lightweight pistons and Carillo rods on e-bay USA

Does anyone have any experience using these components? Although expensive they look trick, however I am somewhat sceptical about the claims of more power due to rod length and also about improved balance factor.

does the ad make a claim of specific HP numbers? Otherwise, any fractional HP gain is "more power" and not deceptive.

I'd venture that they are a benefit; however, "speed costs money, how fast do you want to go", as some old racing dude once said...

I have a set laying around for a motor I never built. Not the same as Jim's. I went the economy route by using a set of Wiseco pistons for a Suzuki with a 78mm bore. Then I had Carillo make a set of rods to fit. The length turned out to be 6.290", compared to 5.877" stock. The pistons weigh in at 250gms. Can't remember what a stock pin weighs, these are around 65gms. The jury is out on what a long rod motor will do that a short rod won't, the differences are marginal. One important issue is going to a modern forged piston and ring pack. One of these days..

http://www.rustpuppy.org/rodstudy.htm

I believe that seller makes those pistons... He has a thread on the britbike forum about them. I also saw a video I believe on google vids where he demonstrates them, and has a norton doing wheelies. I think they'd be great for racing, or if you're a rich man... putting around seems like a little overkill

I wasn't necessarily looking for more power, simply curious about the performance claims and If you had to buy new rods and rings anyway would this be a possible way to go? My main concern is about how the different weights would genuinely affect the balance factor. Bob your experience with Suzuki pistons and custom made rods sounds interesting.

Hi there, about the Suzi pistons, Jim Schmidt had tried them sucessfully when racing few years ago, but due to design he must shorten the jugs.......then he came to this idea about longer rods , not because they are better , but only (in my own mind) because they were compulsory to fit with shorter deck height pistons ; he wanted lighter pistons for less reciprocating weight , and that will definitly improve reducing vibes , then after you must adjust the flywheel to stay with the desired balance factor .That's a big improvment in an Atlas or any "non-isolastic Norton" (Seeley or whatever), see the difference of vibes between a 650 and a 750 featherbed , that's due only to the pistons weight, and bear in mind that the concave crown 750 Atlas pistons were lighter than the cdo ones , we use to fit now cause of unobtainability of the previous one........so I had a bought a set (yes they are expansive ! but life is short......)had not fit them yet, will send some feedback as soon as .

Anytime you can use significantly lightened components to do the same job there will be benefits. Energy produced on combustion doesn't have to move so much weight and less reciprocating mass means less nasty vibrations. If you can afford it why not. Your crank shouldn't whip as much. You would need to rebalance your crank which should run around $100.00 or so. Our pistons look pretty stone age if you compare them to new Triumphs and other modern bikes. Those pistons look only slightly modern but may as far as you want to go off the original design.

If you contact him through his web site you may be able to save the ebay commissions and paypal fees. He seems like a safe bet to deal with outside of ebay. http://users.gotsky.com/jimschmidt/

There is also a guy in Germany who just posted on this site in the last week who was making pistons and rods and he also makes steel cranks. I couldn't find the thread though. You can also buy rods direct from Carillo but this Jim Schmidt guy could be getting dealer discounts anyway so can match the Carillo prices?

I wish I could find the specs on my 750 cafe. It has roughly 24oz. shaved off with a higher balance factor. It ran super smooth in the iso's maybe because of less vibrations from the lightened crank. It really wound out possibly at the expense of just a wee bit of torque in the low end but a treat on a mountain road. That bikes been sitting for 30 years so I want to tear it down and clean the sludge trap before getting it going again.

RennieK said:

... That bikes been sitting for 30 years so I want to tear it down and clean the sludge trap before getting it going again.

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Hence the name "Rip Van Winkle", eh?

dave M said:

I wasn't necessarily looking for more power, simply curious about the performance claims and If you had to buy new rods and rings anyway would this be a possible way to go? My main concern is about how the different weights would genuinely affect the balance factor. Bob your experience with Suzuki pistons and custom made rods sounds interesting.

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Dave, It's is a given fact that the reduction of reciprocating weight is going to raise the balance factor, all other things being equal. The bigger issue is in the net reduction of reciprocating mass, whatever the balance factor. Ken Augustine wrote someplace that you really can't balance a reciprocating force with a rotary one. All it does is move it someplace else. Even with opposed twins there is hell to pay for the stresses imposed internally withing the engine. Lowering the mass involved is gold. It lowers the stress on the entire bottomend, it nets you free power, and it lowers the vibration.

There's is something that's always confused me about the balance factor(s) on Commando motors. I have Kim's CD of Norton manuals. The manual for '73, 750 and 850 lists the balance factor at 52% dry. The manual for 1975 MkIII's lists it as 52% wet and 63% dry. I'm thinking the old manuals could be wrong and they finally fixed it in the MkIII manual. Not unheard of considering the oil line diagram. 52% dry BF will net you a 40% running balance factor. I've had three cranks balanced. Every time I've brought up the published spec and every time I've been told that a BF less than 50% is nuts. Also they mentioned that the amount of oil in the sludge trap on the Norton is unique, most engines have galleries, not a pot of oil like a Norton. Twice I went with 65% and once with 75%, dry. To be honest, there wasn't a huge difference. So, I think the prospect of going with a lighter reciprocating setup and leaving the crank as it is probably going in the right direction anyway.

