The cylinder block has no major external water exits.

As overZealous has explained the water at the rear of the block at cyl 5 & 6 exits up through the holes in the cylinder head gasket & then into the heads
where it meets water that is coming through from the front of the cylinder heads.
This combined water exits at the rear of both cylinder heads into the water manifold that then returns the water via the pipe to the top of the radiator.

With the Mod installed, when the water in that rear manifold reaches 190deg some of the water from the block now has an alternitave & quicker exit route that does not mix with the water at the rear of the heads.

Does it work ? Sharif test proves it does & Nissan wouldn't go to the added expence if it didn't.

What I would like to see is a clear pipe from the block to the thermo housing to see how much flow there is when the thermostat opens.
The large size of the hose and thermo housing suggests a lot, but the openings in the block at bottom of that square are only small.

Maybe a 3/4" (or 1" if it will fit) fitting drilled & tapped into both the rear water manifold & square blanking plate then connected by hose will do the same job.

Thanks Doug & Sharif

 

Thank you sharif.

 

Just happened to read this. Looks excellent, and this is exactly why I'm waiting a little while longer before buying a built motor. It seems that lately, the science of building VQ35's has made some important leaps forward. Thanks for sharing, Sharif, and keep up the good work.

 

Just figured out that this will work for the FWD VQ35 guys too.. The VQ30DE-K (2000/2001, 227hp 3.0) has the same exit plate and thermostat housing adapted into the piping. However, it wraps back around the left side of the engine, as needed in FWD configuration. The VQ35DE FWD blocks, strangely, lack this rear water exit. However, the casting is still there, and the holes are tapped to bolt the water pipe housing up. So, by drilling/dremeling the holes out inside of the casting in the block, and, by borrowing the piping/hoses from the VQ30 allows for a bolt-in sollution for the FWD VQ35 guys.

Travis

 

so what the hell does this all mean? better cooling? more power? wtf...

 

ok i get it, thanks, but is it a really a "must do mod"?

 

Not unless you are pushing the envelope or experiencing troubles with heat.

Race NA or built motor forced induction would be the main candidates.

 

how much labor would be involved with doing this if the engine is already in the car? How many realistic hours?

Would it be a serious pain in the *** to do or just takes time?


I'm extremely interested in this, but first want to see other's findings since it seems that a lot of people are going to jump on board to do this

would there be a benefit to using a lower temp thermostat or would it pretty much be open all the time then and have no benefit?

 

I run no thermostat and unless its extemely cold where you live thats the way I would run. No thermostat and a Nismo cap gave me temps 15 degrees cooler on average.

 

I thought there was a 2nd thermostat installed with this mod back behind the engine - am I not understanding it?

would you be able to skip the thermostat if the car will almost never see below 35 degrees?


would this mod be good for a stock engine or is it more for a sleeved engine where temps are going to be higher?

 

Oh I thought you were asking about the standard thermostat. Yes this would add one to the rear. Which I would subsequently remove also.

 

It provides for additional cooling, and ventilation of coolant more effectively from the rear of the cylinder block. I'd consider it a must-have mod, for anyone running high boost on a built block. The stock block community would also benefit.

In short, your engine will run much cooler at high boost and higher RPM operation. It allows eliminated the tendancy for coolant temps to "Race" upward as load and RPM increase.

You can elect to eliminate the secondary thermostat if you wish.

This modication can be installed with the engine inside the car. Rough estimate on labor time is about 4 hours.

For a street driven stock block with FI, this setup might be overkill. But if you abuse your car, or run high boost, I would consider it a must have. Oh, it also make refilling or purging your cooling system....a 10 minute job.

 

Sharif, how soon are you going to be offering this as a kit?

 

I really didnt have intentions to actively sell the kits. I merely offered it as a convenience to people, that didnt want to piece together all of the OEM parts.

Right now, we are packing and moving to the new shop, so it will be about 1 week before I can order more kits.

 

if you were to not use the 2nd thermostat, I'm assuming you'd have to wait a couple extra minutes for the car to warm up before driving right?

seems like if you're not going to run the 2nd thermostat, you might as well not run the regular thermostat as well right?

 

Your assumtion that the the motor would take longer to warm up is not correct.

The flow of the water into the motor is still controlled by the original thermostat.

Until the motor reaches the original thermostats opening point there is no flow.

What the new thermostat does is allow some (most?) of the block water to flow out without going through the heads when that area of the cooling system is geting close to boiling point .

In short, the overall opperating temp of the motor is still controlled by the original thermostat

 

ah ok

so would not using a 2nd thermostat mean worse cooling for the heads then because the water would exit the engine no matter what and not reach the heads when it could have with the thermostat?

 

Thats exactly correct. The secondary thermostat in the rear of the engine, will only open past 195F, to assist further with cooling.....when the engine is experiencing heavier loads and heat.

 

subscribing.....

I wish there was some directions with pics for the do it yourselfer then I would buy this kit and have at it

 

It's very straightforward, so no instructions are really needed. It all bolts on really nicely, and the area to cut will be clear, once you bolt everything on.