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Note that the bolt + nut that comes with it is too large to go through the hole in the Alfa block. They supply 5/16" or 8mm hardware, and you need more like 1/4" or 6mm dia. So get a long, thin (maybe 3" / 80mm long) bolt, nut, washer when you're ready to lock your flywheel.

though I won't need it for several months.
For $5, these things are a bargain even if you never use it!
 

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Discussion Starter #83
Hi All,
Next question :smile2:. Any advice out there on how to get these cigarette seals out? I haven’t tried yet, but I thought i’d Ask first in case there’s some rookie move i’d Manage to make that would turn this into a debacle.
Thanks!
Mark
 

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Take the bearing cap off , or , use a sheet metal screw into the hole in the cig seal and pull it up— Use a claw hammer to pull it out like a nail
 

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Ps don’t use those orange seals — use brown corteco seals has been bb consensus.
 

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I'd go with @goats' first suggestion, and pull the bearing cap. You're going to want to look down in those channels anyway to make sure they're clean, etc.

The replacement cigarette seals that came with my gasket set were too short. I followed the suggestion on another thread here, and used Ultra Copper sealant; it's been holding up great. There's more than one successful way to deal with that cigarette seal area.
 

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Discussion Starter #87
Thanks Goats and Kevin,
I probably should just pull the bearing cap huh? I ordered some upgrade cigarette seals from Paul Spruell that Jim G had suggested. I did read an older post the other day showing the ultra copper sealant being used in place of the cigarette seals. It looked intriguing.
Back to pulling the cap: should I just re-torque to the specs in the manual, or is there a plastigauge reference I should check with first before proceeding with the final torquing?
Thanks again for the replies!
Mark
 

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Discussion Starter #88
The carbs came back from Top End Performance today:smile2:. Can't wait to mount them on the new solid spacers I bought from Spruell! On a down note, the machine shop called and said the head needs EVERYTHING! Valves, guides, springs, collets, seals (naturally). Has anyone heard of collets being "mushroomed"? The machinist said it was a first for him also? Anyway, should I just purchase all of this from classic Alfa or does anyone out there have a reason I should buy from another source?
Regards
Mark
 

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Collets get mushroomed by the valve shims. This happens when a machine shop surfaces the tops of the valve stem. Which is a common practice on most other engines because the top of the stem gets worn from the rocker pushing on it.

Alfa valve stems do not need to be surfaced. Doing so will put the skirt of the valve shim against the collets.
 

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Discussion Starter #90
Collets get mushroomed by the valve shims. This happens when a machine shop surfaces the tops of the valve stem. Which is a common practice on most other engines because the top of the stem gets worn from the rocker pushing on it.

Alfa valve stems do not need to be surfaced. Doing so will put the skirt of the valve shim against the collets.
Ahhhh. I'll pass that on to the machinist
Thanks!
Mark
 

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Collets get mushroomed by the valve shims. This happens when a machine shop surfaces the tops of the valve stem. Which is a common practice on most other engines because the top of the stem gets worn from the rocker pushing on it.
It is also common practice on Alfa engines worked on by shops not familiar with Alfas. The problem is that the tappet-to-cam clearances must fall within the range that can be adjusted with off-the-shelf shims. Often the shop will set the valves too deep in their seats, resulting in such tight clearance that even the smallest available shim won't give sufficient clearance. You can sometimes solve this by grinding the shims even thinner, but more commonly, a naive shop will just grind down the valve top and figure they've solved it. Putting in a new valve seat is the proper solution, but that would cost more.

The point of all this is that there are a number of machining operations that are different on Alfas - particularly on the heads. Every shop says "well, shucks, if we can machine Chevy V8's for drag racing, we can machine some little Alpha Romero. But often they just can't,
 

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Discussion Starter #92
It is also common practice on Alfa engines worked on by shops not familiar with Alfas. The problem is that the tappet-to-cam clearances must fall within the range that can be adjusted with off-the-shelf shims. Often the shop will set the valves too deep in their seats, resulting in such tight clearance that even the smallest available shim won't give sufficient clearance. You can sometimes solve this by grinding the shims even thinner, but more commonly, a naive shop will just grind down the valve top and figure they've solved it. Putting in a new valve seat is the proper solution, but that would cost more.

The point of all this is that there are a number of machining operations that are different on Alfas - particularly on the heads. Every shop says "well, shucks, if we can machine Chevy V8's for drag racing, we can machine some little Alpha Romero. But often they just can't,
That's funny! My shop say's they're experienced with Alfa's but I'll pass these pieces of advice on to them?.
Regards
Mark
 

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If the valve shim is striking the collet hard enough to mushroom it, wouldn't that be making noise? Is the shim also damaged as a result?
 

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The shim is actually being held up from resting on the stem head because it is resting on the collet. 2 things will happen. First the shim will start to damage the collet. Then the shim will eventually shatter causing running issues and will usually damage the valve cup.

You won't hear any noise until the shim actually breaks.
 

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The shim is actually being held up from resting on the stem head because it is resting on the collet. 2 things will happen. First the shim will start to damage the collet. Then the shim will eventually shatter causing running issues and will usually damage the valve cup.

You won't hear any noise until the shim actually breaks.
Ok, makes sense. I was having trouble visualizing it.
 

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Discussion Starter #96
"It is also common practice on Alfa engines worked on by shops not familiar with Alfas. The problem is that the tappet-to-cam clearances must fall within the range that can be adjusted with off-the-shelf shims. Often the shop will set the valves too deep in their seats, resulting in such tight clearance that even the smallest available shim won't give sufficient clearance. You can sometimes solve this by grinding the shims even thinner, but more commonly, a naive shop will just grind down the valve top and figure they've solved it. Putting in a new valve seat is the proper solution, but that would cost more."

So I'm waiting to hear back from my machine shop, who are putting together a quote for the work they need to do, and thinking about what Jay said about the valve seats. My shop didn't mention needing to replace the seats, but noted the mushrooming....do you guys think I should tell them to replace the seats as well?
Thanks for your collective input! I really don't have much experience with machining. I just drop stuff off and tell 'em to call me when it's done?.
Regards
Mark
 

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My shop didn't mention needing to replace the seats, but noted the mushrooming....do you guys think I should tell them to replace the seats as well?
I'm not saying that you always need to replace the valve seats. Your's may just need to be cleaned up, as long as they can do this without positioning the valve too deep in the head.

What I am saying is that the depth of the seat, the length of the valve and the type of cam you are using will all influence the final valve stem to cam clearance. And, that clearance must be within a range that can be adjusted with available shims.

So one solution is to make the shop responsible for adjusting the cam-tappet clearances. They'll need your cams and should have a full set of shims since they are an Alfa-experienced shop. But verify the clearances before accepting the head and make them promise not to grind the valve stems to the point where the shims are resting on the collets.

The other solution is to instruct them to make sure the valves are in the range that can be adjusted, and then set the final clearances yourself.
 

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Discussion Starter #98
I'm not saying that you always need to replace the valve seats. Your's may just need to be cleaned up, as long as they can do this without positioning the valve too deep in the head.

What I am saying is that the depth of the seat, the length of the valve and the type of cam you are using will all influence the final valve stem to cam clearance. And, that clearance must be within a range that can be adjusted with available shims.

So one solution is to make the shop responsible for adjusting the cam-tappet clearances. They'll need your cams and should have a full set of shims since they are an Alfa-experienced shop. But verify the clearances before accepting the head and make them promise not to grind the valve stems to the point where the shims are resting on the collets.

The other solution is to instruct them to make sure the valves are in the range that can be adjusted, and then set the final clearances yourself.
i'm just going to print all this up and take it into the shop :). i was planning on doing the final clearances myself, but in light of all this new information, i may have them do it if they can't guarantee me i won't run into this "potential" problem.
thanks for clarifying!
mark
 

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i was planning on doing the final clearances myself, but in light of all this new information, i may have them do it if they can't guarantee me i won't run into this "potential" problem.
Just to confuse you further:

- There are a lot of advantages in setting the valve clearances yourself. You will do a more precise job than the 20-year old helper in the machine shop, who is listening to rap through his earbuds while working on your head.

- Unless you have access to a selection of shims, setting the clearances precisely can drive you nuts. The shims come in .025mm variations, from 1.3 - 3.5mm. You find yourself measuring the gap, figuring that you need a 1.025mm shim (say) order that one, it arrives a week later, you install it, measure the gap and immediately say "oh &%$#@, I should have gotten 1.050mm!". Now that car will still run with the clearance .025 off; it'll just drive you nuts.

- Maybe the best solution is to have the shop take the first pass, and then you clean up the job that 20-year old helper did.
 

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When you estimate a shim size, order a few sizes around that. Yes, you will end up with a bunch of extra shims. I did this for several years, and have ended up with a LOT of shims. Finally I can do any adjustment I need. I was even able to sort them into half sizes by carefully measuring, and even made a case to hold them. See attached photos. This is the standard range of shims; there is also a set of larger sums, which is on the reverse side of the holder. You can also occasionally find a bunch of shims on eBay.

Note that in the second pic, there are some wooden plugs that show which shim is currently installed.

Robert
 

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