Decking? Reliability? BHG?

87hilux7mge · 12-10-2011, 04:09 AM

i dont know if decking would net enough gains for the cost and PITA it can be with these motors. my head was decked about .004 IIRC... with the hks 1.2mm hg, .008 off my head and new stock type GE pistons, i calc'd out at 9.58:1 compression. so with alot of milling done to everything, i gained .38 points of compression. i doubt itll show much on a dyno.

biggest thing is if you mill too much out of everything, then you have to account for the belt slack and therefore (i think) retarded timing. (correct me if im wrong on that...) adjustable cam gears can fix that, and provide a power increase, or at least the ability to change where the power is and how long it pulls out.

anyway, in my opinion, it wouldnt be worth it to deck the block in pursuit of power. if it needs to be done, then do it, but otherwise, dont mess with it.

im also unsure of the effects on the quench area when decking on these motors...

as far as i know, reliability isnt affected as long as too much isnt taken out of the block. that more depends on how much care you take with rebuilding it and the carefulness of the machinist.

12-10-2011, 04:09 AM	#2
87hilux7mge walbro fp Join Date: Dec 2010 Location: spokane Posts: 479	i dont know if decking would net enough gains for the cost and PITA it can be with these motors. my head was decked about .004 IIRC... with the hks 1.2mm hg, .008 off my head and new stock type GE pistons, i calc'd out at 9.58:1 compression. so with alot of milling done to everything, i gained .38 points of compression. i doubt itll show much on a dyno. biggest thing is if you mill too much out of everything, then you have to account for the belt slack and therefore (i think) retarded timing. (correct me if im wrong on that...) adjustable cam gears can fix that, and provide a power increase, or at least the ability to change where the power is and how long it pulls out. anyway, in my opinion, it wouldnt be worth it to deck the block in pursuit of power. if it needs to be done, then do it, but otherwise, dont mess with it. im also unsure of the effects on the quench area when decking on these motors... as far as i know, reliability isnt affected as long as too much isnt taken out of the block. that more depends on how much care you take with rebuilding it and the carefulness of the machinist. __________________ 87 toyota 4x4 single cab short box pickup, 7MGZE.