Back In The Shop......Now What's On Your Bench????

[spencerpaving]

I would say 40-50 percent of the bore would be the bandwidth. ...just my 2cents

 

[CFM]

Any thoughts on thickness ? Any reason for 40-50% ? Bell had written that the band width was dependent upon rpm and engine load. I'm guessing it would be most similar to that of a cart engine being a "fixed gear" and all.... He never touched on thickness of band. This saw is for a friend who won't be cutting for heat so much as for camp fires and cleaning up property. So mostly play. He plans on running premixed oxygenated fuel of what burn rate we haven't decided yet seeing as I have a billet chunk for a head lol

 

[CFM]

are there any rules/guidelines to combustion cc in relation to piston area/rpm/case volume????

 

[CFM]

This pretty much sums it up

 

[Deets066]

its ready from factory ? or you make this ?
if you CONGRATULATIONS perfect job

Nothin from factory, made from a 5'x10' 1-1/2" plate and a 20' stick of 4x6 tube steel
Hand build with a torch, welder, and mag drill

 

[spencerpaving]

Any thoughts on thickness ? Any reason for 40-50% ? Bell had written that the band width was dependent upon rpm and engine load. I'm guessing it would be most similar to that of a cart engine being a "fixed gear" and all.... He never touched on thickness of band. This saw is for a friend who won't be cutting for heat so much as for camp fires and cleaning up property. So mostly play. He plans on running premixed oxygenated fuel of what burn rate we haven't decided yet seeing as I have a billet chunk for a head lol

I would go aleast 3/4" I made one that was to thin and it warped at the head studs

 

[Pud]

I'm in 395XP mode today......

View attachment 413083

View attachment 413084

View attachment 413082

I like the middle jug

 

[CFM]

I would go aleast 3/4" I made one that was to thin and it warped at the head studs

Thanks for the replies and info, much appreciated

 

[Mastermind]

I like the middle jug

I finally got a run of 395s to do it with.

Thanks for the replies and info, much appreciated

I've never made a head......so I was of no help.

At one time there saw a site called Race Saws........lots of hot saw building there. It's long gone now though.

 

[mdavlee]

1 1/4" is what I was told.

15-20% sounds about right for band width on there compared to stock cylinders. Have you checked the combustion chamber volume on the cylinder to start with?

 

[CFM]

I finally got a run of 395s to do it with.



I've never made a head......so I was of no help.

At one time there saw a site called Race Saws........lots of hot saw building there. It's long gone now though.

I wont hold it against you....lol. Thank you though all the same.

Maybe you could refresh my memory on idealstic port timing numbers on these older saws and the width i can go on the ports....

 

[pantelis]

Nothin from factory, made from a 5'x10' 1-1/2" plate and a 20' stick of 4x6 tube steel
Hand build with a torch, welder, and mag drill

Perfect job man, congratulations again

 

[CFM]

1 1/4" is what I was told.

15-20% sounds about right for band width on there compared to stock cylinders. Have you checked the combustion chamber volume on the cylinder to start with?

not yet... need to mill the top of the old flat to get it ready for the plexiglass and drip. i was curious if the oem was idealistic for a more performance oriented setting

 

[mdavlee]

It will give you a baseline. Smaller and shape is more towards performance usually.

 

[Mastermind]

I wont hold it against you....lol. Thank you though all the same.

Maybe you could refresh my memory on idealstic port timing numbers on these older saws and the width i can go on the ports....

Keep in mind that all I build are work saws. I look for pull truck torque, and could care less if I increase unloaded RPM.

Just send me a PM with what saw you are doing, and I'll share any build notes I have.

not yet... need to mill the top of the old flat to get it ready for the plexiglass and drip. i was curious if the oem was idealistic for a more performance oriented setting

On many jugs that I cut squish on, I end up with a .300" - .400" wide band (depending on bore size) that is flat. Or square with the bore, if that makes sense. I like to think that the wide flat band quells detonation, and increases squish velocity.

 

[CFM]

Keep in mind that all I build are work saws. I look for pull truck torque, and could care less if I increase unloaded RPM.

Just send me a PM with what saw you are doing, and I'll share any build notes I have.



On many jugs that I cut squish on, I end up with a .300" - .400" wide band (depending on bore size) that is flat. Or square with the bore, if that makes sense. I like to think that the wide flat band quells detonation, and increases squish velocity.

awesome, thanks mastermind. will do tonight after work

 

[bikemike]

View attachment 413205
Billet chunk soon to be new cylinder head.... Hopefully

Are you going to use studs or bolts to hold all that to your block? Id go studs they will save ur threads on the block if it needs to be tore down for trouble shooting. Look great

 

[CFM]

Are you going to use studs or bolts to hold all that to your block? Id go studs they will save ur threads on the block if it needs to be tore down for trouble shooting. Look great

studs for sure

 

[bikemike]

Is it going to be a piped saw or canister box exhaust i have seen 2 cycle heads domed out in many different ways depending on use. Plane engines more torque less rpm were coned out like a oil funnel and the higher rpm engines carts bikes had more a bowl shaped combustion if any of that helps

 

[CFM]

Is it going to be a piped saw or canister box exhaust i have seen 2 cycle heads domed out in many different ways depending on use. Plane engines more torque less rpm were coned out like a oil funnel and the higher rpm engines carts bikes had more a bowl shaped combustion if any of that helps

piped. im not shooting for a real screamer so to speak.... more or less just looking to optimize what i can as best i can