Ben's 734 is a thing. Adjusted the mixture a bit and a quick spin before dark. Dropped the needles and swapped the bowls for some drilled to supply the power jets? Same 34 carbs from the same place? It's still rich cruising but full noise looks like 12.9 - 1 rather than 14+ but hard to get a look when it's trying to pick the wheel up in second. The power is so strong, and you are just thinking wow.
I ordered a steering damper for it. The engine is right forward but the front gets really light. I don't want it provoking bad behavior. It's more than fast enough for me. I opened it going slow in second, it's just so nice. Wish you could have a go on it Nick. And the cam is std profile. I don't know what it's like above 6,500 - 7,000 but it's pulling very hard into that area.
I'd love to know what hp it's getting. I could fit offset rocker buttons for .410" lift but it would shift power up the rpm a bit. It definitely goes harder than with the 38mm, in midrange and into higher rpm. The thing would have been so fun in the '70s-80s. It has that sharp throttle response.
Nice machining on that bearing plate and support. It makes it harder for cranks to flex I expect. Hope it kicks butt. And all stays together.
You wouldn't want me to have a go on it Mark, you'd probably never see it again........
From what you say the new engine we are sorting at the moment should be along the same lines, i'm really looking forward to getting on with it but we have had a few setbacks and as you know delays all add up. Fitting the existing/refurbed engine/gearbox tomorrow as the winter meeting is now only 2 weeks away. Heated the gearchange setup/timing cover in my bar b que to around 80 deg and found what was going on. Nothing to do with the actual gearbox, it was the pawls and quadrant, i replaced the pawl springs and dressed them a little then ground a small amount from the granny tooth that runs on the return spring, then fitted a better stronger return spring. The culmination of that lot is a change similar to that of a late late one, i'm now happy with it. I'm so glad he's going to use late cases on his new motor.................................lol
I made a test adapter for the crank end nearing mount. The Norton spigot nut winds onto one crank ok but not the one we are using yet. The adapter has a washer on the inside and fits over the spigot of the nut so the washer spaces from the alternator rotor. I'll fit the nut and spacer and put a dial indicator on it when it's together and make sure it's running true. It needs to be exact if there is no movement. It just sat on a spacer before. If it's ridged and wrong it wouldn't be good.
We are all set for the weekend but it looks like it's going to be raining, bugger!
Ran up last Saturday and seems good, no leaks from the welded repairs etc. Float level seems good and stable and should be ok with the fitted regulator, although until it's on the track it's hard to say. I've put the jetting back to a sensible set up ready to test in practise. Don't think there will be many there so it'll be a good setting up scene for the Qld titles at Morgan Park. Some more mods to the frame have been done but we know there are one or two things that will need adjustment, toe-in etc. I also put new rings in as the bores needed a fair amount of honing so they'll need bedding in, hopefully the filters he's fitted will stop the crap getting in. Hoping for the best, and wishing for a dry weekend............,.lol.
Invite some kids from a high school to take some video Nick. Schools have classes and good gear. If it's a bit late now invite video students to the titles, talk to their teacher. Good gear means good lenses and stuff. Combine that with on board and interviews etc would be a great thing to have. What we miss are great races that were not put down on film. There is a great video called power bikes I think about Peter Williams and others at the IOM. It would be a great student project, to make something similar, and I'm sure they would enjoy it.
The thing about sidecar racing is it's a team sport, and it would be most interesting having an interview with the passenger as well as the throttle man. Because of how parts of a good team work. What racing these rigs was like 60 years ago. It would actually be a great way to sell bikes if they were still manufactured and you had a streak of wins like 2020-21 causing that major upset.
A good weekend , it rained a little Saturday but not heavy, Sunday was lovely. The handling is well sorted now, bike is steering very well we are pleased with that. Bike still jumped out of third a few times but engine performed well, not well enough to beat the big norton but he was on his tail at all the corners and was pushing him, he just has a lot of straight line speed, about $8000.00 worth more than Matt's bike. All his brand new Molnar cases, crank etc are bound to beat a 62 a65 with an a10 crank in it. I think when we get the 5 speed box in it may be a different storey, Matt can out brake and out corner him anywhere and the advantage of higher corner speed accompanied by better drive out will even things up quite a lot. Anyway there were 6 races, 2nd in all of them.
And AMCN would like to do a spread and feature Nick. You do not happen to have any idea of the Norton's hp? Do you know if they dynoed it? Or are there secrets? I cleared some messages out before.
Oh yes, brilliant by the way, well done.
We are talking about a (920 edit) actually 850, on methanol, and a 745 on petrol. I'm sure that can be evened up even so. It certainly makes it more fun having competition.
Nigel Rollason ran his best engine without a head gasket. Extra bearing where the alternator goes controlling end float and one behind the chain wheel and never any problem with the primary.
This is what compression does, the red one is 12-1 the others 11-1. Heads are 38mm and not flowing much. I haven't run 12-1 with the good head on the 883. I expect it would do the same and then some as it will keep revving. Tony Price used 11.5-1.
