Directional felling

[Meadow Beaver]

I had 2 460 BB kits I tried, I didn't like them. First one I had a problem with the exhaust port, and the second one I had ran ok but it lacked the rpm's I expected.

 

[bitzer]

Blitz ; I see you run a big bore 460 . How much of a bump up was it .??. My 460 at a minimun needs new rings and I was thinking about putting a bb top end on it ..

Hey Tramp,

I was in a hurry the other day and totally missed your first response on when to use humboldts and not. Very good info. Glad you're still alive after that one. I will keep that in mind for future reference. I've had some trees that I suspected to be rotten that I will use a conventional on. Also good to know on a driver tree. I also do a lot of selective cutting and thinnings in hardwood forests aside from lot clearings so I do get into the occaisional snag that I need to to knock out. I've only ever put a conventional in a driver, tho I'm not sure why, guess now I do. Thanks again.


On the 460BB, mine is from Baileys. I also had a cheap one from fleabay that caught a ring after 15 tanks or so. The one from fleabay had a piston that was way too tight and looking back I never should have run it. It also had a very high and square exhaust port. I didn't degree it, but guessing from looking at other saws it was over 180 degrees stock. I ran it stock first to see how it did and it went to hell on me before I got a chance to port it. Lesson learned there.

The Baileys kit is a lot better quality. There are few casting marks and all in all it is pretty clean from imperfections. The piston and rings also look good too. Baileys also warranties them for a year or so and I believe they would take care of any problem you would have. The only problem with the Baileys kit is that the intake and exhaust ports are small. The transfers look fine tho. I ran it stock for a while and then ported it. For me, I like it. The saw (powerhead itself, 3/4 wrap, big dawgs, tall clutch cover) only weighs 15lbs. or so. Its got great response and it will pull a 36" bar with full comp thru hardwood pretty well. I have never run a 660, but with the work I've done I would guess it would out run a stock one. The few porting jobs I have done gave those saws at least another 10 to 15ccs in power compared to a stock saw. So at 84cc I would guess it would compete with a 90+cc stock or better. I put my 460bb on a 440 crankcase so jumping from the 71ccs of the 440 to 84ccs made a big difference to me and with its wieght and manueverablility it really is a great all around saw. I believe it was worth my time and I would do it again.


The arguements against it I have heard are that a 54mm bore is getting way over square for that stroke length so the net increase is only about 5% over the stock 52mm bore, but this was also only speculation by a well known builder on this site. I would guess there is more torque in the larger displacement tho. I have also seen and heard that the 460 oem top end on a 440 has great speed and its worth the power to weight ratio, but they lack in torque compared to a stock 460. To me I thought I could go for the 440bb at 77ccs or get a little more bang for my buck and get the 460bb at 84ccs. The extra work mounting it I believe paid off. The 460 oem top end would require about the same amount of work as the 460bb, but you are getting the extra displacement and saving the cost of the oem. I'm poor so to me BB no brainer! If you are putting a 460bb on a 460 then there is no extra work involved, just bolt it on.

If you really want a noticable difference I would get the Baileys kit and port it or have it ported. It really has to be degreed I believe to make a great top end out of it. I also got this one about 6 months ago and I know they were making changes and also looking at different prototypes at the time. The ports may be a little larger on them now and I know there was a problem with the squish band on some that had been corrected. All in all I think they are worth it.