Which to mod, 046 BB or 066

sILlogger · Feb 6, 2007

ive got an 046 BB and an 066, im considering modding one of them or both-most likely, or having them modded, and am curious as to which has more power to be gained from modding, and if i do not do it myself who is a good builder for the job, not really any chainsaw builders here in southern il. any help would be great

046 has a factory dual port muffler, should i open up the exhaust ports anymore even tho it is a factory dual port?

im gonna keep both of them as working woods saws, just want a lil more power out of them, don't want to start making them a PITA to run and keep up

Tree Sling'r · Feb 6, 2007

you will get more gains from the 460. As far as the BB - I don't like them. I got better gains from my stock kit over the BB with the same mod job.

jack-the-ripper · Feb 6, 2007

What type of modding are you planning on doing? Woods port, race...?

timberwolf · Feb 6, 2007

From what I have seen there is more improvement to be made on a aftermarket jug than a stock jug in terms of % gain, though I would not say the BB modified would beat the stock jug modified. The stock 066 jug has some prety good numbers in it and fairly good casting work. The newer 660 jug is tough to get much on as it is already pretty agressive in terms of porting numbers. Exhaust and transfers are up high, squish is tight, so that takes some options off the table.

The BB jugs can often be tightened up in terms of squish, and in some cases have lower port numbers that can wake the saw up if raised up. Often lots of room to improve casting flaws.

Bottom line also is if you don't like the 046 bb as modified or something goes wrong, a $100 gets you a new one. Mess up an 066 jug and it will set you back a good bit more.

You do realize that if you mod the 046 bb first, you will end up modding the 066, who wants a stock 066 when a modded 046 will cut as fast or faster? :chainsaw:

sILlogger · Feb 6, 2007

the 066

to be honest im going to put new crank seals in my 066 this weekend, and i figured while i was going it id mod it, ( i mean if i'm already into it, y not just go a little farther) i doubt i am the only one, but im like this with everything-just try to squeeze a lil bit more out of it, i don't have a timing wheel to be able to degree the saw, is there a predetermined amount of material to remove?

sawinredneck · Feb 6, 2007

Tree Sling'r said:
you will get more gains from the 460. As far as the BB - I don't like them. I got better gains from my stock kit over the BB with the same mod job.

I totally disagree here!! I have a modded 046 BB that wil out cut any stock 660 you want to bring!

jack-the-ripper said:
What type of modding are you planning on doing? Woods port, race...?

And that is the hundred dollar question!

timberwolf said:
From what I have seen there is more improvement to be made on a aftermarket jug than a stock jug in terms of % gain, though I would not say the BB modified would beat the stock jug modified. The stock 066 jug has some prety good numbers in it and fairly good casting work. The newer 660 jug is tough to get much on as it is already pretty agressive in terms of porting numbers. Exhaust and transfers are up high, squish is tight, so that takes some options off the table.

The BB jugs can often be tightened up in terms of squish, and in some cases have lower port numbers that can wake the saw up if raised up. Often lots of room to improve casting flaws.

Bottom line also is if you don't like the 046 bb as modified or something goes wrong, a $100 gets you a new one. Mess up an 066 jug and it will set you back a good bit more.

You do realize that if you mod the 046 bb first, you will end up modding the 066, who wants a stock 066 when a modded 046 will cut as fast or faster?

It's nice to have the 066 in an 046 package. Nicer yet to have an 088 in an 066 package!!! What do you want to carry around all day? There are days the 046 is more saw than I want, and do you really need to run more than a 32"-36" bar? I lnow I dont!!!

jack-the-ripper · Feb 6, 2007

timberwolf said:
The newer 660 jug is tough to get much on as it is already pretty agressive in terms of porting numbers. Exhaust and transfers are up high, squish is tight, so that takes some options off the table.:

I am thinking quite seriously about having my 660, bought brand new in july of 06', woods ported. What do you think the realistic gains would be? $200 for an increase in torque & rpm. I was told by the builder I could expect the saw to run around 10K in the cut.

sILlogger · Feb 6, 2007

the saw i carry

i run 395-066, with 24" bars day in, day out, that is all I use in the timber, 36" for the big stuff, i use the 046 occasionally on the landing and as my firewood saw, i just want to wring the most out of them and still be able to run them in the woods

tek9tim · Feb 6, 2007

Tree Sling'r said:
you will get more gains from the 460. As far as the BB - I don't like them. I got better gains from my stock kit over the BB with the same mod job.

sawinredneck said:
I totally disagree here!! I have a modded 046 BB that wil out cut any stock 660 you want to bring!

