Hi all, i don't know if i'm posting in the right place but i was wondering if the polini aluminium cylinder kits are as good or better than the malossi aluminium cylinder kits.? If anyone can tell me how well the kits perform or which is the best, and the power/ revs(rpm's) that would be great.
Also what cc do the kits come in E.G 70cc/47mm as that's all i have seen?Thanks.

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which Polini and Malossi cylinder do you want? polini and malossi got many different cylinders

I was wondering which cylinders are the best for the rv engines, best performance, hp and revs. also i didn't know there were lots of types for the rv4 and rv6 etc engines.

for RV engines there were : Polini, Malossi, Giladroni, Rotax, Eurokit, and more...
However I have no idea whitch of these brands still produce rv cylinders...

edit; eurokit still produces the 65cc cylinder, but ask Devlin, it sucks unless you tune it

Have you ever tried any of them, i do have a polini one and a malossi one but the malossi one is wrecked. Both aren't too good so i wanted to see what other kits there are and what ones are the best. Also thanks for the info.

Polini cylinders are very strong, if you want to make it fast, it's possible, just let someone tune it, make sure it's done professionally and it !!may!! be a very very fast cylinder... on the other hand, it's durabillity will go down.
My brother made the cylinder go 120kph, with astounding acceleration
without tuning.

Did he have an rv4 engine?Could you tell me what setup he had as i can only get 100kph at 9000rpm but should pull 120 kph at 11000rpm or more if it would pull past 9000rpm.

the cylinder is capable of doing at least 13.000 rpm, unless you've got the wrong Polini
He had an RV4 engine, an 19mm dellorto carb, a powerfilter and the sprockets were 14-40

Well i have the polini aluminium cylinder with a sort of square cylinder head,well a lot of sides if you know what i mean, if you have a picture of the same kit he had i could tell you if it's the same as mine. Although mine is a little worn out it will only rev to 9,000 in top gear but the power is gone before then and it will get to 10,000rpm in 2nd an 3rd gear. I have an rv6 engine but compared to my rv4 the gear ratios are different and there are like 2 more gears added on the rv4? I have a 19mm carb also, what jet did your brother have as i have a 74 main jet? also i have 15/40 gearing. Did your brother have an exhaust as i have the standard still. i also get 100/105 kph at 9000rpm.
Thanks for the info.

I see you have the same cylinder,,, try a new (oversize) piston, if your cylinder is worn out, this will help.. compression will increase and so will your torque, whitch also increases your rpm's...

my brother had a standard exhaust yes, but it was a 32mm diameter exhaust (no limitations whatsoever... ) catalisator was also removed... make sure you have a large exhaust too, because this also holds down your rpm's.
if you really want to go fast, buy a fast exhaust like an HMR/2 or something like that

Rv4 and rv6 will make the same revs and speed i thought unless you have an altered gearbox

Well compression is quite good when i kick it over on the kick start, i may just get new rings or a new standard piston for the 70 polini kit. Well when i had my rv4 in the bike with 13/40 gearing i got about 85kph or 90 kph with a 70cc but with my rv6 and 13/40 gearing with 50cc i got about 100/105kph, and the gearing/ratios do look different when i had a look and compared the rv4 and rv6 engines.
Yeah i have heard the hmr/2 exhausts are good.
I haven't measured my exhaust but it fits in the cylinder well and the exhaust is standard for my af1 frame 1992 replica(red, purple and green colours). My exhaust has a big expansion chamber but does seem to limit my revs. Also it has a long pipe coming from the expansion but i do have one with a little pipe, which one did your brother have?
Thanks again for the help.

In that case i've learned another thing about rv4 and rv6, the 6, always thought the ratio's of first and last gears were the same guessed wrong
My brother had the same exhaust but then from the newer model, it's slightly bigger, your's is 28mm i guess, (check the inside diameter at the cylinder-side) the af1 replica is an 1988 model though, you have the square dials or the round dials? the round dialled version is the 1989 model and it's called the Sintesi
I had the '88 model; the replica... loved it

edit; expansion chambers don't controll the cubic inches of air that goes through it... the diameter of the exhaust does...
a big expansion chamber doesn't always mean that it's letting more air through.

if you want to go faster, it's !!only possible!! with having an 32mm exhaust if you already have one on it, check the exhaust for a catalysator and if it's there, remove it because this once again influences the amount of air capable of going through

Yeah, i have round dials like the aprilia rs50 extrema, white rev counter and black speedo. Mine is the last shape af1 like yours but mine is 1992 and has the frame like the af1 futura without the ridge down the side of the frame. Well i will measure the exhaust tomorrow to see the size. When you say catalysator what do you mean? Also the rv4 and rv6 ratios for first gear are the same i think but the last gears are different. thomas rs50 on here will be able to tell you if the ratios are different as he knows more than me.
Thanks for the info and help.

its some sort of filter that filteres out the detrimental substances coming through your exhaust.

if you need any help, ask
that's what this forum is initially made for

maybe you could create a gallery? it's a compilation of pictures and information about your AF1, people are able to comment and answer your questions
this way you'll won't have to open a new topic every time you need some information

Oh right, we call it a catalytic converter, i havent seen them on these old af1's only on the new rs50's i think. just filters out the bad gases/ co2 emissions(carbon dioxide).
I had a look at your af1 on your album, looks good. i see you have the short exhaust where your silencer fits on just near the expansion, i do have an exhaust exactly the same but with a different silencer/ end can but haven't tried it, i only have the exhaust that has a long end pipe joining the silencer to the expansion.
Also do you mean create a gallery on the gallery section on the forum or on my album like you have done?
Thanks.