Does anyone want to get in on the first batch of Nort rods & lightweight pistons?
Click on link at bottom for image of rods & pistons
The important diff is that these rods are forged, then final machined - not just machined from billet as others are. To my knowledge - no one else is offering forged alum rods.
The pistons are also forged and weigh in at only 180 grams each bare (.020" over 750 longstroke).
The pistons & pins will be oil cooled through an oilway in the rod.
Note that the rods are longer and the pistons are shorter than stock. This improves the rod/stroke ratio of he Norton, improves power and reduces vibration. You cannot mix these items with stock rods and pistons. Click on link at bottom for image of rods & pistons
Gosh are you telling me that my std Norton rods were not forged?? I thought that at one time the problem with some Norton rods, with the big'D' on them, was that not enough material had been used during the forging process. Mind you the std rod ratio on the 750/820 motors is rather low but was that done to keep piston speed down or as is probably the case simply so they could CHEAPLY use existing bits and pieces without a major redesign?..ie a bodge job.
Re: New forged Norton rods and lightweight pistons#72033 11/13/071:29 am11/13/071:29 am
Yes - stock Norton rods are forged and they are/were great rods. But you can't get forged AFTERMARKET rods (or original/new Norton rods either as far as I know)
The new pistons are forged and weigh in at about 180 grams bare for a 750 - thats about 1/3 less than stock. The pistons are shorter and will require longer rods (6.450" center to center). The longer length improves the rod/stroke ratio for improved power and less vibration. I plan on offering stock size valve pockets and high compression pistons with deeper/larger pockets for big valves. 850 pistons and up with similar weight savings will become available. The goal here is to provide high quality parts that will also reduce stress and vibration (I ride & used to race a featherbed).
The rods are forged by people who make rods for top fuel dragsters. I designed the big ends to be thicker/stronger than other available Norton after market alum rods. The pins and pistons will be oil cooled by a channel drilled lengthwise through the rod and around the pin to squirt under the dome (instead of squirting out the side as on a stock norton rod - note that there is no squirt hole on aftermarket norton rods). The small end weight should be only slightly heavier than a stock norton rod. I don't have the exact weight yet but it will be less than other aftermarket alum and steel Norton rods. The center I beam of the rod is thicker (.8") and will absolutely require for you to widen the notches in the cylinder skirts for approx .060" clearance.
I've put a lot of time and planning into this and I'm trying to determine if others are going to want these rods/pistons and if I should make them available - which translates into how many I should special order the first time.
I hope to offer them initially for $175 per rod and $175 per piston assembly - comes out to $700 per motor and thats competitive with stock aftermarket parts.
I have recieved the first rod and pistons and changes have been made until the design has been finalized. Now I'm ready to jump into it. The parts are not yet available but I have too much invested in this already to do anything but see it through.
They are very nice. Hope it works out. The available replacement Norton rods are forged as I put a set a few years ago after a rod bolt went on me. These have all the original features including the oil hole and seem to be shot peened but not polished. Yours are definitely sexier pieces. Good luck with the programme.
Last time I was having a talk with Mr Reynolds he had new rods in stock with another batch about to be manufactured. Mind you I 'HEAR'9i.e. haven't confirmed it yet) that all spares prices have been increased somewhat since Norton Andover have been taken over so it could be that these rods might be cheaper.......Where are they being made? China does beautiful alloy forging IF you go to the right people. One friend who has alluminium forging done in China and the UK reckons the Chinese is better......He even found a Chinese company that does beautiful tooling for his forgings and they get it spot on first time.
Re: New forged Norton rods and lightweight pistons#72037 11/13/071:42 pm11/13/071:42 pm
Hi there Jim , seen them on your site and on your message , just to let the other people know that I had ordered one set for the next project, and YES , I will sent my crank to Pete Lovel, for tweaking (BDM stress,balance, big bolts and re-aligning), now some people had any experience with 360 or 380 Johnsons cams? that will be to fit into a Featherbed too. Pierre the frog.
Re: New forged Norton rods and lightweight pistons#72038 11/14/073:30 am11/14/073:30 am
Originally posted by beltdriveman: .Where are they being made? China does beautiful alloy forging IF you go to the right people. One friend who has alluminium forging done in China and the UK reckons the Chinese is better......He even found a Chinese company that does beautiful tooling for his forgings and they get it spot on first time.
I bought some chineese vise grips a while back and had to buy pair of "Made in the USA" vise grips to get them off the nut and bolt assembly that they were stuck on! I am sure they are better at forging precision components than manufacturing tools.
If Norton made an airplane,would you fly in it?
Re: New forged Norton rods and lightweight pistons#72039 11/16/075:55 pm11/16/075:55 pm
Re different rod lengths to piston movement. Whilst my 'cranky cranks' prog has escaped me at present so I cannot easily supply values for 89mm stoke. However, below are some for our short stroke 68mm 500 twin crank.rods..the 160mm steel lumps (as used by Gus Kuhn in their 68x68 motor)..std 150 Commando rods and 140mm rods. dimensions in mm. 05 degrees. 0.156824...0.162774...0.160745. 10 degrees...0.625504...0.632774...0.640834. 15 degrees...1.400697...1.416869...1.435357. 20 degrees...2.473593...2.501885...2.534238. and by 50 degrees...11.77493211.11.897571...12.038103
So whats a few thou between friends? Unless you are running the valves toooo close to the pistons... Mr Hopwood and Mr Hele suggested I should be aiming for a rod ratio of around 2.0 but we settled for cheapness and easyness by using std 150mm Commando rods. Even then the barrel lost a fin and both the head and cases required meat removing to get a 10-1 CR. Anyone want to give me a few grand so I can play further??? This time with a 90 degree crank....handlebars 8 inch in dia at 8000 plus due to vibes along the Mountain Mile etc are not good for rider concentration levels....Tis about time another 500 twin push rod Brit motor went round at over the ton......
Re: New forged Norton rods and lightweight pistons#72042 11/17/076:39 pm11/17/076:39 pm
Does it mean that it is better to use "small" valve lift and longer duration ? the johnson cams are respectively 0.360 intake and exhaust and both 272° (at 0.040 ) , and 0.380 in.and exh. and 270° duration (at 0.040).... Pierre.
Re: New forged Norton rods and lightweight pistons#72043 11/17/0710:01 pm11/17/0710:01 pm
Hi there, I think the main object at the beginning was to find lighter pistons with shorter deck height, and so consequently happens the short rod, (correct if I am wrong Jim ), and not specially trying to improve power through changing the rod lenght or any stroke /lenght ratio, I had heard that somewhere people were using 750 GSXR pistons into Cdo jugs, but they had to reduce the cylinder height by milling the top; on the "Victory library " web site there are also some interesting literature about the rod lenght/stroke ratio.
Re: New forged Norton rods and lightweight pistons#72045 11/20/071:39 am11/20/071:39 am
I tried overbore GSXR pistons in the late 1990s in one of my racers and they worked well for me - dropped the weight of 850 pistons down to the weight of 750 pistons. But there is an even bigger weight savings now with improved piston design. I'm going by what I've heard in the industry about a 2 to 1 rod stroke ratio being the ideal - most say that there is more power with the longer dwell time near TDC. Reduced valve to piston clearance is only a few thou. I haven't achieved the 2 to 1 rod stroke ratio but have come close with 1.84 to 1 instead of the stock 1.676 to 1.
My main motivation it to reduce vibration/stress and I think everyone can agree that this would be a great help.
Pushing these through to production is the main issue.