RB26 camshafts in RB20??

[bbenny]

Hey i have done a search without alot of success.

I read in another thread sydneykid and Roy talking about installing standard RB26 cams into an RB20.

I just wanted to know more about it. who has done it. what changes to the head are necessary and what sort of gains seen from such a modification.

any info would be great.

Cheers!

[autObarn]

if you have access to cheap sh rb26 cams and provided no machining is required it may be worth it, but hks rb series cams are cheap and fall in, no mods, no hassle.

[Sydneykid]

1. who has done it

2. what changes to the head are necessary

3. what sort of gains seen from such a modification.

Hi Benny,

1. We have, 4 so far

2. None

3. Very much depends on what else you have done. But from what we have seen, you will get;

A. earlier boost build

B. faster throttle response

C. about 15 rwkw increase in the average power from 4,000 rpm to 7,000 rpm

D. about 10 rwkw increase in max power

If you are on a budget and can do it yourself it is very worthwhile. If you can't DIY then you may well be better off spending a few hundred extra on used aftermarket cams, as the fitting cost will be the same. As Autobarn suggested, there are a few HKS 264's around that are a step up from standard RB26 cams

Hope that helps

[jnr32r]

What sort of power increase would you expect from HKS 264s with a turbo like a 2535 on an RB20?

[Sydneykid]

What sort of power increase would you expect from HKS 264s with a turbo like a 2535 on an RB20?

Maybe another 5 to 10 rwkw.

[bbenny]

Thanks sydneykid.

hmmm well im always keen to try it myself. however i have never installed cams before. but it hasnt stoped me from doing everything else to my car

ill have to read up on it first. any advice?

is there a large price difference between step 1 HKS and GTR cams?

[Sydneykid]

Thanks sydneykid.

hmmm well im always keen to try it myself. however i have never installed cams before. but it hasnt stoped me from doing everything else to my car

ill have to read up on it first. any advice?

is there a large price difference between step 1 HKS and GTR cams?

Hi Benny, since used pairs of standard GTR cams are pretty common, I wouldn't pay more than $300. Used HKS (or any other Japanese brand name) cams seem to go for around $800 for the pair.

[Chris32]

I am also keen on doing this,

SK - have you noticed any differance between R32/33/34 GTR cams? each one seems to come out with differant torque from the factory, just wondering if this is cam related or something else?

Seems like a really good mod, I assume there are further gains to be had with adjsutable cam pulleys as well? Any setting you can recommend to try?

Chris

[Sydneykid]

Hi Chris, I haven't seen any difference between R32 and R33 GTR cams. The R34 exhaust cam has slightly different lobe centres, but it is pretty minor, most likely for emmissions anyway. Adjustable camshaft pulleys are worthwhile, if they fit your budget. I usually start at 2 degrees advanced on the inlet and 4 degrees retarded on the exhaust.

Hope that helps

[Chris32]

Cheers, now just need to find a set and I'll be right! I will get some cam gears as well to optimise the whole setup

Thanks for the info, those pulley settings seem to be what everyone ends up at with RB26's, would those settings still apply for RB20? I guess the best test will be to install them and have a play on the dyno to see whats best, but I guess they will be a good starting point

Chris

[Sydneykid]

As I said. +2/-4 is a good place to start.

[aybee]

sk: when you say they boost power by ~5-10rwkw, is this top end or more in the middle?

[Sydneykid]

sk: when you say they boost power by ~5-10rwkw, is this top end or more in the middle?

Depends on how you tune them.

[bbenny]

thanks for the info Sydney kid, i am just getting a pair of adjustable cam gears, but i think i will add a pair of GTR cams to the trolley and see what results i get.

for everyone interested i will post the results before and after so we can see the true difference.

Oh and any advice when installing them?

[jnr32r]

Anyone know what the difference in specs between the RB20 and the RB26 cams are. Im guessing the RB26 have a longer duration as the HKS would but maybe not as much???

[Sydneykid]

Anyone know what the difference in specs between the RB20 and the RB26 cams are. Im guessing the RB26 have a longer duration as the HKS would but maybe not as much???

Cam timing is pretty much the same (240) but the lift on the standard RB26 cams is much higher (8.6 mm vs 7.8 mm). So you don't loose a lot down low, but the extra lift is great all through the rpm range. Most brands of aftermarket 264's are around 9.2 mm lift and, depending on the condition of the hydraulic lifters, this can be a problem. Plus you loose a bit down low because of the longer duration.

The standard RB26 camshafts into RB20's is a real good, cheap upgrade.

[bbenny]

regarding the difference between an RB20 using hyrdaulic lifters and GTR using solid. it is still ok to use the hyrdo or do i need to change the whole thing?

also what valve springs would you recomend?

thanks!

[Roy]

Whats the go with hydraulic lifters if your current ones are a bit tired. I have been given a price to service a head, lifters and all, but what is involved?

Ive got the cams, valvesprings and cam gears to go in, but if you have a slightly noisy lifter on startup... im imagining its time to do something about the lifters at the same time as the GTR cams go in. ... What started out a s a cheap/budget upgrade to try and fill the lungs of the TD06 a little earlier is slowly turning into a pricey build.

[bbenny]

hmmm thats what i was afraid of roy, something simple and cheap(ish) getting all nasty on me!

have you done the cam instalation yourself? how difficult is it. the only thing im worried about is setting everything in alignment - top dead centre or whatever. i dont want to make a mess of things when i get it all going.

[Roy]

To take the head off and instalibng the cams isnt a real drama, doing it with the head in place holds a few challenges which means i may not be able to do it myslef...

plus with my new accomodationin i no longer have a suitable place to work on my car. The compression test on my engine next week, and a few things falling into place the next 24hrs will play a big role in whether i bother with my current engine, or start with a blank canvas.