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Discussion Starter #1


Since I have never done a valve adjustment, but getting prepared for that task, I decided to take a look at youtube and watched several really poorly done vidoes that did not help me, however found this very well done video that is much more straight forward than anything else I found including infromation on our forum, that is if in fact this, rule of nine. works on a GT. Please give it a glance and let me know if I should follow this proceedure. Many Thanks. Carl
 

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Detritus Maximus
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Unless I am missing something, wouldn't it depend on the firing order and the intake/exhaust valve arrangement?
 

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Opel Rallier since 1977
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Yes, but it looks to me that the Opel valve arrangement is right for this procedure. Never used it but an interesting way to do figure out which valve to adjust. There are easier ways for me, but this looks good to me.

Carl, if you have hydraulic lifters (which is most likely), then the actual adjustment is different. Do you know which lifter type you have?
 

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Discussion Starter #4
Yes, but it looks to me that the Opel valve arrangement is right for this procedure. Never used it but an interesting way to do figure out which valve to adjust. There are easier ways for me, but this looks good to me.

Carl, if you have hydraulic lifters (which is most likely), then the actual adjustment is different. Do you know which lifter type you have?
My Invoice for the engine dated 1/19/99 - from OGTS

Remanufactured 2.0L with custom head
Combo solid grind cam .430 lift 268 duration
.30 OS 2.0L pistons
1.72 chevy stainless steel intake valves
1.50 Chevy stainless steel exhaust valves
Dual valve springs, hardened valve seats

That is all I know.
Also last discussion on gap was I believe 18 however Gil recomended 14 to tone it down a little??
 

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Just Some Dude in Jersey
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It ain't rocket science, I did it once or twice a year when I was 25 and didn't know anything about cars. Run the car, shut it off and remove the valve cover towards the driver's side. Rotate the engine, either by cranking or turning the fan by hand until the lobe on the cam on the valve you are adjusting is pointing straight down. Try to slide the feeler gauge between the lifter and rocker. It should be hard to slide it in. If it slides in easy, leave the feeler gauge there and slowly tighten the rocker nut while wiggling the feeler gauge until you can't slide the feeler gauge back and forth easily and it fights you a little bit pulling it out. That valve is now done, move on to the next one until you run out of valves to adjust. All done! Keep a mental or written note for yourself about which ones you needed to adjust(If your engine already ran and this is just a yearly adjustment). Sometimes you have a rocker nut that likes to vibrate loose. On my long time GT I almost never had to adjust any other valve except for one of them. The same one every time, all the rest were just fine. I added an extra nut to that one to stop the problem.
 

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Opel Rallier since 1977
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My Invoice for the engine dated 1/19/99 - from OGTS

Remanufactured 2.0L with custom head
Combo solid grind cam .430 lift 268 duration
.30 OS 2.0L pistons
1.72 chevy stainless steel intake valves
1.50 Chevy stainless steel exhaust valves
Dual valve springs, hardened valve seats

That is all I know.
Also last discussion on gap was I believe 18 however Gil recomended 14 to tone it down a little??
Ah OK good,Carl; you do indeed have solid lifters. So you measure the gap like shown in the video (between the valve stem tip and the rocker), but adjust the rocker nut on the Opel head to adjust the clearance. Those rockers nuts are self-locking types, so will have some inherent resistance to turning.
 

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Discussion Starter #7
Ah OK good,Carl; you do indeed have solid lifters. So you measure the gap like shown in the video (between the valve stem tip and the rocker), but adjust the rocker nut on the Opel head to adjust the clearance. Those rockers nuts are self-locking types, so will have some inherent resistance to turning.
Many thanks. I now feel like I have enough enformation to move forward and actually enjoy the process/experience. There was so much information, incomplete information and so many discussions, many times not knowing if someone was talking about solid or hydraulic lifters or what is the starting point, etc, etc. The video made it straight forward and SIMPLE.........Thanks for the clarification.
 

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Discussion Starter #8
So the video that I attached made it look simple - even with the amount of information that I have still not 100% sure so a couple of questons as I don't want to fry my engine.
1. Which valve do I start with - if it is #8 closest to the fan being completely open and then adjusting # 1 closest to the engine compartment, which is completely closed then I think I have it. BUT........
2. However with that said the next to adjust is #6 closest to the fan being completely open and then adjusting #3 however # 1 and 2 are more closed than #3. Is that correct or is it always the most open and the corrosponding valve the most closed - I cannot seem to make that happen??????? Help. Thanks, Carl
 

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Discussion Starter #9
In addition to the information above, after more fiddling around with it I noticed the following - the distributor indicates top dead center on cylinder 1 as does a visual inspection, so with that in mind, valve # 8, the valve closest to the fan is completely open and number 1 closest to the passenger area is completely closed. I have not been able to duplicate that on any other combination of cylinders and my question is that the way it is, just need confirmation. Also, after a closer look at the lifters not sure if they are solid as a couple of them look different, that is, looks like the smaller top half has come up inside of the lower wider part. Not having a point of reference I have no idea. Thanking you in advance for your assistance. Making progress one step at a time. Tuning the carb is next......


