Intake block on a 3 cube?

[Four Paws]

I have a 48cc saw (Shindaiwa 488) with a tiny spigot mounted Walbro HDA. I'd like to run a larger carb, but feel the tiny intake boot and spigot will hinder the saw. I have debated welding a block on the jug.

Saw is in the 190-200 psi range - on gas.

I don't really have a goal with the saw. I'd like to be able to run it reliably in the woods. I'd consider turning it into a play thing and running alcohol...would need some guidance to get started down that route.

 

[Four Paws]

Worth my time? Anyone want to talk 3-cubes...any make or model...any fuel...woods port or full on muffler saws?

 

[Stihlbro]

I am all ears, willing to talk, show me some pictures of the saw with intake set up currently. May not have to weld. I need to see throttle linkage, choke and fuel line routing. Fuel.....alcohol with the work required eh, too many gas options. But hey, let's do this!!

 

[Stihlbro]

Did I say 3 cubes are my favorites?

 

[psuiewalsh]

Does the boot bolt to that cylinder? Maybe a bolt on intake?

Sent from my C771 using Tapatalk 2

 

[Stihlbro]

 

[Hedgerow]

Now we talkin...

 

[Stihlbro]

 

[Stihlbro]

 

[Four Paws]

I will get some pictures after work. The jug has a totally round intake tract and utilizes a boot similar to Stihl. The boot and intake tract is very small internally (about as big around as a pinky finger - 1/2" or so). The design of the saw facilitates a lot of room for modification and packaging under stock covers.

Thanks for your replies so far.

 

[Redfin]

Eager to see what you come up with Josh.

 

[Mastermind]

Can I read along?

 

[Hedgerow]

Sometimes an intake block is the only reasonable way to get the carb the saw is begging for, onto the jug.
The 488 is a solid platform to experiment with and I've not seen many threads on them.

 

[Cut4fun]

488 like yours?

 

[Four Paws]

488 like yours?

Yes, That is the intake boot and carb mounting bracket (white piece) from a 488. The metal ring slides into the end of the boot once it slides through the bracket. The carb bolts on into threaded brass inserts molded into the bracket.

 

[Four Paws]

Here are some pictures of the stock components. Feedback, thoughts, discussion, criticism all welcome!

 

[Four Paws]

This saw has a 43mm bore and 33mm stroke. Dual, closed transfers like a Stihl 0XX jug.

 

[Stihlbro]

I'm studying the pictures, it will take me a few times. The area on top of the spigot to back of cylinder wall looks thin. But I foresee a tillotson hl or Walbro wj doable.

 

[Four Paws]

I'm studying the pictures, it will take me a few times. The area on top of the spigot to back of cylinder wall looks thin. But I foresee a tillotson hl or Walbro wj doable.

Thin-ish. I could TIG in some aluminum to fill it up. Then machine the area flat to weld the block on.

One thing I have noticed is that intake ports enter at different angles on different saws. Is there a science to this, or is it simply packaging?

Same goes for exhaust. These newer saws with cylinders tilted back seem to have the exhaust port exiting at a steep downward angle. Older saws, straight out perpendicular to the piston. Again, is this for packaging or power?

 

[Mastermind]

Sir TreeMonkey and I have talked about exhaust exit angle some. He thinks that Husky is onto something with the steeper downward exit. Thinking about how the piston cracks open the port.......I'd say he's right.