This is same gearing, same piece of bitumen. More comp and around 155cfm. Acceleration. Top end is nothing like now but shows that waiting being fixed.
I don't know where your compression is but if you are just 10-1 or something it isn't very high. And maybe you could match the Norton on hp and drive. If it didn't blow up
Compression is around 10.2-1 but anymore will need the piston pockets deepened as initially i did have a little valve contact. The barrel was skimmed 30 thou and the pistons are 10.5-1 A70 venolia's and there is no base gasket. As you know, the valves are pocketed a little in that head. . I hear what you're saying Mark and yes, i know we can go higher, but not with that crank IMHO. It just won't last, i've seen a few 'let go' with those A10 cranks and i'm a little paranoid about it. My old thing was over 11-1 but the norton crank is much stronger especially when offset. The bike will idle easily so i know there's room for improvement but i have to be realistic, that crank is 60+ years old!
It's a real credit to you guys to get it to do what it does. Not blowing stuff up is definitely the trick. I have an old rusted A10 crank on .040" under and rusted I don't think it's good for anything. Not when Chris can get a std one welded to 84mm stroke. My friend did that in Melbourne as well but a bit longer stroke.
With a base gasket you have to adjust tappets, same with not venting into the primary, you have to check it has oil sometimes. It's bad enough they wear tyres out for me.
The front brakes are early BMC Mini sls running in triumph drums. It was a fairly common thing in UK back in the day. The rear is a later 2ls mini complete with drum. Plenty of guys had hydraulic brakes on sidecars back in the day, but to keep people happy we use a cable operated front master cylinder. We are not allowed to link the brakes even though lots of sidecars had linked brakes pre-62. We have a sidecar brake but are not allowed to use it so it's isolated by a valve. Once again lots of sidecars had brakes back in the day, it's just stupid aussie rules, basically as no-one in Victoria has them, no- one else can. We are not allowed disc brakes pre-62. Period 3 which is what the bike is. Funny, you can run 9 + 10 stud triumph crap with 5 speed boxes etc or any aftermarket norton and triumph engines that didn't exist pre-2000 but you can't link your brakes...... daft eh?
Well, after a little deliberation i ordered a 20 thou head gasket from Lani at Copper Gaskets Unlimited. It arrived the other day (took less than 2 weeks) and is a lovely job. The fit around the studs is really good and general quality is excellent. It was only a few dollars more than a standard one (plus post of course) but what a difference in quality! Thanks to Trevor (WM20) for the recommendation, will definitely use them again. Managed to find a set of 3 piece oil rings from an early 750 trumpet (75mm) so will fit those as well. The Venolia forged pistons need 3 piece oil rings really as they use 8 thou clearance, Standard one piece ones tend to make it smoke a little. So after cutting a little more from the piston inlet pockets we should have around 11-1 now. Not measured yet but it's one on the 'to-do' list. 5 speed box is in and 8 plate 3 spring clutch with my old SRM pressure plate and some decent springs. All seems good, we will see..........................
Yes it's one i bought from Gary at SRM about 30 years ago. I also bought a few spare bits and pieces for those pressure plates at swap meetings over the years so i have a few of the radial bearings and end stubbs/pushers. I tried a set of my old 'Gorilla springs' in the clutch but it was bloody heavy so i just put some t120 springs in. It runs very close to the cover with the extra plates so the springs have to be almost flush, With a set of my old ones in there you almost need two hands to operate it lol. I had a special/funny clutch lever/cable arrangement on my old crate and even then after using it for a while i could strangle crocs with my left hand.
If you had 10.2 and took 1/2mm off in gasket height it would mean a chamber of 36.4cc reduced to 34.19 and give about 10.89-1. But what it is you would have to measure. It may be there are some hp hiding in there that a dyno could find as well. They make me nervous but it may be worth finding all you can. And you need to test the gear box.
Having a dyno curve tells you what stuff is doing like exhaust. It would give something to compare with a short stroke version as well. Which can run more comp.
I might get them to make me a copper base gasket I just need to measure comp on a motor. I think the cases face has been machined a bit or something, pistons are a little bit above the deck of a Devimead cylinder. A syringe isn't quite accurate but it seemed quite high.
Either way if this restores parity it should be really fun.
A dyno run and a test day at a track is what's needed but i doubt it'll happen.
My crude/prelim measurements give just under 11-1 so it must have been higher than i thought before. Using a vet syringe, i thought it was fitting for the old dog............. Doing the sums,,,, 84mm stroke, 10.5-1 pistons (with 85mm stroke) So 30 thou off the barrel + say 8 for the base gasket, now another 20 thou = 58 thou If we are not at or near 11-1 i would be very surprised.
Messy job.......couple of blokes i used to know used condoms to contain the oil but i don't think it was any easier or less messy. Still waiting for the oil rings from the 'states.