Important Harley twin cam info

[JerryH]

Originally Posted by pmelby

I'd be more concerned with the problems resulting in the crank halves getting out of phase. Pressed together fly wheels don't inspire a whole lot of confidence in me. The mfg process must work, but it sure looks cheesy on the vid. Does the XL/XR motor have a built up crank, keyed and bolted as in the older models, or is it a pressed assembly (time is money, any monkey can fit the parts, etc.)?



http://youtu.be/1OnDoqAh3MY

cheers,
melby

That video shows very well why "production" engines don't hold up very well. You don't just throw an engine together like that. Building an engine is a time consuming process, done entirely by hand except for the machine work, and everything is carefully measured. True "perfection" does not exist, but you can certainly come a LOT closer to it than they do in a factory. Auto engines do not use roller bearings, and about all I know about them their design, and the fact that they require a lot less oil pressure than plain bearings. They are used in 2 stroke engines where there is no oil pressure. IMO, Harley should use side by side connecting rods, a single piece crank, and rods with replaceable bearings and bolt on bearing caps.Bearing clearances in an auto engine are measured with "Plastigage", which means all the bearings must be installed, and the caps have to be assembled and torqued, then disassembled. Sometimes several times before you get it just right. Bearing journals are measured in several places to check for taper and out of round, as are cylinders and pistons. Everything is very carefully assembled by hand, and every bolt is torqued by hand, in several steps, and in a criss cross pattern until final torque is reached. Auto engine cranks are a one piece casting or forging. they are not "pressed together" That is a recipe for disaster. Parts, especially bearings, are not handled roughly like in the video, and assembly lube is used on everything. Most motorcycle cranks are of the "pressed together" type, which must be welded to hold together. It also means the bearings are not replaceable. The entire crank assembly, including the crank, bearings, and rods must be replaced as a unit. So it is impossible to be sure the clearances are correct from the factory.

[ikonoklass]

Please forgive me my ignorance.

I always thought the cam chain issue was caused by the little rubber shoe that came into contact with metal. Sometimes it held up fine, but other times it wore down until you had metal on metal. So why can't you just go in periodically and replace the little rubber thingy? Seems like it would be cheap and pretty easy.

[ShardPhoenix]

Originally Posted by JerryH

I never got "run off" I got fed up with one particular member in particular (you know who I mean) who claimed to know everything but from his posts almost certainly never worked on anything mechanical. I finally decided to just ignore him.

Was his name JerryH?

[DAKEZ]

Originally Posted by ShardPhoenix

Was his name JerryH?

[Bueller]

Originally Posted by JerryH

That video shows very well why "production" engines don't hold up very well. You don't just throw an engine together like that. Building an engine is a time consuming process, done entirely by hand except for the machine work, and everything is carefully measured. True "perfection" does not exist, but you can certainly come a LOT closer to it than they do in a factory. Auto engines do not use roller bearings, and about all I know about them their design, and the fact that they require a lot less oil pressure than plain bearings. They are used in 2 stroke engines where there is no oil pressure. IMO, Harley should use side by side connecting rods, a single piece crank, and rods with replaceable bearings and bolt on bearing caps.Bearing clearances in an auto engine are measured with "Plastigage", which means all the bearings must be installed, and the caps have to be assembled and torqued, then disassembled. Sometimes several times before you get it just right. Bearing journals are measured in several places to check for taper and out of round, as are cylinders and pistons. Everything is very carefully assembled by hand, and every bolt is torqued by hand, in several steps, and in a criss cross pattern until final torque is reached. Auto engine cranks are a one piece casting or forging. they are not "pressed together" That is a recipe for disaster. Parts, especially bearings, are not handled roughly like in the video, and assembly lube is used on everything. Most motorcycle cranks are of the "pressed together" type, which must be welded to hold together. It also means the bearings are not replaceable. The entire crank assembly, including the crank, bearings, and rods must be replaced as a unit. So it is impossible to be sure the clearances are correct from the factory.

Yet more ignorance.

If you knew anything about the motor design you'd already know the reason why Harley uses a forked connecting rod design instead of side by side connecting rods.

Additionally, if you truly care about tolerances while building an engine you would not use plastigage to measure bearing clearances. Plastigage is a production product for production building, the use of which can have unintended negative consequences in a blueprint build.

You should quit while you're behind and go back to the xt225 forum. You aren't impressing anyone here.

[anotherguy]

For such an all knowing individual you sure do ask some dumb questions.

[fritzcoinc]

Ok. FYI here's what these tensioners look like. These are from an all stock well maintianed 03 88" at 56K miles. As found at tear down condition. In 07 harley changed to hydraulic tensioners and a higher volumum oil pump along with more ridged cam plate.

Outer ( and tool I made to release the outer tensioner )



Inner ( tore it down just in time )



trash from the tensioners took out the return side of the oil pump

[The Dirty One]

Best I can tell,there are about two,maybe four contributors replying to this thread that actually have a clue what they are taking about and have spent more time holding wrenches that computer keyboards and mouses. The rest just show they can google stuff all day but still don't have a elfin clue how to fix anything.what is adventure rider coming to? Lol
I'm still laughing my arse off at the poster on the first page of this ridiculous discussion that thinks evos had cam chains......

