Jump to content
SAU Community

Recommended Posts

Hi guys,

Im in the process of planning some head work and looking at the available options in the way of a 1mm oversize valve set for my RB26 head and im hoping someone can shed some light on exactly what is available and from where. Ferera, Nitto and Naprec are the only brands I have heard of, are there any others worth looking at?

Also on this subject, what other components in the head will need to be changed to facilitate the larger valves?

Thanks :D

Link to comment
https://www.sau.com.au/forums/topic/173364-oversize-valve-selection-rb26dett/
Share on other sites

Hey dude i had my oversize valves made by manley in the US. they fabricate head components for muscle cars but they do custom orders. the valves have exelent alloy propertys and havent shown a sign of wearing, even using my 10.35mm lift cams. youll need to change the retainers, the springs, the lifters, the valve stems need to be complety reworked, and your head will need a nice port and polish job to suit the rest of the components. if you have any questions feel free to pm or mail me. ill do my best in helping you setup your head

Hi Nick

Give proengines a call he makes his own valves and gets some after market types as well check this out might explain more, http://proengines.com.au/perhead.html might help

Cheers Peter

Or talk to nas at thornleigh he did 1mm oversize valves for us, not sure of the brand of valves. Apart from the valve seat nothing else had to be changed for the valves, although we did get the head releived to clear the cams at the same time, and porting of the inlet (and a clean up on the zorst side)

Or talk to nas at thornleigh he did 1mm oversize valves for us, not sure of the brand of valves. Apart from the valve seat nothing else had to be changed for the valves, although we did get the head releived to clear the cams at the same time, and porting of the inlet (and a clean up on the zorst side)

Curious why they would port the inlet and only clean up the exhaust side, when it is common knowledge that the exhaust side is where rb's need the most work

Nick having used a few different brands over the years heres a little wrap up I have made

FERREA are far and away the best....

NAPREC are bigger being 1.5mm oversized but the trumpet angle is the same as standard, around 16 degrees, now this is far from optimal and something nissan could have done better, as the greater the angle, the more flow. They are still good though and do as well as the FERREA's in flow testing just a hassle to order them.

Haven't used Nitto or whatever, but I have used Ferrea's a few times and they are good quality at a good price and have 20 degree angle.

Manley are awesome but you can only get them in blanks, getting them to make customs for you is like having a baby, it takes a long time there is a lot of pain in the arse and crotch but you get a good result at the very end!!!

Hope this helps

I've currently got 2 heads here that I'm doing, one using 1.5mm o/s Naprec valves and one using 1mm o/s Ferreas and personally I would go for the Ferreas. They have a better finish, for example the raduising on the valve heads. The Naprec valves use a 6mm stem on both intake and exhaust which require custom exhaust guides while the Ferrea uses a 7mm exhaust stem, the same as standard so you don't require different guides or seals.

Another option is the Pep Pro valves, these are sold by Austral distributing. They are Taiwanese and are a top quality valve and a little cheaper than the others, definitely cheaper than a genuine Nissan valve. They are made by Shin Ichi which distributed in the US as SI Valves. I have used them in a lot of different engines without any failures.

After saying all that, the standard valves dont have issues. I have a head here that made over 700 RWHP with standard valves and they look like new.

  • 8 years later...

Hey dude i had my oversize valves made by manley in the US. they fabricate head components for muscle cars but they do custom orders. the valves have exelent alloy propertys and havent shown a sign of wearing, even using my 10.35mm lift cams. youll need to change the retainers, the springs, the lifters, the valve stems need to be complety reworked, and your head will need a nice port and polish job to suit the rest of the components. if you have any questions feel free to pm or mail me. ill do my best in helping you setup your head

what exactly has to be done to the valve stems? if they needed to be modified, i would think the valve keepers would need to be as well?

what exactly has to be done to the valve stems? if they needed to be modified, i would think the valve keepers would need to be as well?

Hey Tim,

Might be worth starting a new thread as this one is from 2007 and info is bound to be out of date now.

  • Like 1

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


  • Similar Content

  • Latest Posts

    • Haha luckily we don't have emissions, inspections, or any laws against power adders here. They only thing they somewhat keep an eye out for are ridiculously loud exhausts. 
    • Just wanted to pop in an update on my setup. The CD swap has been great, I love the mazworks housing for the overall simplicity. I ended up sealing my trans tunnel with a thin sheet of aluminum reused some of the holes on the trans tunnel, and laid some window sealing EPS foam around the edges. Works great, really quieted things down and sealed up the car.  As for the power comment. Right now I am also running about 650whp. with the way the bell housing is attached to the face of the transmission I have zero doubts it would be fine, mainly because the input shaft and main shaft bearings are seated into the bell housing adapter. This means the load is NOT on the bolts to maintain the power, rather into he casing of the bell housing; Yes the bolts are doing some work there, but with both shafts locked in zero worries.  End of the day, the Mazworks solution is the easiest and safest. no need to take your trans to a shop to get milled perfectly, it fits with minimal clearancing, and you can use all your existing clutch and flywheel.  Driving wise the CD has been great compared to the big box, I'll probably swap my final drive at some point. The serial 9 shifter is gooooood, my only qualm is how tight it is, it takes a fair bit to get use to, 5th and 6th are a bit eh/hard to find at times, but maybe I need re-adjusting, and I think my clutch master is very tired and needs a rebuild. 
    • If you are keen, have a look at my build thread. Car is for sale for the right money or straight swap for a F80 M3 LCI.
    • Welcome mate.  No point in over thinking it, buying any one of those cars you mentioned is not a smart or logical choice with the availability of many "better" (re price to performance) cars available to you.  The heart wants what the heart wants, buy whatever it leads you too.
    • Hey everyone! Im so grateful to be apart of this community and ill do my best to be apart of this. Firstly, i'm not disclosing my real name due to in real life circumstances surrounding my privacy and public image (sorry lol) Secondly, The only thing personal I am willing to share is that I'm from Sydney and a descendant of one of Sydneys largest mortgage firms. I got gifted my first ever car, a 2022 Porsche Cayenne and I love it to death. Ive been driving it for about 5 or 6 months now and honestly Im so grateful for my parents for gifting me this vehicle. However recently I've been working my ass off to afford my second car (which I need help deciding soooooo community help me out please?). Once decided, im planning to try modify it myself. Recent I've been thinking about getting a Skyline, particularly a 25GT or GT-V, yes I know overrated as hell, but I'm also considering a Chaser which I recently came to love. However my dream is to one day own a 180SX (So hard to find clean versions and im not really into importing).  Lastly before I send this off, I want to apologize if I sound tacky or pretentious. I try not to and want to genuinely learn from everyone and anyone. (Im no expert in this area) Thanks for reading!
×
×
  • Create New...