Can you run a 72cc polini corsa on a small crank af18e?

[dio boy]

So i recently put my motor together
Early af18e
malossi crank
polini corsa
ct black
keihin carb
6.8 gears
SEF majik pipe

My compression is low 120 psi on corsa with no gaskets added... supposed to be around 170.
I just found out you can't run the corsa on an af05 is this the same with early af18?

[Red Eft Performance]

Yes It should work with that motor.
Have you run it yet? Compression should go up a little bit once its broken in a bit.

[Wheelman-111]

Greetings:

Have you assembled? I have read that the AF18 uses different-sized bearings and seals on the smaller-diameter crank end. That might be a weak spot for the build, but I see you listed the Malossi crankshaft, taking that liability away. But with the Malossi crank one would think the bearing would be the wrong size. How does it go togetherz?

My Corsa also compressed at a surprisingly low number, but that didn't seem to hurt the power any.

[dio boy]

I bought the motor with the crank installed ran it for a week... piston and head got mutilated looks like a piece of metal got in there or was in there when i bought it because i never split it. Anyways I'm in the process of installing a new crank bearings and seals, and porting the boost. i have a freshly honed ported corsa I'm going to be trying out. As far as the bearings go i was told the same bearings as used in the af16 will work but I'm not sure... we will see what it looks like.

[dio boy]

And yes 120 psi seems perfect to me i just assumed i would have to add a head gasket to get there

[Red Eft Performance]

If it is a small shaft crank, AF16 bearings and seals wont work.

[patthesoundguy]

I bought the motor with the crank installed ran it for a week... piston and head got mutilated looks like a piece of metal got in there or was in there when i bought it because i never split it. Anyways I'm in the process of installing a new crank bearings and seals, and porting the boost. i have a freshly honed ported corsa I'm going to be trying out. As far as the bearings go i was told the same bearings as used in the af16 will work but I'm not sure... we will see what it looks like.

Check the metal reed springs in the intake .I'm betting there is one missing. That happened with my spree bbk. did you find metal like this? I'm taking those springs out of the intake going on my af18e build not taking any chances with my MHR top end. My spree bbk would still be ripping now if it haddnt eaten that spring at 12k

[paulpauly7]

bearing are the same as af16 stator side seal is the same as af16 the vari side crank seal is the same as the stator side .the vari side crank seal on a af16 is to big for the small shaft crank.Also none of the af16 ramp plates fit on the small shaft crank you need the malossi small shaft vari kit .if you use a af16 ramp plate it will ruin the crank shaft .

[LMH]

Beat me to it Pauly.

[paulpauly7]

this is my setup so id hope i knew the answer lol malossi small shaft crank and polini corsa my compression is at 135 and have 1350km on the motor

[dio boy]

thanks for the input guys! I'm using 87 seals and i have malossi ramp and af18 drive face, also using s trans and malossi fly clutch

[dio boy]

and thanks patthesoundguy i will have to look at that

[veedubh20]

yes it will work.

i had built a early japan af18 , malossi crank (small shaft with s crank bearings,with small shaft seals that use on right side crank seals. crankcase has paper in the middle to assemble both case... need s top conrod bearing to work on polini piston. then good to go.

[LMH]

I wish the later engines used paper gaskets.

[DirtyE]

digging up the past here, but an af18 will work in a af16 crankcase? It will just require 87 bearings/ seals, and a malossi af18 vario?