Port height - too tall for freestyle?

[waxhead]

no dont do that it will chew stuff up with out the front cover to support it

but find out what your base timing

you may be able to smooth the power curve out with more timing

 

[Matt_E]

Hey Matt… I'm just curious as to why you think the boost port has been compromised by the porting and epoxy work.

It appears to me that someone was trying to enhance the flow to the boost port and auxiliary transfer ports.

Flow to the main and aux transfer ports was increased. However, as I understand it, the boost port gets charge up into the combustion chamber on the piston upstroke/intake cycle. As the a/f mix rushes into the cases, the sleeve hanging down into the intake tract deflects some charge up into the boost port while the piston is moving up (hence "boost").
Cut that sleeve and you will indeed improve flow to the tx ports. But as you know, Freestyle port jobs do not/only minimally touch that part of the sleeve precisely because that boost on the upstroke is needed for bottom end.

With that part of the sleeve entirely gone, very little charge will be going that way during that part of the cycle.

I might be waaaaaay off the wall here.

The side angles of the port windows appear to be top end oriented as well - hard to say without better pics.

 

[Crab]

Wax, any idea on the Kawi motors if the same applies? My skirt just below the boost window (below the pistons) was cut straight down and removed. I was told guy's use to do that a lot back in the 90's.

 

[#ZERO]

Can I use the starter with the flywheel cover off? and I don't see a TDC mark. I may have to find TDC too. yippee.....:banghead:

You will need a bendix holder to check your timing with the flywheel cover removed.

You can purchase one at Watcon or you can make one from an old flywheel cover.

If you don't have a TDC mark on your flywheel you will need TDC locating tool.

http://www.watcon.com/Catalog_Pages/Bendix_Holder.htm

http://www.watcon.com/Catalog_Pages/Top_Dead_Center_Tool.htm

 

[ATS_Scott]

You will need a bendix holder to check your timing with the flywheel cover removed.

You can purchase one at Watcon or you can make one from an old flywheel cover.

If you don't have a TDC mark on your flywheel you will need TDC locating tool.

http://www.watcon.com/Catalog_Pages/Bendix_Holder.htm

http://www.watcon.com/Catalog_Pages/Top_Dead_Center_Tool.htm

Cool thanks! Just what I needed to know.

 

[ATS_Scott]

Flow to the main and aux transfer ports was increased. However, as I understand it, the boost port gets charge up into the combustion chamber on the piston upstroke/intake cycle. As the a/f mix rushes into the cases, the sleeve hanging down into the intake tract deflects some charge up into the boost port while the piston is moving up (hence "boost").
Cut that sleeve and you will indeed improve flow to the tx ports. But as you know, Freestyle port jobs do not/only minimally touch that part of the sleeve precisely because that boost on the upstroke is needed for bottom end.

With that part of the sleeve entirely gone, very little charge will be going that way during that part of the cycle.

I might be waaaaaay off the wall here.

The side angles of the port windows appear to be top end oriented as well - hard to say without better pics.

Matt, I did see epoxy at the top of all the transfers to aim the ports higher in the cylinder. I wonder if I just got a diff cylinder, if the mods made to the cases would help get the charge to the boost port? I'd probably have to knife edge the boost port inlet (since there is no case there) which would waste another cylinder if it didn't work. ;-)

 

[Matt_E]

Aiming the ports higher (didn't see that in the pics) will help top end.

Different cases will not help the boost ports significantly. the damage is done by cutting the sleeves.

 

[ATS_Aaron]

ok guys thanks for the replies. Maybe a blaster guy will want it....