And what does that have to do with the price of tea in China? I think you missed what Sling'r said there.

sawinredneck · Feb 6, 2007

tek9tim said:
And what does that have to do with the price of tea in China? I think you missed what Sling'r said there.

In a sense, nothing, in another sense everything, I don't think the modds on his BB where done properly! From what I have seen, a stock 046 does well, a modded 046BB does MUCH better.

Tree Sling'r · Feb 6, 2007

sawinredneck said:
I totally disagree here!! I have a modded 046 BB that wil out cut any stock 660 you want to bring!

And that is the hundred dollar question!

It's nice to have the 066 in an 046 package. Nicer yet to have an 088 in an 066 package!!! What do you want to carry around all day? There are days the 046 is more saw than I want, and do you really need to run more than a 32"-36" bar? I lnow I dont!!!

Andy, I was not comparing a modded 460 to a 660. I said I get better gains from a modded stock (52mm) 460 kit than my modded 460 bb kit (54mm). I did say I get better gains from a 460 than I do from a 660.
As far a doing them wrong... Thats a pretty bold statement for never running my stuff.

sawinredneck · Feb 7, 2007

Tree Sling'r said:
Andy, I was not comparing a modded 460 to a 660. I said I get better gains from a modded stock (52mm) 460 kit than my modded 460 bb kit (54mm). I did say I get better gains from a 460 than I do from a 660.
As far a doing them wrong... Thats a pretty bold statement for never running my stuff.

Well, I never had a built stock 046, but logic dictates, you SHOULD gain more, right? Yes, you said better gains from the 046, I am of the logic the BB kit should be better yet?
I LOVE LOVE LOVE my 046BB!!!! Anything that you can bury a 32" full comp bar in to hedge and have a running saw at the end of that day, that impresses me!!
I got no beef with you slinger, if you build a better saw, I might be interseted in buying it!! But from what I have run so far with mine, I really don't have any need for more!!!

Tree Sling'r · Feb 7, 2007

sawinredneck said:
Well, I never had a built stock 046, but logic dictates, you SHOULD gain more, right? Yes, you said better gains from the 046, I am of the logic the BB kit should be better yet?
I LOVE LOVE LOVE my 046BB!!!! Anything that you can bury a 32" full comp bar in to hedge and have a running saw at the end of that day, that impresses me!!
I got no beef with you slinger, if you build a better saw, I might be interseted in buying it!! But from what I have run so far with mine, I really don't have any need for more!!!

The first 460 I ever had was a modded BB kit. I thought it was alright - nothing more - nothing less.
Having the original piston and cylinder around - I modded it (open and raise exhaust, widen and lower intake, gut out lower transfers, raise uppers, put in four finger ports, remove base gasket, squish at .018)
Built a saw with that kit, matched exhaust on muffler and cylinder, slightly advanced ignition and ran it against the BB saw, set at same rpms - with my preference of torque band. Both saws have same bars 32" and same grind on chains.
I like the orginal modded kit over the BB - just my preference though.

No beef here either Sawinredneck - I just did not think you were comprehending the point I was trying to make.

sawinredneck · Feb 7, 2007

Tree Sling'r said:
The first 460 I ever had was a modded BB kit. I thought it was alright - nothing more - nothing less.
Having the original piston and cylinder around - I modded it (open and raise exhaust, widen and lower intake, gut out lower transfers, raise uppers, put in four finger ports, remove base gasket, squish at .018)
Built a saw with that kit, matched exhaust on muffler and cylinder, slightly advanced ignition and ran it against the BB saw, set at same rpms - with my preference of torque band. Both saws have same bars 32" and same grind on chains.
I like the orginal modded kit over the BB - just my preference though.

No beef here either Sawinredneck - I just did not think you were comprehending the point I was trying to make.

I find that very interesting to say the least!!!!!! I would be interested in hearing from other woners to see if they had the same experiance! That really makes me wonder now!

timberwolf · Feb 7, 2007

I am thinking quite seriously about having my 660, bought brand new in july of 06', woods ported. What do you think the realistic gains would be? $200 for an increase in torque & rpm. I was told by the builder I could expect the saw to run around 10K in the cut.

I would think 10k is a little conservative, that is not much above stock. However depending on the mod done it is possible to gain little in the way of RPM but produce some substantial torque. I Know my 066 mod cuts well above 12,000 in the wood and will pull a ten tooth sprocket with a 20 inch bar and good chain, This is not an aggressive mod, but maybe a little more than 200$ will buy.

