Jump to content
SAU Community

Recommended Posts

well starting to look into options to build up the old 20's bottom end as power and age is starting to take its toll on the old girl.

i think that i am gonna go with arias pistons for the pistons, but not sure what kind of rods to source out?

who makes rb20 rods if anyone?

also i plan on working the rb20's head a bit, if anything to just clean it up and perhaps enlarge the valves a bit to aid in airflow.

thoughts please!

Link to comment
https://www.sau.com.au/forums/topic/93802-building-a-rb20det/
Share on other sites

well starting to look into options to build up the old 20's bottom end as power and age is starting to take its toll on the old girl.

i think that i am gonna go with arias pistons for the pistons, but not sure what kind of rods to source out?

who makes rb20 rods if anyone?

also i plan on working the rb20's head a bit, if anything to just clean it up and perhaps enlarge the valves a bit to aid in airflow.

thoughts please!

err rb30's are single ohc .. :D

hey carl h...i have done pretty much what you want to do. i can say that the arias pistons are great.. haven't had any problems with them...they were nicely made with about 1 - 2 grams difference between the 6... so weight mathcing them was easy....

About the rods i dont know, i used the standard ones...just got them ballanced and weight matched....

in terms of head work i got the head ported and polished with 1mm oversized valves..you will find that ca18 valves are perfect for it..they are 1 mm larger than standard rb20 ones and fit with no trouble...

hope that helps....

Aaron

hey carl h...i have done pretty much what you want to do. i can say that the arias pistons are great..  haven't had any problems with them...they were nicely made with about 1 - 2 grams difference between the 6... so weight mathcing them was easy....

About the rods i dont know, i used the standard ones...just got them ballanced and weight matched....

in terms of head work i got the head ported and polished with 1mm oversized valves..you will find that ca18 valves are perfect for it..they are 1 mm larger than standard rb20 ones and fit with no trouble...

hope that helps....

Aaron

spot on there sir spot on!

as far as the valves, the standard ca18 valves will fit into the head? and if so 1mm will certianly aid in airflow into the motor.

how much power are you making with standard rods, everyone seems to have gotten in on a betting pool on my car when it comes to the motor's internals......

cheers!

in terms of power i havn't done a power run as yet..i am stil adding bits a pieces and changing things around. it made 138 rwkw before it all and this is auto so would be a bit more if manual.

It goes a sh1t load better since i did all of the stuff...the full potential hasn't been reached yet but from the mods i have done and from what i seen other people get i would say that it would have to be easy over 200rwkw...but it has alot of variables...you could put arias pistons in, other rods , over sized valves etc and still have the same amount of power that you started with or very little more...

it will aid greatly if adding biggger turbos and more boost etc

yes the valves do fit..they are in my car now !!

i guess it comes down to what you want to achieve with the engine on whether it will be worth it and whether it make a worthwhile difference.

And whether to get aftermarket rods.....

what do you want to achieve ???

My first recommendation would be to install the pistons for the RB23/24 kit (but leave the stroke the same). That way, you get a bit of capacity, but better you get a bit of off-boost compression (I think I calculated 0.5 increase in C/R). That gives you 9:1 C/R; considering the racing GT-R's we had in Oz ran 9.2:1 and 1.8bar, I think the RB20 will cope.

DRIFTER - if you stick a head of a larger capacity engine onto a smaller capacity block, you LOSE compression. Apart from the fact that a RB30 head will not fit comfortably on a RB20 block. And why would a single cam head flow better than a twin cam head. I think you are thinking of the RB25DE(T) head onto a RB30 block.

ebola...i am still runnning standard cams...but am running os geiken adj cam gears... waiting for gtr cams to see how they wil go with chipped ecu..there was a big thread about it a while ago....in terms of rev limit i have no idea....but with 20's power almost alwasy drops off after about 6800 - 7000 RPM so.....

Theres also a mass of threads about GTR cams NOT working in RB20 due to the ramp rate being greater compared to the standard 20 cams, and therefore the cars that have had GTR cams installed are struggling to idle. I would investigate those threads before throwing in the GTR sticks.

JK

well on my car i have tomei 260/8.8 cams with greddy gears and a gt30r turbo, so it is a bit laggy but pulls like a cut bastard to redline (8.5k).

i mainly want to build the engine not for outright power but for reliablity, i plan on keeping the car round for another few years and i cant imagine that the stock internals are going to keep up with the 450bhp the car puts out on high boost.

  • 4 weeks later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Block bump. $400. As above cyl 6 needs bore or sleeve.
    • I would think making the argument that the travel is limited by a spring flexing against a spring perch as "the same method". Later on in the document they do state that the spring can't bind on full bump travel and cannot come loose in full rebound travel as well. (which is all very sensible). The laws are actually pretty sensible and reasonable. It's just that the people who enforce and check them don't actually read them or know them accurately. "Oh, coilovers? Instant fail mate. Don't even need to look at it." - Guy who will be instantly reported by me. There is probably merit to people who do get defected for height also get defected for the suspension in that state that allows it. I did never consider the people who are complaining about coilovers being picked on are also running around at 50mm off the floor.
    • I think given SAU's knowledge of E85 we can strongly conclude that 10% ethanol in almost any situation is entirely fine. Almost all of the myths against E85 were overblown, let alone E10.
    • From your link See bold text, is this referring to damper settings, if so that may a issue for "some" inspectors, I cannot see aftermarket coilovers having the evidence that "must be available that its functional performance is equivalent to the original" Maybe just remove the adjustment knows and hope for the best???? Meh 5.2 Suspension travel In all instances, modifications to a vehicle’s suspension must ensure the integrity of the system and not compromise the ride quality. At least two thirds of the original suspension travel should be maintained in both directions (rebound (i.e. extension) and bump (i.e. compression)), and rebound must be limited by the same method used by the vehicle manufacturer or if this is not practicable due to the nature of the modification, an equivalent method. If an alternative method is used, evidence must be available that its functional performance is equivalent to the original.
    • They actually don't - They adhere to VSB14 rules just like Victoria. The rules are against CABIN adjustable height, and it quite clearly states that the height has to be within parameters. I asked the VASS engineer to confirm this when I got my car engineered and they refused to engineer the coilovers because they didn't meet the requirements for requiring engineering. (mine are height adjustable.) People "Not wanting to bother" with "Actually reading/knowing/adhering to the rules" should result in fines and immediately losing the ability to issue blue slips and/or RWC's in Vic.
×
×
  • Create New...