Yet another head thread, Need advice |
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Yet another head thread, Need advice |
bbrock |
Nov 11 2017, 06:37 PM
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#1
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914 Guru Group: Members Posts: 5,269 Joined: 17-February 17 From: Montana Member No.: 20,845 Region Association: Rocky Mountains |
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. |
McMark |
Nov 13 2017, 04:04 PM
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#2
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914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
Guides can be used if they fit the specs of what's needed. Some old head rebuilds need oversize guides.
But there's nothing wrong with the NOS guides/springs. The lifters and cam make me nervous. There was a period of time where cams were causing some problems. Not to mention the hardness of the cam and the lifters must be matched so one doesn't eat the other. If I were building that motor I would be getting a new WebCam and lifters, instead of risking that combo. It's not a guaranteed failure, so if you're stuck with what you've got then keep moving forward. |
bbrock |
Nov 13 2017, 04:58 PM
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#3
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914 Guru Group: Members Posts: 5,269 Joined: 17-February 17 From: Montana Member No.: 20,845 Region Association: Rocky Mountains |
The lifters and cam make me nervous. There was a period of time where cams were causing some problems. Not to mention the hardness of the cam and the lifters must be matched so one doesn't eat the other. If I were building that motor I would be getting a new WebCam and lifters, instead of risking that combo. It's not a guaranteed failure, so if you're stuck with what you've got then keep moving forward. Yeah, this has been nagging at me. I'm not stuck with what I've got, but it would open a can of worms. If I started this rebuild today, I'd almost certainly be refurbing the stock FI instead of going to carbs. My plans now are to go ahead and run the carbs to see how I like them, then maybe start working through all my FI bits to eventually go back to that. So, that would wind up being a lot of swapping CAMs. This may betray my ignorance, but since this was a regrind job on a factory CAM, I'm thinking the hardness should match the factory lifters assuming they didn't grind through the hardened layer. Maybe that is wrong thinking. I did get the lifters on the same order with the CAM from Automotion. I'll probably start another thread on the CAM to see if anyone had experience with these Automotion reground CAMs back in the day. Eckler has already responded and is trying to locate specs for me. This is the original numbers matching GA case, so I really don't want to built it with a loose grenade inside. |
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