From bone stock 066 to a decent mod I can see cut times improving 50-60% or more when the muffler mod and engine mod are multiplied together. As always a lot depends on your chain, a dull chain that is not harnesing the saws power will show little gain, good round might show 50% and race chain may show close to 100% gain going from stock saw to ported and mufler modified.

I just did an 066BB mod, it picked up about 35% with good chain (not counting muffler mod, that was already done), still is very close between a modified OEM 066 jug and the 066BB. The OEM jug does offer more flexibility for higher compression and more agressive mods, and given the larger bore (flame speed issues), heavy piston, and worse cylinder to base volume ratio... it is to be expected that the BB should be a little less output per CC, so what it makes up for with the extra CC's is lost in other ways to some extent. Modified they two jugs get pretty closein terms of cut times, though the BB revs lower and likely produces more torque down low. Stock the original jug kicks the BB around, but then it cost 3 times as much too.

sawinredneck · Feb 7, 2007

Thanks!!! That was a great explanation!!! Learning a LOT from this thread!

RiverRat2 · Feb 7, 2007

A OK post Timberwolf!!!!!

timberwolf said:
I would think 10k is a little conservative, that is not much above stock. However depending on the mod done it is possible to gain little in the way of RPM but produce some substantial torque. I Know my 066 mod cuts well above 12,000 in the wood and will pull a ten tooth sprocket with a 20 inch bar and good chain, This is not an aggressive mod, but maybe a little more than 200$ will buy.

From bone stock 066 to a decent mod I can see cut times improving 50-60% or more when the muffler mod and engine mod are multiplied together. As always a lot depends on your chain, a dull chain that is not harnesing the saws power will show little gain, good round might show 50% and race chain may show close to 100% gain going from stock saw to ported and mufler modified.

I just did an 066BB mod, it picked up about 35% with good chain (not counting muffler mod, that was already done), still is very close between a modified OEM 066 jug and the 066BB. The OEM jug does offer more flexibility for higher compression and more agressive mods, and given the larger bore (flame speed issues), heavy piston, and worse cylinder to base volume ratio... it is to be expected that the BB should be a little less output per CC, so what it makes up for with the extra CC's is lost in other ways to some extent. Modified they two jugs get pretty closein terms of cut times, though the BB revs lower and likely produces more torque down low. Stock the original jug kicks the BB around, but then it cost 3 times as much too.

Good Insight, thanks for the info,,,,,

sILlogger · Feb 7, 2007

066

timberwolf,
asking just to clarify, but the 066 BB ultimately makes more power when modded that a modded stock cylinder? not fot as effectively? hopefully i am interpretting this right, i have rebuild saws before, but never modded one and didn't know if i should try it or let someone who does it everyday do it.

Lakeside53 · Feb 7, 2007

There is a little of "you get what" you pay for... if I was going to mod a 660cylinder, find a good used cylinder..

I just had a late model 066 in for "service" - it had an 066 after market Piston and cylinder on it. Very low compression and a tear down revealed a scored piston/cylinder. More to the point, the cylinder was not just scored (and only lightly), but the chrome has pealed of the cylinder about 1/4 inch below the exhaust port in a area about 1/2 inch square. Bright shiny alloy - not burnt.

I've seen every type of wrecked Stihl (mostly Mahle) cylinder, but never one with pealed chrome.

O.k., so my sample of 1 can't necessarily be extrapolated into anything bigger, but...

I believe the initial cause of failure was the base gasket - it was 1mm thick paper, had compressed and leaked on one the side. The customer insists it was the gasket supplied with the cylinder... it should have been 0.5mm thick, and not paper. The OEM gasket is rubber coated steel for a reason.

Any of you guys running big Stihl saws with paper gaskets - check your cylinder bolt torque frequently until you're sure it's all settled down, and every now and then. It's a pain because the "break-away" torque will exceed the initial setting, so you're ever really sure unless you back out the bolt slightly and tighten again.

timberwolf · Feb 7, 2007

The 066 BB (prototype) stock is behind a stock 066 jug, though it does have great low end.

Once modified they are pretty close in cut times, however it is not easy to take the 066bb to the same level of modification as an older 066 Stihl jug (not the new 660 as it is different). Squish on the bb comes out pretty close ~.020 to .025 with the gasket in.

The gains from stock to modifed that can be made are greater with the BB mostly because the BB start out a little lower. The main performance issue I noted with the BB was very short transfer duration.

The 066 BB does turn lower RPM than the Stihl jug both stock and modded with simmilar port numbers. But does make up for that with some torque.

There may be changes to the BB before it becomes final production, so who knows?

Which to mod, 046 BB or 066

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