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> Yet another head thread, Need advice
bbrock
post Nov 11 2017, 06:37 PM
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This is related to the AA/HAM head GB but I didn't want to hijack. But that offer means I need to make some decisions sooner than anticipated on my resto.

The main question is whether to rework these heads or buy new? My very strong preference is to rework what I have, assuming the castings are good. They have not been cleaned so I was thinking about walnut blasting them myself so I can inspect for cracks before deciding whether to move forward on reworking. Is there any reason I should not blast them myself? Any spots that should be masked or blocked before blasting?

Basically, I just want to get to a decision point on whether to rework or buy new. After reading so much about how hard it is getting to find good original castings has me a bit spooked, and if I hit a dead end on reworking, I'd like to do it while the HAM GB is still an option. I also don't know what a basic head rebuild will cost. Anyone have a ballpark estimate? I used to be able to send them out to Cali for a couple hundred bucks, but those days are gone.

Here's a short version of the history my engine. It's GA 2.0L engine that I rebuilt the bottom end on in the late 80s, but the project stalled before I got to the heads. My best guess is that the engine had about 110K-120K miles on it when it was split. That's a guess because the odometer quit at about 92K shortly after I bought the car. The engine ran strong when the FI cooperated when it was pulled, so no reason to suspect any major issues. Other than a busted exhaust stud, the heads look good with no broken fins and very little carbon in the combustion chamber. So, overall, I feel these heads are a good candidate for rebuilding but would appreciate any advice or opinions.
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VaccaRabite
post Nov 28 2017, 01:07 PM
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I see something that looks like a crack in the spark plug hole (which is a super common crack site). Use some machinists die and that will tell you quick if there is a crack there or not. Post 14, Second picture, left hand cylinder, 3 o'clock on the spark plug hole. Could be a casting flaw, but it looks like a crack.

Zach
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bbrock   Yet another head thread   Nov 11 2017, 06:37 PM
bbrock   :bump: :) Even if someone could weigh in on DIY...   Nov 13 2017, 11:18 AM
mgphoto   A few years ago this option was nonexistant. Only ...   Nov 13 2017, 12:21 PM
McMark   No reason not to walnut blast them. Go ahead and ...   Nov 13 2017, 01:27 PM
bbrock   Thanks guys! I very much appreciate this. Wh...   Nov 13 2017, 03:02 PM
mgphoto   Simple way to check for cracks is a propane torch....   Nov 13 2017, 03:20 PM
bbrock   Simple way to check for cracks is a propane torch...   Nov 13 2017, 03:39 PM
McMark   Guides can be used if they fit the specs of what...   Nov 13 2017, 04:04 PM
bbrock   The lifters and cam make me nervous. There was a...   Nov 13 2017, 04:58 PM
McMark   Are there any numbers stamped on the cam? Usually...   Nov 13 2017, 05:06 PM
bbrock   Are there any numbers stamped on the cam? Usuall...   Nov 13 2017, 05:38 PM
McMark   Ah, that makes total sense. :thumbsup: Get those...   Nov 14 2017, 10:55 AM
bbrock   Didn't get the heads blasted last night but wi...   Nov 14 2017, 11:53 AM
bbrock   Finally got my heads walnut blasted. They still n...   Nov 28 2017, 09:51 AM
McMark   Dental type picks are a good way to get the gasket...   Nov 28 2017, 12:15 PM
bbrock   Dental type picks are a good way to get the gaske...   Nov 28 2017, 12:51 PM
Vacca Rabite   I see something that looks like a crack in the spa...   Nov 28 2017, 01:07 PM
bbrock   I see something that looks like a crack in the sp...   Nov 28 2017, 06:18 PM
McMark   You should replace them all. The sodium valve can...   Nov 28 2017, 01:34 PM
bbrock   You should replace them all. The sodium valve ca...   Nov 28 2017, 05:56 PM
nditiz1   Mark is correct my valve snapped in half.   Nov 28 2017, 02:13 PM
Mark Henry   I've never had to use dye to see cracks on a T...   Nov 28 2017, 06:38 PM
bbrock   Did a little more blasting around those exhaust gu...   Nov 30 2017, 10:01 AM
McMark   Manly Stainless are commonly used.   Nov 30 2017, 10:42 AM


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