I have been told by Gord Bush who ported the first set of heads that the intake ports are pretty great - not a lot of room for improvement. However, he feels he can find some more flow through the exhaust.

The problem is as the build continues the engine needs more RPM to continue to make more horsepower, the DE block doesn't seem to have the stiffness to support higher RPM. Oil temperature on the DE would climb rapidly above 7500rpm. That is the main reason for switching to the HR - I need 9000rpm reliable to make 400+ whp.

 

I bit my tongue on this one. Glad to see you did not.

Thanks for SHARING all you know with the community.

 

Yes, Maxima timing components and covers will work, but then the Alternator mount is in the wrong location. (alternator is above the AC compressor in FWD set ups)

Maxima LIM will bolt on but the Maxima uses really funky shaped ports and the intake manifold bolt holes are 6x1.0 and bolt pattern to HR manifold is diffent

HR LIM will not bolt up due to the heads are not far enough apart due to the deck being shorter, I worked on making and adapter plate for short deck HR idea, but then Nissan decided to make a short deck HR (I am surprised no one knows what car it is in), so I gave up on it...

And I am tired of everyone whining so I will spill the beans, the G25 is a short deck'd HR, but is a 2.5 so there is little bitty pistons in it... so there now you know

 

Couldn't find any pics of the VQ25 LIM, is it also a rectangle port LIM?

I'm assuming by your little bitty piston comment that the runner diameter is very small... any room to port them out?

Just brainstorming here... Ultimately the ported Revup head with ITBs will probably be the most cost effective way to make the most N/A power anyway. (never thought I would type 'cost effective' and 'ITBs' in the same sentence!)

 

I have a ported Revup head. And ITBs. Not going to tell you what I'm going to do with them, though. It's proprietary info.

 

Found this

Hal@Dynosty 06:12 AM 07-05-2011 The answer is yes. Revup heads can be used one of two ways on a nonrevup engine: 1. As nonrevup heads, using nonrevup cams. This requires our blockoff plugs. Contact me to purchase. You will use nonrevup front covers for this. 2. As revup heads, using revup cams. This requires some wiring and a Haltech, or swapping stock computer and having the dealer flash. You will also need revup front covers.

 

nice find , too bad FWD can't benifit from this

 

Hu?

That's revup vs DE. That's been a known 'easy' swap. Revup heads and DE heads are identical besides the magnetic exhaust timing components, which really are most useful for emissions purposes.

HR is a very different ballgame.

 

FWD dont want no revup heads, HR head 09 max motor is where its at for the fwd.