Hello everyone. I should of posted my questions here instead of in General Discussions.

Can get a detailed technical answer for my question. 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. I do not know much and I would like to know if it is possible and what is involved?

Thanks!

 

it's not a direct bolt on if that's the main question. There's a conversion that allows for the vq35de head to accept the vq35hr head gasket. (Better cooling channel) but it has to be machined to match. What are your expectations from this mod?

 

Curious. I am curious of what improvements or non-improvements to the function of the vehicle. Before my motor went south prematurely, it was a quick car and I had fun with it. Now since I have the opportunity to tweak with the engine but try and keep it sort of smog legal.

I have read that the HR motor has better internals (what most people on the forums are saying). I'm assuming the internals of the head are also better. I am in need of a set of heads for my DE motor. I can go with an 2006 stock heads or see if I can place a set of HR heads.

Of course the VVT gear for the exhaust side needs to come off. How does the VVT gear from the HR heads work? Is it controlled by the ECU set parameters by reading the crank sensor or does it matter?

I have read on My350Z forum, a member state, it will fit, but I need more information before I can do it.

Just reviewing, I am asking if it is possible to place HR heads on an 06 DE block and what is involved. I already have both type of heads. I will probably have to compare them this weekend. Also, I have read that the 2003 to 2005 VQ35 engines are compatible, but 2006 is different (don't know why). It would not go into specifics, but all the parts for the 2006 has different part numbers than the 2003 to 2005 depending on your VIN (according to Infiniti and part sellers on Ebay). I thought their all the same. Yeah, I was wrong!

Oh yeah, does anyone know where I can download a copy of the FSM for an 2006 infiniti G35 Sports Sedan?

I appreciate all of your help & opinions; Thanks!

 

Well, I got to take a look at my DE heads and the HR heads. There some differences, but all in all, there about the same. The differences that I see off the bat are the cam lobes, the VVT gear on the exhaust side, and cam sensor hole on the exhaust side. The heads actually look identical in length, width, and height. It would probably be different if I accurately measure the block.

I thought that I was done disassembling the motor but I am not even close. Man, there a lot of parts that needs to come out of the car, and yes, I am doing this in the bonnet with the front end still intact.

This is going to take me months to do since all I have one day a week to spend on it.

 

Also wondering the same thing. I'm parting out an '03 G35X Sedan and am going to keep the engine and do a complete rebuild. One of the things I was considering was whether or not its worth doing the DE to HR head modification. What exactly it entails and how much of an improvement it would actually make. Everything I have read so far states that there is machinist modding required to the block in order to properly fit the HR heads but nobody seems to have posted or given the exact details. I see that this thread is older but if you have figured it out or gotten any other information I would love to hear about it lol, Thanks