Thread: Teardown and Rebuild

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I finally tore into my 400 Small Block in my attempt to fix the either blown head gasket or possible warped head. So far I taken off the plug wires, ac unit, carb and valve covers. Still need to take off the manifold, exhaust and heads. I did manage to obtain an extra set of heads from a 350 small block for the reasonable price of a case of beer. The heads look in fare shape but are missing two valve springs and two push rods. Should I need to use the 350 heads what would a fare price be to have them reworked and tested? I'm hoping for the best in that I'm just looking at a blown head gasket and will not need to change the heads out. Any suggestions or other things I should be aware of in the rest of the disassembly and rebuild?

was the motor overheated? if i remember correctly the 400's would crack the block in between 3&5, and 4&6???? if you cant find a worped head or bad gasket look there.

The car blew the upper radiator hose bringing it home. Don't know if the car overheated or not as the idiot light never came on and there is no temperature gauge. I was working on it over the weekend and noticed that one of the rocker arms was busted in two. How common is it to break a rocker arm? This was on the number one cylinder for the valve on the right of the cylinder which would explain why this cylinder was not firing. Would the leak (water in the cylinder) cause enough pressure to break a rocker arm?

Also I'm having difficulty getting to the bottom Head bolts as the exhaust is in the way. With the Exhaust pulled back I probably have about 2 inches of clearance to try to get a ratchet with an extension plus a pivoting extension on the bolts. Am I going about this wrong or does it just take patience and persistence.

if the motor hydraulicked that is probably what caused your rocker arms to break. if that is the case expect to find more to it than just broken rocker arms. you may have bent a connecting rod.

if you having trouble getting the head bolts ,take the manifolds off . this will give you pleanty of room and make it easier going back together .

What is hydraulicked?

Hydrauliked means the cylinder pulls in water, usually from the leaking cooling system. Then when the engine rotates and the valves close it is not able to compress the water as it could the fuel mixture. Since the water will not compress, something has to give. Usually a connecting rod bends, a piston breaks or the cylinderwall cracks. If there is enough water in the cylinder to make it difficult for the exhaust valve to open, then a rocker arm could break. No telling what happened to your motor until you get the head off, unless you had water come out the sparkplug hole when you pulled the plug and turned the motor over.

It could also be a valve that is stuck, or even a defective rocker arm.

Pat

Thanks for the help guy's.