[Tepi]

Originally Posted by JerryH

That video shows very well why "production" engines don't hold up very well. You don't just throw an engine together like that. Building an engine is a time consuming process, done entirely by hand except for the machine work, and everything is carefully measured. True "perfection" does not exist, but you can certainly come a LOT closer to it than they do in a factory. Auto engines do not use roller bearings, and about all I know about them their design, and the fact that they require a lot less oil pressure than plain bearings. They are used in 2 stroke engines where there is no oil pressure. IMO, Harley should use side by side connecting rods, a single piece crank, and rods with replaceable bearings and bolt on bearing caps.Bearing clearances in an auto engine are measured with "Plastigage", which means all the bearings must be installed, and the caps have to be assembled and torqued, then disassembled. Sometimes several times before you get it just right. Bearing journals are measured in several places to check for taper and out of round, as are cylinders and pistons. Everything is very carefully assembled by hand, and every bolt is torqued by hand, in several steps, and in a criss cross pattern until final torque is reached. Auto engine cranks are a one piece casting or forging. they are not "pressed together" That is a recipe for disaster. Parts, especially bearings, are not handled roughly like in the video, and assembly lube is used on everything. Most motorcycle cranks are of the "pressed together" type, which must be welded to hold together. It also means the bearings are not replaceable. The entire crank assembly, including the crank, bearings, and rods must be replaced as a unit. So it is impossible to be sure the clearances are correct from the factory.

Seriously, you really think car engines are hand assembled in the factories, with hand tools? Lol, maybe aston martin, rolls royce or some other fucking expensive car. Not your chevy malibu or ford taurus. Engines are assembled by mostly robotics now, they can pump out cars for the masses at a fast rate.

[Barnone]

JerryH,
Every think that washing your hands and arms in gasoline might be part of the cause of your current health problems.

JerryH got run off the XT225 forum contrary to what he now claims happened.

[slipknot]

Originally Posted by JerryH

Just what is wrong with washing your hands in gasoline? I am 53 and have been doing that since age 8. If you are worried about your smooth soft skin, I wouldn't recommend it. I have also been using gasoline as a parts cleaner all my life.

components of gasoline include: benzene, toluene, and xylene; and the additives ethanol, methanol, and methyl tertiary butyl ether

At least three carcinogens in this group, absorbed through the skin and straight to the liver. Good luck.

[Bueller]

Originally Posted by slipknot

components of gasoline include: benzene, toluene, and xylene; and the additives ethanol, methanol, and methyl tertiary butyl ether

At least three carcinogens in this group, absorbed through the skin and straight to the liver. Good luck.

All except MTBE, which is banned in his state. MTBE is bad, bad stuff and has been banned in about half of all states, with total phase out in the future.

[Berto]

visiting a friend in the burn unit because he set himself on fire using gas as a parts cleaner was a lesson I took to heart. Safety Kleen for me

[JerryH]

Originally Posted by Bueller

Yet more ignorance.

If you knew anything about the motor design you'd already know the reason why Harley uses a forked connecting rod design instead of side by side connecting rods.

Additionally, if you truly care about tolerances while building an engine you would not use plastigage to measure bearing clearances. Plastigage is a production product for production building, the use of which can have unintended negative consequences in a blueprint build.

You should quit while you're behind and go back to the xt225 forum. You aren't impressing anyone here.

Plastigage is not used in production "assembly line" engine building. It takes way too much time. Yes there are better ways to build an engine, but you are talking about $10,000-$20,000+ engines, which require an absolute fortune in equipment and tools to build. I am a fleet services mechanic, who was "promoted" to working on mostly auto electronics a few years ago, one of the reasons I hate them so much. I build engines at home, in my own 2 car garage, which also serves as my workshop for everything else as well including bikes. I do not and never will have the resources to build super expensive engines, but I can sure do better than the factory. I have to outsource all my machine work. But the shop I use is good. I do have a scale for weighing parts, calipers and inside micrometers, an engine hone (several actually) and a number of other fairly simple tools. But boring, planing, decking, crank and cam grinding, etc can obviously not be done at home.

As far as gasoline, I find it difficult that studly and gnarly adventurers would have a problem getting gas on their hands. And my medical problems (mostly arthritis) were not caused by gasoline. It's a genetic issue.

I was not banned from XT225, and as a matter of fact just posted there today. I don't spend much time there, I have a lot of other interests besides the XT. I built my XT out of 3 different model years of bikes, plus a lot of aftermarket parts, some of them on the expensive side. It was built to the best specs I could afford, and will probably outlast me. Now all I have to do is ride it. I don't work in it anymore except maintenance.


And while nobody has ever been banned from XT225, that is not the case here. So I am dropping out of this thread because I plan on staying around for a while. And after seeing how badly Harleys are made, there is a good chance I will never own one anyway, and if I do, it sure wont be a TC, the original topic of this thread.

Happy Thanksgiving to all.

[Bueller]

Originally Posted by JerryH

Plastigage is not used in production "assembly line" engine building. It takes way too much time. Yes there are better ways to build an engine, but you are talking about $10,000-$20,000+ engines, which require an absolute fortune in equipment and tools to build.

"Production" refers to production rebuilding, as you might find in a more local shop. I didn't think it would be necessary to clarify that for someone as experienced as you allegedly are.

As for the questions and discussions you skirted:

The replacement for plastigage is a nothing more than a decent set of mics. It doesn't take a fortune in equipment to measure bearing oil clearance in an engine while avoiding the potential heat dam across a bearing that can be caused by plastigage-induced bearing material compression.

Furthermore, the reason you can't put a side by side connecting rod arrangement in a Harley is because the cylinders aren't offset enough to accommodate such an arrangement.

I agree you should bow out of the thread. Not for fear of a banning, but instead because its painful to watch you do this to yourself