Cracked Head?
#1
Cracked Head?
The 292 in my 64 F-100 starting missing pretty bad. I determined that the cause was fouled plugs due to bad valve seals. Started replacing valve seals (they were like bakelite) and got to the second last cylinder and when I plugged in the air hose to keep the valves up, I heard gurgling...I'm hoping it is just a blown head gasket; the spark plug from that cylinder had white oil all over it, but the crankcase oil and all the other plugs look normal.
Are the Y-blocks known for having cracked heads? I plan on having it pressure tested when I pull it off, just wondering if a crack is likely.
I'm pretty sure this engine only has 24K miles on it. It has sat for a while.
Are the Y-blocks known for having cracked heads? I plan on having it pressure tested when I pull it off, just wondering if a crack is likely.
I'm pretty sure this engine only has 24K miles on it. It has sat for a while.
#2
#4
#5
#6
#7
Good news, glad to hear it. FYI. ARP recommends tightening their bolts or studs three times to be sure the gasket's compression ring, which goes around the cylinder, fully compresses. Bring them to torque spec, then loosen, retorque, 3 times. It may be a good idea for stock bolts too. I had a case where I torqued down a head with stock grade 8 bolts, to 73 ft. lbs, one time. Came back two weeks later to remove head and the breakaway torque of the bolts ranged from 55 lbs to maybe 60. Everyone said it must be the bolts stretching, but I am 90% sure it was the gasket which didnt fully compress on the first torquing.
Trending Topics
#10
Thanks -I'll check them once I run it for a while. That is, if the machine shop ever gets done with my heads!
One other note on the different length head bolts: I took note of where the longer head bolts were as I unbolted the heads, and on the pass side, the two longest ones were next to each other at the back end of the motor. ON the driver side, the two longest were next to each other at the front end of the motor.
Everything I have read in this forum says that the two longer bolts are at each end, (i.e. one at front of motor and one at back of motor).
Maybe I am misinterpreting.
One other note on the different length head bolts: I took note of where the longer head bolts were as I unbolted the heads, and on the pass side, the two longest ones were next to each other at the back end of the motor. ON the driver side, the two longest were next to each other at the front end of the motor.
Everything I have read in this forum says that the two longer bolts are at each end, (i.e. one at front of motor and one at back of motor).
Maybe I am misinterpreting.
#11
No misinterpretation. Longer on the ends, through the dowels. Whoever put the heads on previously screwed up. That is probably the reason for the gasket leak(s), because two bolts were bottomed out, unable to be torqued down properly.
Take a looks at John Mummert's section regarding Y block assembly errors, since you are getting closer to being a "motorhead" .
Concerning the installation of intake gasket and manifold. I am going to try this on my installation soon. Light coat of white grease on head and manifold surfaces, no sealer. RTV around each water port, head and manifold surfaces. Ted Eaton said he uses the grease when dyno testing an engine. It allows installation and removal of manifold without messing up gasket. Others have said they use no sealer or anything else except in the area of the water ports. I have always used sealer on the entire gasket, and when it is time to remove there is a mess that takes time to clean up.
Take a looks at John Mummert's section regarding Y block assembly errors, since you are getting closer to being a "motorhead" .
Concerning the installation of intake gasket and manifold. I am going to try this on my installation soon. Light coat of white grease on head and manifold surfaces, no sealer. RTV around each water port, head and manifold surfaces. Ted Eaton said he uses the grease when dyno testing an engine. It allows installation and removal of manifold without messing up gasket. Others have said they use no sealer or anything else except in the area of the water ports. I have always used sealer on the entire gasket, and when it is time to remove there is a mess that takes time to clean up.
#12
OK - I did take a look at the assembly errors section - Good stuff in there. The machine shop said my heads will be done tommorrow AM, and its supposed to be 45 degrees and no rain here in Cincy tomorrow so I should have the old 292 running by tommorrow evening. I'll post an update with my results on Sunday.
Thanks for all the help!
Thanks for all the help!
#13
UPDATE - A buddy and I got the engine back together last night with no leftover parts! Fired it up, and it ran like crap. We adjusted on the valves for a while (using feeler guage) and got it to smooth out quite a bit, but the engine still vibrates alot like it has a miss (runs better than before though). Using the finger-meter, we noticed that the cylinder which previously had a compression leak seemed to be running a little cooler that the rest, judging by the heat coming from the exhaust manifold.
This morning, I read up on how to adjust the valves using the quarter-turn method. I am going to try that today and see if that gets it to smooth out...Also going to check the compression on that cylinder to see if it still leaks.
This morning, I read up on how to adjust the valves using the quarter-turn method. I am going to try that today and see if that gets it to smooth out...Also going to check the compression on that cylinder to see if it still leaks.
#14