timing cover not decked w/block, little high?

[speedfreak]

ya basically my machinist said the timing cover was lower than the block when he checked it, but now its a little high on both sides of the block, not too much but how much is to much? i measured .005"+/- on both sides. has anyone had bhg or failure definently caused from this. any SME opinions would be great but if anyone knows whats up chime in please.

 

[gaboonviper85]

It needs too be cut with the block...take it back and have him do it again.

That .005" is going too warp the head when you bolt it down causing the cam saddles too be off...it's also going too cause an oil leak as the heads oil feed is really close too the timing cover....sorry man but it needs too be perfect!

 

[speedfreak]

thanks gaboon, thats what i feared, i'd rather not drive way up to my good machinist, think i could go to most shops for this or maybe do it my self? i dont think i need like RA values for this one, but needs just to be flush right?

 

[gaboonviper85]

Ra value is not as huge an issue aslong as you put a nice thin layer of liquid gasket around the top of it....but no it needs to be machined too the exact measurment with the block as the headgasket and head both sit on it and oil flows behind that plate and can cause a big oil leak.

I have personally machined a rear timing cover for a local friend and it was an easy set up on a milling machine....

 

[speedfreak]

got it so: minimum tolerance for timing cover to block surface = 0 either do it right or don't do it. thanks again gaboon.

 

[gaboonviper85]

No problem

 

[IJ.]

Might get away with it if you use a composite HG but it's BHG 100% with a MHG.

 

[lewis15498]

I would expect the machinist to redo it for free considering it was his error in judgement for the most part.

 

[gaboonviper85]

I would expect the machinist to redo it for free considering it was his error in judgement for the most part.

No it's not....not every motor is the same and machinist can only do what's asked of them....unless he assembled the motor and could visibly notice that the gasket sits on that cover then how is he too know how critical it is?

It's up too the customer too research his motor and find the little tricks too his engine and tell the machinist these issues....it's the machinist's job too machine properly and inspect parts for issues prior too machining....it's your job too tell him what you want done.

 

[dragracer]

Just take it back and have him depth mic on each side and cut the cover seperate.

Just to note. I have done several headgasket jobs. On four of them, the cover was high anywhere from .004" to .007" from the factory. None of these were previously tore down. Could be another reason why there is a high headgasket problem on these motors besides the low torque specs on bolts.

Rich

 

[gaboonviper85]

Just take it back and have him depth mic on each side and cut the cover seperate.

Just to note. I have done several headgasket jobs. On four of them, the cover was high anywhere from .004" to .007" from the factory. None of these were previously tore down. Could be another reason why there is a high headgasket problem on these motors besides the low torque specs on bolts.

Rich

Noticed this also:-(