GREEN GHOST
Well-Known Member
Ok, so maybe I should just pull the engine now and change rings lol . . . . Gonna take it one step at a time and not jump to potential worst case
Advice / pointers on replacing valve seal
- Thread starter GREEN GHOST
- Start date
Swinger 340
Well-Known Member
I would go with your original plan first, change the oil seals. Should be a one hour job. If still having a oil fouled plug, then go to the next step. Oil and compression rings are two separate entities. Bought my 340 Dart and it smoked up a storm. All my buddies laugh while I changed the oil seals, per my above instructions. With motor on the floor (they also laugh), I started it up and no smoke. Rebuilt it anyway, because I was restoring the car and I went through everything. 35 years later and still running strong.
GREEN GHOST
Well-Known Member
So another academic question, I'm doing the compression check and the driver side cylinders are great. Passenger side 2 & 8 ridiculously low. I did not pull the fuel line because it's a mechanical pump and figured it really wouldnt pump unless I work the throttle. Not the case, raw fuel coming out of spark plug holes. Question is will the fuel effect the cylinder test or ruin the gauge ? I refuse to believe I have 190 cold across all drivers side bank & 30 on passenger side
Swinger 340
Well-Known Member
Dumb question, you do have the rocker shaft back on? If your valve seals are cracked or even missing, the plugs will look like that.
GREEN GHOST
Well-Known Member
Yes! Just bought a new gauge and all is good, 190 across all cylinders. No idea how I did it but I must of gacked the old gauge. . .false alarm
Good news. That still doesn't mean that there couldn't be a ring problem but the only way to know for sure is to tear it down. I don't think you need to do that yet. What I would do at this point is replace #3 or all the seals if you like. When changing seals with the spring off give the valves a wiggle test to check the guide for excess wear. Put a fresh plug in #3 or all if you like. Drive it and see if #3 fouls again. Keep track of your mileage. How did the rest of the plugs look? Another thing you could do while the plugs are out is to visually inspect the cylinder walls. Maybe you know someone with a bore scope that could check it for you.
This is a big block with 3/8 bolts or studs.
The 17ft-lbs or 200 in-lbs is correct for the small block 5/16 bolts or studs but certainly not enough for the big block application.
FSM torque specs for the big block rocker arm bolts is 25 ft-lbs. I have seen aftermarket rocker arm/cylinder head specs using the thicker rocker shafts at 30-35 ft-lbs.
pishta
I know I'm right....
big block....noted. 
GREEN GHOST
Well-Known Member
Hey, so I been kinda bouncing between this and my other compression results threads. All the plugs looked trashed and it seems to be determined that the carb was leaking and fouling the plugs. I pumped the breaks on the valve seal for the time being and am working on new plugs, wires, & carb . .
I'm doing the rope dance this week myself. I've got one plug that tends to foul and hope this is the fix.
Swinger 340
Well-Known Member
You started this thread asking for info on changing valve seals. I assumed you were puffing out white smoke (oil issue), which could be the valve seals. Black smoke would be a fuel issue possible. The oil issue could foul the plugs, which then would seem like a fuel one. No white smoke, then your correct, look at the carb. If it is Holley, then there is your problem. LOL
GREEN GHOST
Well-Known Member
Since I got this car it's been an absolute Rollercoaster of discovery & trying to figure out exactly what I have lol. . .I knew the carb & fuel system needed attention and despite what the previous owner told me I hope the seals are OK. I did however buy everything needed to replace them, just rather not tackle it now. . . As far as smoke, it typically gets started once every or every other week. Upon start it does puff alittle smoke but not much, I'm thinking it's more condensation in exhaust. . .so in a nutshell after further diagnostics and with alot of help from the forum I'm hoping the carb will resolve the issue. . . If plugs are still getting junked up I guess it'll be onto valve seal changing
GREEN GHOST
Well-Known Member
Nice . .are you using the compressed air or rope method ?
Rat Bastid
Dunamis Metron
I’ve done it both ways and I can do it 10 times faster with air.
Rope Dance means using rope. It works.
1 1/4 I believe... but you could be right...
GREEN GHOST
Well-Known Member
1 1/4"
I agree. On a manual transmission car, just chunk it in gear to keep the engine from turning from air pressure.
I would use the tool you already bought in post #2.
My apologies, I wasn't paying attention to who posted . The compressor in the pic pushes on one side of the retainer. Not ideal but will probably work with low spring pressures. Flip the handle over from where it is in the photo and place on top of the valve. place fingers under coils and pull handle. You will have to adjust the bolt height to get proper amount of travel. refer to post #8 and others for more details, tips and opinions. Also if that tool proves to be completely uncooperative refer to post #2 for a picture of another type of tool as an option. Good luck.
