MR head bolts for VQ37

[TopgunZ]

Hey guys. I am building my block and was told that the "MR" vs the "HR" head bolts were stronger and are suggested to be used up to 700whp. They are actually what nissan uses in their Juke.

Anyone else hear about this?

Also, How much better, if at all, are the moly coated race spec rod and main bearings vs the oem bearings? Anyone foresee issues going with oem bearings?

[1slow370]

where have you found someone running 700whp with them? I hear they are supposed to be slightly better but nothing firsthand yet.

[Boosted Performance]

I would not consider anything other than L19 studs for this application. Would also look into after-market stopper type (ring) head gaskets. Not sure what is available though. HKS was great for the VQ35

[phunk]

What are "MR" head bolts?

[1slow370]

head bolts from the mr16ddt

[phunk]

Ah I had to look it up on wiki, never even heard of that engine.

[TopgunZ]

Well Ive heard from vendors that they are better than the HR's and we have guys running close to 650 on those. So 700 to me is a "bit" better than the HR's.

[phunk]

Why not go all the way with some L19s? I like to get about 95-100lb ft on the DE's, and will aim for the same on my VHR when I assemble it.

[1slow370]

now lets not start the stud vs stretch debate again here if you want to get into that hit up google, some applications are better to use stretch some are better to use stud. It all boils down to if you are for sure going to stay under the limits of the stretch bolt go with it, if there is any question you will go past its limit go stud.

To clarify for anyone who doesn't want to google the engine code these are the OE bolts from the turbo Nissan Puke.

[phunk]

I like using overkill studs and torquing to a spec using the same procedure (lube etc), because its something I can relate and compare to. When you take it to the deeper depths and start getting into TTY you are, IMHO, adding complication and debate. Do we even have any solid information on the difference in factory Nissan bolts, or is it all just hear-say? I dont ever want to change the headgaskets on a VQ after original assembly, so I prefer to avoid the "could i get away with using ___?" gamble! The studs on my DE build are going strong on almost 10 years... So much so that we replaced the main and rod bearings this year without even removing the heads because its not worth messing with.