Why resurface block and head if its going to warp again?

[Datsrboi]

So I understand that even if you do not have a BHG your block is most likely warp still.

Ok so you have to check the head and block surface for straightness to see if its warped and all, but if you did not have a BHG you have to check it still rather you have it or not when you pull the head. The maximum warpage is .05mm/.0020inch.... So if your head it warped at the time your pulling off your head under BHG or not, why would it be worth it to resurface the head for a MLS headgasket that requires that straightness if its just going to warp again eventually? Wouldn't that mean the HKS and Cometic MLS be pointless?

I pulled my head finally and cleaned the block of the old gasket stuff. I checked the block surface with .003 inch and it did fine but now have to go back and check it at .002 inch by what the TSRM ask for (the .003 inch was what the haynes book said.. weird). It just bothers me why waste the money to resurface it if its just going to be off again.

 

[AF1JZ]

It'll warp if you don't have it torqued down correctly. As for the surface, you want to make sure the RA is smooth enough to get a good seal.

So, it isn't a waste of time or money.

 

[Datsrboi]

It'll warp if you don't have it torqued down correctly. As for the surface, you want to make sure the RA is smooth enough to get a good seal.

So, it isn't a waste of time or money.

So the point of the resurface is just for the sealing part? After it seals and the head warps again somehow it wont leak into an another bhg?

 

[IJ.]

The head will warp starting on the exhaust side as it slowly anneals.

In theory it should be straightened first then surfaced as if you only surface it the cam tunnels are still bent/warped.

If you overheat the head badly the whole thing anneals (becomes soft) and will do the banana thing when unbolted (always pays to undo the head bolts in 2>3 passes in the reverse sequence)

Blocks don't warp as often/much but the I-6 is a long wet noodle of a motor no matter how ridged you think it is and after 15+ years will most likely be off a touch.

 

[Datsrboi]

^^ Thank you guys for that explaination. My car is stuck at home and pulling the block to ship it to a shop to get it resurface is out of the to doable right now. Guess all these feeling down that the car is not done yet made me think about the warp thing.

Just to as since I am here, The haynes I was looking at says .003 inch maximum while the TSRM says .002.. My block did ok at .003 but havnt tried the .002 yet since I did not read the tsrm til just now. Will I be ok at .003? Is that what the RA is? I know "search". Just thought I ask while I am at it. If no answer Ill search later.

 

[AF1JZ]

So the point of the resurface is just for the sealing part? After it seals and the head warps again somehow it wont leak into an another bhg?

You have to understand that the majority of the BHG's is because of a incorrect torque from the factory. To minimize the chances of it happening again is to have to have it resurfaced, MHG, and ARP hardware.

 

[IJ.]

RA= Roughness Average

How smooth the surface is, it's as important as how straight it is.

 

[CTsupra]

ditch the haynes manual, and do what the tsrm says.

 

[Poodles]

I have the haynes manual...

it sits on a shelf collecting dust as it's incomplete and sometimes downright wrong. not to mention 99% of the diagrams are pulled directly from the TSRM...

The block doesn't warp nearly as easily as the head, and IJ was right about the head needing to be straightened if it's too badly warped...