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431023

431024
 

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Discussion Starter #10
In addition to the information above, after more fiddling around with it I noticed the following - the distributor indicates top dead center on cylinder 1 as does a visual inspection, so with that in mind, valve # 8, the valve closest to the fan is completely open and number 1 closest to the passenger area is completely closed. I have not been able to duplicate that on any other combination of cylinders and my question is that the way it is, just need confirmation. Also, after a closer look at the lifters not sure if they are solid as a couple of them look different, that is, looks like the smaller top half has come up inside of the lower wider part. Not having a point of reference I have no idea. Thanking you in advance for your assistance. Making progress one step at a time. Tuning the carb is next......


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View attachment 431024
So I figured out my confusion regarding the instructions for adjusting valves.

Valves numbering front to rear 8-1
Valves fully OPENED
, so not knowing engines like a lot of people I thought that meant the valves to be positioned all the way up when it really means the spring is fully compressed. Not being familiar with the internal workings of an engine I am just looking at the external parts, thinking open or closed, and it seemed pretty clear to me, but I was incorrect. I actually found that little tidbit of information on another thread, someone else asked the question. So now that I have joined the club and adjusted my valves 3 times today and I am in the know. However with that said many times those of us in the know assume and the directions that we pass on are not totally clear, we assume a certain level of knowledge that already exists within the recipient and fill in the blanks.
I was once passing through a small town in GA, back in the 80's and stopped to ask directions - the answer was keep following this road and turn right at the last red light????? Because he knew the area that response made complete and total sense, to him....For the directions to be good the recipient needs to really know what they mean.

Anyway based on earlier threads and my earlier questions I was told to set the gap at .018 hot, however Gil suggested that I set them at .014. So again based on what I read I set them cold at .018 with the thought that at normal operating conditions they would actually warm up to around .016 or .015 which is within the range that I have come to believe is close to correct for a 2.0 engine with the cam specified. At this point all I know is the car started and ran - not sure if it is adjusted to the best settings so I am open to suggestions.
Many Thanks, Carl
 

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Opel Rallier since 1977
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Hey Carl,

Glad you figured it all out! Yes, it never occurred to me that there would be some possible interpretation of the term 'valve open' LOL. Your last statement is correct: 'valve open' means 'springs maximally compressed'. It is kinda like 'add oil'... which means you put in 'inside the engine', not 'inside the engine compartment' LOL

And your 'rule of 9' works with the ordering of the valves from rear to front, but most everybody orders the valves front to rear.

There is actually a fair amount of tolerance in the cold adjustment. Typical change in gaps will be in the .002-.006" range. What matters from the standpoint of any potential damage is that:
  • no valve hangs slightly open, due to too tight of a lash (valve burns)
  • the valvetrain does not close up the lash gap when the lifter is on the steep part of the cam lobe, which would happen with too loose of a lash (lifter and lobe damage)
 

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Opel Tinkerer and Rescuer
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Hey Carl,

Glad you figured it all out! Yes, it never occurred to me that there would be some possible interpretation of the term 'valve open' LOL. Your last statement is correct: 'valve open' means 'springs maximally compressed'. It is kinda like 'add oil'... which means you put in 'inside the engine', not 'inside the engine compartment' LOL

And your 'rule of 9' works with the ordering of the valves from rear to front, but most everybody orders the valves front to rear.

There is actually a fair amount of tolerance in the cold adjustment. Typical change in gaps will be in the .002-.006" range. What matters from the standpoint of any potential damage is that:
  • no valve hangs slightly open, due to too tight of a lash (valve burns)
  • the valvetrain does not close up the lash gap when the lifter is on the steep part of the cam lobe, which would happen with too loose of a lash (lifter and lobe damage)
Front to rear or rear to front.. doesnt matter.

Lifter #1 up adjust #8, #8 up and Adjust #1.

I will have a video on this VERY soon.
 

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Discussion Starter #14
Excellent - that video will be a big help. After gaining the understanding to preform the valve adjustment, it does in fact seem fairly simple, however with that said there does seem to be a degree of guess work to determine if the spring is fully depressed. Wish it was more exact like setting the points and easier to determine if you got it wrong, like the points. However electronic ignition kind of cured that, eh. Looking forward to your video. Thanks, Carl
 

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Opel Tinkerer and Rescuer
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431075


Note it doesnt have to be "perfect" when going my the rule of 9. Thats why its good.

See the "UP" lifter can be within 10-20 degrees either side of the Nose.

As your adjusting on the HEEL of the cam, so when

#8 is anywhere close to the Nose..

#1 Will be a 100% on the heel.

So as long as your close to the top travel of the opposing lifter. You will be fine.
 

