| oldfords | -- 08-31-2023 @ 8:48 AM |
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Hey guys, I have an 8ba engine that has been setting several years. I can start it up, but runs terrible. I checked compression and I have 0 pounds on number 5,6,7. All the rest are at or over 100 pounds. I think the valves might be stuck because of just setting. Is there any way to free them without pulling the head. I can if I must, but am looking for something easier. al
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| 37RAGTOPMAN | -- 08-31-2023 @ 12:56 PM |
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HI this may help, pull the all the plugs out, turn the motor by hand, till the one of the pistons are up and on compression stroke. spray rust buster on the valves, try pushing the valves back down, you might hear a click when they do, you will need a good flash light, you might have to tap on them with a brass punch, or make up a tool with a slight bend, to hit the top of the valve, if they loosen up, use MARVEL MYSTERY OIL in the gas, or even drip a little in the carb when runnning,. DO THIS OUT SIDE, for the SMOKE do one at a time, after you have them which you think are free take a compression test to confirm, Hope this helps 37Ragtopman, Maine
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| wmsteed | -- 09-02-2023 @ 10:21 AM |
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Many years ago I had a 1953 speed-boat that had an 8CM Marine engine in it. On several occasions I had trouble with valves sticking after the boat had sat in the garage for several months. On many occasions I used a procedure similar to what 37ragtop suggested, only difference was that I used a hardwood dowel after I sprayed MMO into the cylinder with the stuck valve. With the help of MMO and the leverage provided by the head a loud pop would emit from the engine when the valve snapped closed. With the help of MMO and Stable in the fuel, the problem of stuck valves ended. Bill 36 5 win delx cpe
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| oldfords | -- 09-04-2023 @ 1:00 PM |
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Well, bad news. I got the valves out and they are bent. I think now that I have a problem with the heads. I have a JR400 cam and 8BA heads. Could that be the problem? I don't know why only those three cylinders, but the valves must be coming up and hitting the heads. What do I need to do? The engine is in the car, so I don't want to change cams at this point. Are there other heads, or can I have these machined to fit? I don't know what to do at this point. al
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| carcrazy | -- 09-04-2023 @ 1:47 PM |
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If you are using the Iskenderian 400JR cam, this cam provides 0.400" cam lobe lift or about 0.388" valve lift which is too much for your stock 8BA cylinder heads to accommodate. This is only a guess, but your left head might have had more material machined off of its sealing surface than the right head or the right head was clearanced to provide additional space over the valves. This would account for you having valve clearance problems only on cylinders covered by the left head. There are a couple of things you can do to remedy this problem. The easiest is probably to determine how much space you need to clear the valves when they are fully open and machine the cylinder head in the areas over the valves just enough to provide the required amount of space. Provided you are willing to remove and replace the cam with one that will provide better street performance at idle and lower engine speeds, a stock or aftermarket cam that provides less valve lift would be a better solution.
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| 37RAGTOPMAN | -- 09-04-2023 @ 2:06 PM |
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BE SURE to check the valve lifters for damage, if they bent the valves, they might have damage, check even the cam lobes for marks , hope this helps, 1937Ragtopman,Maine,
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| oldfords | -- 09-04-2023 @ 2:27 PM |
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Thanks for the info. I think I would like to try machining the heads first. How would I determine how much to cut out and would it be the complete circle of the valve? al
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| Catfish Jones | -- 09-04-2023 @ 3:00 PM |
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I realize it may be too late to help with this discussion but the endoscope in the attached picture is a wonderful tool for looking into a cylinder head for bent/stuck valves, rust or scorching on cylinders. Very handy for retrieving lost items with the included hook and magnet attachment. It takes pictures and video. For less that $50 on Amazon it’s a great tool.
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| pauls39coupe | -- 09-04-2023 @ 6:55 PM |
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I have seen this happen before and I suspect it has something to do with the valve angle on the drivers side, and overly milled heads. You should check # 8 for bent valves too. Most likely the heads have been milled somewhere along the line cutting the clearance. The 400jr has a lot of lift so things get close under the best of circumstances. If you can find a pair of un-cut 8BA or 8CM head they may work. Put some strips of modeling clay on the valves and pistons, then turn the engine over by hand. Remove the heads and see how much clearance you have. Do this on both sides as you may be near disaster on the passenger side also. This message was edited by pauls39coupe on 9-4-23 @ 6:56 PM
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| oldfords | -- 09-05-2023 @ 6:37 AM |
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Has anyone ever put two head gaskets on to solve this problem? Just a thought
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| oldfords | -- 09-06-2023 @ 6:31 AM |
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I used a dial indicator and found my valves are lifting .385". I took digital calipers and a micrometer, and as near as I can tell I have .319" to .350" valve clearance in the head. When I consider a gasket compressed to .050", I would need at least .030 more clearance in the head. .319" clearance plus .050" gasket = .369" space available, and .385 required. Can I safely take that much out of the valve port on the head. I have also found a company the makes thicker gaskets.
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| wmsteed | -- 09-08-2023 @ 8:49 AM |
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Many years ago, (1955) a thermostat on the right bank stuck closed on a trip from Los Angeles back to my home in Vegas. The engine got really hot which warped the head, resulting in a blown head gasket. At the time there were a lot of service stations along the rural highways because car problems were an every day event. I limped into a service station up on top of the Baker Grade, took the right head off, bought two head gaskets and a can of Permatex, Lathered the gaskets, head and block with Permatex and reassembled everything. I put water in the engine, it sounded OK so were headed for Vegas. I had to drive the 36 to work for over a week before I could pull the heads and have them surfaced. I drove the 36 for two more years before I had the engine rebuilt. Bill 36 5 win delx cpe
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| TomO | -- 09-08-2023 @ 4:33 PM |
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I have been told that the material in the head combustion chamber is thin and every .001" is needed, by a machinist that specialized in flathead Fords. Tom
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| DanD32 | -- 09-10-2023 @ 5:10 AM |
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Cometic makes head gaskets in different thicknesses for valve clearence problems they are not cheap but might fix your problem without machining anything
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| oldfords | -- 09-11-2023 @ 9:01 AM |
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Thanks, I will for sure check on the gaskets. Cutting the combustion chambers on both heads can't be cheap either.
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