Fingers and Bridge ports

[David Young]

Do you know how much reading we would have to do on as to get this much content.

 

[srcarr52]

On the 562XP and the 550XP I run 10 degrees blowdown.

Strato saws are another beast. The 562 stock is around 11 blowdown.

 

[jmssaws]

How do you figure blow down with fingers

I count from when the fingers open.

 

[Mastermind]

Do you know how much reading we would have to do on as to get this much content.

This thread would be locked........and ten people would be banned.

 

[jmssaws]

In before lock!

 

[tickbitintn]

Do you know how much reading we would have to do on as to get this much content.

ALL of it.....

This thread would be locked........and ten people would be banned.

And at least 10 more threads on various sites talking about it....

 

[Deets066]

I count from when the fingers open.

You suppose a guy could run much shorter BD than normal on just the fingers then? I wouldn't ever run 14 BD on an 066 with the uppers.

 

[jmssaws]

Mine is 116 on the mains 114 on the fingers.

066 is 120 and 116

 

[jmssaws]

You suppose a guy could run much shorter BD than normal on just the fingers then? I wouldn't ever run 14 BD on an 066 with the uppers.

If fingers are adding fresh charge and helping move exhaust out why not give them time to do it before the mains open.

I've opened them 4 degrees before the mains and it worked well but that's as far as I've went, maybe someone else has done more.

 

[jmssaws]

This thread would be locked........and ten people would be banned.

That's a shame too,everyone here can benefit from these threads,we all can build stronger saws from it.

If we take the best parts from every builders saw and put it together were gonna have the best saw there is and I think anybody who wants to build one should feel free to ask how without being called stupid. There is no dumb question.

 

[drf256]

This thread would be locked........and ten people would be banned.

Thats some funny chit.

 

[jmssaws]

Thats some funny chit.

Giant member is funny chit.

I'm changing mine to exceptionally common member.

 

[tickbitintn]

Giant member is some funny chit, I lol'ed first time i saw it. Wife looked at me funny and shook her head..... She call these sites "my facebook"

 

[leadfarmer]

Yup, blown out of the water and still no idle problems or "excessive" fuel use


View attachment 10116 View attachment 10117 View attachment 10120

 

[Al Smith]

Strato saws are another beast. The 562 stock is around 11 blowdown.

Correct me if I'm wrong but from what I gather the first portion of the transfer process bypasses the carb.

 

[paragonbuilder]

Correct me if I'm wrong but from what I gather the first portion of the transfer process bypasses the carb.

Or flows on top of the throttle plate in the carb thus not picking up any fuel and bypassing the crankcase. I think from looking at this 201t I'm working on...


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[Backyard Lumberjack]

Do you know how much reading we would have to do on as to get this much content.

lots and lots... and you prob still wouldn't get this kind of information... but if one does that lots and lots, and then comes across this kind of information... he learns a lot! all that and some parts massaging, etc. too... several comments here are, imo... of significant importance given one is focused on optimization and can deal with the basics so that the pushed or leaned on mods do not alter the saw's perferformance in a negative manner... good stuff!

I spent no less than 4 hours this afternoon and early evening mocking up components to ports, (assembled piston on rod, or in bore at least half dozen times, observing and studying the events) studying piston to bore's components and noting further what, where and with who... the piston meets and hangs with as it does it vertical and descending travels... in part, taking in to account some of the comments made in this thread. and the result of it all is I clearly see numerous additional tweaks, kisses and massages that I can do to improve the cyl porting work I am doing... and this does not even start to address all the opportunities that the piston alone offers... well, you know the old saying... "speed costs money, how fast do you want to go!" lol...

chain saw verson: "speed costs time and knowledge, how many hours do you have... ? " lol

some of the places I went today:

 

[Deets066]

lots and lots... and you prob still wouldn't get this kind of information... but if one does that lots and lots, and then comes across this kind of information... he learns a lot! all that and some parts massaging, etc. too... several comments here are, imo... of significant importance given one is focused on optimization and can deal with the basics so that the pushed or leaned on mods do not alter the saw's perferformance in a negative manner... good stuff!

I spent no less than 4 hours this afternoon and early evening mocking up components to ports, (assembled piston on rod, or in bore at least half dozen times, observing and studying the events) studying piston to bore's components and noting further what, where and with who... the piston meets and hangs with as it does it vertical and descending travels... in part, taking in to account some of the comments made in this thread. and the result of it all is I clearly see numerous additional tweaks, kisses and massages that I can do to improve the cyl porting work I am doing... and this does not even start to address all the opportunities that the piston alone offers... well, you know the old saying... "speed costs money, how fast do you want to go!" lol...

chain saw verson: "speed costs time and knowledge, how many hours do you have... ? " lol

some of the places I went today:

View attachment 10348 View attachment 10349 View attachment 10350

Lots of area in that ex. Looks good, but does it have enough arch in the roof? Hard to tell from that angle

 

[Backyard Lumberjack]

QUOTE="Deets066, post: 50992, member: 290"]Lots of area in that ex. Looks good, but does it have enough arch in the roof? Hard to tell from that angle[/QUOTE]

good question! as in does it have enough... or is it a good port shape? I could further modify the roof, but this isn't a ported cylinder... it just looks like one! lol... and as in the diff in years port timing as in 1970 vs now to ensure a bit more time for exh to depart cyl... I am more focused on flow. plan to keep port timing relatively unmodified, remember, this is not a ported cyl... just deflashed... and I will be optimizing the 'dam' at the exit flange of the exh port to ensure the components do not, in part negate the full potential of my work. I am going to use the 044 steel heat flange as a heat sink... and so I have the port, the flange, the gasket and the muffler, which seems already has baffle removed, but has 1/16" on side and 1/32nd on top of bottom protrusion into port that offers little more than turbulence, sharp edges and flow hinderance.... I want those items to match nicely and be an extension of the port itself... so I plan to dowel pin all of them to locate and register them... then open all to same dims... additionally rather than do too much to roof... and because of some of the stuff here and my hands-on today, I see where I can improve the exhaust event... without having to mess too much with too much of a change to OE port shape. I am always reminded the saw's engine is an air pump... and I am massaging to improve its volumetric efficiency. the porting and casting deflashing has been fun. the rings all sit, fit and ride nicely in bore, no resistance at all... over port and bore shape at ports... and I am pretty excited about getting down and into the piston...

here is general area where I plan to dowel pin everything at the exhaust port. note dots either side...

 

[Agent Orange]

We have a Bridgeport at work and I seriously thought this was some morose thread about losing fingers to equipment.

Glad it's not. I enjoy reading about this stuff.