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Discussion Starter #16
Hey Carl,

Glad you figured it all out! Yes, it never occurred to me that there would be some possible interpretation of the term 'valve open' LOL. Your last statement is correct: 'valve open' means 'springs maximally compressed'. It is kinda like 'add oil'... which means you put in 'inside the engine', not 'inside the engine compartment' LOL

And your 'rule of 9' works with the ordering of the valves from rear to front, but most everybody orders the valves front to rear.

There is actually a fair amount of tolerance in the cold adjustment. Typical change in gaps will be in the .002-.006" range. What matters from the standpoint of any potential damage is that:
  • no valve hangs slightly open, due to too tight of a lash (valve burns)
  • the valvetrain does not close up the lash gap when the lifter is on the steep part of the cam lobe, which would happen with too loose of a lash (lifter and lobe damage)
Thanks Mark, Much appreciated, but now you have me a little concerned/paranoid. Considering what you have come to know about my engine specifications, problems, etc and my recent attempt to adjust the valve lash, do you have a recommendation on a cold setting that in your opinion, which I would trust based on your experience and my lack of, for setting my valves cold. Also with that said, I am also prepared to set the lash while hot in the event that would give me the best chance for success, again your recommendation would be welcomed. I know a 1.9 is .012 however with my cam and a 2.0 engine I was told that .018 was the mark, Gil suggested .014. My recently developed technique is to set valve lash by putting the car in 4th gear and bumping the car, forward, physically to compress the spring to what seems/appears to be the sweet spot, then adjusting the corresponding valve - after setting the gap, I then very slightly bump the car forward a tiny bit and check the lash again and having done that I have found that I was not really at the sweet spot and re-gaped. I also go through the entire process a second time to double check my first results. Having now been through the exercise 5 times it appears that this will be something that becomes easier with practice to develop a feeling for being in the sweet spot before setting the lash - and then feeling good about the results.
Thanks again for your feed back.........Carl
 

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Discussion Starter #17
View attachment 431075

Note it doesnt have to be "perfect" when going my the rule of 9. Thats why its good.

See the "UP" lifter can be within 10-20 degrees either side of the Nose.

As your adjusting on the HEEL of the cam, so when

#8 is anywhere close to the Nose..

#1 Will be a 100% on the heel.

So as long as your close to the top travel of the opposing lifter. You will be fine.
Wow, now that is really great information for a first time valve adjuster like myself and makes a lot of sense and better than that makes me feel more confident knowing I won't fry the engine. :) Between you and Manta Rallier I will soon be an expert. Thanks, Carl
 

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Adjust to 0,30mm first and then check and adjust to 0,30mm with the engine warmed up and running . There is no need to use a 0,40mm or larger clearance, unless you have a 316° or larger cam. At least if we should believe Enem(and they should know after decades of cam manufacturing).
 

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Opel Tinkerer and Rescuer
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Adjust to 0,30mm first and then check and adjust to 0,30mm with the engine warmed up and running . There is no need to use a 0,40mm or larger clearance, unless you have a 316° or larger cam. At least if we should believe Enem(and they should know after decades of cam manufacturing).
What he said... if a custom cam the spec should be on the cam spec sheet. If Stock, go by the manual.

I personally use only hydraulic cams, no matter the motor. I don't build 7,000 - 10,000 RPM motors. I build motors that are built to be just a bit larger than stock using stock EFI. I can get an OR-77 from isky that is hydraulic and works great.
 

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Opel Rallier since 1977
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Adjust to 0,30mm first and then check and adjust to 0,30mm with the engine warmed up and running . There is no need to use a 0,40mm or larger clearance, unless you have a 316° or larger cam. At least if we should believe Enem(and they should know after decades of cam manufacturing).
Stock cam, yes.

Non-stock, go by the manufacturer's lash number, NOT anything based on the stock cam specs, or another cam manufacturer. Additionally, the amount of cam duration has little or nothing to do with the lash setting. It may be so on a given manufacturer's line of cams (like Enem), but another manufacturer's lash ramp designs can be quite different. It is common for US cam designers to use much larger lash settings. For example, Howard's uses lash settings of .016" and .022" (0.4 and 0.55 mm) on their sold flat tappet cam designs, and uses both numbers for the smallest and largest durations, depending on the cam line. But the old Isky solid designs list the valve lash from .018" to .028"; their lash numbers DO increase with duration.

So the lash is set by the cam designer, based on the lash ramp design incorporated into the design. The lash ramp is the slow-rate-of-lift part of the lobe, from 0 lobe lift to where the lobe's lift rate abruptly increases. (And there is a similar slow ramp just before the valve closing.)

To see an example of a lash ramp, here is the detailed cam lobe profile for an Isky OR-4H exhaust lobe on the opening side. The slow, initial part of the lobe lift is the lash ramp area. (Yeah, I know, it is a hydraulic cam so does not technically need a lash ramp, but I suspect that Isky just adopted the solid lifter design with slight change to the lash ramp area. Remember, these were designed in the late 60's! And it is not much different than the stock 1.9L US cam lobe.)
 

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