6401BB Build up.

[MCW]

LOL, now's a great time to learn!

Nah. I'll leave it up to you guys and I'll just cut stuff
If I was to get port timing numbers confused with winegrape fungicide rates at the moment I'd have all sorts of issues!

 

[parrisw]

Nah. I'll leave it up to you guys and I'll just cut stuff
If I was to get port timing numbers confused with winegrape fungicide rates at the moment I'd have all sorts of issues!

ha ha ha. LOL

 

[MCW]

ha ha ha. LOL

Heh heh. I'm seriously seeing numbers on the inside of my eyelids at the moment. Adding a few more would be disastrous
Go nuts though mate and I'll be here in the background lurking. Got the HD filter kit yet?

 

[parrisw]

Heh heh. I'm seriously seeing numbers on the inside of my eyelids at the moment. Adding a few more would be disastrous
Go nuts though mate and I'll be here in the background lurking. Got the HD filter kit yet?

Yup, I'm going. This dang Christmas thing is slowing me down, here with the kids now, putting up the tree, lights, decorations, ect ect......

HD filter kit will be here soon, should be here this week.

 

[timberwolf]

The staggered transfers can be good, lots of different stratigies, but often the rears are a little higher and pointed up a bit, the fronts are low accross the and later opening. This way the two sets of transfers are not fighting to fill the same part of the cylinder.

 

[parrisw]

The staggered transfers can be good, lots of different stratigies, but often the rears are a little higher and pointed up a bit, the fronts are low accross the and later opening. This way the two sets of transfers are not fighting to fill the same part of the cylinder.

Thanks TW. I couldn't see the set closest to the intake, I was looking through the plug hole, and could only see the ex side ones. I'll know when I stick a ring down there and look at it.

 

[MCW]

Yup, I'm going. This dang Christmas thing is slowing me down, here with the kids now, putting up the tree, lights, decorations, ect ect......

HD filter kit will be here soon, should be here this week.

Yeah Christmas has got a lot to answer for...

 

[MCW]

Righteo then.
Was on the phone to Al before who wondered if a Stihl 460BB piston may fit the Dolmar BB kit to gain a wider skirt - firstly yes it is wider! Funnily enough I have a 460BB kit sitting here! Have just taken a few measurements for those curious parties...
Piston pin is the same diameter and a nice fit as is the 460BB piston in the 7900BB bore.

Anyways, here they be...

Measurement 1 is : 15.68mm (0.617")

Measurement 2 is : 13.60mm (0.535")

Measurement 3 is : 36.00mm (1.417")

Measurement 4 is : 32.02mm (1.261")

Measurement 5 is : 33.94mm (1.336")

***The two different Dolmar BB skirt measurements are given due to a step in the piston skirt. Not sure what measurements guys may want.

If anyone wants other measurements taken I most certainly can. I haven't got anything other than a good set of metric calipers but they are quite accurate.

Hope that helps and as you can tell I am very proficient in the use of Microsoft Paint, not...

 

[parrisw]

Righteo then.
Was on the phone to Al before who wondered if a Stihl 460BB piston may fit the Dolmar BB kit to gain a wider skirt - firstly yes it is wider! Funnily enough I have a 460BB kit sitting here! Have just taken a few measurements for those curious parties...
Piston pin is the same diameter and a nice fit as is the 460BB piston in the 7900BB bore.

Anyways, here they be...

Measurement 1 is : 15.68mm (0.617")

Measurement 2 is : 13.60mm (0.535")

Measurement 3 is : 36.00mm (1.417")

Measurement 4 is : 32.02mm (1.261")

Measurement 5 is : 33.94mm (1.336")

***The two different Dolmar BB skirt measurements are given due to a step in the piston skirt. Not sure what measurements guys may want.

If anyone wants other measurements taken I most certainly can. I haven't got anything other than a good set of metric calipers but they are quite accurate.

Hope that helps and as you can tell I am very proficient in the use of Microsoft Paint, not...

WOW!!! That's awesome!! Much easier swap then the 288 piston!! I may have to order up one of them pistons from Baileys! That step in the skirt is wierd Matt?? Mine here doesn't have that.

 

[MCW]

That step in the skirt is wierd Matt?? Mine here doesn't have that.

Neither do my other BB pistons I have here
Yeah will the deck height (or whatever you techy guys call it!) be an issue Will?

 

[MCW]

Matt dropped off the Makita 6401BB today,(thanks Matt) I didn't do any cutting with it today
(too hot over 100F) but I did start it, the compression & throttle response is amazing. My previous newest saw is 1990.. running this one will be a real treat.
Will, I hope you get good results from your BB kit, hopefully these kits will be reliable.

Hey remember Wayne that saw has been given a hiding and locked in a shed. It is meant to have caked on sawdust and oil on it. If I ever see it so shiny that you can see your face in it I'm stealing it back in a midnight ninja raid...

Enjoy it mate, they're a good saw and if you do ever have any dramas with that kit let me know and I'll sort it out for you

 

[parrisw]

Neither do my other BB pistons I have here
Yeah will the deck height (or whatever you techy guys call it!) be an issue Will?

OH ya, ha ha. Guess I got excited about it. Well, ya it looks like it might be an issue, espicially since I've already decked the cylinder base.

Its possible it could be made to work, if you don't deck the cylinder and make it into a popup piston.

 

[parrisw]

So basicly the 046 piston will go past the squish band by .047, you'd need a huge popup to make that work, and there wont be enough meat on the crown to do so.

 

[Jacob J.]

So basicly the 046 piston will go past the squish band by .047, you'd need a huge popup to make that work, and there wont be enough meat on the crown to do so.

Unless you make a thick base gasket, which is what I'm doing in mine. Although I'm using the OEM 52mm cylinder.

 

[parrisw]

Unless you make a thick base gasket, which is what I'm doing in mine. Although I'm using the OEM 52mm cylinder.

Ya, could do that. I'm going to check the viability of the 288 piston.

 

[MCW]

Its possible it could be made to work, if you don't deck the cylinder and make it into a popup piston.

Stop being Mr Negative Will and just make a pop up out of JB Weld. For crying out loud, you're making this sound a lot harder than it really is.

I think

 

[parrisw]

Stop being Mr Negative Will and just make a pop up out of JB Weld. For crying out loud, you're making this sound a lot harder than it really is.

I think

ha ha ha. Well, that's not the problem, the problem is by the time I cut the popup, the piston will be gone. LOL

 

[AUSSIE1]

Unless you make a thick base gasket, which is what I'm doing in mine. Although I'm using the OEM 52mm cylinder.

This is what I had in mind.

Thanks Jacob on the info for that piston.

 

[AUSSIE1]

I'll tell ya one thing though. You won't benefit from the wider skirt with those ring pin locations in the 460bb piston.

 

[Zombiechopper]

don't buy a 460bb piston Will. I have a good one you can have for postage. It ate some dust but very very minor.