Jun Rb25 Cams

[1FSTKR]

Hi,

i have a set of Jun 272 cams with 9.3mm lift. just in the process of re-assembling my head but does anyone know the optimal cam setting to start these bad boys off on????

[PM-R33]

Did you go solid lifters in the 25 head for that much lift?

[1FSTKR]

keeping factory lifters

[KB240RB]

A tad off topic but it relates, how big of a cam (duration and lift) can you use on stock RB25DET S1 valve springs?

[1FSTKR]

hi,

i think anything over 8.9mm of lift you need to machine the head and get new springs

[KB240RB]

Ah ok. Why would you need to machine the head for just adding cams?

[1FSTKR]

its the height of the cam lobe and clashes with the side of the head

[KB240RB]

Damn. ill have to watch out for that when i decide to upgrade the cams.

[TiTAN]

also issues with pushing the hydraulic lifters down too far

[KB240RB]

Probably just best to upgrade to solids when doing cams. I love the solid lifters in my SR20. Just revs and revs with no worries.

[PM-R33]

Until a rocker arm breaks off

Just stirring.

[1FSTKR]

solids are the ultimate, dont get any issues with high revving engines compared to the factory ones

[2rismo]

If the Jun cams are new the info should be on a cam card/sticker on the box. You'll have a degree figure for both the intake and exhaust. Ask your engine builder where they think they should be set but 115btdc and 115atdc will probably get you started. The engine builder should check clearance on them though.

[KB240RB]

haha yeah SR's are known to break Rocker Arms on the stock valvetrain. Ive got almost everything upgraded though. Ive hit 10krpm a few times doing burnouts and such with no issues. Engine has over 10k miles of daily driving and daily drag abuse. Its been good for the little engine that could.

[PM-R33]

10,000rpm........ *drools*

Edited December 5, 2008 by PM-R33

[1FSTKR]

If the Jun cams are new the info should be on a cam card/sticker on the box. You'll have a degree figure for both the intake and exhaust. Ask your engine builder where they think they should be set but 115btdc and 115atdc will probably get you started. The engine builder should check clearance on them though.

thanks for that, i lost the box so though i would ask

[2rismo]

Mate, email or call whoever supplied them and ask them what the install specs are off their stock.

[1FSTKR]

good idea

thanks