Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Doctor Gollum]

Surely the cost of testing/machining would get you most of the way to a replacement head, that hasn't been cooked from the inside out 

£80 to test it, but £2,200 for a new one.

Actually they didn't charge out of pity.

The verdict:

0.18mm so basically a stupidly shaped door stop.

[Andy B]

7 thou" I think I'd still go for the skim .... there's nothing to loose other than the cost of the skim

[Doctor Gollum]

It can't be skimmed. The issue is that no one knows what is an acceptable amount of distortion.

As I understand it, the reason it can't be skimmed is that the head is triangular with the timing cover attached to the block, head and cam covers so any deviation has the potential to make it impossible to reassemble and seal.

They will take quite a few thou, they won't have been made to that level of accuracy in the factory and the gaskets and sealant would take up the delta.

If you can provide the engineering drawings to confirm the factory tolerances then happy days.

[Raeturbo]

This what I meant.   https://5150autosport.com/blogs/product-faq/cylinder-head-sealing-101-mls-cut-ring-o-ringing-and-fire-ringing?srsltid=AfmBOor-pnv3A4mi85Sfl_XA3Q8ZcXs0fcvG9m4bfz4ElFiMJx4UoQNQ

[Doctor Gollum]

Not sure how that would keep the water in.

It's already an MLS gasket fwiw.

[Marks DTM Calib]

It can't be skimmed. The issue is that no one knows what is an acceptable amount of distortion.

As I understand it, the reason it can't be skimmed is that the head is triangular with the timing cover attached to the block, head and cam covers so any deviation has the potential to make it impossible to reassemble and seal.

They will take quite a few thou, they won't have been made to that level of accuracy in the factory and the gaskets and sealant would take up the delta.

If you can provide the engineering drawings to confirm the factory tolerances then happy days.

Unlike you, I have spent enough years in engineering design to know dam well that the parts on that engine will not be machined to a tolerance that would not tolerate a fraction of a millimetre mismatch. If you were to add up the tolerance of all the mating items they will easily be closer to the 0.5mm level.

[Raeturbo]

Not sure how that would keep the water in.

It's already an MLS gasket fwiw.

   It would keep the water out of the combustion chambers if that was the fault

[STEMO]

It can't be skimmed. The issue is that no one knows what is an acceptable amount of distortion.

As I understand it, the reason it can't be skimmed is that the head is triangular with the timing cover attached to the block, head and cam covers so any deviation has the potential to make it impossible to reassemble and seal.

They will take quite a few thou, they won't have been made to that level of accuracy in the factory and the gaskets and sealant would take up the delta.

If you can provide the engineering drawings to confirm the factory tolerances then happy days.

Unlike you, I have spent enough years in engineering design to know dam well that the parts on that engine will not be machined to a tolerance that would not tolerate a fraction of a millimetre mismatch. If you were to add up the tolerance of all the mating items they will easily be closer to the 0.5mm level.

Don't let him get to you, Mark, you know what he's like. 

[Doctor Gollum]

Not sure how that would keep the water in.

It's already an MLS gasket fwiw.

   It would keep the water out of the combustion chambers if that was the fault

I suspect that it was more the result rather than the cause.

[henryd]

It can't be skimmed. The issue is that no one knows what is an acceptable amount of distortion.

As I understand it, the reason it can't be skimmed is that the head is triangular with the timing cover attached to the block, head and cam covers so any deviation has the potential to make it impossible to reassemble and seal.

They will take quite a few thou, they won't have been made to that level of accuracy in the factory and the gaskets and sealant would take up the delta.

If you can provide the engineering drawings to confirm the factory tolerances then happy days.

Unlike you, I have spent enough years in engineering design to know dam well that the parts on that engine will not be machined to a tolerance that would not tolerate a fraction of a millimetre mismatch. If you were to add up the tolerance of all the mating items they will easily be closer to the 0.5mm level.

As Mark says,any head can stand a 7 or 8 thou skim,let's be honest  here,a new head basically scraps the car when added to the parts list and the new head casting is probably bare so more work/ parts being needed

[Doctor Gollum]

It can't be skimmed. The issue is that no one knows what is an acceptable amount of distortion.

As I understand it, the reason it can't be skimmed is that the head is triangular with the timing cover attached to the block, head and cam covers so any deviation has the potential to make it impossible to reassemble and seal.

They will take quite a few thou, they won't have been made to that level of accuracy in the factory and the gaskets and sealant would take up the delta.

If you can provide the engineering drawings to confirm the factory tolerances then happy days.

Unlike you, I have spent enough years in engineering design to know dam well that the parts on that engine will not be machined to a tolerance that would not tolerate a fraction of a millimetre mismatch. If you were to add up the tolerance of all the mating items they will easily be closer to the 0.5mm level.

Thank you for clarifying that. Unfortunately the actual tolerances are apparently a closely guarded secret, which when coupled with the fact that the official line is that the head must not be resurfaced perhaps explains why the place that tested it won't even entertain resurfacing it.

[Kevin Wood]

I've lost count of the number of engine manuals I've read that say the head can't be skimmed. It's just @rse covering, surely?

I the face of F-all to lose I know what I'd do.

[Doctor Gollum]

I've lost count of the number of engine manuals I've read that say the head can't be skimmed. It's just @rse covering, surely?

I the face of F-all to lose I know what I'd do.

I've a 4k mile head on the way for less than the cost of skimming it, Notwithstanding that they wouldn't skim it anyway.

[STEMO]

I've lost count of the number of engine manuals I've read that say the head can't be skimmed. It's just @rse covering, surely?

I the face of F-all to lose I know what I'd do.

I've a 4k mile head on the way for less than the cost of skimming it, Notwithstanding that they wouldn't skim it anyway.

They'd do as they were fickin told if I was paying for it. Them or someone else.

[Doctor Gollum]

It's a moot point.