4mill 110 vs 115

[dicedealer702]

Hey there, can any one tell me the diff. Between the 4 mill 110 rods and 115? I think one is longer then the other. But what's the

performance Differance? Why one. Over the other?

[fastbanshee8]

The 115's are the long rods, which are 5mm longer than the stockers. The advantage of them is they make the motor more reliable, because there is less of a rod angle, and the pistons don't tend to try to rock in the cylinders as much, which helps prevent broken piston skirts.

[firebanshee]

The 110 rods revs quicker but are less reliable,with the longer stoke they side load the piston more and can break skirts.You also do not need to run a 795 series piston, you can run a standard banshee piston.I use to run a short rod crank and it did break skirts.Long rods alot more reliable,need a 795 series piston or a blaster piston.

[Ieat4strokes]

ok...ive been confused on this as well, just havent asked because I didnt wanna look like a retard... Both are 4mm cranks? but one is 5mm longer? dont make sense.....

[papa_smurf49319]

ok...ive been confused on this as well, just havent asked because I didnt wanna look like a retard... Both are 4mm cranks? but one is 5mm longer? dont make sense.....

 

There both 4mm strokers (added stroke) but the 115 uses a longer rod, then the 110. 5mm longer rod, 4mm added stroke.

 

 

 

Cody

[BANSHEE HP]

no performance gains one over the other, theyre both 4mills. the long rod uses a different piston (573 or 795 seris piston) the standard rod uses stock pin height piston that uses a spacer plate, or you have your head/domes machined.

[J-Madd]

Just to clarify, the spacer plate or cut domes is to compensate for the ADDED STROKE only and has nothing to do with the rod length. THe different pin location on the piston is what compesates for different rod lengths.

[Hilarious]

Just to clarify, the spacer plate or cut domes is to compensate for the ADDED STROKE only and has nothing to do with the rod length. THe different pin location on the piston is what compesates for different rod lengths.

 

someone ought to pin this.

 

yes, the crank webs where the rod is attached to the crank dictates the length of piston travel, not the length of the rod.

[87sheerips]

I heard that the short rod is not that big of a deal in the 4mils as far as reliability. My drag bike is a short rod 4mil and I have had good luck with it.

 

Also, the CUB cylinders are setup for a long rod crank so if you are thinking of switching from stock to cub you should def. go with a long rod crank so it is interchangeable

[No Limit Powersports]

There are differences between the long rod and a short rod. Rod to bore ratio is one of the things that I feel gets overlooked more often than not. Different length rods will dwell at tdc and bdc longer. A shorter rod will open the ports sooner but a long rod will close them sooner. So a short rod vs long rod motor can have performance differences. Then on the other hand as said above a longer has less of a rod angle and puts less stress on the piston to cylinder wall. Some builders like short rod ratios and others long. For me it really depends on the bore size for the rod that I like. <BR><BR>And you can setup a cub with a 115 or 110 rod in 65 or 68 bore you would just use the 513 series piston for a 110mm rod 65mm bore or a 9768 series piston for a 110mm rod 68mm bore. For the 115mm rod stuff its a 795 for the 65mm bore, and 573 for the 68mm bore. The piston height only compensates for the rod combinations that we set up a motor for to get the deck height correct and the port duration we we feel they need to be. On a stock cylinder the 513 piston is for the 110 rod and the 795 for the 115. A spacer plate is used to compensate for the added stroke or you can cut a dome and let it pop out the top.<BR> <BR>Here is a flash animation where you can really see the differences! Notice the longer rod exagerated and the tall piston on the short rod both of these have the same deck height and stroke just different rods. Also notice the angle of the rods at the same duration.<BR> <BR>Long rod vs Short rod

Edited May 26, 2010 by M&M ATV

[TNTS355]

Andy that was a great example of how both of the rods worked. I had an idea but now it is crystal clear.

[No Limit Powersports]

I have a good understanding of how it works but everytime i look at that animation i end up studying it for a hour lol. It really shows how the piston speed changes in all 4 quadrants of the rotation.

[SLORYDER]

Anyone have a calculator to show the timings withe the 4 mill and using different rods?

[springer]

hmm..... i like it.

[Larry's Shee]

That animation makes my brain hurt, more things to ponder , lol. Thank you for posting it M&M.