Whtaz Up!!!!! I pulled the head on my 300 today because the previous owner said it was cracked. First I did a compression check and this is what I found, 1>145 psi 2>130 3>zero 4>zero 5>50 (not good) 6>138. I pulled the head, head gasket seemed intack, number 3,4 cylinder the valves were stuck open, with a little tap with a hammer they went back in place. So now my only concern is number# 5, on top of the piston there seems to be a piece or chunk of metal missing, 1mm out of the side, not sure if it goes deep or not, and its not the alignment notch either. What i belive happened was the gasket failed, due to overheating and then it entered into the cylinder causing the chunk of metal to shatter. Any ideas on this theory? What also confirmed it was the previous owner told me water was squirting out of the side in the back which would account for #5 failure....My father said pull the oil pan underneath take the piston out look at it, re-hone the cylinder and put a new piston in #5 put a head gasket back on and see what happens, motor turns over nice no binding, and the cylinder wall on # 5 shows no scoring. Also, there is no ridge in the cylinder wall and seems like it was rebuilt not so long ago. Any Ideas would be great,I'm going to have the head magnaflux to check for fractures, no gross fracture are noticeable.Boy do I love working on this simple to get too engine, had the head off in under an hour

 

Brett,

Flux it and listen to your Dad. It will probably make a daily driver. You will know a lot more when you get the pan off. Remember, you very rarely see any visible cracks. Heat and pressure can force water thru cracks that cannot be seen with the naked eye. Let us know how it's going.

Jim

 

i dont know about the problem you are having but the 240 in my 66 1 ton gets anti freeze in the oil i think. The oil will turn gray on me. I put a knew head gasket on and the oil was fine fore almost a month . now it is turning gray again. I plan on putting a newer 300 in it but for the time being would block sealer get me through till i get my new motor

 

I've heard it will buy you some time!!!! But another thing that might help you would be to pull the head have it fluxed and make sure there are no cracks fairly cheap and easy to do, have the head also checked to make sure it has a flat deck,the head gasket may be fine, but if the deck isn't perfectly flat then it wont seal correctly....I think you could do it for less then 100.00, if you decide to pull the head do it before you put a sealer in.. Good luck let me know
Brett

 

the timing gear cover wasnt compleatly sealed so when it pulled the antifreeze through the block some would leak down pass the gears and into the oil pan. allso my fuel pump went bad and fuel was leaking into the oil i got it fixed now though. thanks

 

Good deal man. How the heck did you discover Anti Freeze making its way through the timing gears??? Good ketch man!!!!!!
Brett