I Bought It With a Knock

[Big_Jim59]

Alu rods dont last long and are for pure racing applications, not sure if anybody use them in bikes. Aftermarket rods (carillo) will be possibly lighter, but honda ones are good enough to not bother with anything else.

Nortons use Aluminum rods but that is a pretty low revving motor. Red line is like 7K

[Big_Jim59]

It's OFF! It's off! (He dances around the shop like Gollum with the Ring of Power) I broke a 14mm 3/8" drive socket on the counter shaft sprocket. So i went up to the local auto parts store, which is surprisingly well stocked with tools, and purchased a 1/2" drive 17 and 14. On my return, while I was waiting for my wife to assist me by stepping on the rear brake, I hit the flywheel nut with my rattle gun and the new 17mm socket. To my surprise and delight it spun right out. I reached back into the "special tools" drawer of my tool box and retrieved my Honda flywheel puller, threaded it into the flywheel and a few taps from the air wrench and it was off. The Counter shaft sprocket nut came off thinks to my trusty Sear's Craftsman 1/2" drive cheater bar, my wife's foot on the rear brake and my considerable weight bearing down on the tool. I want to take this opportunity to thank the force of gravity without whose help none of this would have been possible.

[lloydie]

They are tight buggers to get off ::thumbup:

[VTRDark]

The man's rockin n rolling

Keep up the good work jim. Every man should have a wife in his toolbox.

(:-})

[Big_Jim59]

My wife is game as a helper as long as it's not loud or dirty. I'll never forget the time, when we were dating and I was putting an engine in her VW Beetle. I needed her help to get the engine into the clutch housing. I was rocking it back and forth and she screamed. I shot out from under the car thinking I had pinched her hand. She was standing there, holding her hand and I was in a panic when she said "I got dirty on me!" Her hand was greasy. That was all.

[lloydie]

Least she didn't brake a nail !!!

[sirch345]

It's OFF! It's off! (He dances around the shop like Gollum with the Ring of Power) I broke a 14mm 3/8" drive socket on the counter shaft sprocket. So i went up to the local auto parts store, which is surprisingly well stocked with tools, and purchased a 1/2" drive 17 and 14. On my return, while I was waiting for my wife to assist me by stepping on the rear brake, I hit the flywheel nut with my rattle gun and the new 17mm socket. To my surprise and delight it spun right out. I reached back into the "special tools" drawer of my tool box and retrieved my Honda flywheel puller, threaded it into the flywheel and a few taps from the air wrench and it was off. The Counter shaft sprocket nut came off thinks to my trusty Sear's Craftsman 1/2" drive cheater bar, my wife's foot on the rear brake and my considerable weight bearing down on the tool. I want to take this opportunity to thank the force of gravity without whose help none of this would have been possible.

Well done Jim, and your wife keep up the good work

Chris.

[Big_Jim59]

It's out and the cases are split. The rod bearings and main bearings are a mess. They are all skinned down to the copper and the crank is toast as well. It could be salvaged with careful machine work but why bother. I have a nice used unit on hand. I still don't know why this all happned. It could be the rod got loose and after that the oil pressure went south causing the mains to wear. I just don't know. I checked the used crank and rods and one rod shows .004" (you will have to forgive me. I am forever stuck in inches and feet.) which is right at the outside of the wear limit. The other rod is .003 which is much better. The looser of the two actually shows a bit of wear but I have no idea how many miles is on this crank.



It's all uphill from now on.

[lloydie]

On your way to a fresh mota

[Varastorm]

Don't throw the knackered crank away Jim.

You can cut the tail off & use it as a mandrel for lightening the flywheel

It will go well with those hi comp pistons your secretly thinking about buying

Go on, you know you want to

[Big_Jim59]

Don't throw the knackered crank away Jim.

You can cut the tail off & use it as a mandrel for lightening the flywheel

It will go well with those hi comp pistons your secretly thinking about buying

Go on, you know you want to

I could do a series on what useful things you can do with knackered motorcycle parts. From piston ash trays to old crank paper weights.

Here are my feelings on high compression pistons: back in my shop days I did all the Triumph Trident/BSA Rocket Three work and there was a lot of it. We had a good customer that wanted high compression pistons. He show up one day lovingly cradling a box with three shinny pistons, the crowns of which were peaked higher than any I had ever seen. I was charged with fitting these little jewels and it was a major PITA. I had to find the high spots and grind therm to fit. After they were installed it took ages of experiments with jets to get it to run halfway decent and if memory serve he blew it up in the end. A good fresh stock engine is fine by me. I am a slow rider by contemporary standards rarely riding over 100mph for any length of time.

