Intake blocks vs. boots and adapters monster carbs

[Dolkitafreak]

This thread may get a name alteration depending on how it takes off, but I'm hopeful! So, what are the benefits of running a custom intake block vs running a boot adapted for the carb being used? Is there any benefit of running a block aside from the fact that you make it custom and can run whatever carb your heart desires?

Question: Solo 681 play saw build underway, I would like to run an HT-12 carb I have tucked away, but obviously this takes some shoe-horning. What boots if any make this swap plausible? Much different stud spacing than what I've previously used (c3m, hd-12, rwj, etc etc.) My main question is what boots does everyone use for the moster carbs like the HT or an HL or am I basically forced to run a custom block made of aluminum or delrin?

Would also be sweet if we could get some pictures up of saws running intake blocks, huge carbs, those oh so fun to make throttle linkages, etc. All things go-fast are welcome!

 

[srcarr52]

The only boot large enough for that carb is the Stihl 084/088/880 boot.

 

[Armbru84]

Depending on how you do the block…it can allow you to go a lot further with your porting.

the last play 681 I had I ran a rwj which was already tight in there.

 

[Dolkitafreak]

Depending on how you do the block…it can allow you to go a lot further with your porting.

the last play 681 I had I ran a rwj which was already tight in there.

It’s running a Tilly 296A currently, I just wanna push it further. I see what you’re getting at about the block. I better find some blocks of aluminum.

 

[Armbru84]

3D printing is also doable if you can draw it. few versions below. Or machine aluminum.

 

[Dolkitafreak]

3D printing is also doable if you can draw it. few versions below. Or machine aluminum.

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Good work, thank you for the examples! I hadn’t even considered 3D printing, smart.

 

[Nutball]

I hadn't considered just in welding a manifold onto the cylinder. I'd like to put a bigger carb and manifold on a 590/620 Echo.

 

[Dolkitafreak]

I hadn't considered just in welding a manifold onto the cylinder. I'd like to put a bigger carb and manifold on a 590/620 Echo.

Most of these intake blocks are not designed for a work application, welding that aluminum block to the cylinder allows carb swaps, but it also transfers heat. Not really applicable in a work application, my first saw that ran an intake block eventually goes lean in a long cut due to the carb getting hot, you can run spacers of heat resistant material to help mitigate this, maybe one of the guys above has something that would make it function in a work setting.

 

[srcarr52]

For a GTG play saw I prefer to use a boot, it makes them much less temperamental from the heat transfer. For a full blown race I like to do a bolt up intake block so I can put two gaskets in the way of the heat transfer from the cylinder.

 

[Dolkitafreak]

For a GTG play saw I prefer to use a boot, it makes them much less temperamental from the heat transfer. For a full blown race I like to do a bolt up intake block so I can put two gaskets in the way of the heat transfer from the cylinder.

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What is the ID of the cylinder side of the 084/880 boot?

 

[srcarr52]

What is the ID of the cylinder side of the 084/880 boot?

I don't remember.