[Merc63]

In stock form would these heads flow enough for a 126"?

These are the heads I have, but I am not sure if they have been modified.

I don't know the details on this build, but Im running 122hp and 137tq, with a 45mm mukini. I just ordered a S&S G from Dan Davinci to see if we can get some more air in the engine.

Torque shoots up around 2500, but starts to fall on its face around 4000-4500rpm.

I am kinda shooting in the dark here without knowing the pistons, cams, etc.. But I'd like to see the HP come up in the 130-135range.

 

[wfolarry]

They can be made to flow better but they do flow good out of the box. If the carb doesn't help the heads might need some attention.

 

[Merc63]

Hopefully this larger carb opens things up.

What's a good cam to run with these heads for some mid-high range power? Or is it hard to suggest a cam without knowing the pistons?

Also, is it possible to pull the heads and get some work done to them or would the engine need to be pulled?

 

[CowboyTutt]

Your exhaust could be causing that TQ loss too. What are you running? Knowing so little about the rest of your engine build you really are shooting in the dark as what to modify. -Tutt

 

[Merc63]

Your exhaust could be causing that TQ loss too. What are you running? Knowing so little about the rest of your engine build you really are shooting in the dark as what to modify. -Tutt

I am running a D&D Boarzilla. Just upgraded it from a Thunder header and seen a 12HP/5TQ gain. Next step is the carb to see if she wants more air. Its got a 45 Mukini on it right now.

 

[Merc63]

Is there a method of telling how much power a head is going to max out at by calculating its CFM?

I am just wondering if these heads are going to be the bottle neck or are they good for quite a bit more power then what I am currently putting down in stock form.

 

[HogBag]

Do you know what cam is in the S&S motor.

 

[Merc63]

Its not an S&S.. Its a Harley custom engine. No I have no idea which cams are in it.. We are going to see where this carb upgrade takes us in terms of power and if that doesn't help I am thinking of throwing in a S&S 640 cam.