[mikerwilson]

I'm doing a head swap on my 82 spider due to a worn valve guide (excessive oil consumption, smoking, etc). I've done a head before (several times) on a 1969 Opel GT (basically half a chevy smallblock), but I was wondering if anybody has written a howto or whatnot on getting the valve timing lined up, and any gotchas I may encounter.

I may be able to figure it out as I go, but I'd prefer to not "risk" anything if you know what I mean.

I've searched around the forums for quite a bit here, and haven't been able to find this information. If somebody could point me in the right direction, I'd greatly appreciate it.

Thanks!
Mike

 

[Andrew]

Getting the cams timed involves setting the crankshaft set at TDC #1 on the compression stroke, and lining up the cam timing marks on the cam caps with the #1 lobes pointing outwards, away from each other. There is a vernier arrangement between the cam and the sprocket, so you can fine-tune the timing. It involves taking out the small bolt and loosening the big 22mm bolt, rotating the sprocket relative to the cam, then reassembling.

This is not for the faint of heart if you don't understand the valve/piston relationship, as turning the cams without turning the crank when a piston is at TDC will cause the valves to hit the pistons. I would recommend reading up bigtime on the Alfa procedure specifically before pursuing. There probably is a thread here on the BB on it.

Andrew

 

[mikerwilson]

Thanks for the reply... I have a good concept of how all of this works, I prefer to know what I'm getting into beforehand, and a reference wouldn't be a bad idea... would the Alfa Bible by Pat Braden have a guide to doing an Alfa head swap?

Mike

 

[Andrew]

Pat's books tend to have general guidance, but not specific detailed discussion of this kind of stuff. If you've done heads before it shouldn't be that complex, but it is a fair amount more complicated (and probably preceise) than an Opel GT. I bet money if you do a search on the AlfaBB here you'll find a good discussion of it.

I started on Fiat 850s and graduated to Alfas after rebuilds of two of those, so it can be done.

Andrew

 

[mikerwilson]

Okay, I'll keep searching. I just don't want to get the valve timing wrong or anything like that. I happen to like this motor and don't want to damage it.

Thanks again!

 

[Andrew]

Basically, if you put #1 at TDC, dist rotor at #1, and install the head with the #1 cam lobes pointing outward, 180 degrees from each other, with the marks lined up, you shouldn't hurt anything. Connect the timing chain and at that point sort out the fine points of the cam timing if the marks aren't perfectly aligned.

Note that you can't get the big 22mm nut undone with the cam in the head, and you have to undo the cam caps some to let it upwards. The nut has a lock tab underneath that you should never reuse.

Also note that you want to keep rags and whatnot stuffed in the timing cavity when you're dealing with the lock tab, timing bolts, chain master link, and the like to keep things from falling in.

Tighten the timing chain with the engine NOT running. Loosen the tensioner and let it move outwards on its spring. Rock the engine fore/aft a little, and you can "help" the spring a bit with a small prybar or big screwdriver. Do not turn the engine over on the starter with the tensioner lock bolt loose.

Make sure the head and block are clean and flat, install 6 new o-rings, install roll pins at the 6 oil passages if they aren't already there. Use no sealer on the head gasket unless it's an early 2000 head and block with oil drain-back passages behind #4. In that case, put permatex or whatever around the whole area behind #4. Otherwise you get install oil in the water. For Bosch and Motronic engines this is not a concern, and I believe it's not a concern for earlier engines. The 2000 head gaskets now available contemplate no drain-back holes back there.

Andrew

 

[Andrew]

That should read L-Jet and Motronic in the last paragraph, and by "earlier engines" I mean 1300-1750.

Andrew

 

[mikerwilson]

Thanks a million! That sounds like what I needed!