Jump to content
SAU Community

RB25 + inlet cam gear

Skyrine-Dave
 Share

Recommended Posts

lukevl Collaborator

lukevl

Posted
Posted

If you buy Jap cams for the RB25VVT they will have a conservative inlet so it can run with the VVT. Buy cams to suit a non-VVT Rb25 or RB20 that way your HKS gears (I assume they are the same- 4 bolts and a pin) will bolt on and you will have no VVT.

Link to comment
Share on other sites
Sydneykid Grand Master

Sydneykid

Posted
Posted

I have used the Tomei Poncams (256 for RB25DET and 260 for RB25DET Neo) in a few engines and they work very well. I have tried an adjustable exhaust camshaft pulley on 2 of them and found no improvement. They appear to be very well timed standard.:cheers:

Link to comment
Share on other sites
Skyrine-Dave Mentor

Skyrine-Dave

Posted
  • Author
Posted

Gary thats good info that has been repeated alot around here i have noticed, BUT

does the inlet cam have 4 bolts + locating pin or does i just have 1 big bolt to hold the VVT gear on?

What sort of cams would be suitable in an RB30DET situation.. Limited to 8.5mm lift due to rb25det head?

Reason why i have concerns with the Tomei cams is that they are made to work with the VVT, so therefore you would still bolt the stock cam gear on thus would have the incorrect bolt pattern for my HKS RB cam gear...

Link to comment
Share on other sites
Sydneykid Grand Master

Sydneykid

Posted
Posted
Gary thats good info that has been repeated alot around here i have noticed, BUT

does the inlet cam have 4 bolts + locating pin or does i just have 1 big bolt to hold the VVT gear on?

What sort of cams would be suitable in an RB30DET situation.. Limited to 8.5mm lift due to rb25det head?

Reason why i have concerns with the Tomei cams is that they are made to work with the VVT, so therefore you would still bolt the stock cam gear on thus would have the incorrect bolt pattern for my HKS RB cam gear...

I am certainly not the only one that has found that the RB25DET Tomei Poncams don't need adj pulleys, Croydons have reported the same on a few cars as well.

The standard internals RB30 is not a big rever, so it doesn't really need big duration cams. The 256's should work VERY well. The 8.5 mm lift is not "limited by the RB25 head", I have used the Jun 256/9.3 mm in an RB25, but the valve springs needed to be changed.

As for camshaft selection, it was suggested to me that the RB20DET 256/8.5mm camshafts would work OK in an RB25DET cylinder head with adjustable camshaft pulleys. I have not personally tested this though, but the source is reputable.

Hope that is of some help:cheers:

Link to comment
Share on other sites
Skyrine-Dave Mentor

Skyrine-Dave

Posted
  • Author
Posted

Gradenko: I'd be interested to know how they managed to put that cam gear on the inlet cam!

Does anyone know anyone with Tomei Poncams installed in an RB25DET head? I want to know what the profile is on the front of the cam to hold the cam gear on... Is it 4 bolts and a locating pin, or is it the same as stock with a single bolt??

Link to comment
Share on other sites
  • 2 years later...
ovabooster Collaborator

ovabooster

Posted
Posted

just checked my tome poncams 260 for my neo. the inlet has one bolt.....dat suxs coz i got a set of tomei adj cam gears to go aswell!!! Anyway of still installing it???? And if it could be done then the hud on the stock inlet could be removed?

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Sleepergm
      Max horse power stock internals?

      By Sleepergm · Posted

      And yes would be going to tomei Japan for sure as it’s closer to me … 
    • Sleepergm
      Max horse power stock internals?

      By Sleepergm · Posted

      Yeah I heard the same. Might be hard to order one. But then I guess can go to hks or go to a more expensive n1 block with tomei. Guess will jump the hurdle once I get there next upgrade around. I can’t get work done in the states as the lead time will take for ever on top of shipping to Hong Kong. 
    • joshuaho96
      Max horse power stock internals?

      By joshuaho96 · Posted

      https://www.platinumracingproducts.com/en-us/products/nissan-rb26-cast-blocks This is the solution I was thinking of. I would stay away from Tomei USA, their quality is a question mark to me. If you want an engine machined in the US contact Club DSPORT: https://clubdsport.com/ Tomei JP is probably fine but I recall they stopped doing pre-assembled short or long blocks. In general it's pretty tough to get any kind of RB26 block at the moment with Nissan so severely backordered.
    • joshuaho96
      Nismo front and back LSD

      By joshuaho96 · Posted

      PAR specifically offers stock ratios in their gearset and you could do whatever ratios are physically possible supposedly for no extra cost. I agree 6 ratios is better than 5, the factory 2nd gear is equivalent to the Getrag 2nd gear if you account for the differing final drive ratio though. The Getrag 3rd gear with a 3.916 final drive is equivalent to a 1.6 2nd gear in the FS5R30A. I'm about to swap the transmission out on my car, I'm tempted to send the one I have now out for rebuild with the standard "cross ratio" gearsets out there to see if it really makes such a big difference the next time I pull the transmission.
    • Sleepergm
      Max horse power stock internals?

      By Sleepergm · Posted

      This is what I was looking at next:  https://www.z1motorsports.com/engines/tomei/tomei-rb26-28l-short-block-assemblies-p-45479.html as we can’t bore the cylinders out in hk so better just buy the whole lot in one and install then retune. Everyone saying the weak link are the bolts holding the rods together. I already did valve springs, arp head bolts, hks racing coils, nismo fuel pumps and pressure regulators, injectors etc for the top of the engine. 
×
×
  • Create New...