RB26 camshafts in RB20??

[Mr GTS4]

would it be better to have a set of adjustable cam gears aswell?

[mabru]

The differences are enough to screw up cam timing but shouldn't be enough to cause valve/piston interference. I have a friend here that runs a shop and he swears up and down that he's done a few RB25DETs with RB26 cams and they have no issues. I'll give it a go soon. I have a wonderful Japanese comprehensive inspection first though 8(

[Mr GTS4]

have you got around to doing the mod yet? m car is in getting paint at the moment

[discopotato03]

I've followed both strings on this mod , anyone have any idea why SK can get it to work and most others can't . What are the potential problems aside from bent cams/incorrect cam and CAS timing/cam journal cap bolts . In other words if the cams are exchanged with no dramas and the timing/s are the same its difficult to understand the idle problem . Nissan must have had the multi throttle system in mind with its anti reversion properties when they developed the RB26 profiles which would allow greater overlap period without the rough low speed / idle problems . I would have thought opening up the cams (reducing the overlap) would have got an acceptable idle ie enough trapping efficiency always assuming the valves closed . I guess a bit of reversion at the AFM could cause problems , does SK do anything different to all else here . Would larger capacity inlet ducting/MAF/IC/better filter make any difference .

Cheers A .

[browny]

does SK do anything different to all else here

I think thats the million dollar question. From memory he was going to put together a tech article about installing RB26 cams but I don't think he ever got around to it.

I'm just guessing here, but I wonder if there are some subtle cam timing differences that are causing dificulties (eg setting an RB26 cam up using the RB20 timing marks etc might not put an RB26 cam at true 0 degrees, instead it might be advanced or retarded a bit). Who knows tho.

[Chris32]

I still have my cams in the cupboard at home waiting for a definate answer!!

[Mr GTS4]

wonder if sydneykid could shed some light on the fact?

mine are in the shed awaiting as well. i just want to hear the difference with a nice lumpy note

[Mr GTS4]

has anyone tried this again? sorry to bring it back. sydneykid do you have any sound or video of the cams in a rb20? would like to hear the idle sound

[gtst4d]

do you still think this is a good upgrade sk or have things changed over time

[Mr GTS4]

sydneykid???

[N I B]

Im not sure anyones got this setup to work?

[Mr GTS4]

one did but idle was the problem on standard ecu, would it be possible to idle it upto 1500rpm to make it stable??

[N I B]

Why would you got to all the effort of solid cams and leave the ECU stock?

[Mr GTS4]

$$$

[TurboX]

one did but idle was the problem on standard ecu, would it be possible to idle it upto 1500rpm to make it stable??

A few weeks ago Turbine and I did this mod as I had the GTR cams I bought from Ronin7 and two adjustable cam gears I had enginered from the originals for $300.

We fitted the cams and had the same idling problem. Even setting them to 2000RPM would not have solved the problem. They sounded great though at 3-4K and strong. I think Turbine got a phone movie? Not sure.

Anyway had to pull them out the week after to go to the SAUVIC show so the car would be drivable.

Turbine says "oh well have to learn how to do it for the drag car"

Guess who ended up with the GTR cams and Adj Pulleys?!!

See my BLOG for more on this episode.

[ross80]

So, let me get this right to put rb26 cams in my car rb25det is as simple as purchasing and puting them in?

Around $300 for them right? And do i need an after market computer?

[Roy]

Forgetting the fact that ppl have had troubel getting ths to work...there isnt any really any solid info that you will actually make more power...so add the two up and i wouldnt bother with it.

Lukes01 i think it is offered to help me out and regrind my cams to suit, adn i was goign to take him up on it, but my cams went walk about so cant get them back...if you insist on tryign this, perhaps take a different tact and chase up Lukes01

[Turbine]

Yes Turbox, the cams are in the race car now.

They are standard RB26DETT camshafts both set to zero on the adjustable drive gears.

I fitted the standard RB20DE hydraulic lifters and the standard RB20DE camshaft brackets.

At first I had the cams fitted with no lifters, to get a feel for how they rotated in the head. NO problems at all, smooth and free. So out they came, fitted the lifters back in and refit the cams.

I did apply high temp anti-seize to all of the bolts that mount the cams in. I found that theri was moisture getting into the bolt shanks somehow :confused:

It's interesting that SK mentions about cam timing on the RB's with these cams as a nominal +2IN, -4EX starting point.

This would explain the idle problems when both are set to zero. Moving the cams like the above mentioned actually reduces the valve overlap by 6 degrees total.

RB20's dont have alot of airflow below 2500RPM compared to the big RB26, so....... the horsepower gain could only be through the higher lift.

I'm going to try them at zero first up because i dont care if it idles at 2000RPM, the converter stalls at 5000RPM anyway. I'll let people know how this works out in time.

Turbine.

[Mr GTS4]

"It's interesting that SK mentions about cam timing on the RB's with these cams as a nominal +2IN, -4EX starting point.

This would explain the idle problems when both are set to zero. Moving the cams like the above mentioned actually reduces the valve overlap by 6 degrees total."

so your saying if you did this you might have a better chance of it idleing alittle better?

[DRIFTER]

sk?