Lighting fires from 80mph? That possible?
At 80mph, if I drop mine down to 5th, I might be able to what I think was 92?, before red line?
I question those numbers because I might have only done it twice ever. But don’t quote me on it Matt. Been in a fog since last April. So I’m only about 20% sure.
With my decent stage 1 and the front and rear final drive pulley swap low end is over the top.And mid usually starts to peak at about 85mph. So I’m going based off of that

 

Using the term "lighting fires" is subjective. To me it's having the ability to authoritatively accelerate, not boil the rear tire like if I had a hot 124" in the bike. I could drop a gear, but I like to just roll on the throttle and pull nicely. That's what I want in top gear and in my experience a finely tuned 95" at 10:1 with the 551's will do it. Right now it's just a very overgeared 88" with stage 1 mods. She'll hold 80, but not do too much more if I roll on the throttle. I personally like seeing my digital speedometer increase in more than single-digit increments. Back in my ute, I had an R1 that went up by 5's (with the front wheel off the ground). When my 107" was working, she'd jump by 3's.

 

My wife’s 08x bones with just a stage! Goes really nice. Seems like top end has more grunt then the mid. She likes it that way and is very strict about what I’m allowed to do with it.
I don't know how I survived the 80’s and a good part of the 90’s
My last crash was worst of them all. Only one I didn’t walk away from. Actually was twice. Live and learn.

 

Yea, me too. Back when I got out of the Air Force in the early 00's I apparently had more money than sense and bought that R1. I would regularly see over 150 with it, in a t-shirt and jeans, and sun glasses...

No bad crashes fortunately, but one grounding. Front tire hit a patch of water on a painted arrow in a round-a-bout in Wisconsin on a Sportster. Some boat was draining the bilge on the way home and my front tire found it. Scuffed elbow, that's it. Bike had seen better days tho, speedo hit the curb as the bike spun around on its side.

 

Bumping my old thread:

This build has been bugging me. I'm on deployment right now with nothing better to do than fester into what could be done to get this 106" Evo working as designed. I know the Twinkie works, I put a good couple thousand miles on it since I shoe-horned it in there. The problem is I spent all this money and have nothing to show for it. In theory this is a solid build that should work. Thanks to the Axtell cylinders not letting the pistons cool properly it's shelved in pieces.

I'm thinking about resleeving a set of OEM Harley Evo cylinders with some sleeves from LA Sleeve. I got my own Grizzly mill now so with my 20T press I can get the OEM sleeves out of the cylinders, then bore them out to an interference fit for the new sleeves, then have them finish bored by a pro to a new set of pistons like I started with (domed, not the flat tops). I also still believe I can get a set of piston oil jets in there. That S&S case is beefy and take take a little machining. It's not like that location is high stress anyway.

The only other option that I can find is Revolution Performance nikasil cylinders. They have a 109" kit that uses a 3.875" flat top piston that will bolt right up. The problem is it's a flat top piston, and I'm not really 100% on board with nikasil cylinders. I like the idea of a cast iron sleeve with an aluminum cylinder to help dissipate heat. That and the kit is about $1100.

The damn power that bike had before it popped was intoxicating and I want to make it work.

 

Just read this thread front to back. What an emotional roller coaster. Thanks for sharing everything. Super interesting.

 

What's wrong in going with a flat top@3.875"I...
also what stroke?
I take it to be 4.5"?

 

I suppose there's nothing physically wrong with the 3.875" flat tops, I just want to try making the design thesis work. That and the heads are machined for the 30 degree domes (91cc chamber). Using the Hammer pistons would get me up towards 11:1, where as flat tops would put be down to about 9.5:1. That's leaving a lot of power on the table.

Oh, and 4.625" S&S stroker crank.

 

Correct me if i'm wrong but a 3.875 x 4.625 is 109 cu in. Did you mean 3.8125? I as well when building my 96"er had to go to 30* angle tops to get the compression I needed for the cam and configuration I wanted. But I didn't use a 3.875 Piston. I used an Axtell 3.645 30* when machined was set to 18.1 cc dome and a combustion chamber of 94.3 cc... Other than Hammer, does anyone else make a 3.875" piston or 3.8125". I know that CP/Wiseco and S&S don't...

 

No correction necessary, you're right. My original bore was 3.8215", which in Sportster world is an 88" engine. They also sell a 90" version, 3.875", which would put my bike at 109". The Sportster pistons and the Evo engines with a 4 5/8" stroker crank pistons have the same piston compression height (1.2"). Since Hammer is so big in the Sportster hop-up world they're the ones who make the best selection of pistons. S&S does not make pistons for my build since they never took any OEM cased bores out to 3.8125" (nor 3.875"). Wossner does, that's who makes Axtell's pistons. Wiseco does actually make an 88" Sportster piston, but it comes with rings for Nikasil bores, and it's only a flat top.