Diesel compression tester

[spock500]

As you guys know the head has been off to be reconditioned.

One thing that always bothered me was the 'fizz' when each cylinder was under compression, if you looked down the inlet duct and squirted oil around the valve seal you could see it bubble under pressure.

I pointed this out to the Head Centre who recond the head and back it went for vacuum testin g which came up 100%, I even sent the cams and valve lifters back so it could be tested as is.

I was told that the equipment they use doesnt require lapping in, its so accurate that the seat is cut then it beds in by itself.

 

[spock500]

valve train with crank at TDC;

Just making 100% sure this is how the injector washers sit, dome side down?

 

[Dieselman]

Heat shields sit sharp inner edge upwards.

I forgot the cams are contra rotating but they look odd to me. If No1 is on compression then no4 should be 'on the rock', just finishing exhaust and starting induction.

 

[Number_Cruncher]

The cams look right to me. No 6 is rocking.

They always look a bit odd compared to belt driven engines, as these cams counter rotate owing to the gear drive between cams.

Yes, you've got the injector sealing washer the right way round.

 

[Number_Cruncher]

>>then no4 should be 'on the rock'

As the firing order is

1 - 5 - 3 - 6 - 2 - 4

It should be No 6 that is rocking when No 1 is at TDC compression.

 

[spock500]

its hard to get the cams wrong (he says confidently, the drive gear sprocket has a peg and the actual sprockets have two dimples (see previous pics) along with hole to align with cam mounts.

We are getting there

 

[Dieselman]

>>then no4 should be 'on the rock'

As the firing order is

1 - 5 - 3 - 6 - 2 - 4

It should be No 6 that is rocking when No 1 is at TDC compression.

I was thinking it was a 4 pot motor, and now realise it's the 605 he's on about, so we're both wrong...

 

[Number_Cruncher]

>>so we're both wrong...

Quite so

 

[spock500]

Bought one of these, should be here Sat morning -

http://cgi.ebay.co.uk/ws/eBayISAPI....af0e11e0a0aad2e162e1fc91176a#ebayphotohosting

 

[Dieselman]

Ooh, not cheap, but Franklin tools are good.

I was thinking about your post that said you got no fuel when turning the engine by hand.
You should, are you sure the timing isn't 180 deg out. Keep turning and see if it delivers on the induction TDC stroke instead of compression.

 

[Number_Cruncher]

>>are you sure the timing isn't 180 deg out.

A good question.

Another way to ask this is after setting the cam timing, do you move the engine forward 14 degrees at the crank or 374 degrees before the pump is aligned?

 

[spock500]

I turned it over many times, even took the hoses off to get a bit more spin -

The small recess that the pipe sits in didnt fill at all, when cranked it squirted straight up.

If you go back to the video or the still taken from the video you can see a healthy spray pattern.

 

[Dieselman]

The small recess that the pipe sits in didnt fill at all, when cranked it squirted straight up.

That sounds like the delivery valves don't seal well enough at low speed so the plungers fail to suck fuel in from the rail.
Try putting your thumb over the oriface when turning the engine over to create a vacuum seal.

 

[spock500]

>>are you sure the timing isn't 180 deg out.

A good question.

Another way to ask this is after setting the cam timing, do you move the engine forward 14 degrees at the crank or 374 degrees before the pump is aligned?

I did it as above in my setting up process;

Correct me if I am wrong but my interpretation is that the IP rotates one for every two rotations of the engine, therefore the static timing mark can only be set the compression/injection stroke if the engine is TDC on the compression stroke?

The process I followed is this;

1, Put the engine at TDC using the crank (not worried about compression stroke or not as chain not on)

2, Fit both cams with dimples opposing and pin the inlet cam socket to the cam shaft housing.

3, Fit timing chain with cam shaft sprocket

4, The engine is now set at TDC on the compression stroke.

5, advance by 14 degrees and look for notch central in view port/hole.

6, Fit chain tensioner and rotate engine twice using crank

7, Re-check all of the above

8, Bang head against wall

 

[spock500]

That sounds like the delivery valves don't seal well enough at low speed so the plungers fail to suck fuel in from the rail.
Try putting your thumb over the oriface when turning the engine over to create a vacuum seal.

Shall I take the other four off and see if they are the same, could you explain a bit more about the vacuum seal please?

 

[Dieselman]

Are the cams defiantely on compression for No1 cylinder whan the cam pips are facing each other or are they on overlap.?

 

[spock500]

Are the cams defiantely on compression for No1 cylinder whan the cam pips are facing each other or are they on overlap.?

Please see post 22 photos

 

[Dieselman]

I did wonder whether the pics were allied, in which case it's on compression.

 

[Number_Cruncher]

>>5, advance by 14 degrees and look for notch central in view port/hole.

If you've got 14 degrees between cam and IP being timed, then, the timing of the cam relative to the IP is correct. That's another item less to worry about!

 

[spock500]

Yup, I think I should have bought the compression tester straight away to eliminate or confirm that first.

My thoughts are that it maybe the head gasket; the reason behind this is down to me using a cheaper non laminate gasket as Euro parts had stopped stocking the metal multi layer types.

I feel confident the head is ok (not withstanding the fizzing from valve seals) as its been vacuum tested, so that leave pistons/gasket.,