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Care to share more on this? I have ran my 064 conversion quite a bit and to me it seems lacking as well. I have thought about raising the transfers a few degrees but thought that the shorter blowdown might hurt it more. Mine also has a slight free port at TDC.
So my question really is,how will raising the transfers/shorten the blowdown effect the saw overall?
Mastermind
Work Saw Specialist
Care to share more on this? I have ran my 064 conversion quite a bit and to me it seems lacking as well. I have thought about raising the transfers a few degrees but thought that the shorter blowdown might hurt it more. Mine also has a slight free port at TDC.
So my question really is,how will raising the transfers/shorten the blowdown effect the saw overall?
Some Oh64 jugs I've seen have huge transfer tunnels, I can understand a late model 066 or 660 jug hurting it's performance.
Every saw is different. I've not found a one size fits all "recipe" that brings a saw alive. The size of the crankcase VS the displacement plays a huge part in the timing numbers that work well in a saw.
I won't pretend to understand all this stuff as I'm just beginning to get a glimpse at the puzzle. I have experienced enough Stihl 066 and 046 builds to see what helps them build big power though. The older 046 jugs had about 16 degrees of blowdown.....that set the transfers up there pretty tall. My ms460 has one of those D-shaped jugs that are known runners, with a popup and some serious port work it still needed something. I had raised the exhaust but hadn't brought the transfers up enough to maintain that short blowdown that the factory engineers built in. blsnelling encouraged me to raise them more. I did in steps. The saw started maintaining rpm in the cut.
The Husky 262XP is another saw with incredibly short blowdown numbers. It also has a short intake duration. Figuring out what the engineers were thinking is key to learning what works.... These guys are not stupid.
Crankcase pressure plays a big part in the pumping action of the transfers.....and I feel like the transfers are where the saw is made.
I probably made you have more questions. But thinking about why is where I'm at right now....
Thanks for the info Randy. I built this saw last summer before the talk of this build. I ported it but left the exhaust and transfer timing alone. but raised duration a tad. I have been thinking,like I said, of raising the uppers and doing some more modding to the lowers but just have been skeptical of that.
I remember Brad saying that about the 046 and that has made me think very hard on these 'numbers'. I am by no means an expert and have forgotten more than I remembered about these small engines although I have several strong ported saws. I know that in the next day or so I will be pulling my 064 back down for some more mods.....
I remember Brad saying that about the 046 and that has made me think very hard on these 'numbers'. I am by no means an expert and have forgotten more than I remembered about these small engines although I have several strong ported saws. I know that in the next day or so I will be pulling my 064 back down for some more mods.....
komatsuvarna
Arboristsite MVP
Well Im a dumbass! 
If ya ever put a saw together out of some parts and it has an intellacarb, it must be functional! I had the intellacarb, but my base wasnt drilled for the intellacarb...it did have the boss for it though.
I made no other changes besides opened that hole up and had to make a MAJOR re-tune, but it made a big difference in the saw. Still not where it needs to be for the competition, but much better than it was!
If ya ever put a saw together out of some parts and it has an intellacarb, it must be functional! I had the intellacarb, but my base wasnt drilled for the intellacarb...it did have the boss for it though.
I made no other changes besides opened that hole up and had to make a MAJOR re-tune, but it made a big difference in the saw. Still not where it needs to be for the competition, but much better than it was!
komatsuvarna
Arboristsite MVP
Honestly I don't know for sure. I know it measures the air on the clean side of the air filter to adjust the metering diaphragm in the carb..... and I know they run like **** if ya have it blocked off.:bang:
user 64030
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My understanding is that the intelies are able to determine how dirty the filter is based on the difference in pressures and adjust the fuel to compensate for the reduced airflow through the dirty filter. So as the filter gets dirty, and flows less air the carb mixture inherently richens, so the inteli leans it out to allow the correct mixture. With the port blocked off, I would think it would defiantly have the saw in an extremely over-lean situation to the point of not having enough fuel to even run....
Again just how I understand what was explained to me.
dw
Without a vent, it probably couldn't pump properly.
MacLaren
Addicted to ArboristSite
From my understanding its almost the same as M-Tronic.
The two are not related at all. M-Tronic is an electronically controlled carb. Intellicarb is just a regular carb where the pump diaphragm vents inside the air filter, instead of outside air.
Well Im a dumbass!
If ya ever put a saw together out of some parts and it has an intellacarb, it must be functional! I had the intellacarb, but my base wasnt drilled for the intellacarb...it did have the boss for it though.
I made no other changes besides opened that hole up and had to make a MAJOR re-tune, but it made a big difference in the saw. Still not where it needs to be for the competition, but much better than it was!
D'oh!
komatsuvarna
Arboristsite MVP
what is this, nascar? restrictor plate racing. :jester:
komatsuvarna
Arboristsite MVP
You got any more videos of it now with the carb working right?
No I dont Mike, I didn't upload them cause they were too big, and I done a lot of trial and error. The wood is getting considerable bigger, so I had to start over with a new base line. I will say this,,, after the wood got bigger, the 066 is holding about the same times, the 372 slowed down. Out of about 10 test and tune cuts, the 066 averaged 20.80, the 372 averaged 19.14......
Ill get it, slowly but surely.....
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Ill get it, slowly but surely.....
do what randy do, and put NOS on it.
umpkin2:
komatsuvarna
Arboristsite MVP
do what randy do, and put NOS on it.
Im trying to figure out how to get the handle bar to hold the pressure, I done got the micro switch and timing retard hooked up:msp_biggrin:
