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Discussion Starter #1
My 86 Alfa intake valve clearances all measure .016".

However, the number 1 exhuast only has .005" clearance. Number 2 is .015, number 3 and 4 are .013". Pat Braden wrote that he didn't worry about .005" differnce or less, I'm not either. He also wrote that over .005" difference and the valve should be replaced.

So, my question is- what would most of the esteemed bulletin board members do: change the number 1 exhaust valve, or just shim it to specification and check the clearance more often.

Duke
 

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I would certainly re-shim the exhaust valves and then watch for any further changes over the course of the next few months. Too tight a clearance can allow the valve to 'burn' - the valve head only gets to cool while it is closed - in contact with the head. The exhaust valves have it the worst.

When were the clearances last checked?
 

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My 86 Alfa intake valve clearances all measure .016".

However, the number 1 exhuast only has .005" clearance. Number 2 is .015, number 3 and 4 are .013". Pat Braden wrote that he didn't worry about .005" differnce or less, I'm not either. He also wrote that over .005" difference and the valve should be replaced.

or just shim it to specification and check the clearance more often.

Duke
Difference of .005" and having that clearance of 0.005" when it should be .018"-.020" is huge!!! Maybe Cheryl will shed some light on this, but I'd think pat was saying having a clearance of .013"-.025" was OK, but outside of that something is wrong. Shim it and recheck it often!
 

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Discussion Starter #4
Thanks for your prompt replies!

I will re-shim tomorrow and check more often.

Last time I checked was almost 2 years ago. I know- bad boy, bad boy.


Duke
 

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Alfa Owner's Bible & Valve Clearances?

My 86 Alfa intake valve clearances all measure .016".

However, the number 1 exhuast only has .005" clearance. Number 2 is .015, number 3 and 4 are .013". Pat Braden wrote that he didn't worry about .005" differnce or less, I'm not either. He also wrote that over .005" difference and the valve should be replaced.

So, my question is- what would most of the esteemed bulletin board members do: change the number 1 exhaust valve, or just shim it to specification and check the clearance more often.

Duke
Difference of .005" and having that clearance of 0.005" when it should be .018"-.020" is huge!!! Maybe Cheryl will shed some light on this, but I'd think pat was saying having a clearance of .013"-.025" was OK, but outside of that something is wrong. Shim it and recheck it often!
Please keep in mind that I did not write the book, shy away from answering technical questions, and am not a SME on anything, let alone Alfa Romeo. If you furnish me a page reference, I'll be happy to look at it and tell you what I think it says or see if I see something that is being overlooked in interpretation or context when I get home. Having said that, there are others much more qualified than me to answer this question and give advice so mine would be purely an explanation of what the English says as it is written.

FTR, as far as I recall, Pat did not shim but replaced if the part was questionable; he also measured with micrometers and feeler gauges.

HTH.
 

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Discussion Starter #7
ddouglas,

Marine Corps, not Navy. (The Marine Corps was founded to protect Navy ships. Why do Marines let sailors onto the ships? Sheep would be too obvious.) :)

Ms. Braden- I'm not finding fault with The Alfa Owner's Bible, only trying to make a decision regarding whether to change one valve, replace valve shims, or re-do the head entirely. I've read and re-read your late husband's Alfa books from cover to cover and refer to them often. My basic question is whether I'm facing replacing the head on my Alfa engine.

Duke
 

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Alfa Owner's Bible & Valve Clearances?

ddouglas,

Marine Corps, not Navy. (The Marine Corps was founded to protect Navy ships. Why do Marines let sailors onto the ships? Sheep would be too obvious.) :)

Ms. Braden- I'm not finding fault with The Alfa Owner's Bible, only trying to make a decision regarding whether to change one valve, replace valve shims, or re-do the head entirely. I've read and re-read your late husband's Alfa books from cover to cover and refer to them often. My basic question is whether I'm facing replacing the head on my Alfa engine.

Duke
I was not concerned about you finding fault with the book, and may be it was ddouglas post that threw me off and led me to believe that someone was trying to determine what Pat had written as far as acceptable clearance which didn't seem to follow the math or clearances posted in the discussions.

