Another chainsaw dyno...

[Red97]

So, the saw with more low end torque had the up angled transfers and bigger intake?

Can you get better chain alignment, maybe put a block under the saw? I'm just afraid of the chain jumping off, or pulling too hard on the top corner of the bar adding friction.

Yes, the extra intake and the up angle pulled a little bit better. Not sure if it was 1 thing or the other.

I could prolly get a better angle, it worked and I have not seen the angle to make any real difference. I spin them all by had to check. And make sure.

Even if it throws a chain it has 2" of shaft on the other side of the big sprocket to catch it.

 

[huskyboy]

Yes, the extra intake and the up angle pulled a little bit better. Not sure if it was 1 thing or the other.

I could prolly get a better angle, it worked and I have not seen the angle to make any real difference. I spin them all by had to check. And make sure.

Even if it throws a chain it has 2" of shaft on the other side of the big sprocket to catch it.

Do the uppers open flat or do you stagger them?

 

[Red97]

Do the uppers open flat or do you stagger them?

These were flat

 

[Nutball]

I would think more intake area would help on the high end, so it is probably the transfer angle that gained. The transfers in the MMWS Cross cylinder are angled up a good bit, and they pull hard down low.

Do you use less blow down than stock or the same? I've got my 395 cylinder on the porting bench now, too late to change the transfer timing much though.

 

[Red97]

I would think more intake area would help on the high end, so it is probably the transfer angle that gained. The transfers in the MMWS Cross cylinder are angled up a good bit, and they pull hard down low.

Do you use less blow down than stock or the same? I've got my 395 cylinder on the porting bench now, too late to change the transfer timing much though.

I want to say it is close to the same. It has been a while since I timed a stock 395 cylinder though.

 

[Nutball]

I think mine was 100, 120, 74.5 stock with gasket. I'm keeping it about the same, might loose or gain a degree, i raised the exhaust side transfers just a smidge. It ran a 42" bar very well on an 8 tooth rim, so I don't want to change the torque curve much.

 

[RI Chevy]

Nice job Joe. Is .028 the optimal squish for 395s? I thought the magic number was around .020??? Not sure if that would make any difference in dyno runs.

 

[Red97]

Nice job Joe. Is .028 the optimal squish for 395s? I thought the magic number was around .020??? Not sure if that would make any difference in dyno runs.

A lot like .020 and I'm sure it's fine, but I feel more comfy with a bit more.

 

[RI Chevy]

I hear you Joe. I wonder if it affects power at all?

 

[mrxlh]

I did think about placing a cup of water on the dyno in the video....

Proper vibration measuring equipment gets expensive fast..

Not really, the accelerometer in an iPhone is really accurate, even free vibration software apps.

 

[mrxlh]

Just finished all 261 pages, great job Joe. No one has sent a 266/68/72 yet have they?

 

[Red97]

 

[jacob j.]

This is one of your best yet...

 

[Wolverine]

Yep, another great vid.
I'd have never thought a pipe would gain that much on an unmolested saw.

 

[dall]

Yep, another great vid.
I'd have never thought a pipe would gain that much on an unmolested saw.

slacker

 

[Egg Shooter]

Joe, your channel has become my favorite saw channel and I'm sure it will get even better as you settle in to your comfort zone. Thank you for all the work you put into it.

 

[Nutball]

What precedure do you use for warming up saws before dyno testing, or are they done cold? While we're on the subject, who do you warm up tuned pipes for a good dyno test?

 

[Red97]

Joe, your channel has become my favorite saw channel and I'm sure it will get even better as you settle in to your comfort zone. Thank you for all the work you put into it.

Appreciate that.

 

[Red97]

What precedure do you use for warming up saws before dyno testing, or are they done cold? While we're on the subject, who do you warm up tuned pipes for a good dyno test?

I'll pre fire everything off of the dyno. Get a little bit of heat in then. Make sure everything feels right.

If inboard clutch with working brake. I trip the brake let the saw idle and loop the chain and attach to the dyno.

Release the brake and give a couple of real ligh load pulls to finish hear soaking.

Let the saw idle while I get the program ready. Rev it a few times and make a couple more light test pulls. Then the full power pulls.

Same thing with the pipes.

 

[Maintenance Chief]

I'm impressed, those pipes didn't look ridiculously awkward either.