Nailhead 364 cui, push rod damaged - need help

Tommi

Member
Hello,

I am during a full restauration of a buick 58, special. When I bought the car in the last year, I drove 1 week with the car to check technical parts. Engine seems to work without problems. The Engine Head gaskets are also dry and Engine was not noisy. After this I begann with the full frame off restauration. I am at the point which I want to reinstall the engine into the frame. Yesterday the last work on some minor gaskets on the engine. Then I saw a problem inside the engine. One push rod is damaged. (See attachment, the second (smaller) circle was the upper part from the lifter). I am a "hobby" worker, but I have a friend which can help with cars, but he is also not a specialist about this engine. Have someone from you experience with this engine 364cui? Can this happen sometimes or is this a indicator for a big problem?
Should we only change this push rod and the hydraulic valve lifter (I believe this is possible, I saw the parts in some shops) or make it more sense to reinstall the 2 heads and make a complete rebuild of the parts from the head (exhaust, intake, spring valve, push rods,rockerArms, hydraulic lifters). The engine is not the orginial it was a exchange, we don´t know how many miles on it.

regards
thomas
 

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I think you need to remove that head and see what bent the pushrod. There may be a stuck or bent valve at the heart of this issue. Adding another pushrod and lifter would just end with the same result.
 
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I've seen this happen many times when engines sit. Especially the "Nails" intake valves. Make sure the piston is down in the bore. Then put hand pressure on the valve & push down. There's only about 50-60lbs. of spring pressure on the seat so you should be able to push it down with hand pressure. If the valve is stuck you won't be able to push it down. Spray some penetrate/oil at the valve stem & tap with a hammer, not a sledge. This should free it up until you CAN use hand pressure. Just keep working at it. Once it's running again it will take care of itself. Unless the lifter is "Cupped" it should also be OK.
 
thanks for your answers, I will do this. It is excatly "the intake value". Is there a possibility to check if the intake valu is "bent" without deinstall the complete engine head?
regards thomas
 
Compare the valve stem heights. If the valve was bent even slightly the top/stem will be lower than the rest. If, it is slightly bent while running it will "Straighten" itself out. Make sure the piston is down the bore & you can use a small sledge to repeatedly tap on the valve & the head will come back. I'm also seen this. Of course the correct way to do this is pulling off the head.
 
I followed the steps from tom. Biston was "down", but I can´t move the intake valve (for other it works). Also spraying some penetrate/oil doesn´t help and tap with a hammer. After deep dive looking to the valve I saw it is not full closed, that means it comes also not complete back. I believe it is bent and I must remove the head on the weekend.

My next questions are what the next steps? repair only this intake valve (if all other seems ok), or rebuild both heads complete. I checked some shops, all parts together $700 -$900. ? Can this right?
That are the parts which I believe what I need for full rebuild of the heads
8 x EXHAUST VALVE
8 x INTAKE VALVE
16 x VALVE SPRING INNER
16 x VALVE SPRING OUTER
16 x VALVE GUIDE
16 x ROCKER ARM
16 x PUSHROD
16 x VALVE LIFTER
2 x Rocker Arm Shaft
set Valve Spring Retainer
1 x TIMING CHAIN
1 x CAM SPROCKET
1 x CRANK SPROCKET

I don´t know if it is usefull to change all parts (no experiences). I hope to get a answer from you. In the past I bought parts from oldbuickparts.com, but I have no experience about quality in this case. Any suggestions?

regards
thomas
 
Thomas,

I'd have a shop evaluate both of your heads. Then have them reconditioned only as needed. I would instruct them to use your current parts as long as they are still good. Only replace what can not be reconditioned or is out of specification. Have them call you with what they think is needed after disasssembly and the estimate on the job. Also, ask to have the worn or broken parts returned. You might want to call a few local automotive machine shops to get a general estimate on the cost of reconditioning. This will help you decide where you want to take them for disassembly. Reconditioning and replace as needed costs will be far less then replacement costs, and you will not have to worry about cylinder head problems any more.
 
Hello,

both heads are deinstalled. 1 intake valve is very very stuck, all others valve are deinstalled. A friend checked also the cylinders, on some is a kind of pitting. His opinion was to rebuild the complete nailhead (rebore cylinder, new piston, ...). Near from me is a shop which rebuild complete blocks. After visiting the shop, he told me that they check all parts after complete deinstallation of the block (maybe some parts can be rebuild by the shop or only cleaned), after this I need to oranise the other parts and then they rebuild the complete block. I found some shops in usa where I can get Basic, Master and Delux Set for complete rebuilding, but I have no experience about quality. In the forum I found some threads about kanter.com and egge.com shop. Have someone a tip for me?
 
bent pushrod......

Dang,,, Tom,,,,, to rebuild a entire engine just for a stuck valve and a bent push rod is severe action..... Tom is right , a engine that sits will sometimes do this.... that is why it is important to start a engine up and let it fully warm up even if you dont intend to drive it at the time.... I would pull just that head and check the valves , lube them and put the head back on..... then start it up and make sure there was plenty of oil coming up thru the rocker arm shafts.... if you are not getting lots of oil to the top , pull the rocker arm shafts off and remove the end plugs and run a rifle cleaning brush thru the shafts to clean the sludge out of them .... you will be surprised at how much crud is in there.... then replace the plugs and and reinstall the shaft assemblys , fire the engine up and check the amount of oil coming out of them...that oil is what lubes the valve/valve guides....nothing else.... and it cools the rocker shaft assemblies....
 
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