Rb22, Going Solid Lifters, Which Cams?

[Dave.TAS]

Hey guys,

Dont want to remove the head on my rb22 to drill out the oil restrictors, as my head is overly restricted for running tomei valve springs, too much seat pressure. Want to leave the head on it so that everything stays 100% perfect in that area.

Restrictors are 1.0 front, 1.2 rear. I believe Tomei reccomends 1.5mm front and rear for hydraulic head, and some other aussie companys reccomend 1.3mm front and rear. So mine obviously too restricted, hence the lifter noise.

So for $1300 i can go solid lifters and cams from tomei. Then sell my camtechs, recoup some money, and have a better engine for it. So thats how ive convinced myself haha

But still struggling to decide what size cams to go, I have tomei valve springs so they will handle anything i throw at it.

Options are

260/9.25mm

260/10.25mm

270/9.25mm

270/10.25mm

Car is street driven, gets a very hard time and will be used for some fun track days, no real racing.

Turbo on it at the moment is, due to budget restraints, RB25 stocko. Will later be changing turbo to most responsive 230-250rwkw.

GTR bottom end with N1 oil pump, stock harmonic balancer, Should be able to rev to 8000rpm ok.

Has camtech 268/9mm in it at the moment, idle sounds tough as but havnt driven it due to lifter noise so cannot say if power curve has been shifter up and right too much.

Leaning toward 260/9mm for better drivability, and its still alot bigger than standard.

Happy to listen to good discussion and valid examples etc etc

[Roy]

260/10.25 would be interesting. I am going to use Jun RB26 cams in mine

[Dave.TAS]

I dunno if the 10.25 drops in no machining required and wont touch pistons etc? I have heaps of Tomei RB26 cams at work, havnt looked at the specs tho. Also have stock 26 ones on the shelf

[Dave.TAS]

They are all BNR34 cams at work tho, not sure if that makes a difference..

[Dobz]

Apart from the lift side of things the stock r34 gtr cams are fairly close to the specs of the stock rb20 cams.

Check out this link: factory cam specs

Out of those tomei cams i'd definately go the 260/9.25 for the same reason you give. To make full use of anything bigger you'd have to do some porting.

Edited February 12, 2011 by Dobz

[Dave.TAS]

Thanks dobz, am aware of the factory specs, and rb26 stock cams would be ok and work nicely on a tight budget!

Any one else got anything to add?

[R31Nismoid]

Agree with Dobz.

And Bris... another cam change? haven't you learnt yet? lol...

[Roy]

Well, how much farking around has it taken over the years for the RB26 guys to learn the best combo of head, exhaust, cams and turbos? Nobody is playing with RB20s so it is taking me a long while. If i can get about 280-290rwkws with about the same response as I have now out of a $600 wrecker engine then the experimenation has been worth it...still well under the cost of a built RB26 with the -5/-7/-9 setup

I would actually look at running std RB26 cams before anything else. The R34 runs a difference CAS so ot sure if it talks to the ecu you are running?!?!?!?!

[Dave.TAS]

Ecu is nistune on the RB20 ecu, I could pick up a set of r32 rb26 cams for next to nothing im sure.

Having said that in SRs and CAs ive always had 256/264 drop in cams, and only saw benefits. So i cant really see why the 260 would have much loss, but happy to listen to people in the know!!

[Dave.TAS]

Will check if my spare CAS splines onto the r34 camshafts on monday just outta interest.

[Roy]

Apexi cams seem to use ramp rates different to others and can be tricky to get results from...well so the story goes. Here is my dyno sheet of an internally std RB20 with full Greddy TD06-20G setup before and after Apexi 260/9mm cams. I dont need to explain which colour is what...the std cams went back in so should tell the story

What dobz said, the Rb20 runs a fair bit of cam for a 2L. Remember that the 2L is spread accross 6 cylinders and not 4 so the air to each cylinder and combustion chamber is different to a 4 cylinder and its easy to over cam a 2L six and lose all velocity and cylinder filling...or so it seems.

[STATUS]

still cant belive your going to spend all that money on fitting solids when an hour and a halfs work would have it fixed..... crazy.

[Dave.TAS]

Still deciding trent, only thing stopping me pulling the head off is wasting that greddy head gasket. I have a cometic on the shelf that's new.

If I use gtr cams with tomei lifters it won't cost me anything once I sell the other cams and I'll have a much Better engine for less work??

[R31Nismoid]

Well, how much farking around has it taken over the years for the RB26 guys to learn the best combo of head, exhaust, cams and turbos? Nobody is playing with RB20s so it is taking me a long while. If i can get about 280-290rwkws with about the same response as I have now out of a $600 wrecker engine then the experimenation has been worth it...still well under the cost of a built RB26 with the -5/-7/-9 setup

I would actually look at running std RB26 cams before anything else. The R34 runs a difference CAS so ot sure if it talks to the ecu you are running?!?!?!?!

The head has been evolving each year or so - leave that outta the equation.

But you've just spent so much coin man and NEVER gone forward. Always lost response or power.

Im all for chasing that last 1/10th extra, but you've never found it. Get out there and drive it!

[Nee-san]

Well, how much farking around has it taken over the years for the RB26 guys to learn the best combo of head, exhaust, cams and turbos? Nobody is playing with RB20s so it is taking me a long while. If i can get about 280-290rwkws with about the same response as I have now out of a $600 wrecker engine then the experimenation has been worth it...still well under the cost of a built RB26 with the -5/-7/-9 setup

I would actually look at running std RB26 cams before anything else. The R34 runs a difference CAS so ot sure if it talks to the ecu you are running?!?!?!?!

Yeah, and look at how long the gt2860 thread is, not to mention how long the over 400kw thread is....

People still cannot point to a solution and say " It makes this power at this revs with this transient response because..."

X says you have to use 30000 degree cams with a big lift

Y says Nah Mate use standard cams

Z says I dont use cams a wizard makes my engine powerful

etc etc.

Edited February 12, 2011 by Nee-san

[Dave.TAS]

Gtr 240/8.5ish cams with tomei lifters or 260/9.25 with tomei lifters???

Anyone made solid inserts for stock lifters??

Hard decisions, either was 268/9mm whats in it now is way to big right?

Even if i go solid head then 1.0 F 1.2 R reistrictors is way oversize for solid head right?

Half seems like i should drill restrictors and put stock cams in it.

Someone tlel me what to do this is shit haha

[Dave.TAS]

GTR cams base circle 32mm, tomei cams which work with there solid lifters 29mm. How thick are the shims normally used in the lifters, as in if they are more than 3mm then i can use gtr cams with a thin shim. If not more than that then cant use gtr cams.

[Dave.TAS]

Using gtr cams and lifters, got cams just need lifters, got heaps of shims.

So if u know of a set of lifters let me know

[Roy]

Have you checked the valve stem length differences and whether you can use the GTR lifters in a 20? I have two sets of Tomei solid lifters for VG30, RB20/RB25 and they are different to RB26s and RB25 Neos, to the point that the RB26s obviously have longer valves ?!?!?! Intersting to see how you go

[Dave.TAS]

Yeah will have to find out this week when I measure up the 26 ones. Selling any tomei sets??