Chainsaw Porting Theory

[jmssaws]

066?

Yes

 

[Keith Gandy]

Yes

Id like to see u get in a 661c. Ever ran one? Thoso quads r pretty awesome

 

[jmssaws]

Id like to see u get in a 661c. Ever ran one? Thoso quads r pretty awesome

I've tinkered with one before.
Not many around here yet.

 

[jmssaws]

On a stihl 78 is my favorite intake number and 118 is my favorite transfer number but the exhaust has me thinking lately,I don't believe it needs to be as low as most including me think.

I've been cutting 050 or 060 from the chamber still but instead of leaving it 101-103 I'm raising to 98 and there gaining from it. Instead of 240 there 215-220 but it's not the compression loss making the gain it's blow down, I'm sure your thinking well why not leave the transfers at say 123 and gain blow down but it won't work I've tried.

One number effects the other numbers,I like one set of numbers but everything else determines where everything else needs to be. You dig?

 

[Al Smith]

I don't think questioning the credibility of a builder who is generously sharing information with all of us is an intelligent choice of tact with regard to encouraging further relevant discussion

I think perhaps there might be a lack of communication here .

In no way can it be assumed I intentionaly brought malice upon this gentleman .I merely asked how in the world anybody could do pluralities of one particular saw model by the hundreds .I mean that's a bunch of saws in anybodies book .I'm not abusing ,abasing ,being snippy or anything else .

Now I sometimes use figures of speech such as "hot little hands " which means in pleasant anticipation regarding an item, an idea, a steak dinner or an attractive female to name a few .I interject these little blurbs to spice up a conversation but believe me I have a good command of the English language .For what it's worth I've used that same phrase to identify with things I do myself .

I sometimes forget on forums which are basically a discussion group that some people either fail to see my sense of humor or have none of their own . Perception is not always reality .Enough explanation and drama ,do carry on .

 

[Deets066]

Ive noticed lately Randy likes alil more intake duration on thoso hybrids Deets. I think about 81 on the intake floor? Im at 102/118/78 on mine and didnt hog anything or add fingers or bridges and im pretty happy with it

Before fingers I was 102-119-79 should have left it alone, it was stout

 

[Keith Gandy]

On a stihl 78 is my favorite intake number and 118 is my favorite transfer number but the exhaust has me thinking lately,I don't believe it needs to be as low as most including me think.

I've been cutting 050 or 060 from the chamber still but instead of leaving it 101-103 I'm raising to 98 and there gaining from it. Instead of 240 there 215-220 but it's not the compression loss making the gain it's blow down, I'm sure your thinking well why not leave the transfers at say 123 and gain blow down but it won't work I've tried.

One number effects the other numbers,I like one set of numbers but everything else determines where everything else needs to be. You dig?

Yes. Do u like the same on 1128 Stihls?

 

[jmssaws]

Yes. Do u like the same on 1128 Stihls?

Less blow down on them

 

[jmssaws]

Before fingers I was 102-119-79 should have left it alone, it was stout

Where's the fun in that?
Fix it till it's broke I always say and I've done it many times.

 

[jmssaws]

Before fingers I was 102-119-79 should have left it alone, it was stout

My 460 is 102 115 78 with a popup 064 piston and is stout.
I got a new piston for it but I'm not taking it apart because I know me.

 

[Mastermind]

Just because my name isn't randy and I haven't been on a forum for 10 years doesn't mean I haven't ported a bunch of saws.

Oh bullcrap.........tell the damn truth fapper. Your middle name is Randy.

The lowers are filled and my 66 runs great and has bigger fingers than it.

It ran terrible before fingers, the transfers are to high,I'm going to try some more intake,it's 80

Fingers are at 113 mains 115

Take the exhaust up to 93.

Try it.........I think you'll be surprised.

I think perhaps there might be a lack of communication here .

In no way can it be assumed I intentionaly brought malice upon this gentleman .I merely asked how in the world anybody could do pluralities of one particular saw model by the hundreds .I mean that's a bunch of saws in anybodies book .I'm not abusing ,abasing ,being snippy or anything else .

Now I sometimes use figures of speech such as "hot little hands " which means in pleasant anticipation regarding an item, an idea, a steak dinner or an attractive female to name a few .I interject these little blurbs to spice up a conversation but believe me I have a good command of the English language .For what it's worth I've used that same phrase to identify with things I do myself .

I sometimes forget on forums which are basically a discussion group that some people either fail to see my sense of humor or have none of their own . Perception is not always reality .Enough explanation and drama ,do carry on .

Repped.

Glad to have you here Al.

 

[jmssaws]

Take the exhaust up to 93.

Try it.........I think you'll be surprised.

I already raised to 94 just haven't ran it yet.

I believe I have another problem, I put another known well running cylinder on it and got the same results, no rpm and no 4stroke at 13500 even. I changed carbs but still the same. Wtf would cause it to run out of fuel? I'm going to drill the jet but I've never had to before.

Ignition?

 

[merc_man]

Before fingers I was 102-119-79 should have left it alone, it was stout

What are all those numbers refer to?

 

[jmssaws]

What are all those numbers refer to?

The port openings from tdc.

 

[merc_man]

Does any one have video of doing the port timing numbers?

 

[Mastermind]

I already raised to 94 just haven't ran it yet.

I believe I have another problem, I put another known well running cylinder on it and got the same results, no rpm and no 4stroke at 13500 even. I changed carbs but still the same. Wtf would cause it to run out of fuel? I'm going to drill the jet but I've never had to before.

Ignition?

I'd try a complete ignition from another known runner. Flywheel and all.

 

[CR500]

I've tinkered with one before.
Not many around here yet.

Maybe I should send the 661 instead.... I will pm details later after supercross

Sent from my non internal combustion device.

 

[Mastermind]

Does any one have video of doing the port timing numbers?

Finding port height.

 

[jmssaws]

Does any one have video of doing the port timing numbers?

Randy has one in the technical are I believe.
Get a degree wheel on a saw and it will start making sense

 

[Al Smith]

That is a clever way of doing it I must say .Another way to skin the same cat so to speak .