106 cu inch Mountain Motor

[grbrown]

I have just discovered a couple of conversion kits for Evo engines, by Axtell and JIMS, to stroke and bore them out to 106 cu inches. There are other brands of big bore conversion kits that will mate with a long stroke crank.

Does anyone have first-hand experience of these?

I already have a JIMS 4 5/8" crank, so it is almost too tempting to get on with it! New bore is 4 13/16, giving a mere 1,730cc. Sounds better....

[girlyglide]

Whichever way you choose to go get the crank and pistons balanced or you will be very lucky indeed if you don't get bad vibes.

[the_monster]

second that, makes a world of difference with the delivery of the power.

[Phil]

Originally Posted by girlyglide

Whichever way you choose to go get the crank and pistons balanced or you will be very lucky indeed if you don't get bad vibes.

Phil is right. Increase the stroke & not the bore & the vibes will increase.....A LOT. Increase the bore to match & it helps to balance out. Hobsons choice.

[grbrown]

The chap who built my motor has retired, unfortunately, otherwise I would be talking to him now! Whatever he did to it the motor is wonderfully smooth, far nicer than my wife's Dyna.

[simonDyna]

Just stick a big S&S lump in there and be done with it...you know you want to.

[Roger]

Originally Posted by simonDeuce

Just stick a big S&S lump in there and be done with it...you know you want to.

106" - that's just a baby engine, eh Simon?

[simonDyna]

Originally Posted by Roger

106" - that's just a baby engine, eh Simon?

Teeny weeny!

[grbrown]

Originally Posted by Roger

106" - that's just a baby engine, eh Simon?

There are several engine brands out there I would struggle to choose from, given the will and the means. In the meantime, having sampled a bigger motor, I would like a bit more. I can imagine affording to bore mine out, but not replace it completely!

[simonDyna]

Originally Posted by grbrown

There are several engine brands out there I would struggle to choose from, given the will and the means. In the meantime, having sampled a bigger motor, I would like a bit more. I can imagine affording to bore mine out, but not replace it completely!

All joking aside, how much would you get for the engine in your bike at the moment? £1800-£2k? Maybe a bit more. When that gets taken off the price of a new 124" by S&S, Ultima etc it isnt such a bad idea.

On my old deuce ( and please bear with me, I know it is a TC but the logic is the same ) I did the first upgrade from stock to 95" with 203 cams. Then I stepped up again to 257 cams and SE heads, changed the exhaust, ignition etc and it was a bit of a beast. Then after a while I went to the 124" kit. Each upgrade costs money and it soon adds up.

If you are looking to beef up the motor, you rarely say "thats it, I'm done now". You'll step it up, ride it for a bit and then look at the next hop up.

This time round it was straight out with the engine, stick in a new one and the old one was sold on eBay at the second time of asking for £2300+shipping.

The cost of the 124" that is now in my bike worked out for around what you would pay for a supply and fit for a cam/barrel/head swap in a Harley dealer. It isnt prohibitive by any means.

Some places will even take evo motor PX on new engine deals because they can shift them so easily. If they cant, you can always, always get shot of one for decent money.