Horsepower curiosity

[Fisher]

Currently in the stages of building a 443cc serval banshee. It’s got a 7mm stroker bottom end paired with 68mm big bore top end cylinders. I was planning on pairing this motor with high compression domes (plan on running race gas) as well as some 36mm smart carbs and I was planning on running Shearer small bore in frame pipes. I was just curious if anyone had any good guesses for horsepower range? I was also wondering if the stock serval porting with said pipes would be better for general duning or if I went with a Dune port and did CPI in frame small bore pipes.

[SKEETER]

Duner, CPI.    

[locogato11283]

15 hours ago, Fisher said:

Currently in the stages of building a 443cc serval banshee. It’s got a 7mm stroker bottom end paired with 68mm big bore top end cylinders. I was planning on pairing this motor with high compression domes (plan on running race gas) as well as some 36mm smart carbs and I was planning on running Shearer small bore in frame pipes. I was just curious if anyone had any good guesses for horsepower range? I was also wondering if the stock serval porting with said pipes would be better for general duning or if I went with a Dune port and did CPI in frame small bore pipes.

Who's building the motor?

[Fisher]

4 hours ago, locogato11283 said:

Who's building the motor?

Myself.

[locogato11283]

A 4mm Serval on race gas will make around 100. I'm guessing the 7mm will make 5-10 more.

35PWK and Snipers or Shearers.

[Fisher]

Talked with Shaun at Top Dog for a while, I’m leaving the cylinders on ported so just servals as cast, doing race gas and CPI and smart carb 36mm.

[locogato11283]

I'm guessing 95-100. You're missing out on about 10HP by not porting it. Single or dual carbs?

[Fisher]

Gonna be running dual 36mm smart carbs and the top dog racing turbine flow intake manifolds. Only reason I’m not porting is because I want to keep a decent amount of maintainable bottom end. But my curiosity of overall horsepower is strong. Just want to make sure I can spank on my buddies “95hp” built raptor.

[locogato11283]

47 minutes ago, Fisher said:

Gonna be running dual 36mm smart carbs and the top dog racing turbine flow intake manifolds. Only reason I’m not porting is because I want to keep a decent amount of maintainable bottom end. But my curiosity of overall horsepower is strong. Just want to make sure I can spank on my buddies “95hp” built raptor.

Pretty good chance that Raptor is going to eat you for lunch unless you get good traction off the start. You're really giving up a lot with this setup.

I'd have it ported and it will make 10-15HP more. I'd run 35mm PWK over Smart Carbs.

And I'd run Snipers. That combo should get you in the 115HP range. 

[Fisher]

I got a 6 over arm might go to an 8 over and a fresh set of 12 paddle 74 inch rollout superlite’s with extreme blades, and I don’t want to give up all my bottom end just because I mainly do free shots with the occasional drag racing. And I went with the 36mm smart carbs for ease of use and since they’ll have the bigger engine side spigot they should flow better on the top end.

[locogato11283]

You’re going to be disappointed but I don’t think you really want the advice.

[Fisher]

What are you saying I’d be disappointed in?

[locogato11283]

37 minutes ago, Fisher said:

What are you saying I’d be disappointed in?

The whole thing. It's not going to run very well and you're going to be way down on power.

[caleb90]

Why the fuck would you spend all that money on a build and not port it? 

[Fisher]

My original plan was to port it, I actually brought my cylinders into Shaun at Top Dog racing and he highly advised against porting the cylinders. He mentioned something along the lines of the 68mm CP cylinders for 7mm cranks don’t leave a of room for porting between a serval and cub and the serval alone will feel fairly peaky. Those probably weren’t his exact words but about what I took away from the conversation. And what specifically would cause this motor to “not run very well”?