Isacnr77

Oh I for got to quote u! But I responded, see above! 1more thing, this combo gets u closer to a “squared” engine, like the JZ (86mm bore and 86mm stroke) it will be different characteristics than ur 2.6 block stroked to 2.8/3.0/3.2 the bigger stroke u have without longer deckheigt get u really short rods! And iam no scientist but rod to stroke ratio supposed to change the characteristics of an engine is several ways

I did some research! RD28 block height is same as RB30! 227mm. Cheapest solution is to use stock RD crank (hens u use the RD block) it has 83mm stroke. use the : http://www.wallaceracing.com/rod-length-calc.php webbsite and u put in the numbers together with the specs of RB26 pistons (30mm piston to pin height). Then u get the results that you need 155.5mm length rods! Now to the cleaver solution, RD28 has larger big ends just like the RB30 (RD28/RB30 has same) RB20/25/26 has smaller. So u either need to grind crank so it fits 20/25/26 big end rods and find right length for the stroke(u will not if u don’t order custom) BUT!!! SPOOL in australia offers a 155mm rod for the rb30 to be used with high comp flat top pistons (different pinheights and so on) That rod from spool together with rb26 pistons will leave u only 1 thing left. U need to bore the block to 86mm, RD28 is 85. Well it’s in ur favor, it’s like starting with virgine block(square one) I have the solution and documentation for fitting rb26/25 head to the block also. That is a story in it self. Kind of a lot of modifications to get all the passages right and to get vct to work! Need to come back for that one! This was a bitch to research, all I had to measure and figure out my self. No really good documentation on this topic. But hey! If ur a broke horse farmer and live in sweden and don’t have access to rb30 blocks it’s good cheap Option with some custom work to it! I got 5 complet rd engines in sweden for 450usd so not to much to complain about! “Ghetto stroker deluxe” Sorry for bad English, now I need to get back to work !

Well i have 4 RD28T’s laying around, and I have wanted to build a “poor” mans Rb with them. A lot of searching and talking and yet I haven’t found what pistons and rods combo people run. There are several ways to go I guess when keeping the stock crank and block. 1• 2.8L> Stock RD stroke with Rb25/26 sized lobes. With the bored up 85mm cylinder to 86mm u can run Rb 26 pistons. But then what length rods? 2• 2.?L same as above but with offset ground crank making it a longer stroke. I guess how much it’s offset sets the legth of the rods. Again what length rods and what offset. And what will the final volume be? But in all, with a bored up block to 86mm and re ground crank. Is there a off the shelf forged pistons and rods combo? Simplest way is to go stock 2.8stroke and just get longer rods. I can just throw the engines in the bin if my Swedish ass would even attempt to do these calculations 😂 but iam happy if anyone would try to explain how to calculate it if there is no straight answer.