I'm building a 4.3L VQ for a turbo set up. I had some special solid deck sleeves made to hold these 103mm pistons.

My math shows that I'll have a 4.321L motor.

I'm building the motor for Jon Wells who will be using it in a base model G35 (aka 350z)


We are turboing this motor with help from JWT on some of the turbo stuff.

From what I've read, we are apparently going on the large side of building this motor.

I'm not expecting it to last as long as a normal built VQ, but I still hope it holds up.


Has anyone done something this big other than maybe AEBS? If so, on the back 2 cylinders, the factory block has extra holes for water to enter the head.....even though the block has ports next to those for it to flow to the water galley.

I machined the sleeves to allow water to hit both galleys, but am thinking about not drilling holes in the sleeves for the extra water holes on the back two cylinders.

After years and years of building many a SR20 motor, the factory blocks have extra water jacket holes on the back cylinder for extra cooling.....like the VQ. I have blocked those off before with great success and wonder what my results will be on the VQ.

Any opinions?

thanks guys

 

I would highly suggest searching around on my350z.com. Their FI section is a great resource.

 

I wouldn't mind, but ...

I'm an old school kind of guy for internet use. I cut my teeth on the mailing lists back in the day. The forum, which we run one at work it still a newer concept to me.

With that said, I posted a few things on that side of this.....and was politely asked to move my threads to the "G35 section" of my350z.....which to me is silly since they are really the same car......it's like saying a sedan is not a real G35

I'm also not much of just a reader of forums. I like to contribute...meaning read and write.

Yes, Jon's car is a 350z. But since I own 2 G35's, I like writing about it on here. I'll stay on this one and keep churning.

p.s. you might need to turn your cell phone off.

 

For building the motor and for cooling you should look into doing 2 things:
#1) HR head gaskets (which includes milling/porting a section of the head for proper flow). This will allow you much better/more even coolant channeling across all cylinders.
#2) Use the Nissan Pathfinder mod. The Pathfinder uses the VQ motor as well, but had an extra coolant pipe for better cooling during towing. This mod is good for 10* better cooling or so.

 

1) With the size Bore he is running there are not HR Headgaskets available. They could potentially be custom made, but its not as easy as with most builds.

2) From my understanding you choose one or the other, its not recommended to run both the HR mod and Pathfinder mod together.

-Rob

 

you could look up Nitrouz, he had a fully built 420zTT, 4.2L v6 twin turbo over 700whp, sold it a couple years ago to a friend and its been running since 2005

 

Not much info here for big FI builds, However if you go to my350z.com and post in the 350z Forced indection section you will have more luck. I also drive a G35 and they have never told me I am not welcome there. So i doubt you will have any issues, i do not know of anyone else that ran 103mm pistons however the closed deck sleeves should be the same as 100mm pistons. Several guys have run 100mm pistons with sleeves including myself but I was not involved in the sleeving process at all and I am not really sure what holes you are thinking about plugging? Most sleeved guys do run the pathfinder mod. It if a different coolant log in the rear it has an extra hose so it joins the 2 rear cylinder cooling paths with the centre of the block as well.

This is the best picture I have of it if you look at the black cooling log in the rear you can see the extra hose I have running up under the intake.




Are you using JWT 850bb ki? I hope not it will be much too small to make use of a 4.3L it is the limiting factor on my 3.8L for making big power the best that kit has done is aprox 800whp. When most guys fo 4.0L or larger they start looking to GT35s or larger turbos i guess this is dependant what you are using the car for but the JWT 850bbs will certainly be a limiting factor with that displacment not to mention the piping and Intercoolers are also even more limiting than the turbos themselves. JWT makes great kits for guys looking to stay in the 600whp range.

Good luck and keep us updated.

 

We had some custom made by Cometic. We were going to use some SCE's, but I didn't want to do coppers on these.

Cometic made them after we signed all these disclaimers.......which is funny anyway becasue there really isn't a warranty on a head gasket.

I went a half mil bigger than the bore.

 

I love the mini K&N filter

 

1. Yes, I think we will be doing something similar to what's called the Pathfinder mod, (I just didn't know about that name) I was thinking about tigging some A/N fittings and doing what you are talking about.

As for the block, what we did was opened up the coolant passages BEFORE putting the sleeves in. That should help. Also, we may or may not open up some of the coolant holes filled with the sleeves.

2. JWT question: We are using the piping and exhaust manifolds, as well as the turbo lines. We are NOT using the turbos, nor ordered them.
I've been a JWT buddy for years and liked what I saw........there were some others out there that I thought about......but decided on the JWT because of the price and quality of the manifolds.
Contrary to what most think and written, the intercooler is NOT that big of a factor as what people think. Long term pulls and road racing.......yes........1/4 mile run, no, or even a dyno pull. I've learned that after years of R&D on a FWD SR drag car and dealing with Precision Turbo.
I'm not saying the intercooler will be OK, it may not be. We'll try it and see how it does.

I should have some more updates on the motor build as it goes. I'm sort of waiting on more $$$ from the customer, and to finish some other motors to bring it back into the room.

thanks alot for the tips guys, mean it

 

what does that mean?

 

He is referring to the little K&N filter i had on the breather on my valve cover.


I am also a fan of JWT products, i do have the 850bb kit and the C2 cams and springs. They have given me alot of advice and spent a fair bit of time helping my sort through issues. They have always taken care of me and helped me out more than once when failures were not even conclusively their fault....so dont get me wrong I am not saying they are sub par or anything like that just for an over the top build like this I am not sure the full kit sans-turbos is the best?? I may be wrong though

The intercoolers have been proven to be a bottle neck on the dyno at around 600-650whp a few guys have switched to Greddy units and found it much more efficient when i was building my car a few others were also pushing the limits of an 850bb kit (Rookie & XKR) they both saw gains just by swapping to the Greddy IC. I still run the twin intercooler set up myself and if i ever get back to the dyno i am going to see if i can make over 700whp with an unmodified JWT 850bb kit and i dont really plan to change anything at this time.

Not alot of guys have pushed the limits of the JWT kit so you might gain some new knowledge to share with us. I am curious to see what turbos you use and what mods need to be done to make them "fit with the JWT manis just incase i ever have the urge to go bigger. I am glad you did you did choose this kit to go for big power like I said I hope your build can help us gain more knowledge of the capabilities of this kit.

Good luck and keep us updated on your progress

 

Sylvan,

I will most definitely keep an eye on the intercooler set up. If it is a restriction, we will probably use some Garrett cores that we have here and make some end tanks.



Updates will be posted, thanks

 

I'm trying to upload a 49kb jpeg and it won't let me.

 

hey Jason,

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