New genuine Nissan top end gaskets were used. We used the factory MLS head gaskets as they can withstand quite a bit of power.
New factory cam timing hardware was used as well during this rebuild.
The first step in our assembly was the measure the block, rods, and crank to make sure our bearing and piston to wall creances were adequate. Even though all of our parts were new, we did this just to make sure everything was within spec. We set our main bearing clearances to the tight side of stock and the rods in the middle. The rings are ordered slightly oversized and the gaps are hand filed to be equal and to spec.
Here Howard uses a ring compressor to get the pistons ready for installation. He has lightly lubed the bore and rings with engine oil.
The King XPC rod bearings are pressed into place.
The rod bearings have the rod and bearing backs absolutely dry and the crank face is covered in assembly lube.
10 comments
i had always heard that Nissan engines, particularly the RBs, were underpowered in comparison to how robust they were. Those days, apparently, are long gone when we get 500+ HP out of bolt-on upgrades.
Any downsides to the narrow rod bearings?
Less surface area to maintain the oil film so less pressure needed before getting bearing wear. Good oil flow and pressure can somewhat mitigate it.
Very nice article, really accessible, will there be updates?
Also, I couldn’t help wonder, was there any discussion about the downpipes getting coated? Did any other goodies get thrown in “since you were in there anyway?”
Been a reader since SCC and still miss that magazine!
Other than the PC9 coating on the pistons, the parts were kept mostly stock. This was a customer car and they just wanted their car back. Though it may not seem like a lot was done, the total gets up there pretty quick thanks to the GT-R tax.
Great write up guys. Just to add some context:
The original motor was stock with about 90k mi on it, most of which was spent with the boost up for WOT on E85. It was not in fact bad gas that lead to failure but rather an accidental downshift at WOT which resulted in a low RPM load on the OEM rods. If that had not happened, my guess is the engine would still be alive. That tune had a reduction in torque as mentioned in the article. But even with the motor build, that mistake should not be repeated. if you have a GTR – don’t let that happen!
The owner just dynod the new setup and the results were impressive with the stock turbos. The head work appears to have netted a consistent gain in TQ across the rev range; but more impressively the peak TQ RMP was lowered by over 700 RPM’s down to 3,500 RPM’s.
Great build guys. Hi Howard, Mike and Martin.
I’ve really loved all of these modification articles / videos on the project GT-R. I was wondering if you would be making a video comparing the modified car’s performance to a stock car? Maybe quarter mile, 0-62, and a few laps on a track or Auto-X?
I think it would be really great to have some sort of benchmarking so that owners will know how the mods improve the car in more sure terms.
Thanks,
The car came here with a windowed block so no before!
could you be so kind to share you piston to wall clearance along with main and rod bearing clearance. this seems to be a very secretive issue when it comes to building a vr38 motor for about 1200hp or so.
We don’t give that information away either. Its part of our engine building service.