ms460 big bore update

[1953greg]

installed a baileys big bore kit (used the oem wrist pin clips) and after bout 2.5 gallons of fuel i guess its bout broke in. the piston was scored and not running when i aquired it so this is the first 460 (dual port, half wrap, 24" bar) in my hands, but i have an 066, a 460 whs II modded, and a tired 039 for comparision. definitely dosent have the grunt of the 066 (dual port, full wrap, 28" bar) but the couple pounds lighter sure is welcome. not sure how it wil compare to the modded 460 as it has only 3-4 tanks fuel through it. of course the bb460 wil blow the doors off the 039 as expected.

didnt quite get the "wow" i was expecting but it is plenty of saw. i think it wil b on the heels of the modded 460 and use much less fuel. thats the only complain i have w/ the modded 460.

purchased the tach from baileys and it is very simple to operate, even while in the wood. i set the bb460 for 13400k w/ bar n chain and it runs bout 9600 n the wood. are these numbers bout right? i really didnt expect this much drop.

now im ready to make some chips

good day 1953greg

 

[Tree Sling'r]

installed a baileys big bore kit (used the oem wrist pin clips) and after bout 2.5 gallons of fuel i guess its bout broke in. the piston was scored and not running when i aquired it so this is the first 460 (dual port, half wrap, 24" bar) in my hands, but i have an 066, a 460 whs II modded, and a tired 039 for comparision. definitely dosent have the grunt of the 066 (dual port, full wrap, 28" bar) but the couple pounds lighter sure is welcome. not sure how it wil compare to the modded 460 as it has only 3-4 tanks fuel through it. of course the bb460 wil blow the doors off the 039 as expected.

didnt quite get the "wow" i was expecting but it is plenty of saw. i think it wil b on the heels of the modded 460 and use much less fuel. thats the only complain i have w/ the modded 460.

purchased the tach from baileys and it is very simple to operate, even while in the wood. i set the bb460 for 13400k w/ bar n chain and it runs bout 9600 n the wood. are these numbers bout right? i really didnt expect this much drop.

now im ready to make some chips

good day 1953greg

It should not compare to a modded 660 or 460 for that matter. I know Dean likes torque so your modded 460 more than likley has plenty for a smaller saw. The BB kits are also for torque - I have a WHS modded 460 with BB and it has tons or torque. Mine is running plenty safe at 13,900 and like stated has tons of low end power. You won't get high RPMs with a stock BB. If you mod it and specify what you then yes it is possible. There is lots to work with the BB.
Enjoy, Tree Sling'r.

 

[tek9tim]

You know, I like my big-bore 460. I've only put about a tank and a half through it, but it cuts pretty well. Not nearly as torquey as a bigger saw, but if you "keep it on the pipe" it cuts pretty fast. Looking at the porting, though, it doesn't seem to even be as good as stock, but there is (as Dean has proven) lots of room for improvment. Might have to send mine to him.

 

[1953greg]

compression

tek9tim or treeslinger,

hows the compression on your bb460? did you do the job yourself? if so did you do any modding to the ports?

reason im asking is this bb460 compression is only 115-120 after bout 3 gallons of use. i know i lost some by raising the exhaust 1mm and can get some of it back by removing base gasket (.5mm). somehow the saw starts ok and runs pretty strong but surely it would have more power w/ more compression.

any ideas

thanks 1953greg

 

[Dennis Cahoon]

tek9tim or treeslinger,

hows the compression on your bb460? did you do the job yourself? if so did you do any modding to the ports?

reason im asking is this bb460 compression is only 115-120 after bout 3 gallons of use. i know i lost some by raising the exhaust 1mm and can get some of it back by removing base gasket (.5mm). somehow the saw starts ok and runs pretty strong but surely it would have more power w/ more compression.

any ideas

thanks 1953greg

Are you sure your compression gauge is working properly?

 

[carvinmark]

What should the compression be?

 

[lawnmaniac883]

Compression is quite low. It should be 130-160 or even higher. Might try removing some base gasket to bump it up a little.

 

[Cut4fun]

If you have that brass extension on your compression guage, it will give you low readings. Take the brass ext off and screw straight in for a check. Just a idea.

 

[1953greg]

gage indicates 175 on a modded whs II 460.

compression is definitely low. engine pulls really easily. maybe i can recover some compression by removing the base gasket. any idea how much? does anyone have any first hand compression knowledge w/ these kits?

 

[pinus]

removing of the jug base will increase the compression ratio not too much the compression