Reed cage.... Homebrew style.

by **Snojet Steve** » February 24th, 2007, 3:44 pm

I am so pissed off today. Someone beat me to a 76' GP 292! It's just a 292 single that thinks it is a 440, no big deal or anything. If I see the person responsible they are going to get a face full of GPX dust. Oh well..75' GP-433G on the way, 2 reed valves to play with on it! The Hirths aren't even going to come close even if you have one that is almost 400cc. Sachs is about the only thing that will touch a Yamaha 1 lunger.

by **sno*jetfreak2** » February 25th, 2007, 5:13 pm

[quote=Snojet Steve]I am so pissed off today. Someone beat me to a 76' GP 292! It's just a 292 single that thinks it is a 440, no big deal or anything. If I see the person responsible they are going to get a face full of GPX dust. Oh well..75' GP-433G on the way, 2 reed valves to play with on it! The Hirths aren't even going to come close even if you have one that is almost 400cc. Sachs is about the only thing that will touch a Yamaha 1 lunger.[/quote]

Are you sure?

In anything fan cooled, its not usually a Yamaha that comes out on top. Its actually usually Sachs, Hirth, then Yamaha.

You never hear about Kohlers and those other brands. I have heard that the Kawasaki 292 was a gutless and very horrible engine.

Also its not hard for a single to emulate a 440. You only need around 40hp. I know its possible to squeeze about 50-60hp out of a Sachs 340SS.

Anyways, this is all needless debate. I've done the work, and I will see what its capable of. Its still got a fan and the a big old can exhaust. So I know its not going to touch any motor with a tuned pipe let alone f/a mod.

by **ZR800XC** » March 4th, 2007, 12:14 pm

Your advantage is most likely going to come with the rear transfer port the reed valve is going to allow you to put in. And if you can run passages from your intake area into the transfers without having to run a hole in the piston you'll probably even see better results. But at the same time, you can only make scavaging so efficient without an expansion chamber. I'd say it would be worth a shot. find a set of small reed cages, like AHood recomended. The only way I would deviate from that is if you were allowed to weld on different cages, but I would guess you're not if you can't even run an expansion chamber.

73 Rupp Magnum 440 Tohatsu with reeds.

[img]http://my.core.com/~twister76/reed2.jpg[/img]

[img]http://my.core.com/~twister76/reed3.jpg[/img]

[img]http://my.core.com/~twister76/reed4.jpg[/img]

[img]http://my.core.com/~twister76/reed5.jpg[/img]

by **sno*jetfreak2** » March 6th, 2007, 10:13 am

Thanks for the suggestion.

Yea unfortunatly due to the rules, they clamp you on what kind of mods your allowed to run.

You can't be F/A or Liquid, you can't have stingers, no sleds with different brands of engines, no slides unless it was specific to that model, your allowed to run a single in a twin engine sled but you can't modify the hood(wierd one). Your allowed to port, run mikuni carb, run a limited number of studs, machine has to be safe.

Currently the man owning the scene is a guy from the states with a 72 Sno Jet on Slides running a Sachs 340R.

by **ZR800XC** » March 6th, 2007, 3:29 pm

You can't have "stingers", but can you have an expansion chamber into a muffler???

by **AHood** » March 7th, 2007, 4:10 am

[quote=sno*jetfreak2]Thanks for the suggestion.

Yea unfortunatly due to the rules, they clamp you on what kind of mods your allowed to run.

You can't be F/A or Liquid, you can't have stingers, no sleds with different brands of engines, no slides unless it was specific to that model, your allowed to run a single in a twin engine sled but you can't modify the hood(wierd one). Your allowed to port, run mikuni carb, run a limited number of studs, machine has to be safe.

Currently the man owning the scene is a guy from the states with a 72 Sno Jet on Slides running a Sachs 340R.[/quote]

that doesnt make sense sno jet never used sachs motors so how could he be running a 340R

by **sno*jetfreak2** » March 7th, 2007, 4:44 pm

[quote=AHood]that doesnt make sense sno jet never used sachs motors so how could he be running a 340R[/quote]

1970/71 StarJet... Although it doesn't look anything like a '70/'71 starjet. Try a year later. But no one really knows much about the sleds in question so rules slide. Just like how he manages to run slide suspension... Claims it came from the dealer like that. Sno jet did have a manual put out for dealers to mount Cat slide suspensions under the Sno jets.

[quote=ZR800XC]You can't have "stingers", but can you have an expansion chamber into a muffler???[/quote]

Hmm... I may have to look into this. But the wording was something about stock exhausts only. As far as I know Expansion chambers fall under tuned pipe.