Replacing the valve adjusting set screws?

[aarongarcia]

So I had my first attempt at valve adjustment last week (motor running technique) and it was definitely a learning experience.

While driving down the road the next day I thought about how much easier it would be if the set screws were allen head instead of a stupid slotted head. To anyone who has performed this maintenance with this technique I'm sure you can relate.

I'm familiar with what the screws look like, they aren't just out of the box set screws, they are nicely machined and have a rounded and polished tip. I'm confident that a decent machine shop could replicate them easily enough.

So... What do you all think about the idea of replacing them with some allen head screws?

 

[Cruiserdrew]

Do it, report back, and then sell sets if it works ok. Remember to get the hardness of the material right.

Considering it's a once per year job, using slotted screws isn't that big a deal.

 

[lehiguy]

So I had my first attempt at valve adjustment last week (motor running technique) and it was definitely a learning experience.

While driving down the road the next day I thought about how much easier it would be if the set screws were allen head instead of a stupid slotted head. To anyone who has performed this maintenance with this technique I'm sure you can relate.

I'm familiar with what the screws look like, they aren't just out of the box set screws, they are nicely machined and have a rounded and polished tip. I'm confident that a decent machine shop could replicate them easily enough.

So... What do you all think about the idea of replacing them with some allen head screws?

Back in my younger days I too performed this loathsome task with the motor running. Therefore, I think I am qualified to say that you are a masochist and harbor feelings of deep hatred for your feeler gauges. There are ways of positioning the motor that allow you to do this more accurately with the engine off. I liked to put the trans in the highest gear, jack one rear wheel off the ground and use that to rotate the engine. I would adjust the closed valves only when the companion valve to that cylinder was open. I would cross them off the list and turn the motor some more, adjust more valves and so on untill they were all done. I also set lash at .005 and .007 for a quieter, better running 2F.

 

[aarongarcia]

Well, I did find one place in town that has the correct hardware... (they are 8mm x 1.00 x 30mm by they way.) 1.00 pitch is kinda hard to find. The grade is 10.9 which should be right, I'd probably do a quick and dirty test with a diamond file to compare the two.

They are about $4 each so $48 total. Definitely possible but probably completely unnecessary. I might try it next time I do a big tune up.

@lehiguy I like that method and read it on another post of yours somewhere... I'm going to try it next time for sure. It's simple and just makes sense.

Masochist? Well yeah probably so. I mean it is pretty cool to tell people that you perform maintenance tasks on your engine while its running... but you're right that's a stupid reason!

I guess this thread is done for now, that was quick.

 

[lehiguy]

Well, I did find one place in town that has the correct hardware... (they are 8mm x 1.00 x 30mm by they way.) 1.00 pitch is kinda hard to find. The grade is 10.9 which should be right, I'd probably do a quick and dirty test with a diamond file to compare the two.

They are about $4 each so $48 total. Definitely possible but probably completely unnecessary. I might try it next time I do a big tune up.

@lehiguy I like that method and read it on another post of yours somewhere... I'm going to try it next time for sure. It's simple and just makes sense.

Masochist? Well yeah probably so. I mean it is pretty cool to tell people that you perform maintenance tasks on your engine while its running... but you're right that's a stupid reason!

I guess this thread is done for now, that was quick.

The flying droplets of hot motor oil were my favorite part.

 

[klinetime574]

I also set lash at .005 and .007 for a quieter, better running 2F.

One of those incriminates seems a little on the small side from the stock .008 and .014

My 2F is pretty clacky. I suspect it to be wear on the rocker surfaces that hit the valve spring head; like a small dimple. Thus I'm measuring the gap correctly but there is still a small dimple which makes the lash bigger. Is this why you are using a smaller lash?

 

[lehiguy]

One of those incriminates seems a little on the small side from the stock .008 and .014

My 2F is pretty clacky. I suspect it to be wear on the rocker surfaces that hit the valve spring head; like a small dimple. Thus I'm measuring the gap correctly but there is still a small dimple which makes the lash bigger. Is this why you are using a smaller lash?

