Putting things in places they ought not to be (250R Hybrid Motor build)

**fabiodriven** · 02-14-2014, 10:50 PM

Catty whompus.

**Billy Golightly** · 02-14-2014, 11:44 PM

I know I realized that after the video I forgot to say it...I'll remember next time

**zx10crazy** · 02-18-2014, 11:54 AM

This is an awesome build very impressed with your skills and determination can't wait to see and hear if run!

**Outlaw #24** · 02-19-2014, 12:42 PM

I have been following this build and am about as anxious as you to see this completed

I read your reasoning about the air leakage on the sealing collar of the crank shaft when you are leak checking and want to pipe in on that subject

First off Rad Randy And I were discussing the leak down check about a week before you posted your thread about air leak testing

I have been doing all of my own work on these for YEARS , I never even thought about doing leak checks on these engines. Thanks to Randy's drawings I now have a checker! Don't get me wrong I do leak checks on all the other engines I ever work on and that is quite a few, from 2 strokes to Sprint Car engines. I have to take issue with your theory of the situation with the seal collar though and I have been thinking about this since I read your theory

Yes I see that as being the most likely place to loose the air pressure , I have looked at this objectively and here is how I see it , you can agree or disagree but I have incorporated your theory and this reasoning together to draw the conclusion I have drawn

The seal collar if you look at it and the crank shaft they are a machine fit like a valve in it's seat

I agree with the guy that said about tightening the bolt down after installing the gears and Yes as you theorize it is still very likely that it may leak still

But We are testing Cold and When we heat everything to operating temperature the likelihood of air leaking there is so minimal that it doesn't deserve any further discussion

But I also see the end objective to keep air from leaking while testing, so an O ring could probably be used between the Seal Collar and the crank shaft seating surfaces while testing and then remove it

I will be testing this theory in a couple days as I have an engine I am Getting ready to assemble

Can I ride the Hybrid when You are done

**Outlaw #24** · 02-19-2014, 01:52 PM

You are correct in your assumption El ! Your observation of the o ring on the KTM is what I suggest, but to remove it after testing because it may change the tolerances if left in place ! I did look at the fiche but had to fish around a bit

**Billy Golightly** · 02-19-2014, 02:43 PM

yeah, I realize I may be splitting hairs there - but it just doesn't seem right to me, that the machined ID portion of the collar as it is shown on the Honda parts break down, is intended to be sitting over top of the splines, and not further back "in" on the crank where the splines arent cut. As it is drawn, basically the only thing sealing that collar (besides the bolt and crash washer on the end, lets forget they are there because it helps my case

) is the lipped edge of the collar being up against the crank webbing, since the lip is a larger diameter than the bearing surface. If you picture putting a cup against a wall or flat edge, thats basically the only thing sealing it, is that lipped edge as it is drawn in the parts break down. I feel like flipping it around, and using the precision machined ID to go past where the splines are cut, back to where the bearing surface of the crank is still completely round would provide a *much* better seal.

**Billy Golightly** · 02-19-2014, 02:47 PM

Originally Posted by Outlaw #24