Question for the "porters"

[motomedik]

How does one go about figuring how much to lower the intake, if at all. I have several saws I've ported but feel as if the intake timing may unleash more power, but too afraid to remove some thing I can never put back. These are not race saws, and I want to hang onto torque as much as possible.My ports are widened, squish as close to .020" as possible, lower transfers worked for flow, MM's, trying for 24-25 degrees of blowdown.
Working on 272, 262, 385 Huskies

 

[woodgrenade]

Subscribed..... Hey Jason!

 

[ronT2]

Hey Jason, I usually take it off the piston skirt if I want a little more intake duration. Pistons are cheaper than jugs.

 

[motomedik]

Yeah, I did that before but the 262 is running a new husky piston, and I worry about shortening the skirt for longevity (not that a few thou makes any diff, probably). Might be able to get a Golf to test with.
Hey, Wood grenade!!

 

[gink595]

How do you lower the transfers? Or did you mean lower transfer port?

What kind of blowdown do you have now?

 

[ronT2]

I have a Golf in my 2150…so far so good. You should be able to get your hands on a Meteor PC1650A or Episan #??? if you’re looking for something better to experiment with.

 

[ironman_gq]

You know you've gone too far when the saw freeports at TDC. Someone should point Brad over here I think he's seen just about everything and can probably give some solid advice.

 

[Tzed250]

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Have you tried marking the intake on the piston to see how much overlap you have?

.

 

[ronT2]

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Have you tried marking the intake on the piston to see how much overlap you have?

.

As in widening for more area versus duration?

 

[parrisw]

If your going to play with timing, you need to invest in a degree wheel, no way around it, and then you need to learn to be consistent with it. Then you can measure what exactly you have. Hard to help when I don't know what your starting point is. 25° is allot of blowdown, and sometimes hard to achieve in my experience, but the saws you speak of I've never ported before?? So I could very well be wrong.

 

[Dan_IN_MN]

If your going to play with timing, you need to invest in a degree wheel, no way around it, and then you need to learn to be consistent with it. Then you can measure what exactly you have. Hard to help when I don't know what your starting point is. 25° is allot of blowdown, and sometimes hard to achieve in my experience, but the saws you speak of I've never ported before?? So I could very well be wrong.

I have a question about using a degree wheel.

When using the wheel, say when the piston is going down, is the point to measure when the piston just clears the exhaust port? The top of the piston even with the top of the exhaust port?

Maybe it doesn't matter.

Thank you,

 

[parrisw]

I have a question about using a degree wheel.

When using the wheel, say when the piston is going down, is the point to measure when the piston just clears the exhaust port? The top of the piston even with the top of the exhaust port?

Maybe it doesn't matter.

Thank you,

Yes it matters. I measure from when I can first see it open. Shine a light through the plug hole and it makes it easier to see.

I start with durations, then get timing. You can figure out timing from the duration number though. And look through the plug hole with a small pen light to get transfer timing.

 

[gink595]

If your going to play with timing, you need to invest in a degree wheel, no way around it, and then you need to learn to be consistent with it. Then you can measure what exactly you have. Hard to help when I don't know what your starting point is. 25° is allot of blowdown, and sometimes hard to achieve in my experience, but the saws you speak of I've never ported before?? So I could very well be wrong.

All the saws I've had a degree wheel on have had at least 20* of blowdown, I wouldn't think it would be too hard to acheive 25* if needed. My 066 has 36* of BD. I think the 50 I just got numbers on had 21*.

 

[Tzed250]

As in widening for more area versus duration?

No, overlap of the skirt bottom to port floor.

 

[parrisw]

All the saws I've had a degree wheel on have had at least 20* of blowdown, I wouldn't think it would be too hard to acheive 25* if needed. My 066 has 36* of BD. I think the 50 I just got numbers on had 21*.

True, but that would require to raise the EX quite a bit, not typical for a work saw. The makita BB I just did has 25° blowdown. But the huskies I've done so far mostly 372 end up at 20°, the one I'm doing now, I'm hoping for more though.

 

[gink595]

True, but that would require to raise the EX quite a bit, not typical for a work saw. The makita BB I just did has 25° blowdown. But the huskies I've done so far mostly 372 end up at 20°, the one I'm doing now, I'm hoping for more though.

True, but that would require to raise the EX quite a bit, not typical OF MY work saws. The makita BB I just did has 25° blowdown. But the huskies I've done so far mostly 372 end up at 20°, the one I'm doing now, I'm hoping for more though.

There I fixed it

 

[Metals406]

There I fixed it

:hmm3grin2orange::hmm3grin2orange:

 

[parrisw]

There I fixed it

LOL, nice one!!!

For the saws he's working on, he'll have to raise the ex a fair amount to get up to 25° most likely.

He really needs a degree wheel.

 

[ronT2]

All the saws I've had a degree wheel on have had at least 20* of blowdown, I wouldn't think it would be too hard to acheive 25* if needed. My 066 has 36* of BD. I think the 50 I just got numbers on had 21*.

What is the exhaust duration on your 066?

 

[parrisw]

What is the exhaust duration on your 066?

I'd say allot, with that much blowdown.