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Discussion Starter #1
Has anybody out there had trouble with cigarette seals leaking shortly after a motor rebuild??? I build at least 1 or 2 motors a month and I NEVER had cig seals leak but the last few motors are starting to leak at the cig seals???? The seals seem to get very soft and Im also having the same issues with the rear half moon seals too. They seem to swell up to twice their size. I have not changed the motor oil that I have been using. And I also add a half bottle of Red Line break in additive on start up. Is this just me????? Anyone?
 

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And you're not doing anything different? They leak immediately or after a period of time? Haven't changed gasket suppliers? I just installed a set of Reinz in a GTV, so far so good but it's only been minimal mileage yet.

Andrew
 

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Discussion Starter #3
Hi Andrew, I've change nothing and I get the seals from Centerline or Classic alfa or with the Rienz complete kit. Id say it starts in about 500 miles or so. I have pulled out a set with about 1000 miles on them and they have become very "soft" and basically pull right out of the rear main cap... ??????? Cam end or half moon seals also swell up to twice the size and are also very soft and leak like mad...
 

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Huh, well we'll see how the GTV I just did holds up. I don't have anything to add. Sounds like the rubber isn't as good as it once was? Bummer.
Andrew
 

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Sounds like the manufacturer used EPDM or Neoprene rubber instead of Nitrile. These are attacked by petroleum oil.

It could be a legitimate mistake or it could be intensionally using a cheaper polymer.

If in doubt, put your rubber seals in a jar of oil and let them sit for a few days. If they swell, throw them out.
 

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Discussion Starter #8
Good idea I will do that. Also keep in mind the half moons are doing the same thing, but those are easily replaceable. I've got 2 motors ready to assemble but not until we find out whats going on. I just use a common 20/50 oil and a can of Red Line break in with zinc, same assembly grease, same Permatex, same assemble procedure.... Thanks for the input guys.
 

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Some mechanics I know discard them and fill the cavities with silicon sealant. Don't overdo it, the overflow will fill the crank seal.
It won't as long as you first fit the CS with extra sealant and all overflown residue of sealant easily can be removed before refitting oil pan AND crank seal. As well every amount squeezed out shows you've done it properly.
 

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I can't answer to the rubber getting soft.

But I've bought seals from all the major suppliers (U.S. and Europe) and they are all to short and undersized in diameter. Even the Reniz ones.

The only ones I've gotten that are correct are the ones from Spruell's. He is having them made.

Here are the tech bulletins on the seals and there sizes.
 

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It's not an issue when newly bought CS are too short or smaller dia.

Adding extra sealant will provide no leaking. I'm often using old CS as long as they are soft enough.

CS are not rocket science; you can remove them and replace with Permatex as well. The trick only is how to fill the holes with sealant or extra sealant when using sealant AND CS.

When Alfa engineered that engine type nearly 70 years ago there simply wasn't a sealant good enough to replace them. That's all.
 

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Discussion Starter #14
Sometimes the simplest things give you the greatest grief... I myself have never had issues with the seals, I figured out a few little tricks to make then never leak. That was years ago, suddenly in the pass half a year I have had them start leaking shortly after installing them. After stripping down the motors AGAIN the seal would almost fall out if you turn the motor over, VERY lose and soft. This is not an issue of installation or sealant in my opinion. I think its the actual material failing...…
 

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THAT'S why I mentioned to use often old CS!

They won't shrink any more.

Once again: It's not rocket science to get them not leaking.
 

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Just finished my bottom end and used Permatex Ultra Black in lieu of the seals. Just fill until is comes out at the crank seal overfill at top and trim excess with xacto knife. Expecting no leaks !
 
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