Tomei 2.8 stroker kit for RB26?

[Scooby]

SK;

Thanks, I've not seen anyone quote their experience with this conversion. Problem is that, as mentioned previously, while I agree it's a great idea (hence my interest) and YOU can do it, that doesn't mean that a lot of others can. And as you don't own a workshop I can't ask you to. Your position and a lot of others people's is very different in that respect. Re the RIPS girdle I sent a message to them on that subject and got no response. Agree your point re sellers of aftermarket gear but it gets back to the simple question of 'who doesn't have an aftermarket agenda and can do the job properly'. I have received advice from someone who runs a large outlet and has extensive experience with GTRs. I also know he won't try to sell me gear I don't need, and he said 'stay away' because it's not worth the grief of the detail to get it really right.

Dror;

My experience matches yours with advice from the better known workshops. Issues with block/girdle prep = big $ and when AVO says 'there's a lot to it if you want to get the little things right on a road car' you know it's going to hurt your wallet like hell. I've been quoted $15k to have it done properly drive in, drive out. Even taking off a bit for engine in/out and dissasembly by me it still seems like a lot when considering, as SK correctly pointed out, that RB 30 parts are often cheaper.

Purple32;

Thanks I'll try them I've heard Ben is very good.

Appreciate the advice guys, thanks.

[Sydneykid]

My experience matches yours with advice from the better known workshops. Issues with block/girdle prep = big $ and when AVO says 'there's a lot to it if you want to get the little things right on a road car' you know it's going to hurt your wallet like hell.

I would ask;

What are the exact issues with "block/girdle prep"?

What are "the little things" that you have to get "right on a road car"?

From my experience there are just as many "little things to get right" on an RB26. In fact there are more, because to get the same power you have to rev the RB26 to 20% higher rpm. That means 9,600 rpm instead of 8,000 rpm. If it's an RB28 that means 11% more rpm. These are not insignificant increases.

Have you considered their effect on transmission ratios? You really should shorten the final drive ratio, that means the 2 diff ratios need changing. The speedo will need recalibrating. The clutch needs to be capable of handling the 20% higher launch rpm. You will need heavier valve springs, that will mean more camshaft lobe wear, valve seat pounding etc

When I did the first RB30 in a GTR 4+ years ago, I looked at ALL of the issues and made the decision accordingly.

[N I B]

What size is Australias fastest GTR? or Japans for that matter.

[BoOsTeD_RB26]

Mario's GTR700 is a 2.7 isn't it? Fastest in Southern Hemisphere.

[N I B]

My point!

[lwells]

What size is Australias fastest GTR? or Japans for that matter.

Fastest where though? Down the strip or round a track?

LW.

[N I B]

All forms of motorsport.

We do many RB30 twin cams but i have not found them better than 2.7s.

Each to their own tho.

[Emre]

The extra torque from the RB30 would make all the difference on a street, track oriented car.

If you are going for the maximum hp a block can support than things are different. For this reason, Mario's car is totally irrelevant.

If you want 500hp, a stock RB26 will do the job.

If you want 7-800hp why wouldn't you want the extra 400cc...?

[NXTIME]

Mario's GTR700 is a 2.7 isn't it? Fastest in Southern Hemisphere.

There is a HUGE difference between revving an engine for 8-9 seconds and revving it for tens of minutes on end around a track.

[Emre]

There is a HUGE difference between revving an engine for 8-9 seconds and revving it for tens of minutes on end around a track.

You point is very true, but it can be argued that you don't have to run 1200hp on the track, hence you don't have to rev to 12000rpm or whatever Mario's car rev to.

If a 750hp RB 26 was going to cost me as much as the 750hp RB30, I would go with the RB30.

[Dynamix]

Mario's car can rev to something like 13,000 odd rpm, cant it? Larger capacity doesn't like to rev so hard, thats why his car is only 2.7L probly....

What use will the motor have; drag, curcuit, street??, that might infulence your decision a bit more...

With that many VL's out there doing fast 1/4 mile times with tough rb30's, i'll be going for it

[Alf]

With that many VL's out there doing fast 1/4 mile times with tough rb30's, i'll be going for it

Considering Mario's 33 and Danny's VL are both in the high 8's says alot about the strength and potential of the RB30 even with the crappy single cam head.

[Maxx]

Mario's car is using JUN engine isn't it? check JUN web site and u will found that JUN are also using their new 3L kit in GTR instead of 2.7L...

[Scooby]

I would ask;

What are the exact issues with "block/girdle prep"?  

What are "the little things" that you have to get "right on a road car"?

From my experience there are just as many "little things to get right" on an RB26. In fact there are more, because to get the same power you have to rev the RB26 to 20% higher rpm.  That means 9,600 rpm instead of 8,000 rpm.  If it's an RB28 that means 11% more rpm.   These are not insignificant increases.

Have you considered their effect on transmission ratios?  You really should shorten the final drive ratio, that means the 2 diff ratios need changing.  The speedo will need recalibrating.  The clutch needs to be capable of handling the 20% higher launch rpm.  You will need heavier valve springs, that will mean more camshaft lobe wear, valve seat pounding etc

When I did the first RB30 in a GTR 4+ years ago, I looked at ALL of the issues and made the decision accordingly.

SK;

the people from whom I've sought advice, in suggesting that there are 'little things' you have to get right on a road car including those you've mentioned (wouldn't I have to change diff ratios and speedo recal with an RB30 anywayas it revs lower?) also suggested that there's a lot of machining work to be done - far more than a good RB26 build. I've read the RB30 thread and buggered if I can really see it but that might not mean much either. As I said it's difficult to find and gte access to people who have done this conversion on a GTR. AVO couldn't even give me a ballpark on the phone, I had to call them back a week later.

re block issues, there are two things that I understand can be a problem. one is cracking due to greater torque/ torsional stress in a 4wd (they had no concerns in a 2wd) and the other, as Dror has found, is the $ to address this issue. which leads us back to the issue of 'while you can do it not everyone can, but you can't build me a motor and the people that we have access to, and can, want huge $'.

yep I'd love to try it because I agree it makes such good sense and the torque - presumably - is quite awesome but at this point, for a 4wd road car seeking to make about 400 rwkw it doesn't seem viable/worth the angst to do the conversion.

Cheers

[Fitzpatrick Speed Works]

I dont know how old this thread is it was sent to me by another member, but i have personally made my own block adaptor/girddle to perform the rb26 sump rb30 block conversion and although the car is not running that has no bearing on the fact my solution works and is cheap. There are a few minor issues that need to be addressed but even if you payed the most ridiculous labour prices i can't see the price of making the engine fit the sump using my plate coming out and anymore than $1300-1500 including the plate!!!