Intake block on a 3 cube?

[Stihlbro]

The heat from welding I have seen affect the plating. The cylinders that I am aware of that had welded intake blocks put on, got sent off to be replated. That adds additional cost. I've yet to see a block welded on that did not have to be epoxied to fill voids.
When I say the area is thin, I am picturing milling of the spicot, if done enough to get a block, that area is what I am concerned with.

 

[Redfin]

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.

If you think about it the ex pulse is being pulled down with the piston until the trans start pushing it. Just makes sense it leaves the port on it original path? Well at least to me it does.

 

[Stihlbro]

I've never seen a shindawa saw. Are the larger models made the same? Is a larger intake boot used. What size carb?

 

[Four Paws]

I've never seen a shindawa saw. Are the larger models made the same? Is a larger intake boot used. What size carb?

The larger Shindaiwa saws have a flange like the 2 series Husqvarnas. They also use HDA carbs - largest has a 16.66mm venturi from a 70cc saw.

The 488 uses an HDA with a 13.5mm venturi.

 

[Stihlbro]

Do you have a husky 365/372 intake boot or a 044 or 066 boot to mock up?

Do you have a block of aluminum you and widdle on and fit up? Go around the spicot. Can you mount it at the base and cylinder fin?

I have boxes of carbs/boots and stuff. If you need some to stuff to try, let me know and I'll get it to you.

 

[Four Paws]

I have a 066 boot on a saw I could use for a mock up.

I guess I could epoxy a sleeve on the spigot and build up the area behind it with epoxy. Then grind. I would prefer to hard mount the carb for simplicity.

I have some giant hunks of 6061 - I could cut a small square off to play with...or go buy some.

Would you cut the spigot off, or shorten it, then bolt the block on? Seal the surfaces with motoseal or hondabond or whatever?

Should I be planning on external boost port (s)?

 

[Hedgerow]

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.

Levi's 025 has a steep downward exhaust.
I wonder what the stock timing #'s are on the little Shinny?

 

[Hedgerow]

I have a 066 boot on a saw I could use for a mock up.

I guess I could epoxy a sleeve on the spigot and build up the area behind it with epoxy. Then grind. I would prefer to hard mount the carb for simplicity.

I have some giant hunks of 6061 - I could cut a small square off to play with...or go buy some.

Would you cut the spigot off, or shorten it, then bolt the block on? Seal the surfaces with motoseal or hondabond or whatever?

Should I be planning on external boost port (s)?

I would hold off on the externals till you get a good feel for what direction you want to go from stock.
They may not be needed. Though some may feel they never hurt. You were wanting to actually use this saw for some work, right?

 

[Four Paws]

I would hold off on the externals till you get a good feel for what direction you want to go from stock.
They may not be needed. Though some may feel they never hurt. You were wanting to actually use this saw for some work, right?

I have a few of them, so if it ends up a toy, that's fine.

I wonder what the stock timing #'s are on the little Shinny?

Stock:
Squish is about .043-.044
exhaust is 102
intake 70
Transfers 126
blow down 24
case compression 54

With a stock piston, I have previously cut the base and tightened the Squish to .020" with a gasket...on a woods saw. If I cut more off the base, it would free-port. Timing changes approximately 1.5 degrees.

 

[Four Paws]

I have boxes of carbs/boots and stuff. If you need some to stuff to try, let me know and I'll get it to you.

Once we all decide on a direction to take this saw, I would be very thankful to have some things to try.

I know a lot of muffler saws are running over 90 on the exhaust. Curious if anyone wants to talk numbers, port shapes, 'generalities' for a good starting point for a 3-cube saw on alcohol.

 

[Hedgerow]

Once we all decide on a direction to take this saw, I would be very thankful to have some things to try.

I know a lot of muffler saws are running over 90 on the exhaust. Curious if anyone wants to talk numbers, port shapes, 'generalities' for a good starting point for a 3-cube saw on alcohol.

Big and square...
Then raise your transfers to 19 degrees of blow down..
Then let us know how you think it runs..
We'll go from there.

 

[Hedgerow]

Don't touch the exhaust till you get more than 105...

 

[Four Paws]

Any single ring 43mm pistons out there?

 

[Stihlbro]

If it were me, I would fit a block of aluminum over the spigot. Epoxy around spigot to block. Secure block to cylinder with Allen head fasteners. Two from cylinder fins in top of block. Two from face of block to cylinder base. Make the block flush with spigot. With this you should be able to make your inlet what ever size you need.
For carburetor, I would start with a tillotson hs. Like a husky 181/281. You may need to space carb back towards rear handle to aid in throttle linkage.

Or you maybe be able to make a larger intake boot work and fabricate carb mounting for secure ment.



Port timing wise, I would start with 96/97 on the exhaust, even out the transfers, upper 70's on the intake. Make the ports as wide as you can. See how the saw performs. Still can do finger ports and alter port timing after you run it.

 

[psuiewalsh]

Would there be any gain to fit a large washer around the current to fit a 385 boot then bolt a block to the case in carb box

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[mdavlee]

Would there be any gain to fit a large washer around the current to fit a 385 boot then bolt a block to the case in carb box

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Still have the small spigot as a bottle neck.

 

[Stihlbro]

Still have the small spigot as a bottle neck.

I bet the boots inlet is as much as you can make the spicot.

 

[Stihlbro]

Would there be any gain to fit a large washer around the current to fit a 385 boot then bolt a block to the case in carb box

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I smell what you stepping in.......

 

[Four Paws]

Hey guys. Had a crazy busy day, hence my absence. Appreciate all the feedback and good ideas.

The ability of fitting a block to the jug with screws is probable. As far as the epoxy I will use to seal and fill the area between the block and the jug/spigot...is JB weld sufficient, or should I be looking for Devcon, or ??

 

[Mastermind]

JB Weld pours better.