Thanks for the benefit of your experience Bob, The efficacy of lighter components was obvious to me, however I was unaware that Carillo would readily make custom con-rods, this of course opens up the possibility of using a wide variety of pistons from other bikes. The balance factor was my main concern, but as usual with anything Norton the theoretical situation and the actual situation don't seem to tally too closely. $1250 is a bit rich for me at the moment, but I might keep my eyes open for some suitable pistons from another marque.

has any body used Jim Schmidts rods and pistons in a std mounted 850, without rebalacing.I was going to buy carrillos any way when I found his web site, what scares me is the fact it goes away from std components fitting, and the price, but it is all well thought out top quality gear but a seized piston or gudgeon pin would be an expenseive repaire

grandpaul said:

Hence the name "Rip Van Winkle", eh?

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Exactly!

I remember at one point after the announcement that Norton was closing, how discouraged I was. I felt all the tech stuff I'd learned was now all worthless. I still loved and rode my bike back then but I felt I was on a dead end street.

Back then I had a change of career that had me working 12/7 learning, running and maintaining a lot of technology. I was totally out of the bike scene for the next 25 years or so (haven't tabulated the exact number). I'm talking totally detached, mc's were totally out of my everyday life as a result of my brain drain running my business. 5-6 years ago I paid a junk hauler $1500.00 to haul away $100,000.00 worth of defunct equipment in this digital age. I had that sinking feeling again, all the techie stuff I'd learned and equipment I'd invested in was again worthless to me.

What I learned: "If you buy equipment to work for you, you'll work for it."

Now I've decided to 1st and foremost get some enjoyment out of life which brought me to digging out my long lost Nortons. When I discovered this site I was blown away. Nortons hadn't died back in 75 when they quit making them, to the contrary, they seemed to be stronger than ever. With the internet tying everything together, new parts still available, learning about Dreer, Hemmings, Maney and on and on I really felt like Rip Van Winkle would have felt after his 20 year sleep. A lot has been happening while I was in my "Big Sleep"!

Another thing I have learned is not to rush into things so unless I win the loto it'll take a while for my restorations but I'd love to ride one to Lumby next summer.

Great story!

Since I plan on doing this till I retire, I wonder what I'm going to want to be doing AFTER that?

Thanks for the interest in the Lightweight Norton pistons.

For detailed info please visit my NEW webpage at:

www.jsmotorsport.com

Also see the various links at the top of my web page for detailed info on the test bike, crank balancing specs, rod & piston details etc.

The lightweight pistons & rods are being used on the street as well as the track. Customers report that their bikes run much smoother and there have been no problems. No modifications are necessary for installation - everything fits right in. They are expensive because they are custom made but I sell them as cheap as I can while staying in business and you get what you pay for. You can save $100 by going to my shopping cart web page and avoiding the ebay charges.

Also visit the youtube Lightweight Norton piston demo at:

http://www.youtube.com/watch?v=lX0rn_QosTg

The pistons are lighter and so the balance factor for a Commando is increased from 52% (stock) to about 65% and this is an improvement in my opinion. When Commando cranks are rebalanced the factor is often increased to around 63% so they run smoother throughout the mid/high RPM range where they need it. Of course you can always rebalance your crank but I think you are better off with the higher balance factor.

The rods are a special proprietary design and are lighter than the standard Norton Carrillo rods. How this can be is explained in my "piston and rods" technical link at the top of my webpage. They are longer than stock rods and give you a better rod length to stroke ratio of 1.83:1 instead of 1.67 to 1 (stock). You don’t have to take my word for it – talk to anyone who knows what they are doing in the engine and racing industry and they’ll tell you that rod length/stroke ratios closer to 2:1 are better and less stressfull than ratios around 1.5:1 Even the Triumph people will tell you that long rod Triumphs run better than short rods.

Its cold outside but I’m riding again later today – I just can’t resist another smooth blast on my tricked out Norton.

Jim Schmidt

Hi Jim, thanks for chiming in and welcome to this forum! You have some nice looking parts there and I'm sure I speak for all in saying the $100.00 off ebay prices is appreciated!

grandpaul said:

Great story!

Since I plan on doing this till I retire, I wonder what I'm going to want to be doing AFTER that?

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Simple, don't retire!

+1, Welcome to the forum Jim. Your pistons and rods sound great and the BSA cam followers are also on my wish list, How much does it cost to re-grind a cam to work with those? I have just started gathering the parts to build another motor and this sounds like a nice combo. Chuck.

RennieK said:

grandpaul said:

Great story!

Since I plan on doing this till I retire, I wonder what I'm going to want to be doing AFTER that?

Click to expand...

Simple, don't retire!

Click to expand...

Since the financial turmoil of the last couple years this has become my "plan" too....

PS, Jim, I watch your YouTube video at least once a week and sigh and drool a lot. Absolutely beautiful parts. One kid in college and another to go, but eventually they'll graduate and I know what MY graduation gift is!!!

FYI, Jean Gindrat? from France has been using this same idea but with 6.362" aluminum rods and custom made pistons in his winning Norton Racer for a long while (the last 4 seasons as I remember). Jean's custom piston assembly weights in at only 230 grams. There is still room for improvement. I know MAP offered the "long-Rod concept a very long time in their catalog, so this concept is not news, but I have been told there is reluctance to the change. Too bad there is not more interest as the costs could be reduced significantly. Just because the factory didn't do it doesn't make it worse they needed to make money while we get to play (ok experiment) to make these Brit bike engines better. Currently I ride a Triumph, a 76 degree crank (a protptype - my labor was cheap!) with custom pistons in a billet nikasil barrel. What a difference over stock. Don't know who follows Tim Joyce on his formula 750 racer but I've seen it run at Barber this year. I was impressed. The parts are certainly proven. So, just having bought an 850, I'm waiting to see if I can get a chance to test some of their new Norton items. I will attest that Marino's stuff is good quality and reasonably priced. Was curious when I found this thread as this was something I was already planning to do during my Norton's overhaul. Need to stay on his good side so don't tell him I said to call.

British Bike Guy
Mark Turner