In my experience with Pat, he had a set of parameters that he used to decide when an engine was too tired to drive anymore and needed to be rebuilt or replaced, one of them was how many cylinders did not produce the proper pressure number when tested and then which cylinders they were entered into it. As far as making a decision as to how to repair the engine, replacing the valve or shimming it, and as I stated earlier I was not aware of Pat shimming, it will probably give you some more life out of the engine, but in the long run at some point you will have to rebuild the head. For us, the procedure was a little simpler, when Pat's parameters were met, he pulled the engine and replaced it with another one. So he was always in the process of rebuilding an engine for something. When Pat rebuilt an engine he always replaced the internals surrounding the valves even if the valves were still good.
 

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ddouglas,

Marine Corps, not Navy. (The Marine Corps was founded to protect Navy ships. Why do Marines let sailors onto the ships? Sheep would be too obvious.) :)
Hey Now! Not sure which is worse, men who have to wear bell bottoms or the men that hang out with them! yes, this goes back to our earlier discussion about the ship my brother was first on-"Devil Dog's" which you let me know they consequently retired and used for military testing and sunk it. The marines and their sea men, hand in hand LOL!
I'd think Pat's advice maybe on the fact that the valve seats are proably toast on that engine with that little clearance (going back to it being OFF *not at* .005").
 

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Discussion Starter #10
Cheryl,

I found that one of the camshaft lobes was galled, along with the follower being galled. I used a correct thickness valve shim to bring the clearance to .021". I think I'll drive the car another thousand miles or so and check it again.

Normally, I drive the car hard (Italian tune-up fashion). These past two years, I've driven it almost monthly on the highway over 300 miles each way, and cruise along about 80 mph. During this period, I have not checked the valve clearances. I checked them because I could hear more valve noise than previously. This to me is proof that the engine is still strong, even though the car has about 130K miles on it, and the design is very rugged and reliable.

Yes, I will keep an eye on the engine and check the valve clearances more often. I also learned to never let the chain tensioner mechanism come all the way out, replacing the little plate holding the tensioner in place without removing the head, and all about setting the timing by finding TDC on the number 1 cylinder, moving the cams and what tool to use, etc. Good thing I took the week off work. It only took me two days to replace the exhaust cam, replace the tensioning device, etc. Another lesson learned is that the pointer for the crankshaft position was never replaced when the water pump was replaced by a PO. My next adventure will be to replace the heater hose from the top of the throttle to behind the firewall. I've decided to wait until Christmas break when its really cold and I can contour my body under the dash.

Duke
 

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How about the other exhaust valve clearances? Did you adjust (re-shim) those also?

Have you done a compression test?

Is there plenty of oil in the head to bathe the cam lobes & buckets? What oil are you using? There is info about many modern oils having insufficient additives (zinc?) that our older engines need.
 

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There is info about many modern oils having insufficient additives (zinc?) that our older engines need.
By saying modern are you stating that synthetic oil does not lubricate the engine as well as Shell oil?
 

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By saying modern are you stating that synthetic oil does not lubricate the engine as well as Shell oil?
Are you putting words into my mouth (keyboard)? :)

It is my understanding that many modern formulations of motor oil have reduced levels of additives that our engines require. Something about reducing pollution or contamination of catalytic converters. Our engines have flat tappets that are supposed to need those additives to prevent galling (Duke's mention of galling on one lobe of the cam shaft brought this subject to mind.) Modern engines are designed with the reduced levels of these additives in mind (roller cam followers for example)
 

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I way I read Eric's statement is that there is info many modern oils have insufficient zinc needed for older engines. I believe by modern, Eric means oils of the past few years. I didn't see the word synthetic.
 

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Are you putting words into my mouth (keyboard)? :)

It is my understanding that many modern formulations of motor oil have reduced levels of additives that our engines require. Something about reducing pollution or contamination of catalytic converters. Our engines have flat tappets that are supposed to need those additives to prevent galling (Duke's mention of galling on one lobe of the cam shaft brought this subject to mind.) Modern engines are designed with the reduced levels of these additives in mind (roller cam followers for example)
There are still many modern engines that use DOHC with flat tappets. Galling can be many different things, but I'm sure Duke will say what type he's using and if it's synthetic, I would be really surprised (tag that along with the oil to be blamed). You are correct in what you're saying, but realize, modern oil has to also comply with older engines (much like not being able to use synthetic after replacing your piston rings-the synthetic is a very slippery breed-it don't need the zinc or moly additives and will not allow enough FRICTION for piston rings to seat properly-my source on this information is Total Seal Piston Rings).
 

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I way I read Eric's statement is that there is info many modern oils have insufficient zinc needed for older engines. I believe by modern, Eric means oils of the past few years. I didn't see the word synthetic.
Castrol GTX isn't synthetic and is also a very good oil. Any whoo, I got questions that need answered-see you in the next thread.
 