The ends of your rockers should be pretty smooth, I have not seen them deteriorate on a Cruiser unless there was a loss of lubrication. Way back in my glory days I bought an FJ40. The valve lash seemed sloppy to me, I was used to motorcycles and Honda cars, I had never seen anything with as much lash as Toyota calls for on the 2F. So I experimented with tighter lash and found that it ran quieter and slightly stronger. Some argue that you risk burning a valve which is pure nonsense; any lash greater than zero on a hot engine is a closed valve and therefore not at risk of burning. The .005 and .007 are conservative really, and typical of other, newer engines with solid lifters.

 

[klinetime574]

The ends of your rockers should be pretty smooth, I have not seen them deteriorate on a Cruiser unless there was a loss of lubrication. Way back in my glory days I bought an FJ40. The valve lash seemed sloppy to me, I was used to motorcycles and Honda cars, I had never seen anything with as much lash as Toyota calls for on the 2F. So I experimented with tighter lash and found that it ran quieter and slightly stronger. Some argue that you risk burning a valve which is pure nonsense; any lash greater than zero on a hot engine is a closed valve and therefore not at risk of burning. The .005 and .007 are conservative really, and typical of other, newer engines with solid lifters.

I've had some oil leaks for a long time, I hope there is no wear.

I'll experiment with tighter lash as soon as I have time. Your statement seems very logical to me. And I don't like my noisy 2F, It's already enough of a tractor

 

[GM60]

The ends of your rockers should be pretty smooth, I have not seen them deteriorate on a Cruiser unless there was a loss of lubrication. Way back in my glory days I bought an FJ40. The valve lash seemed sloppy to me, I was used to motorcycles and Honda cars, I had never seen anything with as much lash as Toyota calls for on the 2F. So I experimented with tighter lash and found that it ran quieter and slightly stronger. Some argue that you risk burning a valve which is pure nonsense; any lash greater than zero on a hot engine is a closed valve and therefore not at risk of burning. The .005 and .007 are conservative really, and typical of other, newer engines with solid lifters.

I'd be wary about reducing the valve lash settings to half manufacturers spec, especially on the exhaust valves.
There has to be a clearance between valve stem tip and rocker, when the engine is HOT.
When the valve lash is adjusted in the workshop, the engine may well be warmed up, and in some cases may seem "hot", but it is not truely "HOT".
When the engine is subjected to heavy loads, the exhaust valves will be running at way higher temp than when the adjustment is being done in the shop, at idle, and under zero load.
Driving up steep long inclines, pushing through soft deep sand, towing a van, or just pushing into a strong headwind at highway speeds, can push the exhaust temp way way up beyond no-load idle temp, and that reduced valve lash setting may end up being severely reduced.

Manufacturers specs may sometimes seem excessive, but they are there for a reason, and have been calculated after the engine has been tested under a wide variety of driving conditions.

 

[lehiguy]

I'd be wary about reducing the valve lash settings to half manufacturers spec, especially on the exhaust valves.
There has to be a clearance between valve stem tip and rocker, when the engine is HOT.
When the valve lash is adjusted in the workshop, the engine may well be warmed up, and in some cases may seem "hot", but it is not truely "HOT".
When the engine is subjected to heavy loads, the exhaust valves will be running at way higher temp than when the adjustment is being done in the shop, at idle, and under zero load.
Driving up steep long inclines, pushing through soft deep sand, towing a van, or just pushing into a strong headwind at highway speeds, can push the exhaust temp way way up beyond no-load idle temp, and that reduced valve lash setting may end up being severely reduced.

Manufacturers specs may sometimes seem excessive, but they are there for a reason, and have been calculated after the engine has been tested under a wide variety of driving conditions.

A valve cannot be "more closed" because the rocker tip is farther away from the valve stem. The engine will seize before it gets hot enough to appreciably diminish the valve lash. Plenty of other engines have double or more the volumetric efficiency of a 2f (meaning they make more heat) and they suffer no such issues.

