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Message started by eau de sauvage on 11/04/17 at 18:07:58

Title: Checking valve clearance by gut feeling only.
Post by eau de sauvage on 11/04/17 at 18:07:58

Because checking the valve clearance on the S40 is such an epic pita, I am mulling over in an unused crevice of my mind whether I could eventually get away with simply rocking the rocker back and forth by hand to decide whether I really need to back them off and start from scratch or whether they feel good enough to leave.

The last few times I've set the valves I've tried to get a feeling of what the right clearance feels like.

Just canvassing opinions on this.

Title: Re: Checking valve clearance by gut feeling only.
Post by justin_o_guy2 on 11/04/17 at 18:28:46

I'd call it a skilled hand that can do that.
Before you try that, lift on the adjuster and press the oil out of the cam follower to cam.
There is a less pure guesswork approach.
The thread pitch on the adjusters means X turns = Y thousandths.

Title: Re: Checking valve clearance by gut feeling only.
Post by Papa Bear on 11/05/17 at 09:22:12

"Checking valve clearance by gut feeling only."

That's like the "butt dyno" ;)

(every time I wash & polish my bike I swear it runs faster/better)

Title: Re: Checking valve clearance by gut feeling only.
Post by eau de sauvage on 11/06/17 at 00:42:13

I'm surprised that there's not much response to this, I would have expected a whole bunch of 'sure, I've been doing that for 30 years' type of comments.

It's just that the nerves in the fingers are extremely sensitive to vibration even the types of micro vibration just feeling an apparently smooth fabric, just stirring pasta gently with a wooden spoon I can tell just by how the pasta hits the spoon whether it's cooked or not and so I thought that it would be pretty easy to tell.

How about this, I know that too tight is going to be bad due to burned valves but how much play would one need to put into the valves to do cause very bad things to happen?

For example using the 0.08—0.13 specs how bad would it be if the valves were at .2? .3?

Title: Re: Checking valve clearance by gut feeling only.
Post by justin_o_guy2 on 11/06/17 at 04:00:29

6A757374696E5F6F5F67757932000 wrote:

Look in tech.
It's been done.

Title: Re: Checking valve clearance by gut feeling only.
Post by Dave on 11/06/17 at 04:14:25

I don't really understand (or support) the topic of this thread.

Using feeler gauges to check the clearance is not all that difficult, and it assures the job is done correctly. If you bend the feeler gauge into a Z shape they are pretty easy to get into the small space.

Attempting to adjust the valves by hand/feel is iffy - especially since you will only be able to confirm when the "tightest" valve is touching the rocker.......the other valve could be anywhere. If you don't have them adjusted the same - you get 2 "ticks" instead of just 1 tick when the engine is running.

Title: Re: Checking valve clearance by gut feeling only.
Post by Armen on 11/06/17 at 05:06:36

More clearance?
Eau de Savage asked:
"For example using the 0.08—0.13 specs how bad would it be if the valves were at .2? .3?"

The analogy I used when teaching mechanics, was to think of the rocker to valve like hammer to steel. If you take a hammer, hold it very close to a piece of steel, and move the hammer, the steel moves with little trauma to the surface. If you move the hammer a distance away form the steel, and move with the same force and speed, you are more likely to deform the surface of the steel.
Valve clearances are determined to allow for almost no clearance when the valve (which is exposed to combustion heat at the large, heat absorbing end) expands/elongates.
Short answer, loose valves soon become very loose valves.

At Honda school we were taught to use two feeler gauges, or one long one folded over, on bikes with a forked rocker arm. This cancels out false readings caused by the rocker arm rocking sideways on the shaft.

Speaking of Honda school, I remember one of the guys saying that the way he adjusted valves on a twin cam 450 Honda (a bit of a PITA), was to get the bike running, loosen the clearance til the bike rattled, then tighten til the bike was quiet. Can't remember what the teacher threw at him, but it got his attention ;D

Title: Re: Checking valve clearance by gut feeling only.
Post by Gary_in_NJ on 11/06/17 at 05:24:36

I'm with Dave on this one. If you're not going to do the job correctly (which is easy), why bother doing it at all. You have an equal chance of making worse than better. Take the 15 minutes to check it proper.

Title: Re: Checking valve clearance by gut feeling only.
Post by Ruttly on 11/06/17 at 06:35:12

Yup , Just do it right

I think he might have read a old BSA manual like the one I have.
It says the valve adjustment should be "Lil to Nil" , I still used a feeler gauge !

Title: Re: Checking valve clearance by gut feeling only.
Post by Kris01 on 11/07/17 at 17:25:32

Ruttly, is that a technical term? Google won't give me an accurate number for "Lil to nil"! LOL

Title: Re: Checking valve clearance by gut feeling only.
Post by Ruttly on 11/07/17 at 20:13:50

Technical term , no. I have several very old manuals and they are fun to read because there is nothing technical about the old bikes. Put it together,if it starts ride it , if not try again !

Title: Re: Checking valve clearance by gut feeling only.
Post by zipidachimp on 11/07/17 at 20:53:53

I like to whistle past the graveyard...........! 8-)

Title: Re: Checking valve clearance by gut feeling only.
Post by Ruttly on 11/08/17 at 06:51:55

LiL to NiL is a British term "little to none" :o

Title: Re: Checking valve clearance by gut feeling only.
Post by eau de sauvage on 11/12/17 at 20:12:20

OK, as I said I was just canvassing opinions. I guess the idea was that I was making the assumption that they clearance would more likely get looser rather than tighter and that if I could get used to what a .13 gap felt like that if I felt similar then I'd be good to go and if it was tighter it would be more obvious. But I have been doing it right and will continue to do so.

