Engine/Torque Stays

1965T120R

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1965 T120R 650cc Custom Rigid
[h=5]Just a simple question. I see on a lot of custom Vintage pre 70 Triumphs that the Engine/Torque Stays are left off. How in the hell do they keep from vibrating the entire top of the engine right off the lower cases?[/h]
CRY
 
I assume you mean torque settings not suggested in workshop manuals for older bikes?
I started striping and rebuilding engines in the late 60's, through the 70's I was building my race engines and the first time I used a torque bar was only about 5 years ago. One gets an understanding and feel for what's required.
I'm not knocking modern mechanics but some read too much and don't spanner enough.
 
No I am not talking about settings I am talking about the parts that hold the top of the entire head assembly to the frame. Parts like these pictured. I see on a lot of custom Triumphs these left off. These simple Engine Mounts if you will are part of the 4 point engine mounting design just like on a Harley to help keep the engine from vibrating itself to pieces. I myself being a mechanic since my freshman high school days find it quite stupid anybody would leave off an obviously needed engine mount. CRY
 

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I think the old 650s and 750s cylinder barrels would stay attached to the lower engine even sitting running on a bench!

I doubt they are really needed and merely serve to distribute the vibration around a bit. I' ve never seen nor heard of anyone having a problem without them.

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I think the old 650s and 750s cylinder barrels would stay attached to the lower engine even sitting running on a bench!

I doubt they are really needed and merely serve to distribute the vibration around a bit. I' ve never seen nor heard of anyone having a problem without them.

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Well I for one think if it was designed for the purpose of helping to hold the engine together then that is why they were designed. As my builder explained to me with Harley Engines with all of that Torque the unit will eventually vibrate itself apart and he has been building customs and doing repair for 26t years. These engines are not like a v6 or v8 or inline 4 banger but with 2 pistons going up and down and a small crank spinning at full RPM that is a lot of vibration coming out of a relatively small chunk of metal and only supported by tubing around it.

To each their own but if it came designed with the parts for a reason there MUST be a reason.
 
I am talking about the parts that hold the top of the entire head assembly to the frame.

Understand your comment now.
I'd always refit the stays when mounting a motor into a frame, BUT for show-ponies anything goes.
I'm not impressed with the sausage factory type of custom being built of late. I know some may say cafe racers (custom) are all similar but they are functional with design flair and therefore must be some what similar to each other.
 
Understand your comment now.
I'd always refit the stays when mounting a motor into a frame, BUT for show-ponies anything goes.
I'm not impressed with the sausage factory type of custom being built of late. I know some may say cafe racers (custom) are all similar but they are functional with design flair and therefore must be some what similar to each other.

Well my Rigid surely will not be a show pony unless it is a local event and I show up really early and polish the snot out of her before viewing and judging. She is going to be a daily rider and I want her as bullet proof as I can make her.

Ya show bikes that people trailer in are just that................trailered bikes only and probably rarely started and even more rarely ridden. Must be nice to have that kind of money to do that but then again just my view I would rather have a Stable full of old Pre 1969 Motorcycles(Triumph,Norton,BSA,Harley) than the hottest custom bike money could build because I would get a lot more pleasure in viewing the older more vintage machines oh and riding them too. TUP

It just puzzles me though why some of these street jockeys leave off the Engine Stays. Insanity.
 
Quote, "It just puzzles me though why some of these street jockeys leave off the Engine Stays."

It must be a matter of style over substance or mechanical ignorance.

Back to show bikes, I've been told of the occasional show bike without mechanical internals. I did speak to an owner once who admitted that he can't start his bike as he doesn't keep oil in it.
 
Well then those poor blokes with out their Engine Stays in place can keep right on wrenching while I will be riding. TUP
 
Harleys have two cylinders in a V that are reciprocating. Triumphs have two cylinders side by side that aren't reciprocating but traveling up and down together. I've seen them run on just a bench before and never feared the cylinders are ready to blow off the top.

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Harleys have two cylinders in a V that are reciprocating. Triumphs have two cylinders side by side that aren't reciprocating but traveling up and down together. I've seen them run on just a bench before and never feared the cylinders are ready to blow off the top.

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That is all fine and dandy but that is only on a bench and my bet is not run for very long either. What I am talking about and I am sure the designers designed around on the pre 1970 units(which is my point of focus because that is the model I am working with and building) was long distance riding at full speed shifting through gears up and down under stresses where the entire engine unit is torquing itself in a multitude of directions at once. The torque is the same on most any motorcycle engine whether it be Triumph,Harley or Honda. You have an engine with it's transmission unit as one(except Harley and other older pre 1965 models of some makes) being twisted and vibrated all at one instance and only 4 mounting points by design holding it steady. You take out one of those points you put undo stresses on the other three points and with the one unsecured where do you think the engine will begin to fail first? Yes at that point not secured. That is NOT something I would think is very intelligent at all. CRY
 
Those stays should be refitted when an engine goes back into a frame but not to hold the engine together. The purpose is to reduce vibration of the engine as a complete unit within the frame and therefore save the frame from undue stress.
 
Those stays should be refitted when an engine goes back into a frame but not to hold the engine together. The purpose is to reduce vibration of the engine as a complete unit within the frame and therefore save the frame from undue stress.

Correct plus from all I have been reading and talking to mechanics in my area it also helps the entire head unit from vibrating itself to death by as you said steadying everything. Dual purpose mounts.
 
Correct plus from all I have been reading and talking to mechanics in my area it also helps the entire head unit from vibrating itself to death by as you said steadying everything. Dual purpose mounts.

Not an issue worthy of debate but I don't accept horizontal stays help preserve the head in any way.
When I worked in the M/C industry I saw plenty of cracked frames, almost always because of loose engine bolts.
 
I would think that the torque stays are there to limit vibration and movement of the engine in the frame.
I can see there might be something in them in stopping the twisting of the engine in the frame when accelerating and decelerating, this would eventually either break the frame or the engine mounts, I can't see it actually doing anything to stop the head from separating from the cylinders, especially when you look at the rigid pre unit motors, where the torque stays are longer, horizontal and attached to a simple clamp around the frame.
Certainly on a Velocette if they are left off then the petrol tanks have been known to crack around the seams from the added vibration.
Best to keep them on your bike.
 
Quote, "

Back to show bikes, I've been told of the occasional show bike without mechanical internals. I did speak to an owner once who admitted that he can't start his bike as he doesn't keep oil in it.

FACE
 
By the time Triumph went to 750cc, they only used one bracket on the rear valve cover.

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Then it sounds like they worked out some of the vibration issues.
 
Well it just seems common sense if they went from 4 to 1 on the 750's something changed unless they were trying to cut corners. Now was this change under Meridian or under Hinckley?
 
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