 

[GM60]

A valve cannot be "more closed" because the rocker tip is farther away from the valve stem. The engine will seize before it gets hot enough to appreciably diminish the valve lash. Plenty of other engines have double or more the volumetric efficiency of a 2f (meaning they make more heat) and they suffer no such issues.

The valve cannot be "more" closed, but it will certainly will be closed for "longer" time, meaning it can disperse more heat through it's longer period in contact at the valve seat.

Engine temp and exhaust gas temp are two vastly different things.
It's possible for engine temp to be within the normal range, while at the same time having EGT and exhaust valve temp at dangerously high levels.

"Other engines" are exactly that. They are other engines, not 2f.
To find a similar engine to the 2f, take a look at the old Chev 6 which it was copied from, and see what the exhaust valve lash specs were for it.

 

[lehiguy]

The valve cannot be "more" closed, but it will certainly will be closed for "longer" time, meaning it can disperse more heat through it's longer period in contact at the valve seat.

Engine temp and exhaust gas temp are two vastly different things.
It's possible for engine temp to be within the normal range, while at the same time having EGT and exhaust valve temp at dangerously high levels.

"Other engines" are exactly that. They are other engines, not 2f.
To find a similar engine to the 2f, take a look at the old Chev 6 which it was copied from, and see what the exhaust valve lash specs were for it.

And yet folks are swapping in cams with 20 degrees more duration and .050" more lift without any ill effects, so that argument obviously holds no water. My own testing and that of other Mudders has determined that cold valve clearance vs. hot clearance is less than .001" so that too is without foundation. Since valves tend to wear tighter as the valve face and the valve seat slowly wear down effectively raising the valve up in the guide, it could be argued that more lash is better for maintainence-challenged people. Beyond that, decreasing the lash as I always did cannot have any adverse affects on the engine. It may actually have the benefit of extending the life of the valve stem. Too much clearance can result in rocker and valve stem damage. The rocker should push the valve open, not crash into the stem. I don't know why Toyota likes such large amounts of valve clearance. I can say that both the 2Fs that I owned ran better at .005 and .007. My 22R did not. It ran worse at tighter-then-stock clearance. I reccommend you try it and see what you think.

 

[GM60]

My own testing and that of other Mudders has determined that cold valve clearance vs. hot clearance is less than .001" so that too is without foundation.

But that is exactly the point. Regarding your "testing", you have never actually measured the hot clearance.
What you have really measured is the clearance with the engine at operating temp, but idleing under zero load.
That is the reason for the manufacturers spec.
Exhaust valve temp under heavy load will be far higher than exhaust valve temp at idle.

Your theory is that Toyota has deliberately set the valve lash spec at double the size that is really needed, for no reason other than that they wanted an engine with excess valve train clatter, and that theory is what I think really has no foundation.

 

[lehiguy]

But that is exactly the point. Regarding your "testing", you have never actually measured the hot clearance.
What you have really measured is the clearance with the engine at operating temp, but idleing under zero load.
That is the reason for the manufacturers spec.
Exhaust valve temp under heavy load will be far higher than exhaust valve temp at idle.

Your theory is that Toyota has deliberately set the valve lash spec at double the size that is really needed, for no reason other than that they wanted an engine with excess valve train clatter, and that theory is what I think really has no foundation.

Show me a piston engine, any engine made by anybody that has that much expansion in any part of it. As I said before, the heat required to create that much expansion would seize the engine and melt the pistons. Horsepower is the result of heat, internal combustion engines are heat engines, the more power you make, the more heat you have to create. A 2F engine doesn't make much power and therefore, it really doesn't make much heat. Halfing the valve lash, as long as you keep an eye on it, cannot possibly have any detrimental effects. Sounds like its not for you, and that's fine, but there is no danger in it.

