I'm having hand surgery next week so won't be able to ride for 6 to 8 weeks... time to work on the engine...

This time around we're going from 95" to 106" using an S&S 4 1/2" stroker flywheel and S&S 3 7/8" forged pistons. Also upgrading the stock clutch to a Barnett clutch, Timken conversion, powder coating the wheels, and installing an LED headlight.

You may wonder why I'm not going with a 107" kit and to be honest, I gave that a lot of thought. However, I'm also probably going to add a turbo charger in the spring (or a soon as funds allow), and the 107" kit would require boring the cylinders to 3.928" (as on a 98"). The head gasket used on 3.928" cylinders is very narrow in places and when the turbo is added, can be prone to leaking.

You may also wonder why I don't just add the turbo and be done with it, and that too is a good question. In planning for the turbo, it was clear that I would need to beef up the bottom end. I considered a standard balance, plug, weld job using the OE flywheels/crank but for around the same final cost I can get the S&S flywheels/crank. It is an insidious process because once I decided to go with the S&S bottom end, the little voice in my head suggested that I might as well stoke it for just a little more money... evil little voice.

So, stroke it I will, and then add the turbo. This sure is fun!
Progress so far...

 

How bout a blower? Is it possible?

 

A super charger would certainly be possible. Procharger makes v-twin supercharger kits:http://www.procharger.com/motorcycle.shtml, but I like turbos. No parasitic loss.

 

Yeah buddy, love this stuff! So any headwork planned and with the turbo, what do you do for the throttle body - just leave it stock?

 

Lovin these threads. Subscribed to see the progress.

Can't wait to see the numbers of your stroked S&S 106.

 

Headwork was done when I went to 95" so I'm good there. I am having the tb ported and polished as part of the 106" upgrade (forgot to list it). With the turbo I'll upgrade the fuel injectors.

 

Will you have to use the 6.2g injectors?

 

I have not discussed which particular injectors the shop that will build the turbo recommends. I know that HPI sells a "turbo" fuel injector that flows at 7.5 and 8.6, depending on pressure. But I don't know whether those will be needed or whether 6.2 sized will be sufficient.

 

Going turbo or charger what compression you aiming for? 9:1? Couple steps colder plug would be needed. Just thinking a stroker kit would be harder to yield the lower compression needed.

 

Actually, we'll be keeping compression at 10.5:1. I know that many turbo systems, especially in Harleys, call for lower compression. Sanger Cycles, the folks who be building my turbo system, use water injection to cool the charge, not an intercooler. Because they use water injection, there is no need to lower compression. Thus, I get to keep the 10.5:1 compression and the water injection cools the charge in the combustion chamber. Even at 10 psi of boost, which is the most they recommend, you do not obtain dangerously high compression.