Hi i'm in the uk and just wanted to know if you can buy any race cranks for the rv6 engine, as i want to put a race crank in, If not will an am6 crank fit the rv6 engine as it looks very similar,also the rv6 engine is bigger inside compared to an rv3 and rv4. If you have any! sites please tell me them, also if you know of any very fast high performance exhausts for the af1 or am6 as they fit.

Finally on the right side of the rv engine there is a gear/ cog on the crankshaft/ crank, this drives the clutch etc, this is smaller than the am6 and so will take 10-20 kmh off the max speed, is there anyway i can change this with the am6.

Thanks for your help and for trying to understand my question, sorry i don't speak dutch.

an am6 crank doesn`t fit in a rv6 engine

Thanks for the information, They look so much the same though, could you tell me wht part of the crank won fit. Also how can i achieve top speed with my af1, any exhausts/ cranks, to fit to make it fast, i have a polini 70cc, cast iron cylinder kit.

ask thomasrs50 on this forum, he knows a lot of rv6!

If you know of any very fast high performance exhausts for the af1 or am6 as they fit.

it depends on the cilinder you use, I would recommand a gianelli or a yasuni hmr2 as they run well on every setup

if you really want a hihg performance 70cc zaust, buy yourself a MK pro race or something like that

Finally on the right side of the rv engine there is a gear/ cog on the crankshaft/ crank, this drives the clutch etc, this is smaller than the am6 and so will take 10-20 kmh off the max speed, is there anyway i can change this with the am6.

you have to count the gearing of the clutch as well, and then divide it by the gearing that comes from the crank

don't forget that also that the gear box ratio can differ

and finally the crank, the best thing is to buy a barakit am6 conrod (see barakit site), they are very cheap, but very good

Thanks for the information thomasrs50, i will check out the barakit am6 conrod, i have an rv3 crank and an rv6 crank they look different and the rv3 one may be a bit heavier not sure, Which one should i use for best performance/ speed/ revs.
Also you say the gear ratios can differ, how? because both my gears in both my engine look the same for the top gear, as on my 3 speed it is like 2nd then 4th and then 6th in my rv6.

Finally you say a metrakit exhaust, i think this would be great but is very expensive over here, also do you know anyone who can tell me how to make a custom/homemade exhaust myself.
Thanks again for the help.

Thomasrs50 could you respond to my last post? thanks.

about the ratio, I'll look for back home (in 2 weeks)

and the crank does not really matter, as long as the conrod is oké

Ok thanks, also do you mean you will be looking at the ratios between the rv6 and am6 to see if there is any difference anywhere to make any engine faster, and you are looking at the rarios in 2 weeks? Thanks again.

Indeedy,

but for as far as I know, the 'sprockets' from the rv gearbox are much smaller than the ones inside an am6, so the ratio must be different

this is the gear ratio from rv3:

1 - 3,3
2 - 1,68
3 - 1,15

and this is from an am5 (the am6 is quite similar)

1 - 3,0
2 - 2,06
3 - 1,53
4 - 1,23
5 - 1,04

I can't find the one from rv6, but I'll just take a look back home, think I still have a spare RV6

Thanks, but i don't know much about gear ratios, could you tell me how to work them out and what the numbers actually mean (3,3) is this how many turns the gearbox cogs do? Because from comparing the am5 and rv3 it looks like the am5 is a lot faster than the rv3 as the 5th gear is taller(bigger) and so more speed is avaliable.

the ratio is number of teeth (?) from the secundary shaft divided by the number from the first

fe: 75/25 = 3

this means the rpm comming from the crank is diveded by 3

but you'll have the calculate the reduction of the cluch first before you can use this one

Hi thanks that sort of makes sense. But do you know if the rv6 engine is quicker than the am6 or the am6 quicker than the rv6, also would the am6 6 speed gears fit into the rv6 casings. as minarelli must have kept some part of the design the same.

Thanks again for the help and info.