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Af16e big bore options
Posted: Tue Apr 19, 2011 11:17 am
by BlackHornet
Hey guys, sorry if this has been covered already...I did a search but I am on my phone so I may have missed it. If there is a thread, please just post the link.
Question:
Which big bore kits will work well with the af16e without doing any work to the boost ports? When I say work well, I mean reliable without sacrificing power. I know you can't have the extremes of both but there is a happy medium somewhere.
Thanks
Re: Af16e big bore options
Posted: Tue Apr 19, 2011 12:08 pm
by Trafficjamz
BlackHornet wrote:Hey guys, sorry if this has been covered already...I did a search but I am on my phone so I may have missed it. If there is a thread, please just post the link.
Question:
Which big bore kits will work well with the af16e without doing any work to the boost ports? When I say work well, I mean reliable without sacrificing power. I know you can't have the extremes of both but there is a happy medium somewhere.
Thanks
66cc (45mm)
72cc polini (47mm)
75cc niksal (49mm)
Re: Af16e big bore options
Posted: Tue Apr 19, 2011 1:28 pm
by Wheelman-111
Greetings:
I suspect many if not most of these kits come in two versions. Just be sure the vendor knows you have the US-model Elite with an AF16 block. It's not a huge deal to ream the smaller boost port out to AF18 size, but kits for those engines can NOT just bolt-on without running a risk of base gasket failure. (Some would say otherwise...) Knowledgable sellers will send you the correct kit.
Re: Af16e big bore options
Posted: Tue Apr 19, 2011 5:29 pm
by Trafficjamz
Wheelman-111 wrote:Greetings......kits for those engines can NOT just bolt-on without running a risk of base gasket failure. (Some would say otherwise...)
I agree that the big boost port kits should have the case cut to match the jug.
But why would the gasket fail if the correct gasket was used?

Re: Af16e big bore options
Posted: Tue Apr 19, 2011 5:38 pm
by Wheelman-111
Greetings:
I stand corrected, Jamz.
I see no reason why the gasket would fail in the situation shown. However that tiny 16 case boost port wheezing into the cavernous Dio port would cause insomnia.
The converse - a 16-sized cylinder on an 18-size boost port - clearly would NOT work. Thanks for clearing this up.
Re: Af16e big bore options
Posted: Tue Apr 19, 2011 6:09 pm
by BlackHornet
so are there kits just for the af16? all ive see was af18 kits
Re: Af16e big bore options
Posted: Tue Apr 19, 2011 9:45 pm
by Wheelman-111
Greetings:
The Nikasil 49mm/78cc kit I ordered from DayWot was definitely sized for the smaller 16 boost port. I have read some posts suggesting there is also an 18-sized cylinder from this same kit. My Corsa is clearly sized to the 16 case. Both Ruima 51s and the Char-Mo from VT Cycles has the bigger 18 boost port cutout. I recommend you ax the Seller before buying, or be prepared to carve your block to the 18 gasket size. It's not hard to do, but you have to strip the cases of its bearings, etc. to avoid getting schmutz in them.
Re: Af16e big bore options
Posted: Tue Apr 19, 2011 10:35 pm
by KingJeff801
The Corsa I just got from SIP is for the AF16
Re: Af16e big bore options
Posted: Wed Apr 20, 2011 3:38 pm
by kingkamehameha
I'm running a malossi cast iron 72cc with a virgin boost port and I hit high 60's low 70's. I beat a lot of bikes that have the nickasil or ruima bores with cut boost ports.
Re: Af16e big bore options
Posted: Wed Apr 20, 2011 3:59 pm
by Trafficjamz
kingkamehameha wrote:I'm running a malossi cast iron 72cc with a virgin boost port and I hit high 60's low 70's. I beat a lot of bikes that have the nickasil or ruima bores with cut boost ports.
How are the temps on that setup.
What carb and pipe?
Re: Af16e big bore options
Posted: Wed Apr 20, 2011 6:47 pm
by eliteguy50
Wheelman-111 wrote:Greetings:
I suspect many if not most of these kits come in two versions. Just be sure the vendor knows you have the US-model Elite with an AF16 block. It's not a huge deal to ream the smaller boost port out to AF18 size, but kits for those engines can NOT just bolt-on without running a risk of base gasket failure. (Some would say otherwise...) Knowledgable sellers will send you the correct kit.
Does anyone know if all af16 engines have the smaller port is it just the USA model af16?
Re: Af16e big bore options
Posted: Wed Apr 20, 2011 7:56 pm
by tazland001
I just looked on my dio without the cylinder on the engine and the port is the same. This is a dio not an elite sr and has the original dio engine on it. Just to clarify. lol
Taz
Re: Af16e big bore options
Posted: Wed Apr 20, 2011 8:33 pm
by losthope
Trafficjamz wrote:kingkamehameha wrote:I'm running a malossi cast iron 72cc with a virgin boost port and I hit high 60's low 70's. I beat a lot of bikes that have the nickasil or ruima bores with cut boost ports.
How are the temps on that setup.
What carb and pipe?
I run a 51mm ruima bore with an unported boost port and have never had a problem. Im sure it would make more power with the boost port ported. ive hit 60mph with it.with 9.1.1 gears
Re: Af16e big bore options
Posted: Fri Apr 22, 2011 2:49 am
by kingkamehameha
Trafficjamz wrote:kingkamehameha wrote:I'm running a malossi cast iron 72cc with a virgin boost port and I hit high 60's low 70's. I beat a lot of bikes that have the nickasil or ruima bores with cut boost ports.
How are the temps on that setup.
What carb and pipe?
Nothing special just a 28mm oko and v8 pipe I think its the typhoon
Re: Af16e big bore options
Posted: Sat Apr 23, 2011 9:57 am
by SpreeMadness520
Trafficjamz is just sorting out his competition. Haha