Max decking of block and head

[bosco659]

Anyone know what the max amount of material that can be removed from a 7MGTE block and head (decking in preparation for a MHG)?

[Jeeves]

Can't recall off the top of my head, sorry. Search Supraforums.com.

[mrnickleye]

Just did the valves for my 7mge. I spent hours researching your question for this engine. All recommended keeping the same combustion chamber dimensions by using thicker head gaskets to do so after milling the head and/or block. There are several gaskets on the Internet market. Make SURE your machine shop is the most recommended in your area (ask around at some repair shops) &(not necessarily the cheapest), and that they measure and report to you the amount they shave off. ie: milled 2mm, get a 3-4mm gasket. Do NOT ad a head gasket shim (as some shops do to compensate for the milling). These 7m's are known to blow gaskets, and a shim will blow sooner.
Use NEW bolts, too....

[bosco659]

Thanks for the info to all.

[bgrieger]

Hey Vic,


Straight from the TSRM: No idea. Maximum warpage is listed as .0039, or .1mm, and the block maximum allowable warpage is .0020, or .05mm.

The TSRM actually does not have machining limits listed, perhaps because they would recommend replacement rather than machine work. Off the seat of my pants, knowing most people running larger than 2mm gaskets have problems, you probably have a full 1mm total allowable machining between the head and the block, given the stock gasket is supposed to be 1mm after compression.

I'll check my Haynes manual to see if it has anything listed, but they generally just copy the TSRM and such anyhow...