1150 EF updating project

[Blower]

I understand the port matching, but why port the head on a blower bike?

I don´t really port the head , I only going to smooth rough surfaces . I take the pics before and after .
BTW why not port blowered engine ( if there is something to port ) . Actually many bikes has too big ports form factory .

[lecroy]

"Our goal is to always max out the flow relative to valve size." Paul Gast

The head has a lot to do with how they keep making the smaller engines have more power. I need to take some pictures of some of the head my friends use. One is a pro-mod engine and this thing is opened up so big that there are no intake spigots! Next time I am out to the shop I'll take some pictures for you.

Those little flaws and bends won't mean much to a compressor pushing air into the engine. It's the nice part about the compressor, we don't need a fancy head and high compression pistons.

[Blower]

"Our goal is to always max out the flow relative to valve size." Paul Gast
Those little flaws and bends won't mean much to a compressor pushing air into the engine. It's the nice part about the compressor, we don't need a fancy head and high compression pistons.

That´s why I can leave the intake port smaller to get better torque when engine is not under boost . Exhaust port is different story . Engine is 1150 cc and if ít gets 50% more air/fuel mixture , so exhaust ports should flow like 1750 cc normally aspirated engine .

[lecroy]

Consider that when Terry Kizer was setting all those national records, he was doing it with stock cams and a stock head. The only change was to the valve seat pressure.

I have never played with a blower in my life. What you would seem to have going for you is that you don't have the back pressure. With a turbocharger, the exhaust pressure before the turbine is about the same as the manifold pressure. My back pressure is higher. I have to increase the seat pressure on the exhaust valves as well as the intake. It would seem that you only need to up the intake.

Any idea how much pressure you plan to run with it?

[49er]

Consider that when Terry Kizer was setting all those national records, he was doing it with stock cams and a stock head. The only change was to the valve seat pressure.

I have never played with a blower in my life. What you would seem to have going for you is that you don't have the back pressure. With a turbocharger, the exhaust pressure before the turbine is about the same as the manifold pressure. My back pressure is higher. I have to increase the seat pressure on the exhaust valves as well as the intake. It would seem that you only need to up the intake.

Any idea how much pressure you plan to run with it?

Nice fab work Blower. You're certainly a man on a mission. What Lecroy has said about keeping the porting and cams stock rings true.
It's a pity that others tweeking their road machines haven't taken notice of the fact the records are broken by guys like Terry Kizer using cleverly tuned stock setups. You can't retain good bottom end performance with too radical modifications. If you're racing, then that's a different story!

[Blower]

Consider that when Terry Kizer was setting all those national records, he was doing it with stock cams and a stock head. The only change was to the valve seat pressure.

I have never played with a blower in my life. What you would seem to have going for you is that you don't have the back pressure. With a turbocharger, the exhaust pressure before the turbine is about the same as the manifold pressure. My back pressure is higher. I have to increase the seat pressure on the exhaust valves as well as the intake. It would seem that you only need to up the intake.

Any idea how much pressure you plan to run with it?

Charging air pressure is going to be under 10 psi , so I think I don´t need to put any stronger valve springs to get more seat pressure ( if thats what you mean ) .

[lecroy]

Yes, that and just to get an idea of what your up to. You will know if the springs are too weak.

[Blower]

Two hours porting yesterday and only intake ports inlets ported . From 34.5mm (1.34") to 37mm (1.45") .

Before :



And after :




Before :



And after :

[lecroy]

Any pictures of under the valves looking thru the combustion chamber?

[Blower]

Any pictures of under the valves looking thru the combustion chamber?

Got only intake ports finished . Starting today with exhaust ports and if I have time with combustion chamber .
I put some pics tomorrow .

[Blower]

I get finished with exhaust ports and combustion chambers . Not so good polished , but better than originals .

[rapidray]

Blower, you DON'T want the intake ports SMOOTH! You want them roughed up as much as possible to promote turbulence & fuel atomization as much as possible! I finish all of the heads we do with a 60 grit cartridge roll on the intake side. You can polish the exhaust side as it helps to slow down the carbon buildup a little but you DEFINITELY want the intakes ROUGH! Ray.

[Blower]

Blower, you DON'T want the intake ports SMOOTH! You want them roughed up as much as possible to promote turbulence & fuel atomization as much as possible! I finish all of the heads we do with a 60 grit cartridge roll on the intake side. You can polish the exhaust side as it helps to slow down the carbon buildup a little but you DEFINITELY want the intakes ROUGH! Ray.

Intake ports are not so smooth . I finish them with 120 grit disc roll . Exhaust ports and combustion chambers are smoother .

[49er]

Blower, you DON'T want the intake ports SMOOTH! You want them roughed up as much as possible to promote turbulence & fuel atomization as much as possible! I finish all of the heads we do with a 60 grit cartridge roll on the intake side. You can polish the exhaust side as it helps to slow down the carbon buildup a little but you DEFINITELY want the intakes ROUGH! Ray.

I agree, the inlet ports need the surface slightly roughed to promote ideal fuel /air atomisation.
I doubt the benefit of porting the inlets without retarding the inlet opening on the cam. The combination of supercharging and the advanced opening figures of the stock 1150 cams will result in an unburnt charge being forced directly into the exhaust at lower rpms. The bottom to mid range is the very area that you should be expecting the most improvement when running a supercharged system. The exhaust cam timing and valve size also need to be considered for optimum performance.

[Blower]

I agree, the inlet ports need the surface slightly roughed to promote ideal fuel /air atomisation.
I doubt the benefit of porting the inlets without retarding the inlet opening on the cam. The combination of supercharging and the advanced opening figures of the stock 1150 cams will result in an unburnt charge being forced directly into the exhaust at lower rpms. The bottom to mid range is the very area that you should be expecting the most improvement when running a supercharged system. The exhaust cam timing and valve size also need to be considered for optimum performance.

Can you tell any numbers , how many degrees to retard inlet and how many degrees advance exhaust ?