avanti reed

[rumiman]

i am building up an avanti kit with an lth reed manifold, ron kindly modified the piston with an oval cutaway in the skirt to increase inlet timing, but would not recommend windows in the piston due to the fact the piston was not manufactured/strengthened in the relevant areas to accept them, i fully appreciate his view as he obviously would be reluctant to endorse anything that may detract from his kits reliability, my question is - has anyone done such a conversion with success ? especially interested to hear of a modified one that has some miles under its belt.

[coaster]

Have you considered using a TS1/RB/Supermonza piston with the windows already in place? Ron was selling some Matika ones a while back

[Psychedelicropcircle]

[URL=http://s1066.photobucket.com/user/psychedelicropcircle/media/null_zpsfdfa2465.jpg.html][/URL

That'll be why he doesn't recommend! The half moon works fine. Pretty sure he didn't want to use TS Pistons something to do with gas tracking beyond the grooves near the Gideon pin area.

[rumiman]

ron explained to me that due to the width of the bridged exhaust port, very few pistons have a wide enough skirt to close the port at tdc - including his own ts1 type pistons, i was going to use the piston as ron sent it with the oval cutaway in the skirt unless someone could confirm through actual use that windows where safe to instal.

[coaster]

Some pistons have the shape of the windows 'cast' in on the inside, maybe that type is safer? That broken one in the photo does look to have a rather large window, my TS1 pistons had 2 smaller windows I seem to remember.

[rumiman]

yes coaster, beefing up the casting in the window area is the usual/safe method for piston construction, the avanti piston does not have these but is quite a thick piston overall, i have a few thousand miles on a pair of "windowed " standard moto-rumi pistons, some pistons can take it some may best left as they are, just don" t want to find out the hard way with my avanti piston if someone else already has the answer?

[Psychedelicropcircle]

just don" t want to find out the hard way with my avanti piston if someone else already has the answer?

See post number 3 avanti piston

[rumiman]

hi crop circle man ! yes i did see it and appreciate you taking the time to reply, but like coaster says that is a wide window / patio !!