west bend 580 -5 port pistons

[steve miller]

i dont know how to get them on computer if you wanna pm me a cell number i no how to do it with my phone ..sorry ..and thanks everyone ..my cell number is 607 -661-3295

[steve miller]

ok you guys i figured it out ..boy do i feel like a fool..!!! i been looking at piston backwards holes are in fact lined up with intake NOT exhaust and theres matching holes drilled in the intake runner ..are they to give it an extra shot of fuel on the way down ..jeeeez sorry you guys ...

[ted johnson]

Lotsa guys have cut holes in the piston skirt and the transfer wall , especially the Macs and West Bend 610/820's. It's of limited value in an engine that's charged thru the bottom of the crankcase like the 580. Most hopped up 580/700's had the intake side of the skirt notched and the transfer wall notched to match. This helps fuel flow into the transfer passage when the piston is near bottom dead center, and the crank cheek is masking the bottom of the transfer passage. The holes were probably put there for that purpose.

[steve miller]

thanks ted jeeeez im embarrassed i coulda figured this out myself ..i cant belive i looked ast piston backwards i was convinced i had it pointing the right way .well when i ran one up the bore i see the holes matched up to 2 holes drilled in the intake runner ..i guess thats how this person did it insted of winow porting the piston ..i have over 30 west bends its cool becouse every single one of them thats ported is a little different ..

[Andy Symons]

I know the aftermarket pistons for the v5s had the exhaust side filled in to raise compression but were the OEM v5 pistons filled in that way also - as opposed to the stock 3 port piston? I don't remember and don't have OEM ones to compare 3 vs 5. Since I don't, I also can't easily verify the difference in the arc the deflector encompasses - I'm assuming the 5 port deflector went further around than the 3 port due to the location of the 2 extra ports. Yes? No?

By the way, Steve, I'm assuming your 6 pistons are all stock bore?

Andy

[steve miller]

yes andy ...all stock bore .there all in west bend boxes..?..im pretty sure all 5 ports come from the factory with higher comp.piston than 3 port ..whenever i get a 3 port i put a 5 port piston in it i dunno if it makes them any better .but i like to weld up the 3 port ones and mess around with couple motors i dont care to much about ..

[Andy Symons]

But how about the deflectors, Steve? If you compare the stock 3 port to the oem 5 port, does the intake deflector extend a little farther to each side on the 5 port because of the extra ports' positions?

[steve miller]

hi andy ,,im not sure what you mean by deflector ?? the skirt on every 580 west bend engine i ever seen weather 3 or 5 port is the same every piston ive ever seen is identical other than the dome on a 5 port piston is filled in a little more ..pin height ,deck height,skirt length,ring lands are same place ,i guess alot of people cut the intake side on some pistons to get more gas in them.. i have some pretty funny lookin pistons lol i have one im not jokin has 90 tiny holes drilled all over the bottom ..hope i helped answer your question ..

[Terry Bentley]

Do those 5-port pistons resemble any of these? The deflector is on intake side, top of piston, like seen in pics. Its what the fuel slams into, then deflected up, when ports open.

[Andy Symons]

Yes, exactly, Terry. My question Steve is, if you carefully measure the distance from one edge of the deflector, around the intake side of the circumference of the piston, to the other edge (perhaps using a protractor), would the 5 port deflector be "wider", that is, cover more degrees of circumference than the 3 port piston?

I remember that west bend came under some criticism that the placement of the 2 extra ports wasn't optimal and think I heard that the piston deflector was changed to accomodate the extra flow of mixture coming from the extra ports so that scavenging was maximized. However that was a long time ago and I've never had two stock pistons to compare.

The piston on the left in the photo seems to look different but with the different mods and lighting it's really hard to tell. Would have to measure two stock pistons - 3 port vs 5 port.