Boring factory 107" cylinders

[VernDiesel]

Adam been real pleased with my S&S Super street. The Fuel Moto Db reducer is a great tip if you start making power and want to improve its sound without having something too loud. It already freed up some flow & power from 116/116 to 118/122.

Are the two calculators you guys listed on line somewhere.  Going to try to figure out my options for a 120 build.

[Adam76]

Adam been real pleased with my S&S Super street. The Fuel Moto Db reducer is a great tip if you start making power and want to improve its sound without having something too loud. It already freed up some flow & power from 116/116 to 118/122.

Thanks Vern, can you tell me a bit more about the Fuel Moto insert you are talking about? How is it different to the S&S Db reducer that comes with the exhaust?

Thanks

[VernDiesel]

S&S Super street Db reducer is 1 3/4" diameter. Fuel Moto is 1 7/8 diameter. I used the longer non louvered. I just cut it to the same length internally as to the stock Db reducer. This cut off the tuning tongue. The shorter inserts would allow for the use of the tuning tongue but as you have seen from my dyno chart in the dyno section I didn't have dip to contend with. Later I also used some even larger pipe but you are safe with the Fuel Moto.

https://www.fuelmotousa.com/i-23898837-fuel-moto-dynamic-exhaust-tuning-inserts.html#!make%3DHARLEY-DAVIDSON

Sorry not sure how to make that link work.  Its FM home. Then drop down exhaust menu, pick exhaust accessories, then click item 17 exhaust tuning inserts.

[VernDiesel]

rigidthumper, Earlier in this thread you linked a Suburban HD page with 4.180 piston & cylinder kits that could go with the cylinders & 4.375 stroke that Adam has. I already have I believe the same or same length cylinders from my now 3 1/2 year old 37k mile MoCo stage 3 107 to 114 kit. And the factory 2019 107 I believe 88cc heads. I see Suburban has just the piston kit; SS148185D08. The site says these pistons have an 8cc dome to get compression up to 12.0-1 with 88cc heads.

Earlier I said I was considering Star's new F35A cam. George say's its designed to fit in a stock engine. It closes 10 degrees later than the 30 30 at 35 after bottom, has 572 lift and is designed for 10.5 to 11.5-1. I have 64mm TB & intake and am thinking of having Wards port the intake. Suburban also lists exchange heads so I should probably do that as well as I am not trying to leave much on the table. Would you have any concerns with this combo?

Naturally in construction terms measure twice cut once. I am a hobbyist here not a pro builder. But would you have concern that the compression or cranking compression be too high that it risks detonation? Or that measurements would be too close that it risks valve piston contact? Any ideas suggestions or options I should consider? All suggestions concerns welcome.


Ohio HD,  You must be somewhat local to me.  I see your link but are you also affiliated to a local speed/machine shop?

[rigidthumper]

What are your goals? I've seen 150TQ & 125HP with stock heads and a 124 kit. At this power level, I would get the 124" cylinder/piston combo. Not that much more money, but an easy displacement bump. Pistons available from 11:1 and up. Ward ported heads/TB, 11.5:1CR, Georges cam, 64TB, 145+TQ 130+HP should be in the neighborhood (after proper tuning).

[Adam76]

What are you guys recommending for softail exhausts for my 117" build?
The last part of the puzzle is the exhaust....

The M8 softails seem very exhaust sensitive, and I don't want to mess up my build with a poor exhaust choice.

I'm currently looking at the Supertrapp Fatshot 2-1 with an open end cap.
Thanks

[VernDiesel]

Ridgid I don't have specific power goals. Mostly plan was to get more out of what I have and make sure its a reliable blast to ride. I want to get rid of my SE Pro tuner for various reasons and move to PV or other. Get rid of the catalyst in my pipe so that I could get more through it without it becoming a hindrance. So I was going to step up the cam, port the intake, bigger injectors, upgrade the compensator to make it more bulletproof and re tune it. Thought maybe 133 HP for a 15 HP bump would be achievable and that maybe I would be satisfied with that at least for a few seasons.

Plan on doing a leak down test and check crank runout. Make sure she is healthy. If leak down test wasn't great we could freshen it with hone & re ring and or do valve work if needed. Then you showed where I  can actually take those heads to 4.180. Get better pistons better rings more compression for not a lot of money and not a lot more work. But at that point with heads already off I'd probably get the heads done. Not sure what this combo could make. Perhaps 140 HP.

If instead I buy jugs, pistons to match, for big cubes big power (150 HP) I would also likely need to buy exhaust. The bike is recreation and just has to be fast fun & reliable. So I was just trying to pick a semi economical & sensible way of doing that.

"Ward ported heads/TB, 11.5:1CR, Georges cam, 64TB, 145+TQ 130+HP should be in the neighborhood (after proper tuning).  Are you talking about a 120ci with the F35A?  Lots of torque little HP?



Adam sorry I don't want to hi jack your thread. I've liked the S&S pipe for this displacement & power level.  Interested in what others suggest. 

[Adam76]

Adam sorry I don't want to hi jack your thread. I've liked the S&S pipe for this displacement & power level.  Interested in what others suggest. 

Yes, the S&S pipe seems to be the one that I see people use the most, with good results. 

I'm just looking for other good options, because I'm not a huge fan of the pipe for my particular bike.

Cheers

[JSD]

Adam the short TB types give away a bit off torque and are noisy enough to get the WA fun crew on ya arse. My mate has on on a lowrider S we wrapped the baffle with glass pack from KTM but its still loud. 

[Adam76]

Thanks JSD, I was never considering a TBR short 2-1 pipe.....

Think I'm going to end up with the S&S superstreet or possibly the Supertrapp Fatshot 2-1 which my local tuner likes quite a lot.

Don't think I can go wrong with either of these 2 pipes.
Cheers

[To The Max]

A.P.E. are making very good  torque and hp curves with the superstreet on big bore builds and they arn't noisy

[Adam76]

My CP 4.125" pistons arrived today.  Will drop them off to the machine shop with the cylinders sometime next week.

I'm going to mock it up and measure deck height and trim the base of the 114" cylinders in going to use.

But out of curiosity, how far are you guys finding the factory pistons down the hole on a stock 114" motor?
5 thou?  10 thou?  More?

[Adam76]

M8 114" Cylinder base gaskets -

Cometic Gasket CG-C10242-010 0.010" Thick Cylinder Base Gasket
OR   
Cometic C10177-010 .010" Rubber Coated Steel Base Gasket Set

Which gasket is the way to go for my M8 build?  I didn't realise Cometic did 2 different types. Priced differently too.

Thanks

[kd]

M8 114" Cylinder base gaskets -

Cometic Gasket CG-C10242-010 0.010" Thick Cylinder Base Gasket
OR   
Cometic C10177-010 .010" Rubber Coated Steel Base Gasket Set

Which gasket is the way to go for my M8 build?  I didn't realise Cometic did 2 different types. Priced differently too.

Thanks

FWIW, the rubber (micro) coated steel gaskets are excellent and the .010" thickness will be exactly that under compression when torqued.

[Adam76]

Thanks kd.