What Is The Largest Spec Cams I Can Fit To My Gtr Head

[Marko R1]

hi guys,

i am looking at upgrading my cams but i want to know how far i can go with the rb26 head before i need to change buckets & springs...

as far as i am aware tomei pon cams @ IN 260/EX 260 Lift 9.15 is close to the max?

fyi im building an rb30 & my goal is 400+awkw (street setup)

regards,

marko

[N1GTR]

You can use stock valvetrain and get that number. Just use lots of head porting and boost.

[proengines]

Up to 264 advertised duration around 9ish mm lift. That's for the off the shelf Japanese ones anyway.

[The Dan]

You can use stock valvetrain and get that number. Just use lots of head porting and boost.

+1

[Swiper the Fox]

You can use stock valvetrain and get that number. Just use lots of head porting and boost.

a stock head with 'drop-in cams' will make 400KW. No need for porting.

[Weapon]

HKS make 272 deg drop in cams with 9.15mm lift last time i looked around

[Marko R1]

paul - my cams are as follows:

A269IN (inlet) has 'U6' stamped on it

A252X (exhuast) has 'U7' stamped on it

lift are identical @ 9.15mm (as per my vernier)

[...Joshwa]

I donno about a RB26 head. .

But I got a set of custom cams made for my 25/30. . Running 264 10.7mm lift on intake, 270 10.2mm lift on exhaust. .

Using stock lifters and springs etc etc.

[sneakey pete]

You can use stock valvetrain and get that number. Just use lots of head porting and boost.

Lots of boost. yeah, who cares about response...

[pure_methamphetamachine]

9.15mm lift. ANy more and you have to machine the head

So:

Tomei Poncam

HKS Step 1

A'PEXi Sttep 1

GReddy Step 1

You can get different durations from every manufacturer, but the lift will all be around 9.1 to 9.15mm

[Marko R1]

should i look at matching my exhaust cam with my inlet cam taking into consideration the below specs:

A269IN (inlet) 9.15mm lift

A252X (exhuast) 9.15mm lift

...or can the 252degree be adjusted out with the cam gears - NFI

[Angus Smart]

i just went and bought

tomei 270 11.8mm and tomei buckets.. obviously needs work for cam lobe clearance and buckets replaced.

i thought since the bottom end will be pretty soild, the top end deserves a bit of a tickle too..

i'll prob have a set of hks or tomei cams for sale that will suit standard buckets. will get them measured up when i pull em out.

[pure_methamphetamachine]

You going to use step 2 or 3 springs Angus?

No offence, you know your pistons need to be scalloped for that lift?

[Angus Smart]

You going to use step 2 or 3 springs Angus?

No offence, you know your pistons need to be scalloped for that lift?

Using supertech springs, you sure about scalloped?

[Beer Baron]

lol, with nearly 12mm lift you will be highly likely to end up with valve meeting piston and any decent rpm... it will certainly need checking and most likely new pistons.

[Swiper the Fox]

lol, with nearly 12mm lift you will be highly likely to end up with valve meeting piston and any decent rpm... it will certainly need checking and most likely new pistons.

not exactly...there is a way to keep everything friendly. Its doesn't involve pistons either.

Edited March 24, 2009 by DiRTgarage

[Beer Baron]

yeah of course there are ways to stop it happening, but they only work if you do it before your engine is built. ie it needs to be checked while everything is in the build.

[Angus Smart]

i'm sure my engine builder will not have a problem at all.

nothing has been built yet... slowest build ever perhaps?

[Marko R1]

good things come to those who wait

[Beer Baron]

i'm sure my engine builder will not have a problem at all.

nothing has been built yet... slowest build ever perhaps?

then you have nothing to worry about.