Any opinions on welding the crankpin?

[Mr. Torque]

[N-gin]

umm have it in a jig when you weld it
Not really sure on what your question is.
Send it out.

[Mr. Torque]

Heard of people tig welding the crank pin to the flywheels. Just wondering if anyone has an opinion be it pro or con on this practice?

[wurk_truk]

Pro.

I had R&R install new rods, weld, balance, and true a crank for my bike.  $1200

Worth every penny.

[trex]

Had mine done by DarkHorse, got the H beam rods and Timken bearing also.

[Lama]

Falicon will true and weld the crankpin for $160

[akajjmon]

My entire "Jims" 4.500" bottom end is at Darkhorse having whatever passes for gris gris in wisconson done to it.
pretty pricey but be it good insurance or just overkill I will have that peace of mind of knowing etc.
besides.. at my age I expect it to be pricey to have someone play with my crank!!!!!

[Hilly13]

Heard of people tig welding the crank pin to the flywheels. Just wondering if anyone has an opinion be it pro or con on this practice?

If your splitting the cases then it is worthwhile insurance IMO, the stock crank pin on the twin cams has been know to shift putting the wheels out of phase creating horrible run out, bad juju.
Not every crank is going to slip but you have no way of knowing if yours is one of them untill it does!
Plug, weld and true will stop that from happening, add balancing, swapping rods, etc for a tough bottom end.

[prodrag1320]

we weld & pin them all the time,we machine a hole centered half thru the pin & half tru the f/wheel,then weld over it,about 1" on both sides of c. pin(nothing new,we`ve been setting up racing lower ends like this for 30 years)

[Mr. Torque]

Kirby could you post a picture of your pinned crank?

[prodrag1320]

go to my site, www.veetwinperformance.com ,go to services,then race machining,theres a pic on there

[Mr. Torque]

Thanks Kirby and to all.

[wurk_truk]

Not Kirby.

But here's the deal on Harley cranks for Twin Cams engines...  the crank is made of three pieces and these pieces are pressed together. 

The flywheel with pinion, the crank pin, and the other flywheel with the splined output shaft.

If one of the wheel 'spin' on the crank pin... the crank is bent.  ALSO... if the crank 'opens' or closes up' on the end without the pin... the crank is bent.

Pretty much, I feel that this is truly a SMALL problem.  Think of the thousands and thousands of bikes MOCO sells.  Now...  think of how many members are on ALL the Harley enthusiast sites... which is a SMALL number compared to the whole group.  Now... on the sites... those that have crank problems are really in the minority.  So cranks twisting is a small thing and one not need to worry over it UNLESS one is going for a really nice boost in power.  THEN it is simply a SMART thing to do.

I had a crank twist up on a stock 09 bike.  SO, I eventually pulled the engine out, and sent the bottom end to Hyperformance and they had the crank all rebuilt and did a Timken bearing (another subject).  Randy can straighten and weld a crank like Falicon does for a few hundred.

But I wanted the Timken at the time....

John Dahmer at Hobans can do the same thing and have equal results.

Here's a pic of my completed crank before install.  Run out was .0005 (five TEN thousandths) after this operation. (checked in cases).



I got the Full Monty and had the balance, new rods that are H Beams with FULL wrist pin support; balanced; and plugged.  The thought is the plug AND the weld work in conjunction to hold the crank pin to the flywheels.  This is generally called 'pro plugging' and can be done by itself or along with welding.

If the budget is tight... you do NOT want to try this yourself.  Send to:  Hyperformance; Falicon; or Vee Twin Performance.

If money is better... for a full Monty...Have Hyperformance or Hobans Crankworks (John Dahmer) do the job.  (Hyperformance will send out to R&R).

Once this is done... you will enjoy the peace of mind that your bottom end is GOOD for just about ANY performance upgrade you may plan.

Also... sending the whole bottom to ANY of these... they could bore the cases to allow one to install the true big bore kits, as opposed to drop in kits.  (you've never stated your bike or engine, so...)

Pic of Kirby's crank work.  You can see he welds about the same as I had.



Here's a video showing why cranks are welded.

Crankshaft True and Tig

[TA63]

Wurk, just because your average HD rider puts on about 1k per year and is oblivious to the crankshaft issues does not mean its minor.  I had a bone stock 88 with 11k.  It had .022 runout, destroyed the oil pump and cam plate, and vibrated like crazy.  Its ridiculous.

[Deye76]

Go ahead and weld the OE tin cup, and then come back and complain about your runout.

Or while it's down, don't be a cheap azz, and let John (Hoban, pro-plug) make it last.
Gonna need a bird, like the oil threads soon.   Sheesh. 

[akajjmon]

Truk, could you be a little more specific?

[wurk_truk]

Sorry....

[N-gin]

Had mine done at Revolution Performance
Had them put oversize bearings, True, plug, weld, balance, lighten, for $500



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[flatfifth2003]

Had mine done at Revolution Performance
Had them put oversize bearings, True, plug, weld, balance, lighten, for $500



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I been thinking about doing the same, what was the turnaround time for that?

[N-gin]

From the day I shipped it to the day it was back on my porch was exactly 12 days. Im only 450 milesfrom them too so shipping was two days.
As soon as they receive it they have a 7-10 day turnaround. Now this turnaround day is dependent upon when they put it into the computer as receiving it. So call in two days if you are close and three if you are not so they can receive the crank early.

[gryphon]

I asked about this a little while back and was appalled by the number of guys who had those welds crack within a very short time. Many of them claimed to have had it done by some very reputable shops (no shops on this site that I'm aware of). Really made me wonder just how much good it really does.

[rbabos]

I asked about this a little while back and was appalled by the number of guys who had those welds crack within a very short time. Many of them claimed to have had it done by some very reputable shops (no shops on this site that I'm aware of). Really made me wonder just how much good it really does.

Well, if the welds crack it shows  one of two things. The wheels are moving on the pin from poor press fit stressing the welds or the weld sucked and was on the virge of cracking when it cooled off anyway.
Good press fit and a pro plug will do more than relying on the weld to hold it together. Done right, the weld sees practically no forces and acts as redundancy for anti rotation. Looks cool too if done right.
Ron