660 big bore - worth it?

[Mike1974]

Hey Guys ...

Using the 660 for 90% milling ... some felling work when I have big stuff o deal with. Otherwise, I do everything with 026 and a dinky 172 for limbing.

Thinking of getting a 42" bar and granberg mini-mill to half/quarter larger cants before dropping them on the logosol M7 for lumber making.

I was thinking that a big bore (about 10 more CCs) and dual port muffler (the factory mod) would probably be worth it ... about $175 in total.

What do you guys think ... is it worth it?

I've actually bogged the 660, with a sharp chain, in some knotty cherry. I've got some rock-hard maple and a bunch of locust too.

Was thinking this might give some extra oomph.

Please let me know thoughts.

Thanks.

Mike

 

[smokinj]

Hey Guys ...

Using the 660 for 90% milling ... some felling work when I have big stuff o deal with. Otherwise, I do everything with 026 and a dinky 172 for limbing.

Thinking of getting a 42" bar and granberg mini-mill to half/quarter larger cants before dropping them on the logosol M7 for lumber making.

I was thinking that a big bore (about 10 more CCs) and dual port muffler (the factory mod) would probably be worth it ... about $175 in total.

What do you guys think ... is it worth it?

I've actually bogged the 660, with a sharp chain, in some knotty cherry. I've got some rock-hard maple and a bunch of locust too.

Was thinking this might give some extra oomph.

Please let me know thoughts.

Thanks.

Mike

I'd start with muffler and then see where your at

 

[biggenius29]

Talk to treesling'r he does awsome mods. I got my 460 moded by him and the thing rocks. I talked to him about moding the OEM cylinder or getting a BB cylinder and getting that modded, he said you will get your most gaines by a OEM. He mods the muffler too.

Something to think of.

 

[BobL]

My take on this is if the 660 is running well leave the BB and go for a muffler mod. If it needs a new P&C then consider a BB and a MM.

RE: 42" bar and minimill?
Something to be aware of is for smaller logs they will either need to be lifted well above the ground or the operator has to leave more exposed bar above the log. My experience with these type of mills is that neither solutions are satisfactory.

If the mill is moved down the bar to accommodate smaller logs this means the powerhead is higher up above the log and especially a heavier saw like a 660 is not well balanced in such a situations and may want to tip over. This means the operator has to focus on keeping the saw vertical and requires extra concentration and energy in doing so.

Too much bar exposed above the cut also represents an unnecessary risk. If the log is lifted above the ground this means a lot of spinning chain poking through on the other side down around the operators feet and legs and not all that visible from the milling position

A solution to this is to change the bar size to suit each cut size but after a while this becomes a PITA.

In the long run most commercial minimills I have see are also too flimsy to survive any lengthy use, especially with a big saw like a 660. From what I have seen they eventually become sloppy and I can't see how they can generate a square cut after a while.

Last but by no means least, is that vertical mills throw sawdust up all over the place, and unless there is a breeze, the operator ends up covered in sawdust. There are ways around this problem, like cutting with the top of the bar, but the minimill is not capable of this.

Don't get me wrong, minimills are very useful devices but for more comfortable and safe milling with a 42" bar and a 660 I'd go for a full Alaskan and a cant hook first. You can always get a minimill with a smaller bar later for specific tasks.

The only advantage of the minimill is the weight of lifting it and the saw on and off the log, but that is quickly outweighed by avoiding the above problems. I cut everything smaller than 40" with my 42" bar on 54" rails with my alaskan.

 

[Gologit]

Talk to treesling'r he does awsome mods. I got my 460 moded by him and the thing rocks. I talked to him about moding the OEM cylinder or getting a BB cylinder and getting that modded, he said you will get your most gaines by a OEM. He mods the muffler too.

Something to think of.

Another vote for Treesling'r. He does excellent work and he's as good as his word.

 

[mtngun]

Quality of the BB kits has varied considerably. Baileys recently hired a QC czar to address that, but I don't know how much progress has been made.

I was very disappointed in my 2008 vintage BB kit. The fit and finish were fine, similar to OEM, but the combustion chamber was too big, resulting in low compression even with squish set to 0.020".

That was before Baileys hired the QC czar, so the current crop of BB kits may be better -- I just don't know.

My take is that the BB kit would be great for milling if they fixed the compression issue.

I DO NOT RECOMMEND THE DUAL PORT MUFFLER COVER for the 066. The DP covers are expensive, loud, blow exhaust on the operator of an Alaskan mill, and produce no noticeable increase in power compared to a modified single port. Instead, open up the cage on the muffler and open up the single port as much as possible while maintaining the spark arrestor.

 

[Mike1974]

Thanks guys - lots of things to think about here.

Sounds like I'll stay away from the big bore. Had no idea they were having quality issues. THANKS for that warning. Nothing pisses me off like poor quality.

Thanks for the details on mini-mill use Bob - but just as FYI, the reason for the long bar and mini-mill is just to half/quarter a couple monsters I have that are over 30" before putting them on the logosol. I don't plan on doing any "production" milling with the mini.

I don't know if I'm comfortable modding the muffler myself ... and with the M7 mill, I don't think I'd have the same issue with the dual-port spitting exhaust at me as with the Alaskan.

I think I'll get the factory dual-port. Though I have heard arguments from both sides - that it adds some oomph and that it doesn't. Though, it should definitely help it run cooler, which can't hurt given the stress of milling.

I'll get that ordered ... and update on my thoughts with it.

Thanks again guys. Love this forum

Mike

 

[excess650]

My 066 has a BB kit from early 2008 and a DP muffler. It DEFINITELY has more grunt than my 660 with decreased squish and DP muffler. I have used the 066BB primarily for milling, have milled with it in hot weather, and have had zero problems with it. It has the grooved rings, and the piston/rings/cylinder looked great when I checked a few weeks back while changing the clutch. I do run premium fuel at 40-1 with a synthetic blend oil, and have tuned it overly rich to limit max RPM.

The piston in my BB was installed as received, but the piston in my 660 was massaged to open the windows for better flow. The BB is stronger despite not having received the same treatment.

I will say that my kit does freeport slightly as viewed through the exhaust port at BDC, and I'm sure that it would be better if the piston skirt was slightly longer. Decreasing squish would only increase the freeporting, so the .5mm Stihl base gasket will remain. The problems most often seen with the BB kits seem to appear AFTER the cylinders have been modified in port size. While the transfers are smaller than the OEM cylinders, the BB kits definitely have more grunt than OEM.

 

[mtngun]

the BB kits definitely have more grunt than OEM.

Your BB kit may well make more grunt, but mine didn't. I guarantee that a very low compression ratio does not result in "grunt" or anything else except lame performance.

Judging by the reports on this forum, the BB kits have evolved over the years, generally getting better, but sometimes taking a step backwards. Every batch seems to be different, and you just don't know what you are going to end up with.

I can only speak to my personal experience with one 2008 vintage BB kit, and it was a disappointment. It hasn't failed catastrophically, but the compression has always been borderline low, seemingly due to an overly large combustion chamber.

Grande Dog has stated in other threads that he has been working hard to address the BB issues. He is most welcome to step into this conversation and bring us up to date. I would be particularly interested to know what changes have been made to the combustion chamber. If he convinces me that the issues have been addressed, I would consider buying another BB kit to replace my wimpy kit. The BB kit is an awesome concept, ideally suited for milling, they just need to get the bugs worked out.