365 BB Kit

[bjorn773]

I just bought a 365 last week. I have not even cut with it yet. Being a power junkie, I ordered a BB kit for it. I'm debating whether to do some cutting with it first stock so I have a basis for comparison. OR, do I just install the BB kit and never look back.

 

[funky sawman]

I just bought a 365 last week. I have not even cut with it yet. Being a power junkie, I ordered a BB kit for it. I'm debating whether to do some cutting with it first stock so I have a basis for comparison. OR, do I just install the BB kit and never look back.

If you use the big bore yo have got to clean up the ports by grinding to see any gain over the oem 365 p+c

 

[bjorn773]

If you use the big bore yo have got to clean up the ports by grinding to see any gain over the oem 365 p+c

I'm not opposed to that. Wouldn't the 52mm p&c have more free flowing ports already? I haven't seen it yet, it should be here in a couple of hours.

 

[blsnelling]

I have not run a stock 372BB, but most unmodded BB kits that I've run are stronger than their stock counterparts. In other words, I would expect it to at least run with a stock 372.

 

[nmurph]

If you use the big bore yo have got to clean up the ports by grinding to see any gain over the oem 365 p+c

ouch!!! FSM, do you have specific experience with this BB vs a stock 365, or are you speaking of BB's in general?

 

[funky sawman]

I'm not opposed to that. Wouldn't the 52mm p&c have more free flowing ports already? I haven't seen it yet, it should be here in a couple of hours.

The ports are actually less free flowing on the aftermarket than the stock p+c

 

[funky sawman]

ouch!!! FSM, do you have specific experience with this BB vs a stock 365, or are you speaking of BB's in general?

I've used and compaired all the big bore kits except the 066bb and the dolmar7900bb and the stihl ms361bb

 

[bjorn773]

Should I be able to extract more power from the new p&c setup by just widening the intake/exhaust ports without messing with the transfers? I'm new to porting and don't want to mess up a brand new p&c. I'm comfortable enough with my skill level to do the in/exh, but nervous about transfers and timing.

 

[blsnelling]

I've used and compaired all the big bore kits except the 066bb and the dolmar7900bb and the stihl ms361bb

What others are there? The 7900BB is stronger than stock, as well as the 361BB. I have both. I don't recall if I ever ran my 066BB stock.

 

[funky sawman]

What others are there? The 7900BB is stronger than stock, as well as the 361BB. I have both. I don't recall if I ever ran my 066BB stock.

Umm, let see here, the 044bb, 046bb the 395bb

 

[blsnelling]

Umm, let see here, the 044bb, 046bb the 395bb

And those three I haven't messed with , lol

 

[bjorn773]

Perhaps the BB kits have improved recently. The port size is quite a bit larger, though it is far from perfect. At least on the exhaust side, I don't have the jug pulled yet.

 

[bjorn773]

Would sharpening up the divider between the two transfer ports help in flow? It seems like the blunt edge it has now would be restrictive.

 

[blsnelling]

Are you talking at the cylinder wall or at the transfer intake at the base of the cylinder?

 

[bjorn773]

At the base of the cylinder.

 

[blsnelling]

At the base of the cylinder.

Good The divider on the cylinder wall is needed to keep the rings tucked in. Yes, I sharpen that divider. Others don't, but I think most do.

 

[bjorn773]

Around .020 squish still a good number on a saw this size? I haven't measured yet, just wondering what I'm aiming for.

 

[blsnelling]

Around .020 squish still a good number on a saw this size? I haven't measured yet, just wondering what I'm aiming for.

That's plenty. I'd go as low as .018".

 

[bjorn773]

Thanks. I see what you guys were talking about in the ports. The quality control on the ports is not the greatest. The exhaust was crooked, like twisted, at least a degree or two when gunsighting through the port with the piston used as a gauge. I guess that's why they are so much cheaper than OE. It cleaned up pretty well though.

 

[blsnelling]

Thanks. I see what you guys were talking about in the ports. The quality control on the ports is not the greatest. The exhaust was crooked, like twisted, at least a degree or two when gunsighting through the port with the piston used as a gauge. I guess that's why they are so much cheaper than OE. It cleaned up pretty well though.

Even more important is that the floor and roof be curved.