Haven't seen anything about the left side crank bearing yet

[mp]

I assume they did NOT go back to the proven twin Timken tapered bearings?

[bobscogin]

Over ruled by the accounting department.

Bob

[rbabos]

I assume they did NOT go back to the proven twin Timken tapered bearings?

Pretty sure the straight roller has proven itself also.
Ron

[masstch]

I assume they did NOT go back to the proven twin Timken tapered bearings?

Pretty sure the straight roller has proven itself also.
Ron

Bingo!
I think it's fairly safe to say that the TC *cranks* of at least the last five or six years have proven themselves pretty well in a lot of builds. I don't know what or when they did it but they seem to be better than the earlier units.


Sent from my iPhone using Tapatalk

[N-gin]

With more torque down low we will see how well the cranks are going be.
Is there any design change with them?

[FSG]

using the 24605-07 bearing which has been around for some time

[mattVA]

Good to know they trust it for their new engine. I used dual 24605-07 instead of timken on my build. Saved a bunch of money.

Sent from my SAMSUNG-SM-G920A using Tapatalk

[mp]

I'm no Twin Cam expert, but doesn't Harley sell the Timken upgrade as a result of the roller bearing causing crank scissoring?

[rbabos]

I'm no Twin Cam expert, but doesn't Harley sell the Timken upgrade as a result of the roller bearing causing crank scissoring?

A timken won't stop a crank from shifting regardless of the internet. Nor will a roller bearing cause shifting.   A solid,  stable crank comes from  how much area on the crankpin is available for press fit into the flywheel bore . The bigger the pin and the more press fit, the better the crank will resist moving. In a nut shell, it's better to put money into a crank and lock it up then expect a bearing that still has running clearance to try and save a "Potty mouth"ty crank.
Ron

[masstch]

I'm no Twin Cam expert, but doesn't Harley sell the Timken upgrade as a result of the roller bearing causing crank scissoring?

Harley (and others) sell the Timken upgrade because of market demands.
HD moved away from the Timken in 2003(?).
People who had scissoring or *any* crank issues thereafter assumed a causal relationship, bad-mouthed MoCo for 'cheapening' and profiting; wanted the Timken back.
Causal relationship wasn't found, but,
confidence was acquired with the installation of the conversion when crank repair was being done.

[mp]

I dunno...  There were virtually no failures when the Timkens held the crank in place and there have been many since the roller bearing came along to speed production and increase slop.  I've heard the automatic primary chain tensioners cause problems as well, from over-tightening after a big bump and stressing the crank.  But those came along several years after the roller bearing.

[rbabos]

I dunno...  There were virtually no failures when the Timkens held the crank in place and there have been many since the roller bearing came along to speed production and increase slop.  I've heard the automatic primary chain tensioners cause problems as well, from over-tightening after a big bump and stressing the crank.  But those came along several years after the roller bearing.

It was poor crank production basically and or QC. Remember 07's, the worst ever. An upgraded better heat treated bearing (Lefty) now but very few cranks slip as the years went on. Also note the SE versions compensators compared to the 07s has eased up on shock loading the crank also. No bearing or tensioner version can really stop a crank from slipping at the crank pin if the press isn't good enough. This new M8 with bigger crank pin will again increase durability of the crank, if the press is done right.  Both in slip and better all around alignment retention.  Let's hope so this time.
Also, for a timken to actually stop output shaft flex to get the most out of it and control what it claims to do,  it would need to be preloaded, not set up with clearance as is the common practice.
Ron

[koko3052]

Just how much bigger is the crank pin?

[SixShooter14]

using the 24605-07 bearing which has been around for some time

FSG, where are you getting these cool pics? Is there a parts catalog or brochure?

Thanks

[04 SE Deuce]

You can't shore up a marginal crank with main bearings.  Fueling guys tried a support bearing in the cam plate...broke the cases when the crank shifted.

[CowboyTutt]

King of Cubes also tried a dual Timken conversion on both crank ends and it broke the cases.  Regards,  -Tutt