifolds off I think, whilst you're just not getting into the spirit of it and aren't suggesting that the op take more bits off.
drydog
Member
You know me already....I wouldn't even pay for a female stripper.
Let alone some one hacking into my perfect yet untimed engine. (wishfull thinking)
VicS
Well-known member
....anyway, I still reckon the timings out.
How then do you explain that Gary says he has checked and double checked that the timing marks line up.
anoccasionalyachtsman
Well-known member
I can't.
drydog
Member
Vic, I don't believe the timing is correct unfortunately.
The fact the engine is not firing and does not seem to have any compression is telling me another story. entirely.
How else can it not work if the timing is actually right? - I know for a fact that if you have oxygen, compression and timing correct in a diesel engine it will run on quick start for as long as you spray the intake.
Even if there is almost no compression and the timings right it will still run on quickstart.
No start or firing on quickstart = no timing.
Even if it has bent valves on 2 cylinders the 3rd one will still fire if it has compression.
If you can explain otherwise I'd be much obliged..
Heckler
Active member
He said fill the port, if you look at the pics of the head that myself and others have posted you will see, as I pointed out, that the inlet on these engines are weird. They go through the middle of the rocker cover. If you take the cover off, a couple of nuts, then the inlet ports are pointing up and you can quite easily put some diesel in the ones where you see the valves are shut! The piston, looking at the parts diagram is a flat one with the combustion chamber in the head. This confirmed by the OP having difficulty in getting a wire in to the combustion chamber to test for tdc. Suggest you read all the previous, there is a lot of info there!
Stu
VicS
Well-known member
So Gary is mistaken about the marks lining up ?
It looks pretty straightforward to me, not exactly rocket science, and he has expressed no doubts about identifying them or interpreting the diagram in the manual.