Crank Rods

[Honda 250r 001]

Did IMS at one point ever make an aftermarket rod for the 250r?

And is Vesrah a good brand or has anyone ever tried their rod kit for the 250r? Or would i be better off going with the Pro X?

[hartwill]

i would only buy an oem honda crank. i learned my lesson the hard way. it would probly only cost you $100 more from service honda than installing a new rod, and the quality is worth it to me. unless you need a short rod then i would only use a pro x. oh and pro x doesnt make a long rod version any more. id still buy a oem handa crank and run a spacer plate.

[86 Quad R]

pro-X or OEM rods here.

IMS did make an aftermarket rod, not very good in my opinion.

Vesrah is an excellent rod; Pro-X is as well. I would say Honda OEM is the best, Pro-X & Vesrah are second best & equal to each other, HotRod rods are fine, however; a last choice.

Has anyone ever lost a Hotrod rod in a cylinder below a 370CC? I am curious if this is a common occurrence that I am not aware of?

PS: Honda OEM rods are still available from your favorite builder…

Carlos.
:)

[86 Quad R]

yup i have. at about 10 hours use.

Let us know more; you lost a HotRod rod on a 310R or? The rod broke, bent, wore out or failed at either end?

If this is common, then HotRod cranks have more than just the tin failure issues, now a rod failure issue?

Carlos.

[Honda 250r 001]

Ok! thanks
ive been hearing a lot about these KTM rods being used on 250r cranks. Is there a KTM rod that you can use with stock stroke and stock size piston just for the added strength?

[86 Quad R]

the hot rods crank has a reputation for letting loose at the big end of the rod and the weisco cranks are the majority that are having the tins to fail. there are plenty of documented cases of this in this forum and others. however, i personally have never had a hot rod "rod" (or any other for that matter) that was installed on a OEM crank to fail as of yet. just from an observation standpoint i'm inclined to think that alot of the failures are largely caused by the cranks "run out" being at an unexceptable tolerance out of the box and installed as such. this was not the case with the crank i had to fail. it simply gave up the ghost at random...... at and around 10 hours of run time.

Guess I have been fortunate, having run HotRod cranks and rods (not by choice) with zero failures, some have had +50 hours on them when I sold the engines. I also checked the HotRod cranks (when new) and have found all the ones I have run to spec out excellent on run out, all within .0005” TIR.

Still, my preference is Honda OEM, I also prefer to run a Honda OEM rebuilt crank verses a new HotRod, guess just paranoid from all the failures I keep reading about.

I would never run a Wiseco, unless I want to destroy my engine.

Carlos.

[Fear250r]

No more wiseco for me!!!

[8686]

Originally posted by Fear250r
No more wiseco for me!!!

What happened with the Wiseco cranks you guys were running?

[Fear250r]

This....

http://i259.photobucket.com/albums/hh300/Fear250r/IMG_1389.jpg

[atv fan 28]

And this!


<a href="http://tinypic.com?ref=zmax4w" target="_blank"><img src="http://i56.tinypic.com/zmax4w.jpg" border="0" alt="Image and video hosting by TinyPic"></a>

Are most of the Wiseco tin failures occurring at TDC & BDC as in the two pictures posted above? If they are; I think I may know why…

Carlos.

[8686]

Originally posted by acecarlos
Are most of the Wiseco tin failures occurring at TDC & BDC as in the two pictures posted above? If they are; I think I may know why…

Carlos.

Spill it!

[hartwill]

that just happened to me. when I took it out the tins were loose. I could spin both of them about 1/4 in. only one let loose though. I have some pics also. I will upload them later. supposedly that's why they fly apart is because they get loose on the webbings.

[Honda 250r 001]

Originally posted by 8686
Spill it!

I would love to hear also.

[latheboy]

....or should we call BDT Motorsports???

J/K Carlos, just had to throw that in there. LOL

Before I go on here and explain why (I think) HotRod cranks see more tin failures than Honda OEM’s and why Wiseco’s are a grenade without the safety pin in place; I want to hear back from Karl M first…I will be seeing him tomorrow during my 363R dyno runs…

Latheboy; I am trying my best…:)

Carlos.

[mxduner]

Originally posted by acecarlos
Are most of the Wiseco tin failures occurring at TDC & BDC as in the two pictures posted above? If they are; I think I may know why…

Carlos. most i have seen were at bdc. and on the mag side as well.

here is mine at 5 tanks of gas.

[Fear250r]

Should we sticky this? Don't use wiseco cranks!!

98% percent on the money:

“What I was told by a company that builds a lot of shifter Kart engine, those cranks don’t go through the same process as what the OEM Honda cranks did when those tins are press formed onto the crank webs. Not as tight pressed on & a bit more loose fitting than the Honda”…Neil

OEM Honda crank tins are first Annealed, formed on Deep Draw tooling, then the tins are placed over the crank half’s, and the holding lip is first crimped by a full form (360 degree Die) followed by a lip roll Die. The assembled crank with tins is fully Heat Treated to relieve stress; the assembled crank is then finished after the final main shaft grind…this is how it was done back in 85-89.

HotRod cranks don’t go through nearly the same manufacturing, forming & heat treat process, just to cost prohibitive when making such small quantities.

Don’t really know why the Wiseco’s are worse than the HotRod cranks (rumor has it they are built in the same Twain factory as the Hotrods), possibly Wiseco cut corners further to reduce cost at the expense of failures…

Now the question of why is failure more prevalent on HotRod & Wiseco crank tins at BDC & TDC? One possible explanation is that the HotRods (Wiseco’s as well) do not use a final roll die to form the lip securing the tins to the crank half’s, they also do not stress relieve the tins through a heat treat process. The forming die they use has 2 pinch points (two 180 degree half’s forming a 360 degree die), each pinch point is located at the top & bottom of the crank, or BDC & TDC. Without a post stress relieve process, the BDC & TDC pinch points provide the ideal point for a crack to propagate into full material failure…

Honda did it the right way, not cutting any corners, with quality being the number one focus; the production volume justified the tooling & process expenditure for Honda…

Carlos.

[Jason Hall]

Great explanation Acecarlos, thanks for that. I have seen the tin coating come loose on stock cranks also. I have Ran the Shiat out of Hot Rods and Wiseco cranks In the past. I would like to know the entire story with the pictured cranks. Did they have any other problems like piston failure at the same time? Did the rider free rev the dog pee out of It to clear It out because jetting was not right. I'm almost sure the stock crank I saw fail was because of being free revved often. The extreme centrifugal force caused the tin to rub the case causing the tin to turn red and get mangled In the bottom end. I have also bought Brand new Wiseco cranks and found that the timing marks are Non existent and had to mark the end of the crank myself. Could It be a balance Issue? Could the crank get flooded with fuel Inside the tin coating? Wow, I'm just full of question's LOL.

Jason:

I like how you think; perfect…I had the same thought you did of the crank flooding and throwing it out of balance, followed by rubbing in the case; it makes sense. Note on some of the pictures, the o-ring that seals the tins on the crank is missing, is it gone, when and where did it go…?

I agree any crank can fail, Honda OEM cranks are built better and have a higher tolerance for “free revved” than the others, plus a good builder may massage everything together with a higher skill level and help minimize the negative effects a less quality product like a crank may have…

Carlos.