I'm new here, hello all and thanks for having me. This question is for the more advanced techs among you. I have a 97 evo motor I am rebuilding. The cases are split so I figured I may as well add a few cubes. I ran into a fellow that has a set of T&O 4.75 stroke wheels and a pair of Merch 3.80 bore cyls w/ pistons for 4.75 stroke. This would give me 107.75 ci. My question is will it all work together and with the stock cases. More so the cyls, the wheels shouldn't be a problem. Thanks in advance for any feedback.

 

For Big Twin kits with 3-13/16 (3.8125)” pistons, bore cases 4.005-4.010” X 1.500”.

Chiming in not as a advanced tech, just researched reinventing the wheel once. The above spec is for Axtell's big bore kit, it is a 3.8125 which means the Merch cylinder bore will work with a Evo spigot. Axtell techs state a 97 case bored spigot will hold but reported failures say different because Evo cases are weak in the spigot area. A aftermarket case would be the no failure approach to your question

A set of stock Evo heads cannot support a 107" without extensive work that costs will out weigh aftermarket heads that just need cleaned up

I do not know what size the Merch cylinder bolt pattern is and would need to be researched.

 

Thanks for that. Thats what I kind of suspected. The cyls might outsize the cases capabilities. So I guess the thing to do then is just get the wheels and go with S&S 3.625 big bore kit. Still gives me 98 ci. I guess I can live with that.

 

By what I have heard, the max stroke you can put in the bike is 4.625 the reason is that the heads will hit the frame. Motor to frame clearance issues..

 

Does S&S offer 4.750 stroke pistons for a Evo, I'm aware of the T&O flywheels, know it was popular in the Shovels and ride with 2 bikes that run the 4.750 but don't know how far T&O carried into the Evo

 

I've owned my 1990 Glide from new and have studied boosting performance for much of that time! A popular upgrade was to install a stroker kit, of which there were several brands, to give 89", using the stock bore. Alongside them there was a market for aftermarket cases, such as Axtell, who produced beefed-up cases suitable for larger displacement and higher power outputs. Merch made (may still do) new engines up to 131", Axtell made cases and cylinder kits up to 107" IIRC.

The parts you mention are not suitable IMHO for stock cases. I will also observe that the cost of those components, in their heyday, were very high, which is why I never built one! I bought a crate S&S 107" instead, much cheaper.