Nicasil 49mm Bore; Noob? Dubh?

[Wheelman-111]

Greetings:

DayWOT's store for an asking price of $129. + 25 shipping. Provenance unknown. Doesn't look Italian...

http://cgi.ebay.com/ebaymotors/ws/eBayI ... otohosting

The 49mm bore yields 78cc. Nicasil's super-hard surface and aluminum's superior heat conductivity are attractive in Theory. But we all know about Theory and practice not necessarily coinciding.

Is Anyone running this particular bore kit and willing to share? Has Anyone heard anything about the performance and durability? Does Anyone care to speculate? Is there Anyone out there??

[wiguy05]

Aluminum/nicasil cylinders have been used for many years on snowmobiles, both liquid and air cooled. Seems to work excellently as they are much higher performance than the scooters we use. The nicasil coating is VERY hard and lasts a long time without wear. Only downside is the replating process is very pricey. A standard snowmobile jug costs $250-300 to replate.

[Wheelman-111]

Greetings:

I was aware of Nicasil sleds, which were entering the scene at about the time I quit riding. (Mid-70s) Remember the first air-coolled Mercury Sno-Twister? That machine absolutely dominated from its introduction. Suzuki was an early adopter in the motorcycling world - their 2-stroke triples had Nic., methinks.

But what of this specific bore?

[burnt_toast]

A few people have tried but haven't heard anything good or bad about this specific one

I've ran a total of three aluminum Airsal T6 70cc kits on my jog type setups with varying results. Over time only 1 of the 3 survived. 1 failed due to weak/faulty circlip, 1 failed due to high miles and improper tune, 1 running was just bare bones with stock carb still see it passing hands on craigslist with mileage climbing

See about the boost port. If its flush for S case, I would consider trying it out. alum kits have great cooling capacity and lots of power, you even get weight reduction.

[Wheelman-111]

Greetings:

Thanks BeeTee. Whadja mean by:

See about the boost port. If its flush for S case...

?

Have Roto-Zip, will carve...

[burnt_toast]

Greetings:

Thanks BeeTee. Whadja mean by:

See about the boost port. If its flush for S case...

?

Have Roto-Zip, will carve...

Hey if you're up for carving then dont even worry I mentioned that, I personally like the smaller boost port on the 72cc bores for theoretical increased flow and better cooling. larger boost needed for strokers and 80cc+ but on 72cc I feel you would loose some velocity. No info or data to prove it but my personal engineering consensus.

Im skeptical about it being 78cc too although it does say 49mm on head package.

Note the base gasket to see what I mean about BP

[Wheelman-111]

Greetings:

Yup, 78.**ccs based on peerless Wheelman clackalayshun skills.
pi Rsquared x L
4.9 divided by two, piece of pi, carry the four, stroke at 4.14 ...
Trust me, it works out to 78-ish.

Why would you say a smaller boost port = better flow? More velocity for sure, but flow depends on diameter restriction or the absence thereof.

I haven't had the cylinder off the 16; dunno what to expect. I do know I removed a good cm.squared from Flash II's AF05 case to fit the big Malossi cylinder's boost port. Transfer ports were pretty good as delivered.

[Eft37]

I've been eying that bore kit since I got an Elite, it's been the cheapest I've seen. (Limp?)

Who gets to guinea pig?

[Wheelman-111]

Greetings:

I may take the plunge. I like the idea of the aluminum cylinder, hard-coated. I also like 78cc, a cool 8.33~% bigger than 72.

Patrick says the Polini is "more forgiving", but if you know what you're doing the Nic will "be fine". I guess that means jetting way rich to begin. Al-you-mini-yum melts quicker'n Arn.

My only reservation is regarding the boost port question raised by BeeTee. To port or not to port. That is the question.

[bradthreee]

Fork out tha doh and go wit da bess!!!! Stop being such a wennie yo!

[808BMW]

It is 49mm, my friend has this on his bike right now.

He said he likes it, and it runs cool, but he's pulling it off to try a malossi aluminum bore. I haven't seen it since he was breaking it in, I'll ask him what he thought about it and why hes switching.

[tru72]

to me best 72ish bore the price.
once ported its comes very close to my polini or malossi set up. So far i have gotten to go with that bore 72 mph. Polini 73. For something that half the price to me it works really well. Runs cooler that steel bores. Very had to kill it, your getting has to be way off to do so. Only down fall is that you cant hone it , so a cast iron bore has more life to it!
aloha
D

[tru72]

and yes, a polini is not more forgiving at all.. correct break in on a polini is about 5 to 10 tanks, no stress on the motor.
the best ones to buy is used ones since they have gone thru alot of heat cycles. I always buy seized ones for cheap because it seems to be broken in already hehe!

[burnt_toast]

there you have it wheelman, take the plunge

[losthope]

how much would it cost to get a bore ported? And who would be recommended to port it? thanks