Hey guys. I picked up these camel hump heads with no accessory holes for cheap. I'm trying to figure out what was done to them by way of a rebuild. The valves and combustion chambers have carbon on them, but their is paint in all the exhaust and intake ports, as well as the threaded holes. Also, it has triple valve springs and the springs have 2 shims underneath them. I am assuming that these heads had a freshening up with new springs while still using the old valves. Is this correct?
Looks like aftermarket screw in studs and guideplates. The springs are dual springs with a damper. It doesn't look like they were run long after cleaning, but that doesn't mean a lot. A look at the combustion chamber might help, but you really need to take the valves out of the heads to see what you have. Then you can look at the seats and check the valve guides for wear.
For future reference, how do I tell the difference between a triple spring and a double with a damper? I will post pics of the chambers when I get home tonight
The "flat" spring is a damper. What are the last three digits of the casting number, between the springs and guides? That will tell you what is was before any changes.
last 3 numbers between the springs and the guides? Do you mean the last 3 casting numbers on the head?
paint in the ports and threads but carbon on the valves and combustion chambers? I'd say "Rattle Can" rebuild!
Tap the tips of the valves with a hammer to move the valves in the guides. Then pour solvent in each runner (exhaust then intake) with the head on its side and see if any leaks out. Quick way to see if the valves are bent or will seal on the seat.
I would think the same thing but the heads were disassembled and painted with the high build red oxide paint under the valve cover. Maybe they were, but the engine I bough them with had the whole bottom end machined with new flat top forged pistons, so I'm not really sure where this whole thing was in the rebuild process when the previous owner died.
Unless you personally know the machinist that rebuilt the heads I would assume they are just cores and will need everything. Maybe a $100 each if you need that casting number for your project. If they need a complete rebuild including hardened seats you would be better off buying new aftermarket heads ready to bolt on units from Dart, Edelbrock, Patriot or others. Even new GM performance heads that out flow those double humps are a little over $300 each ready to run. There is no magic in the Chevy Fuelie heads from the 1960s, they were great in the day but there are better choices now.
And a stock 5.3 out of a Tahoe with a cam swap will blow a gen 1 SBC out of the water. If the year were 1963 there would be plenty of magic in the fuelie heads.
They are the standard 1.94/1.50 heads, not the HiPo 2.02/1.60 heads. They look pretty fresh, but like has been mentioned before, you don't know what was done to them when they were apart. Only way of knowing is taking them apart and checking them. Or you can do the "gas in the port" test and hope for the best.
Looks good to me. Bolt them on and run them. Yes newer heads will out flow and out perform those guys, but this board isn't about newer anything really. Posted using the Full Custom H.A.M.B. App!
i would take them apart , then check the valve springs and valve guides. i'd also look to see if they had hardened seats on the exhaust ...then decide what needs to be done to them
I did acetone in the ports last night on one head and they checked out fine. going to do it to the other side tonight. Was the only difference in the heads valve size? Or are the castings of the ports different? I don't mind the smaller valves on the 327 its going on. If I want to take these apart to port them a little bit, can I do that and just assemble the valves and springs in the same spots they were removed from since these have been run already? What am I looking for to see if it has been upgraded to hardened valve seats?
When you take the valves out, look at the seat area in the head. there will be a separate ring around the seat indicating it has the hardened seats. You can get without them if the valves are stainless (yours are not). I notice that the center cylinder valves are sunk in the head and the outer valves are flush. You will need to check the valve height. Run a straightedge across the valve tips. This will tell you how good the valve job was performed.
With those springs I see a Flat Cam in you future, have someone one with a spring tester see what spring rate those are before you use them... Looked at your picture of the springs again, they may be OK but I'd still test the seat pressure at the correct installed height Have Fun!
I have some slight difference in height. If I lay the straight edge across the valves I get about .010-.020 worth of rock out of it on the end cylinders. I assume this can be ran? If they don't have hardened seats then I'm gonna have them done anyways.
If you clean around in the combustion chamber and around the valves you will see if it had seats in it they will not have the same texture as the cast chamber.
Don't worry to much about having hardened seats you really don't need them. As others have said, check vavle spring pressure, check valve guide clearance ( a real problem with Chevy, wiggle valve side to side in the guide, should be very tight), and then maybe manually lap the valves in, to see if they seat correctly.
To answer your first post, the heads have been rebuilt and run. The shims are used to get correct valve spring compression once the heads have had the valve seats re-surfaced. This is why some of the valves are "deeper" in the combustion chamber than others. The tool used to do the re-surfacing process slides into the valve guide, so I would guess that the guides were at least "ok" at the time of the re-build. Otherwise the re-surfacing of the seats could not be done properly. You could clean them up and use them as is. If you decide, as one of your later posts suggests, on a new cam and springs then you should investigate the quality of the re-build. As stated before, check the valves and guides for proper size and clearance. Port the heads if you like. Get some wire brushes designed for high speed and use a die grinder to clean them up. Replace the valves in the same location as they were removed from, and get some SS exhaust valves vs. hardened seats. Have your machine shop check the assembly for proper installed valve spring height. Buy new rocker arms, fulcrum balls, and lock nuts. Just get stock replacements, no need for 1.6:1 or roller tip, save your money. Then drive it.
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