SO Im about to order my hks 2mm mhg when I see that they have a 3mm one :shock: So I got to thinking, since I am turboing the 6M, would it be beneficial to get a 3mm for a little bit lower CR, as opposed to a 2MM? Has anyone tried using the 3MM?
stick with the 2mm... you don't want to lower it too much while using a MHG.... you are loosing a substantial efficiency of the combustion chamber... which is the quench area... but putting too less of a quench area will have affects on the combustion process...
HKS listed the 3mm is to compensate on machining the head and block for preperation and if the block is in need of decking it
I run a 8.0:1 CR Ross Racing pistons and a 2mm HKS bead MHG... this is due to machining of the head 0.010 and the block 0.015 this is just for compensation of the machining of the block and head
Well I figure since it has not ever been resurfaced (either). THat I will at leist need a 1.2-1.5mm gasket to match what it taken off. However I figured I could maybe lower the CR a tiny bit to maybe aid in reliability of my settup, as I have the stock CR from the 6M...
Unless you are planning to run very high boost, like 20+ psi, I would recommend the 2mm. Stock is like 1.0 or 1.2 mm. Even if you get the head and block decked, you will still be lowering compression with the 2mm HG.
Stick with the 2.0mm MHG, you will only want the 3.0 if you've had some major machining done. I'm using a 2.0mm MHG in my 7m, no machining as the motor was basically brand new, and that lowered the compression to around 7.9:1 I think(this is according to HKS anyway) and that is borderling on too low.
Where did you guys get yours from & for how much? Where is the cheapest place to get a HKS MHG and ARP head stud kit? And does the heads tuds come with the nuts or do you have to purchase those seperate? Thanks