A question for those builders that approve building up on a stock bottom end???

Started by 838, September 28, 2020, 07:15:04 PM

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838

My decision in this situation was to stage 2 the 96" that's in there now. I installed a CR570II, 32t darkhorse and will be getting her tuned in the next few weeks.

I'm going to build a separate 124 on the bench (over the next year), install, and then sell the stage 2 motor.  :bike:

Right now the bike has a map from a SE204 on her with a few adjustments.. little engine likes the cr570II :)

kd

KD

838

No. Just not on dyno yet. Used PV data logs and mega log viewer to make a map based off an se204 calibration. Monitoring for  temps, knock retard and ve's on PV unit.

Adam76

Quote from: 838 on October 14, 2020, 12:31:16 PM
My decision in this situation was to stage 2 the 96" that's in there now. I installed a CR570II, 32t darkhorse and will be getting her tuned in the next few weeks.

I'm going to build a separate 124 on the bench (over the next year), install, and then sell the stage 2 motor.  :bike:
Sounds like a good plan.

What compression will your CR570-2 build be? Any headwork at all?

Would you gain much by going from 96" to 103" at the same time with that build? Probably not that much I'm guessing, as that cam does so well as a bolt in anyways.
Thanks

838

The cr570-2 will stay a 96". Basically stock otherwise. Where it looks like there would be a benefit to going 103 would be in the lower rpm range and this is a light bike and I downshift so no real reason to go 103. I don't know if headwork would help this any and I'm saving money for a 124" so I'd rather put that money there vs. doing headwork for the 570-2.

Adam76

Quote from: 838 on October 14, 2020, 06:02:17 PM
The cr570-2 will stay a 96". Basically stock otherwise. Where it looks like there would be a benefit to going 103 would be in the lower rpm range and this is a light bike and I downshift so no real reason to go 103. I don't know if headwork would help this any and I'm saving money for a 124" so I'd rather put that money there vs. doing headwork for the 570-2.
👍  Makes sense, good luck with it and let us know what you have with your final tune.

shindig

838 - you would for sure benefit from the 103.    You can up the compression to suit the 570-2 you want to use.  But I would just throw in a 107 kit for $600.  Headwork/tb leave alone.  Nice super cheap build.

Bafflingbs

After reading all of these types of threads, I admit it, I got worried about my FM 110" build. So, -$6,800 later, I now have a Darkhorse MOW crank, Timken conversion, high flow cam plate and oil pump, etc., etc. My build at the time, clocked in at 117/130. My primary started making a lot of noise, and was getting worse, so, I was afraid to ride it too far. At the time of the 110 install, the runout on my cam side, was .004. Not bad- not great. Worry, worry, worry..... I became obsessed with it, and began regretting the engine build. Am I concerned about my spending? Fk yes! Am I at piece with the outcome? Fk yeah!!! It runs soo damn good now! And runs as quiet as a church mouse. My only regret, not doing it all at once, in a shop that can machine the case themselves. I definitely would've gone bigger! 117-124" for sure. Instead, I did the upper first, lower second. Consequence: labor cost for complete tear down twice. [attach=0]
2015 FLHXS: 117hp/130tq FM 110", Darkhorse Man-O-War crank
Retired Motor Officer

Jaystn62

Quote from: Hossamania on October 06, 2020, 12:14:42 PM
What's the point of a stout 103" if you're going to ride it nice? Might as well keep it stock and catch up when the fellows ahead decide to stop for a while...     :potstir:
I have to agree with Hoss. I built the 107" in my bike with a stock bottom end with intentions of some spirited riding. I have yet to do a "burnout". I don't dump the clutch in any gear. But I feel I push it. It feels, sounds and runs better than stock. Not saying I won't be putting a Dark Horse bottom end in it but if I do I'm going big after that.

Adam76

Quote from: Jaystn62 on December 03, 2020, 11:42:00 PM
Quote from: Hossamania on October 06, 2020, 12:14:42 PM
What's the point of a stout 103" if you're going to ride it nice? Might as well keep it stock and catch up when the fellows ahead decide to stop for a while...     :potstir:
I have to agree with Hoss. I built the 107" in my bike with a stock bottom end with intentions of some spirited riding. I have yet to do a "burnout". I don't dump the clutch in any gear. But I feel I push it. It feels, sounds and runs better than stock. Not saying I won't be putting a Dark Horse bottom end in it but if I do I'm going big after that.

Hi Jaystn62, can I ask what the rest of the 107" top end build specs were and what tq/hp you got? Thanks  :up:

Die Hard

I view a strong bottom end it as cheap insurance. You are gambling building for more power on a stock lower end in my opinion. The problem is, if you stay stock on the bottom and lose the gamble, you've not only lost the entire bottom end and possibly the case, you run a high risk of trashing the top end components in the process.


Life is too short to drink cheap whiskey.