R34 GTR cams -> R32 GTR ??

[SteveL]

Is there anything to be gained putting stock R34 GTR cams into an R32 GTR (also pretty stock) ?? Can probably get a set 'cheap'....

Also i assume they would 'bolt in' (valve clearances to be checked, of course).

TIA

[Gav]

Funny you should mention this. Just got the latest HPI magazine (delivered to Bulgaria) and they go through the differences in the R32,33 and 34 RB26 donks.

They state that the R34 cams are NOT compatible with earlier RB26 heads.

[gtrken]

You would need the R34 CAS as well because the dog tooth configuration is different.

Cheers

Ken

[SteveL]

You would need the R34 CAS as well because the dog tooth configuration is different.

That's probably why they aren't compatible according to what Gav mentions.

I just checked FAST and the bare R34 GTR head (PN 11040-05U00) is listed as a direct replacement for the original R32 GTR head (PN 11040-05U80), but the cams for each have quite different PN's, plus the R34 GTR cams are not listed in the supercession chain for R32 GTR (the head was).

This means that the cam journal's, lifter bores, seal bores, etc are the same for R32/R34 GTR (and probably R33), but something to do with the cams is not. Since both inlet and exhaust have different PN's between the models, it must be more than just the CAS coupling (eg cam sprocket mount/location).

[gtrken]

Steve, pretty sure they fit, just the CAS is the drama.

Get onto PNBlight ( peter Blight ) on this forum. He is from Bunbury WA and fitted a pair in his R33 GTR I believe.

Cheers

Ken

[SteveL]

Steve, pretty sure they fit, just the CAS is the drama.

Get onto PNBlight ( peter Blight ) on this forum. He is from Bunbury WA and fitted a pair in his R33 GTR I believe.

Ta, will do.

[rev210]

I fitted R34 GTR cams (tomei 260deg 9mm lift) to my R32 gtr.

Yep the input to the CAS is different and you need to modify the CAS to make the exhaust cam fit into it.

Unless you are a fearless / foolish shed mechanic with a little bit of skill (or is that luck) like me don't try it or you will not like the costs you will incur from the damage it might cause.

As for factory spec R34 cams.... what a monumental waste of time, not to mention you could be quite unlucky with the shims side of things and that will cost you too. No gains at all is my bet. The words cheap and cam upgrade are not often used together.

R34 turbo's are certainly an 'upgrade' the cams are not.

[SteveL]

Well turns out they were brand new R34 GTR N1 cams so I grabbed em for $280 the pair, which I didn't think was too bad.

As for modifications/machining doing valve clearances...doesn't bother me, I have a lot of experience as well as access to a wide range of metal working equipment, in fact I regard it as something of a challenge

Thanks for all the input.

[lwells]

Do post back with your progress

LW.

[ylwgtr2]

Hi steveL.....I fitted a set of R33 GTR Hks cams to my R34 GTR....what i done with the cam angle sensor was put the engine at TDC (with the std cams) marked the disc in relation to the CAS body then I took the dog drive off....then i took an old 32 CAS and took off the internal spline drive coupling and glued up the 34 CAS shaft(slow drying glue)then slid it over the 34 CAS shaft.....i then fitted it in the engine and rotated the CAS shaft by spinning the disc on the front until the marks i had put on there earlier lined up...i then let the glue dry then removed the sensor.....i then drilled and roll pinned the internal spline coupling to the shaft and its still working to this day...

Hope that helps some

Oh i think from memory that i lathed down the 34 shaft to make the coupling

fit on....i done this a while ago

[rev210]

Well turns out they were brand new R34 GTR N1 cams so I grabbed em for $280 the pair, which I didn't think was too bad.

As for modifications/machining doing valve clearances...doesn't bother me, I have a lot of experience as well as access to a wide range of metal working equipment, in fact I regard it as something of a challenge

Thanks for all the input.

Thats cheap for a set of new cams. However there is no gain to be had over what you have now.

The valve timing is the same for both the N1 & standard R34 gtr.

In opens 3BTDC, closes 57ABDC

Ex opens 59BBDC, closes 3BTDC

As you can see with the same lift as the R32 cams there is nothing that makes the effort worthwhile from a power perspective. For the same money you could just buy a couple of adjustable cam gears bolt them on the stock cams, and then you will be able to gain some real power in about an hour or work.

Hope that saves you some time.

[SteveL]

In opens 3BTDC, closes 57ABDC  

Ex opens 59BBDC, closes 3BTDC

These are timing figures, not lift. I've read elsewhere that the lift is greater for N1's compared with stock (not a lot, but more nonetheless),

We'll see.

Oh and I can get a set of locally made adjustable cam gears very cheaply (mates rates ), so they'll be going on as well. They're not the fancy coloured ones but do the same job.

[rev210]

I didn't post the cam lift as it is identical. I posted the timing as I thought you already knew the valve timing for the R32 since the R34 is slightly different, although not in a way that would benifit power.

To save you some time the lift is the same based on cam specs @ seat to seat

Int Lift @ Valve: 8.58mm

Exh Lift @ Valve: 8.28mm

For both R32 gtr and R34 gtr. Thats why people sell their R34 N1 spec cams and upgrade them to aftermarket 9mm lift units.

The cam gear is a good way to go, who needs pretty ones when the cam gear cover hides them, nothing like mates rates

Most people have found the R32 cams like 2 degrees advance and 4 degrees or retard timing wise as a base for stock turbo's. Things would vary a bit based on different turbo's and boost for these settings I'd imagine.