Feedback on 122” Plan

[Mattls6]

Bike is a '21 Street Bob that I bought 2nd hand with the HD stage 3 122" kit. While in process of waking up the 122" I fubared up. I'm OCD so I'm mad as hell at myself. Likely need to pull the cylinders, at a minimum, to retrieve a couple of cam bearing rollers.

Want to turn this unfortunate situation into a positive one. Assuming crank runout is OK, ideally I'd like to zero deck the cylinders and achieve a .030-.035" quench via proper gasket selection. I'll cc the heads, take the needed measurements to get the static compression figure. From there, I figure I'll choose the cam accordingly for the targeted DCR.

I don't have a ton of familiarity with these 4-valve M8s, but an engine is an engine. Before I do anything:

1. Any perceived issues with the above plan?
2. Will be using bolt in cams and will measure, but...any initial PTV concerns based on the limited information above?
3. Is there a target PTV clearance for the M8 on the intake and exhaust sides that I should be aware of?

I appreciate the input. Just trying to think things through before I dig in.

[FLDavetrain]

How did this roller bearing fail and how can you be sure there's nothing lurking in the crank case sump?

[Mattls6]

Bearing broke during removal, completely my fault. Have removed em without issue and just was off my game that day. 

Pulled the sump plug, been fishing around with a couple different magnets.

[Ohio HD]

With the top end off, try pouring (slowly) some kerosene in over the flywheels and the inner case walls to see if anything comes out of the sump plug. Not the oxygen sensor opening. It helps if you know how many rollers are missing from the bearing. If you could retrieve the number that are missing, you're golden. As long as they're not broken and in pieces. 

The good news is if you have the top end off, your half way to opening up the lower end.

Good luck, hope you find them.

[kd]

   I may also consider before disassembling the top end, spraying a stream of Varsol through from the cam plate side to thin out the residual oil. I expect the rollers are held in place with the surface tension of the heavy engine oil film.  A good solid stream from the cam bearing hole (hopefully they dropped fairly close to straight down) may wash the oil film that is sticking the rollers to the case or flywheels.  With enough volume they may migrate toward the sump plug hole and present themselves to your magnet.  You may even have to lean the bike over to assist them in the flow.  In the very least they will be more mobile and you may be able to use a length of wire to sweep them toward the drain hole.  Crack a cold one, turn on some tunes and take your time. Patience is they key to saving yourself pulling it all apart.  As you probably already know.  I would avoid using air until it is the Hail Mary attempt before pulling a barrel off.  like Ohio said, confirm the count of rollers and make sure you get them all.  If you get them back, remember to re-lube your flywheel and rod bearing with a clean squirt gun loaded with fresh engine oil.  Good fishin bud.   

[Mattls6]

Appreciate the the tips. I'll put in the time this weekend to try and get the 2 rollers and 1 cage out before tearing everything down. Man, I'd be relieved if it works out.

[Adam76]

Man, I feel your pain. I've been there and it sucks. In the end I had to split the cases and pull the flywheel.

Hopefully you find all the pieces and you don't have to go into the bottom end.

All the best with the build. 

[Mattls6]

I put the time in and tried all the suggestions but came up short. What can you do, comes with the territory I guess.

Time to split the cases. Crank has good runout but figure it's a good time to have Darkhorse beef up the stock assembly so I don't have to ever go back in...

Not sure the 122" setup will go back in, thinking more cubes, compression and cam for a nice ~140 rwhp. Probably a 128" or 130" with a TTS 250, CR512, Redshift 552 or the like. Been so focused on bolt-in cams that I'm a little behind on some of the other options out there. Open to suggestions for a cam with a wide powerband that still pulls good up top.

[Ohio HD]

Too bad you can't fish them out. It's a long shot at best anyway.

There's several good examples of 140 / 140 motors in the dyno section. I pulled three real quick that have stock heads. If you plan to have the heads ported, there are a lot more examples of 124" and 128" motors making really good power.


https://harleytechtalk.com/htt/index.php/topic,110525.0.html

https://harleytechtalk.com/htt/index.php/topic,117195.0.html

https://harleytechtalk.com/htt/index.php/topic,111209.0.html

[Mattls6]

Too bad you can't fish them out. It's a long shot at best anyway.

There's several good examples of 140 / 140 motors in the dyno section. I pulled three real quick that have stock heads. If you plan to have the heads ported, there are a lot more examples of 124" and 128" motors making really good power.


https://harleytechtalk.com/htt/index.php/topic,110525.0.html

https://harleytechtalk.com/htt/index.php/topic,117195.0.html

https://harleytechtalk.com/htt/index.php/topic,111209.0.html

Thank you, all very nice options, hard to make a bad choice between those 3. That first graph is my tuner, I should probably keep things simple and follow his recipe of 124/128 + TTS 250, seems to flat out work.

I'd love to ride this thing to the drag strip, clip off a 10.9x pass or 2, ride it home. Heads would help me get there but the monetary output for 8-10hp is a tough pill to swallow, we shall see.

[Hossamania]

A little nitrous gets you over the hump for less money....

[Ohio HD]

Thank you, all very nice options, hard to make a bad choice between those 3. That first graph is my tuner, I should probably keep things simple and follow his recipe of 124/128 + TTS 250, seems to flat out work.

I'd love to ride this thing to the drag strip, clip off a 10.9x pass or 2, ride it home. Heads would help me get there but the monetary output for 8-10hp is a tough pill to swallow, we shall see.

The TTS 250 seems to do a great job with the bigger motors. I think if your guy at JDS has some proven formulas, it can't hurt to follow his lead.

[Ohio HD]

By the way, drop the oil pan and clean all of that out.

[Mattls6]

Will do!