welded crankshaft runout

[RifRafRacing]

yeah I dont wont to point a finger.Again not knowing the condition of the crank in the first place was my error.turns out I made the best lousy $100 mistake I could have.Stan G.was so interested and knowing about these cranks.turns out I have the early style,which with the oil hole on the left end makes it very weak.Im getting a new left end in the deal.

[rosco15]

Stan is the Man. He's done my last 2 cranks.

[RifRafRacing]

shipped crank to maine this morning,Im geared now.I have a fresh trans from R&D,STAN the MAN crank,and Im gonna go after a fresh clutch basket/gear setup.Stan made a good point "dont compromise",put the money into the important parts and you'll get 300+ passes out of it,without any problems.

[lecroy]

I have a fresh trans from R&D,STAN the MAN crank,and Im gonna go after a fresh clutch basket/gear setup.Stan made a good point "dont compromise",put the money into the important parts and you'll get 300+ passes out of it,without any problems.

You went to a good place for the tranny. I have never delt with Mark but hear nothing but good things. I guess he originally built the one I have in the engine I am putting together now. However...

What work did R&D do? Did you tell them it was for a 1400cc sprayed dragbike?

Billet shaft or stock?
Any billet gears?
What kind of bearings?
Standard, 2-3 or full auto?

Or did you opt for the simple $100 race cut job on all stock parts? I posted some pictures of what happens to stock gears a while back. If you just wanting a low end job (no auto, but able to handle T/G with some billet parts ) cost is going to be about the same as the crank. If your riding it I would stay away from the auto. Others will say different.

[RifRafRacing]

havent sat infront of this thing for about a week.Yah 5 spd,no auto,billet shaft,2nd,3rd and heavy duty bearings.Mark said this will take what I can throw at it.Scored a really sweet V&H clutch basket,springs are tight,gear looks new and like no wear marks.

[lecroy]

havent sat infront of this thing for about a week.Yah 5 spd,no auto,billet shaft,2nd,3rd and heavy duty bearings.Mark said this will take what I can throw at it.Scored a really sweet V&H clutch basket,springs are tight,gear looks new and like no wear marks.

Sounds good! Your on you way now.

Let me know when you put the tranny in if you find a good way to shim it. I ended up with a C clip to allow the oil to feed into the open part of the C, to the bearing. Then shimmed this. Just a pain. (I am assuming your bearings have no clip grooves)

[lecroy]

I used a shim for the clutch and ground it to the thickness I needed. The C clip is just fo the oil flow.

[RifRafRacing]

Crankenstein

Lecroy,got the crank back from stan and he says get it runnin 8.5's put 350 passes on it then send it back for a check up.I understand the issue about oil to the small end of the output transmission shaft.What has everyone else done in the past?Mark @ R&D didnt mention anything about getting oil to that bearing.

[lecroy]

Good to hear about the crank. Yes, they are right about the older crank. You can go billet as well, but it will cost you. The other down side from what I have heard from Pearson is that the parts do not fit good with the starter and they have had problems with them slipping. They are really made for a starter nut. I am waiting to hear about the guy buying the Falicon crank for his street bike and if he runs into problems with the press fit. That crank belongs in a promod drag bike, not a little street bike.

Let see, 350 passes. Say we run 15 races a year and make on average 8 runs, thats 120 passes/year. So, call him in 3 years. The kids bike went 5 years with the same crank, but it is a small tire and that makes all the difference in the world.

>What has everyone else done in the past?

That is a VERY good question. I posted it on DB.com and no one understood the problem that responded, even after posting pictures. I did ask a friend of mine who builds engines for their bikes and they don't shim them at all! Just a drop of Loctite holds them in place. I showed him what I was doing and the R&D and FBG documents that talk about it and he thought maybe they have seen problems because of the parts shifting position. That C clip and shim won't move but it is a poor solution IMO. I just couldn't come up with anything better. Post what you come up with!!!! Ask Mark, Bill or Kevin. Someone should have something better, or they just let the oil come from the inside??!!

[Big Jay]

no,it was APE but I cant say that it wasnt out of tolerance to begin with.I didnt ask them enough questions,I saw cranshaft welding for $100. and I went for it.Things happen for a reason sometime,now Im going in the right direction.

When we weld the cranks, we first check them to make sure that are not twisted out of index. Then we weld them.

We make this check by inserting a precision ground rod through all four wrist pin holes at once. If it won't go through all four, it is twisted.

If they are twisted, we send them back unwelded and have the customer contact Stan at GRC to have it fixed.

[terbang]

Speaking of welded cranks. I've got a 1982 crank that was welded from the factory. It's got a dodgey rod. Can this be easily replaced or are they a oncer after welding..?

[lecroy]

When we weld the cranks, we first check them to make sure that are not twisted out of index. Then we weld them.

We make this check by inserting a precision ground rod through all four wrist pin holes at once. If it won't go through all four, it is twisted.

If they are twisted, we send them back unwelded and have the customer contact Stan at GRC to have it fixed.

From his post, it sounds like you didn't do your job this time.

Do you recommend to potential buyers not to have their old cranks welded without having them fully inspected first, or do you assume the buyer understands what they are asking for?

[Big Jay]

From his post, it sounds like you didn't do your job this time.

Do you recommend to potential buyers not to have their old cranks welded without having them fully inspected first, or do you assume the buyer understands what they are asking for?

Not sure I understand the question. The customer sends us the crank to have the pins welded. We have to assume the customer does not have the rod to check it for index, so we do it. We have never welded a crank theat the indexing rod doesn't go through all four rods.

Jay

[lecroy]

This is his original post:

not quite as bad as what I was seeing before.still shows .015" bow at the 2 inside bearings and .006 and .008 at the next 2 working my way out.

This was after receiving the crank from you. Also, note that he was planning to put this into a larger bore drag bike. I would have thought your guys would have asked what the application was and then make recommendations, not just go ahead and weld it.

I can see where you wouldn't expect much for the $100, but I would rather a company ask some good questions and tell me what really needs to be done. For the few minutes you spend asking questions, you may make more money on a bigger job and the customers gets what they need. Come on, how many Suzuki drag bikes do you know that are running the stock helical gears?

Maybe I missed something but I don't see where your company provided any service. Sounds like Stan did a good job rebuilding it for him after the fact.

I have used many of your products over the years and have never had any problems. The quality of your parts has always been very good IMO. The wrist pins your company custom made for me appear to be top notch. From reading his posts I would not have guessed it was your company doing the work. I would offer him a refund, but I'm not running the show.

[RifRafRacing]

hey,Im not bitchin here.Im a machinist and should have checked it before I sent it out.Thats old news anyway,the crank is done.I talked to mark @ R&D and he said their isnt an oil starvation issue at the output shaft small end,with the bearing against the outer plate.I still like your c-clip setup.