I had a bmw 650 LS once and took it to my mechanic who was a 1970's Czeck speedway champion or something. Anyway, I was having some handling problems and the bike was brand new, he walked around it eyeballing it carefully and said in his thick accent 'Frame iz bendt', I took it back to the BM workshop and told them the frame is bent which they refused to believe.

They put it on their 500,000 jig and informed me that the frame was bent. I wanted a new bike but they refused and instead gave me a new frame. Which seemed like more work and expense than simply replacing the bike.

Also when I worked as a colour lab technician I could make adjustments by eye that were more accurate than people could generally do using a densitometer.

Title: Re: Checking valve clearance by gut feeling only.
Post by norm92de on 11/12/17 at 21:16:00

If our bikes had a single valve per cylinder you could get pretty close doing it the way you describe. However on the savage we have two valves, therefore one valve could be .050" the other .004" and it would feel just the same as if both were .004".

I think, as someone mentioned, it would be more accurate using two feeler gauges since the rocker shaft must have some clearance and therefore some variation is probable from side to side.

Title: Re: Checking valve clearance by gut feeling only.
Post by Dave on 11/13/17 at 03:27:05

3938253A6E653332570 wrote:

I think, as someone mentioned, it would be more accurate using two feeler gauges since the rocker shaft must have some clearance and therefore some variation is probable from side to side.

I use 2 feeler gauges - but not in the way you describe.

I use a 0.004" gauges and adjust so that it will slide through.....but then use a 0.005" as a "no go" gauge. If the 0.005" goes through - I tighten it up a tiny bit more until on the 0.004" gauge slides through.

Title: Re: Checking valve clearance by gut feeling only.
Post by Ruttly on 11/13/17 at 09:34:35

My gut says use a feeler gauge ! ;D ;D ;D

Been working on engines since I was ten and I never play the guessing game !
Not sure what you call it , lazy or dumb !

Title: Re: Checking valve clearance by gut feeling only.
Post by verslagen1 on 11/13/17 at 10:14:08

If you were checking something daily, then you might get the muscle memory to know exactly how to much to turn it to get the right setting. But we do it once every 3 months. Not enough to do it w/out aids. At least you'll need a degree wheel on your screwdriver.
http://www.savageriders.com/verslagen/ValveAdj/vvat-top%20view.jpg

Title: Re: Checking valve clearance by gut feeling only.
Post by norm92de on 11/13/17 at 16:13:52

Dave,
That is exactly what I do. If there is any variance due to the "play" in the rocker shaft- oh well. :)

Title: Re: Checking valve clearance by gut feeling only.
Post by eau de sauvage on 11/14/17 at 02:26:34

OK thx. Just to clarify, by 'play in the rocker shaft' that is referring to the rod that the rocker pivots on, yes? And that has some play that becomes part of the clearance?

Title: Re: Checking valve clearance by gut feeling only.
Post by Armen on 11/14/17 at 04:10:39

Hey Eau,
Here's the deal:
The fit of the rocker arm on the shaft has to have some clearance to allow oil to pass through the shaft, and allow the rocker to 'rock.' If you lever up one end of the rocker with a feeler gauge, the clearance on the other end diminishes. To cancel out the movement, you use one feeler under each finger of the rocker arm. This keeps the rocker parallel to the rocker shaft. The more the rocker-to-shaft, the more the clearance readings will be compromised.
When Honda introduced the V-4 Interceptor in the early 80's, they toasted a lot of valve train components. At Honda school, they taught us this way to adjust valves on a forked rocker. Turned out there were much bigger problems with the valve train, and Honda did a major redo of the top end oiling a few years later.

Title: Re: Checking valve clearance by gut feeling only.
Post by batman on 11/14/17 at 20:54:29

"by gut feeling".On the lighter side,my old gut is way to fat and nerve endings to poor to be used as a feeler gauge! ::) :) :) :)

Title: Re: Checking valve clearance by gut feeling only.
Post by eau de sauvage on 11/16/17 at 01:20:49

@Armen,

OK thx will go the two feeler gauge route.

Title: Re: Checking valve clearance by gut feeling only.
Post by Armen on 11/16/17 at 19:33:29

Gung-ho!

Title: Re: Checking valve clearance by gut feeling only.
Post by jcstokes on 11/17/17 at 00:21:16

Someone on this forum (tech section) had gauges that were bent at right angles and mounted on a stick. he claimed these were more effective and easier to use than the Z bend gauges. These gauges were very short.

Title: Re: Checking valve clearance by gut feeling only.
Post by eau de sauvage on 11/17/17 at 22:38:34

4A4353544F4B4553200 wrote:

...snip

Yeah, I have them they'd be the motion pro guages they are easier to use than the normal ones that are hand bend. I might even order another set of the motion pros. Just checked the valves on my GS, what a dream just slide them in, takes about 90 to do all four!

I'm in luck, found one on ebay with free postage to Australia, so only $10 AUD delivered! I'm sure the other one I have cost a lot more delivered.

https://www.ebay.com.au/itm/282350256043