 

[Mace]

There is danger in it. By overtightening the valve lasy, you significantly increase the chances of the valves staying open when they are not supposed to be. You can easily burn valves this way. Plus you can actually increase the wear on the valves and rockers by having them in contact the entire time.

Also, the reccomended valve lash alters depending on your cam profile.

So Lehi, what cam were you running with this lash and how long did you actually run the combo?

 

[lehiguy]

There is danger in it. By overtightening the valve lasy, you significantly increase the chances of the valves staying open when they are not supposed to be. You can easily burn valves this way. Plus you can actually increase the wear on the valves and rockers by having them in contact the entire time.

Also, the reccomended valve lash alters depending on your cam profile.

So Lehi, what cam were you running with this lash and how long did you actually run the combo?

I ran both my 2F stock cams that way for years and years. I drive about 20,000 miles a year, so there are at least 100,000 miles of operation in that state without any issues. I always checked lash on a regular basis. Both motors were running strong they day we parted. I recommend that you try it.

 

[Cruiserdrew]

I recommend that you try it.

For anyone else reading this thread: lehiguy's advice is not approved by Toyota or anyone else who might know. He's some guy on the internet giving advice that contradicts the advice of the engineers who built this motor. He may be right, but then 2Fs with valve lash set the way the factory recommends last for 300k miles without major issues, so carefully consider your options before you take his advice.

Lehi-I'm not bashing you at all, you usually have something good to say, but tightening up valve lash from spec is frought with danger. People reading these threads may take your advice thinking it is the collective wisdom of this forum. It isn't. The only good thing it does is make the motor quieter. The potential bad things it may do are burn valves and increase wear. Plus, if you truly check it once per year as you say, you might get away with it, but most guys set the valves and because it's a PIA never mess with it again. I think it would be safer to set to the factory specs, and that is my advice.

 

[lehiguy]

For anyone else reading this thread: lehiguy's advice is not approved by Toyota or anyone else who might know. He's some guy on the internet giving advice that contradicts the advice of the engineers who built this motor. He may be right, but then 2Fs with valve lash set the way the factory recommends last for 300k miles without major issues, so carefully consider your options before you take his advice.

Lehi-I'm not bashing you at all, you usually have something good to say, but tightening up valve lash from spec is frought with danger. People reading these threads may take your advice thinking it is the collective wisdom of this forum. It isn't. The only good thing it does is make the motor quieter. The potential bad things it may do are burn valves and increase wear. Plus, if you truly check it once per year as you say, you might get away with it, but most guys set the valves and because it's a PIA never mess with it again. I think it would be safer to set to the factory specs, and that is my advice.

I find this whole thing entertaining. Not endorsed by Toyota? No kidding? Neither is a desmog, headers, head milling beyond a cetain point, different cams, different air cleaners, suspension lifts, body modifications, changing seats, changing mirrors and a host of other things that we ALL have done, not the least of which is Mace's turbo. Come on folks, lighten up. If you're a maintainance-challenged dufus, do not attemp any of these things. In fact, you should stop reading all postings on Mud altogether. If that's not you, then I'm saying from experience of running tighter lash spanning more than 100,000 miles that a tighter lash with the stock cam runs stronger and quieter, period. Stone me if you like.

 

[Mace]

I find this whole thing entertaining. Not endorsed by Toyota? No kidding? Neither is a desmog, headers, head milling beyond a cetain point, different cams, different air cleaners, suspension lifts, body modifications, changing seats, changing mirrors and a host of other things that we ALL have done, not the least of which is Mace's turbo. Come on folks, lighten up. If you're a maintainance-challenged dufus, do not attemp any of these things. In fact, you should stop reading all postings on Mud altogether. If that's not you, then I'm saying from experience of running tighter lash spanning more than 100,000 miles that a tighter lash with the stock cam runs stronger and quieter, period. Stone me if you like.

I don't think any of those mods come with the statement "cannot possibly have any detrimental effects"....

Signed,
Dufus

 

[tclark]

This is almost like watching Jerry Springer....