6401 woods port build

doing this for an as member.

more info soon

scott

Ok.

I wanna see how this goes. I still have a 6400 topend and am looking for a dead HD 6401.

Hmm.

step 1

parrisw said:

Hmm.

Click to expand...

:hmm3grin2orange:

between 145-150

dur
in 145
ex 148
tr 98
bl 25
sq .026

skirt width
ex 1.197
in 1.086 because of cylinder design
port width
in .814
ex .926
bottom of ex port to bottom of piston skirt at tdc .025
bore 1.852 or 47mm

not looking to good

the wood in the vid is soft maple cut 1 year ago.
this is my first time in a dolmar/ mikita.
not mutch room to drop the cylinder to raise comp.
it should have a new piston but owner said use it.
any one know of a pisto swap? 47mm bore, 12mm pin, top of pin to crown
.542, total piston hight 1.511.

ports can be widened to ex 55% in 50%. not to good.
was hoping to drop the cylinder but not mutch room there. i think it will end up having a little free port when finished.

need to make a manderal. another day or two and i'll have more info.

scott

i think if i welded a piece in tr port where it's marked in the pic above, bored it to 48mm, and had it replated, i could make it run like it should.

this thing has a nice big carb and boot, but a itty bitty tiny intake port

maybe i'm just:bang:

could weld a popup on the piston also.

what to do, what to do, what to do. tiz a mistery is'nt it.

can't sleep so back to work

replating will cost nearly what a 79cc top-end cost and more than an 84cc BB, but it won't be as much fun to do or read. so, carry on.

Ill call on getting you a new piston for that

opcorn: rep coming!

When I opened the thread, I thought for sure this was going to be a big bore build. I agree that there's not too much to work with if you're trying to widen the ports on the 64cc factory jug.

Do yourself a favor and start with an OEM 7900 P&C. They're only $189. LINK

i think the reason he's trying to build this saw Brad is because there is so much potential with how big the transfers are if you would possibly make that one transfer a closed one and how it replated u just might have a screamer but u are also limited on your exh so back to beating ur head against the wall

redlinefever said:

i think the reason he's trying to build this saw Brad is because there is so much potential with how big the transfers are if you would possibly make that one transfer a closed one and how it replated u just might have a screamer but u are also limited on your exh so back to beating ur head against the wall

Click to expand...

It's all about the compromises isn't it

I've always been curious about porting a 64cc cylinder. This should be good!

I'm looking forward to this build when you get your free out of jail card!

Cool ideas.

Have you thought about the roof of the transfers? That might be their limitations. It's a 90º right angle on the inside. I had the idea of porting that area to try and create a curved roof. I'm might try it just for kicks. It's tricky, but might be doable.

Here's the sixty four and some yellow box. That motor can be made plenty strong I think. I do plan on building a piped 6401 as I think that's where that jug's system will shine. I just need a home depot find.

<embed width="600" height="361" type="application/x-shockwave-flash" allowFullscreen="true" allowNetworking="all" wmode="transparent" src="http://static.photobucket.com/player.swf?file=http://vid701.photobucket.com/albums/ww11/CHEVYTOWN/VIDS/D4-1.flv">

But the 7900 powerplant has it covered and then some. I'm looking forward to porting it