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Porting my 350 husky pt 1

Huskybill

Huskybill

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Ok I started porting my 45 mm piston kit for my husky 350. Rough milling first. We get free performance from porting.
 

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Huskybill

Huskybill

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I have a few of them, never ran one. This cylinder is a 45 mm big bore kit. i think this big bore kit makes the 350 a 353. i have a new stock 353 with low hours. The 350 Is ready to use a Dremel with a carbide bit, lots of work to smooth it out for flow.
This cross bar we milled out the verticle bar, next we will make the horizontal bar rounded or made into a wedge for flow too.
 

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Huskybill

Huskybill

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The backwards corner that wraps around above the screw threaded hole needs to be made straight no more curves. One can use the base gasket as a template it the base shape is that far off. Above the bearing bore there’s a square flat area that needs to be chamfered. That inside square corner over the bearings bugs me. It needs to be a ramp instead of a square inside corner.
 

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cuinrearview

cuinrearview

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A flat top piston makes a 350 a 353. Both use the same 45mm cylinder.

I too remove the sharp edges in the bearing cup. You can shave. 010 or so off of the top to set squish right near .020 with no gasket if you won't be cutting the base and band on the cylinder.
 
Huskybill

Huskybill

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Porting is also a test. I hit a bump we’re i took out the vertical rib in the transfer port. I didn’t chamfer the port yet. The piston upper edge hits the port. It has a square edge where the bump occurs. I’ll chamfer the upper section of the transfer port. Is the bump is gone I’m ok.

if not next cylinder I’ll leave a tiny verticle rib in the port. Next victim.
 
wcorey

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It's pretty obvious that the cylinder base on these was originally designed around use of a different cylinder, an open port one at that.
But since the 353/350's market niche is a detuned saw to the point of that major restriction being added across the lower cylinder transfers, the mismatch to the base didn't make much difference so they just left it.

Be mindful of the area along the lower edge of the transfer caps (as well as the cap screws) when opening up the lowers, easy to grind too far and lose some of the gasket sealing surface.
 
cuinrearview

cuinrearview

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It's pretty obvious that the cylinder base on these was originally designed around use of a different cylinder, an open port one at that.
But since the 353/350's market niche is a detuned saw to the point of that major restriction being added across the lower cylinder transfers, the mismatch to the base didn't make much difference so they just left it.

Be mindful of the area along the lower edge of the transfer caps (as well as the cap screws) when opening up the lowers, easy to grind too far and lose some of the gasket sealing surface.
JB FTW
 
blsnelling

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Porting is also a test. I hit a bump we’re i took out the vertical rib in the transfer port. I didn’t chamfer the port yet. The piston upper edge hits the port. It has a square edge where the bump occurs. I’ll chamfer the upper section of the transfer port. Is the bump is gone I’m ok.

if not next cylinder I’ll leave a tiny verticle rib in the port. Next victim.
I would not have removed that rib. By doing so you turned a quad port into a double port.

Also, there's a lot of work needed where the charge enters the lower transfer duct.
 
Huskybill

Huskybill

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That verticle rib can be thinned not removed to allow a faster easier flow.

Experimenting......don’t know if we don’t try. Taking it past the edge. Now to pull it back. Next cylinder up.......lol
 
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