Why do you think it will produce extra heat? If a cyclinder and piston kit make noises then there is definitely an issue. I'm assuming you're referring to the valve train, not the 1250/1275 kit because they don't make noise.

I have a 1275 and a 1250, they both purr like kittens. No heat issues what so ever.

 

Yes, or a louder sewing machine, more clanging and banging, whatever terms are used to describe our beloved sportster noise.

I didn't mean the actual cylinders and pistons themselves.
Good to know, thanx!

 

Based on what I've read, they should be very street able.
Proper maintenance and break in assumed.
I have flogged my stock motor pretty hard, and used a very questionable break in technique. Don't see why 1250/1275 should be fragile.
If you start stroking and case boring you might see issues.

Edit: 1275 kit is my next major intended move.

 

Thanks for your help guys, in you opinion do you guys think Hammer 1275cc it's a better and more durable product than the S&S 1250cc???

 

I would say that because I have a Hammer 1250 kit. No problems or issues and Hammer is great to work with. Really good customer service.

 

Beautiful bike brother, but see that's my problem their customer service, I tried to contact Hammer (Aaron) and explained what happen with my old engine over heated and explode while going on the Highway (100mph, 5000rpm, for about 40min) ask him about durability and if it will heat up the same of the HD stock, And I got reply from Aaron saying that "because I melted my old stock engine they rather pass on this at all". I replied why? And they said that "they have no time to deal with problems and that they want it all their projects to be a success." And he (Aaron) told me to contact their competitors and that they will be happy to sell let a kit.

So now what you guys recommend me to do, because everybody tells me Hammer is the best but they don't want to sell me a kit! I think this whole situation is stupid BTW

 

Did you guys that installed the 1275cc kit needed a special size gaskets or the normal "stock" size will it work??

 

Kit comes with the gaskets you need.

 

Have I got this right, that you asked them about an engine that failed, but which they had nothing to do with?

 

After speaking with you I'm sure they had their reasons. Could be they didn't want you killing their engine the same way you killed the stock one. There are two sides to every situation and we only know yours....