[sirch345]

It's out and the cases are split. The rod bearings and main bearings are a mess. They are all skinned down to the copper and the crank is toast as well. It could be salvaged with careful machine work but why bother. I have a nice used unit on hand. I still don't know why this all happned. It could be the rod got loose and after that the oil pressure went south causing the mains to wear. I just don't know. I checked the used crank and rods and one rod shows .004" (you will have to forgive me. I am forever stuck in inches and feet.) which is right at the outside of the wear limit. The other rod is .003 which is much better. The looser of the two actually shows a bit of wear but I have no idea how many miles is on this crank.



It's all uphill from now on.

That's nice picture to see, that's progress

Here are my feelings on high compression pistons: back in my shop days I did all the Triumph Trident/BSA Rocket Three work and there was a lot of it. We had a good customer that wanted high compression pistons. He show up one day lovingly cradling a box with three shinny pistons, the crowns of which were peaked higher than any I had ever seen. I was charged with fitting these little jewels and it was a major PITA. I had to find the high spots and grind therm to fit. After they were installed it took ages of experiments with jets to get it to run halfway decent and if memory serve he blew it up in the end. A good fresh stock engine is fine by me. I am a slow rider by contemporary standards rarely riding over 100mph for any length of time.

Very interesting to hear your take on high compression pistons Jim, and the mention of the Triumph Trident and the BSA Rocket Three. I basically grew up with both of them, but never actually owned one. I always loved the sound of those three cylinder engines. When I was at the National Motorcycle Museum here in the UK I came across a Triumph Trident that had been modified to a four cylinder 1000cc machine, named The Triumph Quadrant, IIRC it was built in the mid-seventies. Unfortunately it never made it into production, but looking back at what we got from the big four Japanese manufacturers, it looks like we were heading in the right direction.

Getting back to high compression pistons. I used to have two Triton motorcycles, (Jim you probably know what a Triton consisted off, but for those of you who don't, the Tri came from the Triumph name, and the ton came from the Norton name. The Norton with it's featherbed frame handled better than the Triumph did, but the Triumph engine was better than the Nortons, hence the Triton gave you the best of both worlds.) plus a Triumph 650 Thunderbird at different times. All three of those bikes had pre-unit construction engines (separate engine and gearboxes). The modification back then was to fit the Bonneville camshafts on the inlet side and use a Bonneville cylinderhead because they were twin carbed. You then fitted high compression pistons which meant you then had a Bonneville spec engine. From what I found in fitting high compression pistons was more vibration. Although British bikes did vibrate enough before adding high compression pistons, fitting high compression pistons in my experience certainly made the vibration worse.

Chris.

[Varastorm]

sirch345 wrote: I used to have two Triton motorcycles...

Coincidence or what, years ago I bought an old Honda CJ250 from a guy who owned a Triton & I bumped into him tonight.

I haven't seen him in 20 years or so, the first thing was out of my mouth? When are you going to sell me that Triton

Never, he said. Its still leaning against the wall rotting in the cellar under his house

Shame, real shame

[Big_Jim59]

I worked on a rode many a three cylinder Triumph. They were really sweet. They made really good smooth power and not like a Japanese four. The power was there just off idle. The sound was fantastic from a rumbling purr at idle to a throaty shreak at full cry. The weight was rather high but because the C of G was really low the handling was really great. They were designed really as an extra cylinder on the Triumph 500, which still if my favorite Triumph twin. That engine is bullet proof. There were two things wrong with the Triumph threes, they were built horribly. The Japanese knew that you couldn't get away with building junk but the Brits and the American's hadn't figured that out. There was something wrong with every three cylinder we sold and sometimes there were things that were majorly wrong. The second factor in their demise was the advent of the Honda CB750. It was just so much more bike. It made the Triumphs look dated and they were. Richard Mann won the Dayton 200 (a grueling race with no slow sections) in 1970 on a Honda 750. In 1971 he won on a BSA Rocket Three. The difference is the Honda win destroyed the motorcycle. He nursed it to the finish line with it drinking oil. Not so the BSA. The BSA/Triumph three was a truly great engine that was too little too late.

I am quite familiar with the Triton. Cut new or redrill the engine plates and you were good to go. I never had much dealings with the old pre-unit Triumphs. I wonder if the addition of higher compression pistons didn't serve up a while plate of bottom end trouble. The later unit twins would break cranks. Sammy, a particularly good race tuner said of the 650 units Triumph "it will make 42 real horsepower and at 42.5 it will break the crank." I have seen a few broken cranks but in those days it was hard to tell if it was from performance or just bad OEM parts.

I am glad to be at, what I consider, the bottom of the project. The mystery has been reveled and now, all that is left is spending money and careful reassembly.

[Varastorm]

I'll be following the rebuild & looking foreword to seeing some more cracking photo's Jim