Hello everyone. I hope I can get a detailed answer for my curiosity. Can a VQ35HR cylinder heads be installed on a VQ35DE short block? If so, what is involved? Can I use the parts from the stock DE engine or do I need HR parts? I am thinking of performing this on a 2006 G35 Sedan with a 5 speed Auto/sequential shifter.

 

If you do this I will do it next.

 

Check out this forum post on it:

http://www.nissanclub.com/forums/eng...ort-block.html

 

Thanks for the link, but I have already looked at the thread before I posted here. I did not find information specifically about a RWD VQ35DE motor from a 2006 G35. Most of them are Maximum and Altima owners.

What I did read, the motor for the FWD and RWD VQ35DE are different. Also read customization is required if you want to put a HR head from a RWD on a FWD VQ35DE motor; but what about if the motor is already for a RWD? The difference stated in the thread was the tranny hookup between the HR block and the DE block and also something about the deck being too high and needs to be shaved so the DE intake manifold can be used; otherwise, you would have to buy additional parts or modify your old parts. But was the comment referring to a RWD or FWD, and is it a 6MT or a 5AT.

I also read on another forum (do not remember which forum) that someone did a motor comparison between the VQ35DE, the rev-up, and the VQ35HR (did not mention the year of the engines.) Within the thread it had a head comparison between the HR and DE.

Discovered that the rev-up and the HR heads are almost identical and the DE heads have measurable differences. The cooling passages as well as the exhaust and intake passages are bigger on the HR heads than the DE. The intake valve diameter is bigger and the exhaust diameter is smaller in the HR than the DE. The heads are the same in size and will use the current head bolt location, but that is where it went off on tangents and the thread lost its momentum. I have read many threads pertaining to the topic, but the thread always broke off into tangent and speculations.

One of the forums, someone stated that the variable valve timing gear is on both the exhaust and the intake; where on my 06 G35 it is only on the intake side. Also stated that the ECU controls the variable valve timing. How does it do that when there is no connectors or sensors on that gear? Is the gear set to a certain tension for a specific speed/rotation and when the the gear spins to that speed/rotation, then the gear reacts accordingly? Does the gear on the exhaust side do the same thing? I noticed the gear on the exhaust side is like a tension filled wind up coil. Why did they do that? Wouldn't it be better to place the gear from the intake side there too? Would it work that way? Is it for smog purposes?



I don't know much and I'm just scratching the surface, but I need to understand why this can or cannot work. All of your help would be most appreciated. Yeah, I live in California, and they have one of the most strict smog laws in the United States. I still want to be smog legal and yet maximize my cars potential.
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2006 Twilight Blue Infiniti G35 Sports Sedan | Stillen 2nd Gen Cat - Back Exhaust | Stillen lightened standard size pulley set | Motordyne ISO thermal TB cooper bypass 5/16 Plenum spacer kit | JWT pop charger with Z-tube | Tokico Blue HP suspension | LED in and out (where applicable) | AMS Oil in the motor, tranny, and rear diff w/ slip lock | Slot / drilled rotors | Back windows 5% tint; front windows 55% tint | Misimoto External Tranny Cooler | 1 7/8 core full aluminum racing radiator | Super Blue in the Brake line | Tranny sequential shifter adjusted for immediate shift by Infiniti Marin

 

Does anyone know the answer to my question? Can a HR head be placed on a DE short block? What's involved?

 

did you ever try this?

 

I've looked into it but since the block deck heights are different, cam sensors are located in different positions, lower intakes are different because of deck height, HR uses mag exhaust actuation, piston valve notching is way different and even if you got a HR head bolted onto the DE you would need to check valve clearance because the HR has larger valves and the DE pistons may hit. I'm not sure about the timing cover working either.

If I was going to put a HR in a older gen car I would just move it all with the wiring harness and ECU. The lower end of the HR is just plain awesomeness anyway so you might as well use it too