So Mike, are you saying you are running ART pistons in your motor? And that they make 900 or bigger pistons for SOHC 750,s?
Then could you please enlighten us and perhaps give us the weight of any of them?
I weighed a few forged ones today, we could do a comparison..
There may be a bigger choice of cam grinds than I was aware of, but there are less offering them.. so which ones are the new technology superior ones??.. seems like a lot of them are like.. well like 30 year old ones.... who knows..
ART doesn't offer aftermarket pistons EXCEPT those used in Yoshimura, HRC and other factory race kits. I think they are busy enough with OEM R/D and MotoGp etc to leave small batch aftermarket pistons to other, smaller vendors. I did once have Yosh pistons (and OEM) in my engine so I guess I did use them. Obviously you don't think much of ART pistons though they I'd guess they have more accumulated race and street miles on them then any other bike piston. Like I said before....look at a modern piston from a ZX-10, CBR1000, R1.....tell me they are a poor design and or have poor quality machining. Also keep in mind they make thousands upon thousands of those pistons and still maintain great tolerances. They know how to make a great piston even in OEM street application.
If you think those old Venolia and Arias, with those huge rings, non tapered cement filled wrist pins, huge, fat skirts, no detonation grooves, big oil retention grooves cut in the skirt are better....well...I don't know what to say. At least Yosh had the right idea back in the day with light pistons and nice, light tapered pins. Their springs and retainers were better made too.
Cosworth made a very, very nice aftermarket piston with a really nice pin. Unfortunately a majority of bike owners wouldn't pry open their wallets to spend the extra dough on a superior product so Cosworth discontinued their bike line. Hey....why spend 600.00 dollars on a set of real nice pistons/pins/rings when I can get clunky Wiseco's for 300.00. That was...and more often than not now, the mentality.
You asked about new and superior products for the CB. Well considering it's old as dirt I don't know why anyone would even pursue it BUT people have. When you build your next engine purchase Kibblewhite's 5mm valve conversion kit, a real adjustable cam sprocket (not that useless RC piece) and the KA cam chain tensioner. Now the 5mm kit might give you a financial stroke but if you are a serious playa......
As for cams who care who grinds them as long as all the grinds are available. As Jay pointed out....one company supplied billets. Hard welding, while not new' is a superior product to iron billet cams. Christ how many more than 30 grinds do you need for this engine anyway?? I'd be more interested in cams with different lobe seperations rather than different lift/duration combonations at this point.
I'll take pics with the weights of stock K, F, F2 pistons. I'll also take pics with weights of a new Wiseco 836 piston and pin and an old clunky Action Fours (or something) 836 piston and straight wall pin. I'll even take a pic with the weight of an old Arias 71mm piston.
Finally....keep in mind old is old stuff is old stuff. RC stuff was OK in the 70's but compared to modern pieces in genrally falls short. This is particularly true of pistons/pins, springs, valves (especially since you can get 5mm stem pieces), cam sprockets, can chain tensioners etc. If you want to live in the past and reminisce how that Cobra CB made 100HP (not on a good day) and would blow the doors off anything that rolled you are welcome to do so but don't expect me to believe it. I wasn't in diapers.
PS....if you want to buy a real nice pin call Kelly Roberts at Racing Engine Components. They will make anything (just don't tell him you only have 50.00 to spend).
