NitroX5 Posted January 21, 2013 Report Share Posted January 21, 2013 Let' see: Plan to build another engine, aim K24-->350Hp, later a 20G--> 400+?? I have possibility to choose between engine internals, just can't decide it since a long time. I used to like very much my 2.5 setup, currently running the R engine, so sure it will 83 bore again with 9.0 compression. RN head, 7-7500rev limit. Stock pistons should handle 400-500hp as rods as well...yes with the right tune. Dilemma: 139.5 or 147mm rod setup Left N right RN N: Full rod assembly: 1165g (w stock rod 1215g) Piston: 560g 83mm 2435cc Pro & cons: heavier but may handle more heat stress and tolerate slight tune issues I have H rods for them but now this does not matter, stock rod would be enough also RN: Full rod assembly: 1065g Piston: 425g 83mm 2521cc Pro & cons: lighter, especially at the end of the rods, good for everything less friction but no Teflon coat by stock weaker ring lands better rod ratio, develop more torque, sooner: ~320NM vs ~270NM it spends more time at TDC, good for combustion better off boost power (also spools sooner a bigger turbo) Rod compound made some kind of "sintered" technology, stronger Well, the RN setup will win, but still looks tiny and weak. However it has been proved by other members it could handle serious power. City economy is also an important point of view and for that the RN suits better again. Need some opinions here... Regards Greg Link to comment Share on other sites More sharing options...
mdlimy Posted January 21, 2013 Report Share Posted January 21, 2013 i defiantly agree that the rn setup is better, in this case 147mm rods. I do agree that stock the internals will handle what you throw at them(with a good tune of course) but im just curious what your reasoning is for not using forged H beam rods? for the price its almost a no brainer since the motor is already apart. I vote 147mm forged h beam rods and stock pistons(if your on a budget). Your goals are modest and with good tuning you wouldn't have a problem running a bone stock bottom end, you already know this, any upgrades are purely for margin of error in tuning or simply a piece of mind. Robbie Link to comment Share on other sites More sharing options...
Volvo5.0 Posted January 21, 2013 Report Share Posted January 21, 2013 I vote 147mm forged h beam rods and stock pistons(if your on a budget). That would be my vote also, but if the choices are 139.5mm H-beams or 147mm STOCK rods.... I'd use the better rods. Link to comment Share on other sites More sharing options...
Fishey Posted January 21, 2013 Report Share Posted January 21, 2013 It all depends on how much power you are trying to make. Link to comment Share on other sites More sharing options...
fischmama Posted January 23, 2013 Report Share Posted January 23, 2013 A few issues I see with the original post and whats being said/done. 1. You said you are using the R engine with 9.0 compression? It is 8.5 stock, the B5254T2 is 9.0 2. If you are using the B5254T2 or T4 you will have a 93.2mm crank so unless you put the 90mm crank in you wont be able to use the above combos. 3. Stock internals for the R engine are 143mm rods Link to comment Share on other sites More sharing options...
nari Posted January 23, 2013 Report Share Posted January 23, 2013 A few issues I see with the original post and whats being said/done. 1. You said you are using the R engine with 9.0 compression? It is 8.5 stock, the B5254T2 is 9.0 2. If you are using the B5254T2 or T4 you will have a 93.2mm crank so unless you put the 90mm crank in you wont be able to use the above combos. 3. Stock internals for the R engine are 143mm rods I believe he meant R engine as the current b5234Tx. The older 2.5 setup was a LPT engine. Link to comment Share on other sites More sharing options...
fischmama Posted January 23, 2013 Report Share Posted January 23, 2013 I believe he meant R engine as the current b5234Tx. The older 2.5 setup was a LPT engine. Makes sense... forgot about the 00 R engine. Link to comment Share on other sites More sharing options...
NitroX5 Posted January 23, 2013 Author Report Share Posted January 23, 2013 Yup ,see my sig. S70R -->'98 1. Just mentioned that my previous engine was 2.5 LPT and I liked it, so the next build will be the same... (current is the stock B5234T4 '98) 2. My project engine: B5244T3 2001 and it has 90 sroke, so my mistake was I beleived it is 2521cc Anyway.. I stay to the RN option and give it a try. Link to comment Share on other sites More sharing options...
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