Cheap Rods

[robertwb70]

POWER IS NOT WHAT CAUSES A ROD TO FAIL(RARELY-VERY RARELY)

POWER PUTS A COMPRESSIVE LOAD ON A ROD-THEY ARE VERY STRONG IN THAT DIRECTION

RPM S ARE WHAT STRESSES CONRODS-THEY USUALY BREAK AT THE BOLTS(WEAKEST LINK)OR AT THE SHOULDER(THINNEST PART)

STOCK NISSAN RODS CAN PROBABLY HANDLE MORE POWER THAN YOU COULD MAKE WITHOUT NITROMETHANE.BUT KEEP THE RPMS BELOW 6500

[Open4Cycle]

Very interesting! The 454 rods would be easy to retro-fit. Not sure how the rod caps are put togother on the Crower but if the rod caps couldn't be milled and brought together for a smaller hole then you only need to buy bearings for a .020 undersized 454 crank. That would leave you .006" to grind from the KA crank.

[king_johnthegreat]

Detonation destroys rods much faster than RPM's, look at NASCAR rods, they sustain rediculous engine RPM's at a constant loading, and support over 500 hp; but you could easily ruin them from detonation. Yes, NASCAR rods exhibit a bit more technology in the area of coping with high RPM's for long durations, but that is really little to offset the primary danger of uncontrolled ignition. Much improved rods will still fall from the effects of knock, but minor combustion abberations will be kept under better control with beefier rods. It is my opinion that if you wish to boost to the extent of fearing for the integrity of stock rods, you should invest in a rod that is specifically engineered for the application. Be it Carillo, Crower, Pauter, or another specialty brand who offers to custom fabricate the rods to spec, you would be much better putting your money and trust into them. Rods that are longer here, narrower there, similar there; yeah, they might fit for the most part, but the fact remains that they are not supposed to. Normally that wouldn't matter, but there are plenty that do fit perfectly because they are designed to. Look at the rods as compared in the beginning of the thread:

C-C length : 6.495"Big End Bore : 2.086 or 2.087" (i have heard both)Big End Width : .975" Pin Dia. : .827"Small End Width : .975"

5.4L Ford

C-C length : 6.657"Big End Bore : 2.086" Big End Width : .939" Pin Dia. : .865"Small End Width : .939"The Ford rods are longer, making the comp. ratio greater; thereby meaning that you must order either custom pistons, or lower comp. ratio pistons. If you do the latter, you have to hope that even still the valve clearances are going to be adaquate around the outer portion of the piston deck. Usually, lower ratio pistons have the same deck height around outer portion to help protect the rings, they simply dish the deck center area, and alter the wrist pin elevation. That may not be enough to accomodate a rod that is longer than stock by .162". Don't forget that these rods are also narrower by .036"; a difficult amount to even attemp to add, and too much to ignore. Not only that, but the wrist pin bore from the Ford is bigger by .038", meaning that you would have to bore your nice new pistons to accomodate the Ford pins; not that any body knows if they are the same length. How fun would it be to have to cut down the Ford pins, and how frustrating would it be to have to find longer ones (Being that the Nissan's are too small in dia., and the Ford's could be too short). No offense, but this idea really sucks. It is a logistical nightmare, and an engineer's senior thesis for grad school. Just bite the bullet and drop the dough on KA rods..John

[robertwb70]

DETONATION WILL DESTROY THE WHOLE ENGINE-BUT THE ALUMINUM PISTONS WILL BE FIRST NOT THE RODS(NOT THAT IT DOES THEM ANY GOOD)AS FOR NASCAR THEY USE THE BEST PARTS MONEY CAN BUY(NO BUDGET)AND THE CARS ARE TUNED TO PERFECTION FROM MANY YEARS EXPERIENCE.WE MOSTLY RELY ON THE COMPUTER TO KEEP OUR ENGINES OUT OF DETONATION BUT IT MUST STILL BE TUNED CORRECTLYLONGER RODS DO NOT RAISE THE COMP-RATIO(THE STROKE IS STILL SAME)IT DOES CHANGE THE COMP-HEIGHT REQUIRED FOR THE PISTON NOT TO HIT THE HEAD

RIGHT ON WITH THE COMMENT ABOUT JUST GETTING CORRECT RODS FOR THE APPLICATION-TRYING TO SAVE A FEW BUCKS BY USING ANOTHER TYPE STOCK ROD IS FOOLISH-YOU WOULD STILL HAVE A STOCK ROD AND THE MODS REQ TO MAKE IT WORK WOULD NEGATE ANY SAVINGS-AND YOU WOULD STILL HAVE A STOCK ROD

AND I KEEP READING-GETTING CUSTOM PISTONS MADE -DOES SOMEONE THINK THIS IS CHEAP?WHY CUT CORNERS ON RODS ONLY TO SPEND MORE ON CUSTOM PISTONS?THERE ARE READILY AVAILABLE PISTON/RODS FOR THIS ENGINE ITS ALWAYS CHEAPER TO USE PRE EXISTING(PROVEN) PARTS-WHY DEVIATE?JUST TO BE DIFFERENT-IF THATS WHAT YOU WANT IT IS NOT GOING TO BE CHEAP

[C-Kwik]

LONGER RODS DO NOT RAISE THE COMP-RATIO(THE STROKE IS STILL SAME)IT DOES CHANGE THE COMP-HEIGHT REQUIRED FOR THE PISTON NOT TO HIT THE HEAD

Not if the piston is designed to handle a longer rod by locating the wrist pin higher up in the piston by the same amount as the increase in rod length. This would be the right way to do it.

[robertwb70]

YEP-THATS CALLED THE COMPRESSION(PIN)HEIGHT OF THE PISTON

THIS GETS CHANGED TO ALLOW A LONGER ROD-BUT A KA ALREADY HAS A VERY GOOD ROD/STROKE RATIO

[TrunkMonkey]

quit yelling.

-demetrius

[robertwb70]

quit yelling.

-demetrius

sorry demetrius-its just easier to read caps

[C-Kwik]

Actually it's not. Unless you grew up reading caps, it's a whole lot easier reading proper grammer.