I was thinking of the head mod along with the web cam. Sounds like equal gain .That should make the prairie smoke the b.f.

 

What is the head mod? Is it adding BF heads to the Prairie? I hadn't heard that Mickey was done with that experiment yet.

 

Dynoray made a post on the web cam thread about head porting. I am interested.

 

Oh.
Mickey D said porting didn't help much because the bend in the intake manifolds didn't allow a whole lot of flow. SOme people say it is worth it, some say not. The ports and manifolds were redesigned on the BF. That is one reason a BF has so much power, even with lower compression.

 

Nyroc, are you talking about the head? I had my snowmobile cylinders ported but I think dynoray was talking about the head. Do you think it is worth it?

 

Yup, I was talking about porting the head. I suggested to Kisssofdeath that he port his head along with the Big Bore, but Mickey told him not to.

He didn't say it wouldn't help, he said it would not make much power per dollar.

I don't know for a fact it that is true, but I do know that other people have said you have to port them, and Mickey said you won't get much.

I dunno. I guess I have lost the need for speed and I don't really want to mod my 650.

 

Nyroc,
Has anyone tried to install the BF carbs and airbox on a Prairie yet? I would love to have the bigger carbs and less restrictive design. What do you think?

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

You would probably have to make your own intakes to do that, since the head geomtery and distance is not quite the same.

Mickey was workin on getting BF heads to work. If they work. That would be the ticket. A 900cc Prairie with BF heads and carbs.

 

900cc that would be awsum. How about just the bf heads on the 700?

 

Dynoray has ported a lot of heads on local P650's, and has run them on the dyno too. You get some very good HP gains with the heads ported....... I also saw Mickey's post on carb and intake manifold flow rates which would indicate that the unaltered stock heads can flow as much air as can be supplied by the carbs/intake manifolds; possibly the stock carb and intake manifold can't flow enough air for one of his big-bore kits? I've also seen dyno printouts and witnessed drag races between ported and unported P650's that definitely indicate to the contrary; I have been consistently beaten by 2 lengths over 200ft by an identically prepared (but ported) P650. The stock heads are restricted in the area around the valve stem; maybe to increase air velocity at low RPM's for better bottom end response?