Just checked them Chris and they were fine, all 4 giving good similar spray. I've taken the head back off and all seems normal and yes... The gasket was the correct way up 😊
I've left the head upside down overnight with paraffin in the Valve seats to see if they are seating properly.
Would you all recommend I get the head skimmed anyway as I didn't bother the first time around?
I've left the head upside down overnight with paraffin in the Valve seats to see if they are seating properly.
Would you all recommend I get the head skimmed anyway as I didn't bother the first time around?
jamesmartin
Well-Known Member
only if heads pitted were fire ring sits or head is warped
Bit of an update, ended up taking the head to be skimmed as the compression was so poor, the guy who did the work said it was way out so was hoping to get better readings when the next test was done. Unfortunately I'm now getting a reading of 220psi across all four cylinders which although now consistent is still nowhere near enough. I did the test without the manifolds connected or the fuel lines as I belive this wouldn't effect the test (the injectors are clamped and sealed). Valves could be leaking but can't believe they would all leak as bad as each other. I'm now thinking wrong head gasket (I did measure and it came up with a 3 hole which is what came off) or dodgy head gasket. It has to be something that is related to all four cylinders as they all read the same. Any other ideas chaps?
jamesmartin
Well-Known Member
easy enough to check heads straight , if you add oil to cylinder after first test if it makes it better rings/bores are worn ,a poor valve to make so much difference youd hear, is gauge accurate and how long do you wind it over on starter ,is it turning fast or not , 3 hole on an engine that had a 1 hole wouldnt make that difference,and would run unnoticeable from before
The gasket was an elring err5263 said it was original equipment from adventure 4x4 in Leeds. Engine turns over good and takes 4-5 revolutions to reach just over 200 psi. The truck ran well before overhaul and haven't touched pistons so it had to be something to do With top end. Guage is brand new so presume accurate but just had Everything back together again this afternoon and still not starting so believe the reading.
tetsu0san
Active Member
When the head is off unless you are on a tight budget or schedule I think you should do as much as you can to make sure you don't have to do it all again. Lap in the valves, change the stem seals, skim the surface (or at least get it checked) etc. Then you don't have to do it again later.
jamesmartin
Well-Known Member
Bit of an update but not getting anywhere.
To recap..
Had head skimmed and valves reseated by engine rebuilders,
Got another set of cylinder head bolts and another head gasket
Checked cam/valve timing and bang on
All valve clearances adjusted to 0.20mm using 1-8 4-5 etc
Head tightened correctly using 40nm, 60 degree's, 60 degree's, then 20 degrees on centre bolts with correct sequence.
Did another compression test through glow plug hole without manifolds or rocker cover on but with injectors and new seals clamped down and got the following results :
200,210,220,210
Now at least they are within the tolerances of each other but still way off.
My assumptions :
Has to be something that controls all four pistons as too much of a coincidence for piston rings to be worn that much at the same rate or had to be cracked internally across all four cylinders
Unless anyone can come up with a eureka moment I think a leak down test is the next move although can't find anyone at the moment who is mobile.
Saved this thing from the scrappers as it ran well but doesn't even do that now
To recap..
Had head skimmed and valves reseated by engine rebuilders,
Got another set of cylinder head bolts and another head gasket
Checked cam/valve timing and bang on
All valve clearances adjusted to 0.20mm using 1-8 4-5 etc
Head tightened correctly using 40nm, 60 degree's, 60 degree's, then 20 degrees on centre bolts with correct sequence.
Did another compression test through glow plug hole without manifolds or rocker cover on but with injectors and new seals clamped down and got the following results :
200,210,220,210
Now at least they are within the tolerances of each other but still way off.
My assumptions :
Has to be something that controls all four pistons as too much of a coincidence for piston rings to be worn that much at the same rate or had to be cracked internally across all four cylinders
Unless anyone can come up with a eureka moment I think a leak down test is the next move although can't find anyone at the moment who is mobile.
Saved this thing from the scrappers as it ran well but doesn't even do that now
tetsu0san
Active Member
What did the bores look like with the head off? And did you get the head pressure tested before it was skimmed? It's a shame you didn't know the compression test before you started all this but as was said before, did you try the compression with oil in the bores as this will prove worn piston rings?
Not sure about the extra 20 degrees on the centre bolts, but I don't think it's anything to worry about. Never heard of that one though. And what head gasket did you get this time? Same again?
Just to recap, why were you doing all of this again?
Not sure about the extra 20 degrees on the centre bolts, but I don't think it's anything to worry about. Never heard of that one though. And what head gasket did you get this time? Same again?
Just to recap, why were you doing all of this again?
Bit of an update but not getting anywhere.
To recap..
Had head skimmed and valves reseated by engine rebuilders,
Got another set of cylinder head bolts and another head gasket
Checked cam/valve timing and bang on
All valve clearances adjusted to 0.20mm using 1-8 4-5 etc
Head tightened correctly using 40nm, 60 degree's, 60 degree's, then 20 degrees on centre bolts with correct sequence.
Did another compression test through glow plug hole without manifolds or rocker cover on but with injectors and new seals clamped down and got the following results :
200,210,220,210
Now at least they are within the tolerances of each other but still way off.
My assumptions :
Has to be something that controls all four pistons as too much of a coincidence for piston rings to be worn that much at the same rate or had to be cracked internally across all four cylinders
Unless anyone can come up with a eureka moment I think a leak down test is the next move although can't find anyone at the moment who is mobile.
Saved this thing from the scrappers as it ran well but doesn't even do that now
Did you try as James said and put a small drop of oil, a teaspoon, down one of the bores to see if that improves the reading ... then do the others as you may have a crack between cylinders or just leaky rings ...
