I'm currently going from 96 to 107, and since the engine is going to be apart I decided to go ahead and have the crank done. I had thought about going up to 117, but I decided not to because everything I'm planning matches the 107, but if I had a 103, I don't think I would have gone to a 107, 4 ci just doesn't seem like a lot. I wasn't willing to go from 96 to 103 because I figure if I'm not going 10% or more, forget it. But to each his own, as long as the OP is happy, that's what really matters. BTW, I would go ahead and do the heads, I think that's worth the investment, and will probably bring you more power for less $$$.

 

Varooom,

Thanks for the info! I did not ask the right question. I wanted to ask about the "butt temp" engine hot air heat we get off the engine. However, if the oil temp is relatively the same between the 96, 103, and 107 then the engines are running the same relative temps from stock to 107.

 

Wonder what caused Mr. Twister to become banned?
He was always such a helpful, warm-hearted soul, willing to lend a hand, with great insight, and well thought out responses, and always took the high road.
We will all miss him.............for about 2.3 seconds.

 

I did a 107 in the summer of 2010 and I decided to do the crank (trued, welded, balanced, left side timmens) after I had already had the cylinders bored and bought 107 pistons. I had Revolution Performance do the work, so I sent my crank in the cases. To be honest, if I hadn't already bought pistons and bored cylinders I would have done the 117. The cases are split and it's not that much more to bore them. You're buying pistons anyway and the cylinders would'nt be that much more. If you decide to go that route Frank at Dragos has some cylinders he has developed for the blower bikes that should be the strongest out there.

 

Dissention will not be tolerated here

 

That's exactly what I was thinking! Everyone is focusing on peak hp/tq, I am with you I bet an overlap graph shows alot of pick up throughout the rpm band between the 107 motor over the 103 motor. To the OP don't focus so much on numbers though, it is how the bike rides.

 

Not trying to be a post jumper just answering a comment.
Stonecold
The cylinders you are talking about are relined they will handle 30 lbs of boost.
We can use stock cylinders or Axtell Or Rev Pef or S&S or HD. The liners are removed than installed with new ones. Here are some pictures. And if you look real close you can see the out side shell in the pics are Axtell cylinders with new liners..... Just food for thought......

 

Very interesting.

 

I like my power before 4000 RPM personally. As long as the owner is ahppy, that's what counts.

~Joe

 

I am currently doing the 107" Fuelmoto build on wifes TG , i think thats just the little xtra this heavy beast needs without getting radical. I already have tw555 cams installed as you can see in my sig. along with other mods.
Im putting the 103" pistons and jugs on my 96" FatBob and having those jugs bored for the 107", almost a free upgrade on Bob.
Also having the Fuelmoto A head job with man. releases done for the 103" and the B job done for the 107".
Looking forward to hearing more about the 777 cams as i still have a couple of 96" bikes to mess with.