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Alfa Owner's Bible & Valve Clearances?

Cheryl,

I found that one of the camshaft lobes was galled, along with the follower being galled. I used a correct thickness valve shim to bring the clearance to .021". I think I'll drive the car another thousand miles or so and check it again.

Normally, I drive the car hard (Italian tune-up fashion). These past two years, I've driven it almost monthly on the highway over 300 miles each way, and cruise along about 80 mph. During this period, I have not checked the valve clearances. I checked them because I could hear more valve noise than previously. This to me is proof that the engine is still strong, even though the car has about 130K miles on it, and the design is very rugged and reliable.

Yes, I will keep an eye on the engine and check the valve clearances more often. I also learned to never let the chain tensioner mechanism come all the way out, replacing the little plate holding the tensioner in place without removing the head, and all about setting the timing by finding TDC on the number 1 cylinder, moving the cams and what tool to use, etc. Good thing I took the week off work. It only took me two days to replace the exhaust cam, replace the tensioning device, etc. Another lesson learned is that the pointer for the crankshaft position was never replaced when the water pump was replaced by a PO. My next adventure will be to replace the heater hose from the top of the throttle to behind the firewall. I've decided to wait until Christmas break when its really cold and I can contour my body under the dash.

Duke
Duke:

Glad to hear that you are making progress and have some of the issues solved or sorted out. I don't know of anyone's body that could comfortably contour under the dash except for maybe a contortionist, but then maybe they're just used to the pain and ignore it. But I can understand waiting until cooler weather to solve that warm problem. Here's another thought, my Berlina heater valve leaked for sometime, it kept my feet warm as I drove, although, a little damp. Pat did finally get around to fixing that for me. I had one pair of shoes that I drove with in the meantime so that I wouldn't ruin all of them.

On oils, since that also seems to be a topic of discussion Pat used a variety of brands, Quaker State, Pennzoil, Valvoline, and Mobil 1. In cars that had proper compression, were getting the mileage he expected, etc. he used 10/40 of those brands. When he started seeing mileage decrease or low compression in a/some of the cylinders he bumped up to 20/50 to drive the car a little longer before rebuilding, resurfacing, honing, etc. The only cars that I had to buy "special" oil for were the two diesels; not Alfas.

We all take time off of work for various reasons to accomplish things that we just don't seem to have the time to do in our regular schedules. At least yours is Alfa related and you can see the accomplishment in the time spent, even if you did learn a few lessons about the chain tensioner clip and TDC. You usually only drop the clip or chain once and have to fish it out before you learn a better or more careful way to approach it. Providing your a typical male, I'm sure everyone in the neighborhood could here the explicatives when that occurred.
 

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Discussion Starter #18
Cheryl,

Your right again, my wife came out to the garage twice, and one of the neighbors called to make sure I was okay. Funny how I felt better afterwards :). Honestly, I enjoyed working on the car after getting the chain tensioner re-installed.

Eric and Douglas,

I've been using Castrol GTX 20/50 weight almost exclusively. The only exception is that I will sometimes use the high mileage oil. There was plenty of oil in the oil wells on top of the head. I personally think its more important that the oil level be maintained and the oil is changed frequently. If anything, with my car it takes more than 3 months to accrue 3000 miles.

Yesterday, I talked with the local Alfa repair shop owner who said that the valve most likely stretched. He didn't have an explanation why it was just one valve, but I bought some valve shims from him and all the valve clearances are properly set to factory specifications, and I will not neglect the clearances in the future.

The Alfa is running great again- I took her for an Italian tune up just a few minutes ago and she is purring again. That's what's important to me.

Thanks all for the tips and support. I enjoy the humor immensely. We can all disagree about things regarding the Alfa, but we can also share the camaraderie of Alfa ownership and all that goes with it.

Duke
 

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Glad to hear you are 'on the road'.

For sure keep a watch on the valve clearances. Either that valve was always away off (and now you're good to go many more miles) or the valve &/or seat is failing/faulty (and it'd be better to find out sooner vs having something fail catastrophically). We'll all be hoping for the former.
 

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I enjoy the humor immensely. We can all disagree about things regarding the Alfa, but we can also share the camaraderie of Alfa ownership and all that goes with it.

Duke
I agree 100%! I thought you'd enjoy the NAVY/Marine joke. Glad to hear she is back on the road!
 
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