6401BB Build up.

[Zombiechopper]

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

actually, thats true. You could relocate the ring(s). I need that done on my other piston but I'm too lazy to get on it since the mahle top is back on now and running tickity boo. I widened the transfers into the ring ends on my BB.... live and learn!

 

[Zombiechopper]

here's the one you can have Will

 

[Metals406]

actually, thats true. You could relocate the ring(s). I need that done on my other piston but I'm too lazy to get on it since the mahle top is back on now and running tickity boo. I widened the transfers into the ring ends on my BB.... live and learn!

Perhaps running the piston backwards will work? Worked for me before when I had an ADD moment on transfers.

 

[Metals406]

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

You got a TIG now mang. . . And a lathe. Weld on a couple bad pistons for practice, and then weld yourself a pop-up.

 

[MCW]

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

Thats what the JB weld is for Just mould a new one.

 

[Zombiechopper]

Perhaps running the piston backwards will work? Worked for me before when I had an ADD moment on transfers.

nope, I checked that first!. Its right boogered. I can put the rings in one spot one on top of the other if I get around to relocating one or both of them. I have the OEM top running awesome though now so I'll probably just let it be.

My problem actually happened because I was doing a 361 rework porting and the 460 late at night working on both. The 361 transfers go way into the intake and its fine so I got too used to looking at that and didn't turn the brain on when I started hacking into the 460

 

[tdi-rick]

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

It wouldn't be the first time two pack epoxy has been used on a piston crown.
An Australian Championship winning engine (albeit a four stroke) had its concave piston crowns partially filled with it to bump up the compression as the rules stated that the cc's were measured excluding carbon

The rules were changed to include all carbon after the scrutineer twigged to what was going on.

 

[MCW]

It wouldn't be the first time two pack epoxy has been used on a piston crown.
An Australian Championship winning engine (albeit a four stroke) had its concave piston crowns partially filled with it to bump up the compression as the rules stated that the cc's were measured excluding carbon

The rules were changed to include all carbon after the scrutineer twigged to what was going on.

It didn't happen to be you did it Rick?

 

[tdi-rick]

It didn't happen to be you did it Rick?

Naa, but i really liked that one, simple and effective.

 

[parrisw]

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.

Thanks allot for the offer, but I'm going to hold off for now, until I find out how much work for the 288 piston, it has wider skirts and the ring end in the right location. It just need pin spacers machined.

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

Geeze, good thing someone is paying attention, never thought of that!!

You got a TIG now mang. . . And a lathe. Weld on a couple bad pistons for practice, and then weld yourself a pop-up.

Yep I doo!!! But that's not the problem in this case, the 460bb piston is too tall. I've been wanting an excuse to weld a popup.

 

[parrisw]

Ok, here is the 288 piston comparison. Well pretty much the same boat as the 460bb but more work.

84.8994483cc kit piston pin center to crown is .760

288 piston is .8645 pin center to crown.

So that a difference of .1045 that the 288 is taller. But it has optimal ring end location, its a single ring piston, it will need pin spacers to run, and a thick gasket.

So I've decided for now, that I'm just going to run the kit piston and see what I can get out of it with that. I'm sure I'll be happy with it. If not well, I can still do something about it. Any other 54mm pistons out there?

 

[parrisw]

Ok, I checked the transfer timing issue. And its not staggered timing, its actually a difference of a chamfer, one side has a big chamfer and one side doesn't. That's ok, easy to fix, since they will be raised a bit.

 

[gmax]

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

I can see my face looking at the bar.. does that count? . I just got back with with a trailer load of wood from the Cudlee creek golf course , so it had a little workout.
It's all good mate, nice and smooth with lots of grunt, I'll video some cookie cutting later on, I love the air filter easy to clean & nothing gets past it

 

[MCW]

I can see my face looking at the bar.. does that count? . I just got back with with a trailer load of wood from the Cudlee creek golf course , so it had a little workout.
It's all good mate, nice and smooth with lots of grunt, I'll video some cookie cutting later on, I love the air filter easy to clean & nothing gets past it

Good job Wayne. I stuck my last remaining BB kit on one of my other 7900's this arvo and the result was the same - impressive...

 

[gmax]

Good job Wayne. I stuck my last remaining BB kit on one of my other 7900's this arvo and the result was the same - impressive...

Good stuff, I'll do some more cutting on Wednesday when it's cooler, I want to run it a fair bit just to make sure it's going to be reliable, I doubt there will be any problems with the BB kit, the quality looks good.

 

[MCW]

Good stuff, I'll do some more cutting on Wednesday when it's cooler, I want to run it a fair bit just to make sure it's going to be reliable, I doubt there will be any problems with the BB kit, the quality looks good.

I'm confident they'll hang together but you never know. Have fun running it mate and make sure you leave some trees on that golf course

 

[Metals406]

nope, I checked that first!. Its right boogered. I can put the rings in one spot one on top of the other if I get around to relocating one or both of them. I have the OEM top running awesome though now so I'll probably just let it be.

My problem actually happened because I was doing a 361 rework porting and the 460 late at night working on both. The 361 transfers go way into the intake and its fine so I got too used to looking at that and didn't turn the brain on when I started hacking into the 460

Well shucks. . . A pity it wouldn't work. Sounds like you got her handled though.

Yep I doo!!! But that's not the problem in this case, the 460bb piston is too tall. I've been wanting an excuse to weld a popup.

Well then, my suggestion sucks!

 

[parrisw]

Well shucks. . . A pity it wouldn't work. Sounds like you got her handled though.



Well then, my suggestion sucks!

LOL!

Well I'm in the middle of grinding the heck out of this cylinder right now.

Man these lowers need allot of work, almost got it roughed in. I've decided to leave the transfer timing alone for now, just clean them up. Give this thing lots of blowdown and see how it likes it, since these saws run off a really tight case. They need all they can get.

 

[Metals406]

LOL!

Well I'm in the middle of grinding the heck out of this cylinder right now.

Man these lowers need allot of work, almost got it roughed in. I've decided to leave the transfer timing alone for now, just clean them up. Give this thing lots of blowdown and see how it likes it, since these saws run off a really tight case. They need all they can get.

They looked real tight from your pics. . . Can't wait to see the results!

 

[parrisw]

Results are in! Everything is roughed in now, a little smoothing out to do yet. Jut got to stick it back together and check the ex timing to see if its where I want it.