Mcadam I Figured Some Crazy Stuff About The De-stroker.

[PROJECTRB240SX]

GIVE ME YOUR EMAIL ADDY AND I'LL TELL YOU EVERYTHING I FIGURED OUT AND ALL MY EQUATIONS AND FINAL PRODUCTS. THIS ENGINE IS GOING TO BE AWESOME THATS ALL I KNOW.

[Imissmyturbo]

[email protected]

[PROJECTRB240SX]

SHOULD I JUST POST IT ON HERE, I'M GIVING YOU THE OPTION SINCE THIS IS YOUR BABY.

[McAdam]

hey man, thats cool! [email protected] go ahead, post it on here! I think sharing information is the key to a strong car community. i was doing some numbers and with a 87mm bore, i came up with around 2486cc's. I only have a few secret plans burbling right now, lol most of them involve heavy custom welding/machining. anyone know where I can get a camshaft custom made from scratch for under a grand? lol

so, you're 18, eh? thats cool. I have been into cars since I was about 16. (I'm 23 now, lol old fart!) ever since I got my first car and my parents told me I was responsible for all upkeep and repairs. lets see..... I am 16 have no money and my car breaks, do I ...

a) pay a shop an obscene amount of money to fix it and be stuck in the same position when it breaks again

or

b) fix it myself and learn a bit in the process so that next time it breaks I won't be stuck in the dark

geee, lemme think...

McAdam

[PROJECTRB240SX]

WELL I SENT AN EMAIL TO YOU, AND THE WRONG PERSON.

WELL LAST NIGHT I STARTED DESIGNING THE ENGINE AND GETTING NUMBERS. WITH STOCK PISTON BORE IT WILL ONLY LOSE .1L SO IT WILL BE A 2.4LWITH 88MM PISTONS IT WILL RETAIN THE 2.5L NOW FOR THE MATH STOCK: ORIGINAL HEAD CC: 46DESTROKED CC BELOW DECK: 12NEW HEAD CC: 58SWEPT PATH: 405CCC/R = (405 + 58) / 58C/R = 8 TO 1 88 MM PISTONS: OVER BORE HEAD CC: 47DESTROKED CC BELOW DECK: 12NEW HEAD CC: 59SWEPT PATH: 424CCC/R = (424 + 59) / 59C/R = 8.2 TO 1

[PROJECTRB240SX]

THE 2.4L WILL HAVE A REV LIMIT OF ABOUT 10.5 - 11K RPM

THE 2.5L WILL HAVE A REV LIMIT OR ABOUT 11 - 12K RPM

THESE BOTH WILL BE MATCHED WITH SPECIFIC CAMS AND INJECTORS FOR THE REV LIMIT.

[McAdam]

MMmmmm, yummy! I think some blaancing and lightening of the internals would be in order before you'd want to rev that thing to 12K RPM's lol! how are you figuring out the redlines of these theoretical engines?

it would be fun to hear that engine note churning 12 thousand revs with a turbo! hell I think it would sound better left N/A! F1 anyone? you could make it to 60 without shifting!

McAdam

[Imissmyturbo]

I would guess you are trying to make a race engine for an engine running 10K+ isn't going to last a long time. It may last a few months daily driven but when reving that high you are putting a ton of stress on the rods and piston rings. I am sure you know that though.......Now I have a question. The stock redline on an RB25DET is 6500-7000 right? What would it take to make it rev to 8000? Would the hydro lifters have to be swaped for solid ones from a 26 head? I would also guess the stock cams wouldn't make power past the stock redline.

[PROJECTRB240SX]

7500 FOR THE RB25DE. TO MAKE IT REV TO ABOUT 8000 IS JUST FUEL TUNING AND OIL. OK MAX RPM IS BASED ON ENGINE TIMING AND FUEL MAPPING. THE ENGINE CAN ONLY TAKE 7500 RPM SAFELY AND AFTER THAT THE FUEL FALLS AND OIL PRESSURE REDUCES AND THE ENGINE BECOMES LOADED WITH AIR AND LOWERS THE FUEL RATIO CAUSING STRESS AND PROBLEMS. NOW THE MORE AREA ON THE TOP OF THE PISTON THE MORE THAT STRESS IS DIFFUSED. THE SHORTER/LIGHTER THE STROKE THE LESS AMOUNT OF TIME/STRESS IS PUT ON THE ENGINE TO COMPLETE A REVOLUTION. SO THEORETICALLY THE SHORTER THE STROKE AND THE WIDER THE PISTON THE MORE REVS THE ENGINE CAN HANDLE. THEN YOU BALANCE AND LIGHTEN THE LOAD AND INCREASE DENSITY AND UPGRADE MATERIALS ON THE INSIDE TO HANDLE THE STRESS MATCH THAT WITH A LOWER C/R AND ADD TONS OF BOOST AND YOU GOT A QUICK REVVING HIGH HORSEPOWER TOPEND MOTOR.

I FOUND THE REDLINE EQUATION LAST NIGHT AND I'M GOING TO GET A AUTOMOTIVE MATHBOOK TO GET THE EXACT NUMBERS.

[PROJECTRB240SX]

CAM PROFILES ARE A DEFINATE MUST YOU NEED TO FIND THE PROFILE THAT WILL WORK FOR YOU. AND YES SOON AFTER THE STOCK CAM PROFILE FAILS TO BE EFFECIENT AND CAN CAUSE SERIOUS ENGINE DAMAGE AND/OR MAJOR LOSS OF POWER.

[Imissmyturbo]

You said 7500 for the RB25DE. Does that include the DET also? Just want to be clear. Would the stock valve spring and lifters be ok to 8000-8500?

[PROJECTRB240SX]

I'M NOT TO SURE ABOUT THE DET BUT I THINK ITS 7500 ALSO. THE VALVE SPRINGS I WOULD CHANGE BUT THE HYDRO LIFTERS SHOULD BE FINE. TRY A 1MM WIDER PISTON AND THAT SHOULD BRING IT UP TO AROUND 8K IF I REMEMBER CORRECTLY. BUT WHEN YOU RAISE THE REDLINE YOU NEED TO ADD MORE OIL AND FUEL SO YOU NEED TO CHANGE INJECTORS AND OIL PUMP, THEN COOLING BECOMES AND ISSUE SO YOU NEED A BETTER WATER PUMP AND THERMOSTAT. WHEN YOU DESIGN AN ENGINE THINK OF THE WHOLE SYSTEM NOT JUST THE END PRODUCT.

[PROJECTRB240SX]

OK HERE IS A QUICK FACT:

THE ENZO REDLINES A 11.5K RPM, CORRECT?WELL THE STROKE TO BORE RATIO ON THAT ENGINE IS 1.22

THIS RB HAS A STROKE TO BORE RATIO OF 1.26

NOW THE ENZO RUNS A 11.5 TO 1 COMPRESSION RATIO MAKING ITS POWER AT 7500RPM TILL REDLINE, ON PREMIUM GAS.

THIS ENGINE WOULD HAVE A 8 TO 1 RATIO WITH A LARGE T-60+ TURBO RUNNING 1+ BAR OF BOOST. THIS ENGINE WOULD BE MAKING ITS POWER AT 8 - 8.5K RPM TILL REDLINE.

THIS 11K THEORETICAL REDLINE IS A POSSIBILITY AND I WILL ACHEIVE IT THROUGH TRIAL AND ERROR.

[WRX to RB25DET]

All I can say is I feel smarter after reading all of that... Keep up the good work guys! all sounds like it should work to me!