martynv8
Well-Known Member
Cheers Dave. I'm beginning to think they are gonna need changing with the oil
biketeacherdave
Well-Known Member
it
it goes to show after all your hard work the hg can still fail lets hopes its a simple fix and last 100k next timeCheers Dave. I'm beginning to think they are gonna need changing with the oil
ukadamwest
Well-Known Member
Between 3 and 5 ?Yep, it was running beautifully for 10k, then misfire on 3&5, it always blows between the middle cylinders. I was hoping the top hats would give better protection around the fire rings
the middle two on the right bank ? i would hazard that the head hasnt been machined properly or theres something on the block that is causing the failure there. is it possible that a top hat is mis seated and causing the HGF?
jamesmartin
Well-Known Member
possible or head was so overheated it wont stay flat
martynv8
Well-Known Member
Yes Adam, middle 2 on right bank.
These were the first to go a couple of years back. The heads were from Emmotts & checked before fitting on the new engine - maybe something was missed. Will see what the block shows next week.
ukadamwest
Well-Known Member
All the bolt placements on the head bolts make a 4 square around the cylinder.. the only weak point is on 7 and 8 where the water channel runs close to the cylinder..
for 3 and 5 to keep going suggests there is something going on the mating of the surfaces.. as a second guess maybe there is some debris in the bolt threads preventing the torque down to be correct, and allowing the head to distort slightly.. but that is a just a hipshoot guess.. first guess i would say that something is going on there with the block or head face.. there's no way you should have had 3 HGF at all, let one in the same position.. if the block and head face checks out maybe there is some movement on the top hat causing gasket damage. have you seen the gaskets when removed ?
for 3 and 5 to keep going suggests there is something going on the mating of the surfaces.. as a second guess maybe there is some debris in the bolt threads preventing the torque down to be correct, and allowing the head to distort slightly.. but that is a just a hipshoot guess.. first guess i would say that something is going on there with the block or head face.. there's no way you should have had 3 HGF at all, let one in the same position.. if the block and head face checks out maybe there is some movement on the top hat causing gasket damage. have you seen the gaskets when removed ?
martynv8
Well-Known Member
Hi Adam,
Just to clarify, the previous HG failures were on the old engine (block) & old heads. 1st was blow between middle cylinders on right bank, then middle cylinders on left bank. This failure is with new block & new heads. Maybe weak fueling on 3 or 5 causing it to overheat on that cylinder? It's the only cause i can think of that would carry over to the new engine.
ukadamwest
Well-Known Member
Ah ok. Understand.
is the inlet manifold the one carried over ?
is the inlet manifold the one carried over ?
martynv8
Well-Known Member
Yep....?
ukadamwest
Well-Known Member
maybe the inlet manifold was distorted from the previous HGF and is allowing air to be sucked in causing that area to burn lean and generate too much heat ?
jamesmartin
Well-Known Member
head gaskets usually go between the middle 2
martynv8
Well-Known Member
It certainly seems so
martynv8
Well-Known Member
Quite possible i guess. Is there a way of checking this?
jamesmartin
Well-Known Member
check temp of exhaust ports
martynv8
Well-Known Member
Blimey, its taken a dozen posts before I get a diesel bashing!
ukadamwest
Well-Known Member
Ah what can you do.. some prefer the burble of a V8; some prefer the clatter of a diesel... and drag queens..
ukadamwest
Well-Known Member
straight edge maybe.. i would think that not many people would consider to check the mating face of the inlet manifold.. something is causing it !!
