One of the items on the winters list is to replace all the valve seals. I’m trying to decide whether to stuff a rope method, the air pressure method, or just pull the head. I do have a couple of the steel valve gaskets Charlie S. did the group buy on a couple years ago. Car seems to have about 88,000 miles on it. 1970 Duster with 198. Thoughts??
Valve seal replacement
- Thread starter dddDuster
- Start date
-
Run piston to top and use compressed air.
Very easy on slant 6 to replace valve seals.
Very easy on slant 6 to replace valve seals.
Rope trick is sure fire. No chance of dropping a valve in.
As easy as they are to work on, I would have the head reworked. You can have it milled for more compression and use that thin head gasket, too. If it needs seals, it probably needs guide work and a valve job. Just one peon's opinion.
Mopar44134
Well-Known Member
I’ve never done the rope trick. I have on numerous occasion used compressed air. Piston will push down if its at the top of the bore.
65TerrorCuda
Well-Known Member
I do better work on the bench, I vote pull it
iScamp
Well-Known Member
To summarize:
Question: Should I use
air pressure, rope trick, or pull the head.
Answer: yes.
So my 2 cents (1.68 cents after taxes)... with only 88K miles I wouldn't pull the head.
Air pressure method is easier and quicker.
I prefer the rope method because that's how I've always done it. So there, another definite ambiguous answer.
Question: Should I use
air pressure, rope trick, or pull the head.
Answer: yes.
So my 2 cents (1.68 cents after taxes)... with only 88K miles I wouldn't pull the head.
Air pressure method is easier and quicker.
I prefer the rope method because that's how I've always done it. So there, another definite ambiguous answer.
Any of the above methods will work, it's all in what "YOU" are comfortable with. I have done it both ways with the head on with no problems. With the head on, and you do the work you may have an incident. If that happens, you will have to pull the head. It's one of the "Flip a coin" to make your decision.
Thanks all for all the replies. Here is what I’ve decided. I will first try the air pressure method, but will divert to the rope thing if the engine tries to rotate. I’m not sure what to think about stuffing rope through the drool tubes……. Seems odd to me. Now, once I screw up and drop a valve I will pull the head. Here’s my next question, does anyone have a recommendation for a head porter? If I pull the head, I will want to pocket port and clean up the runners, increase valve size if possible, install hardened exhaust seats, check and replace the guides as needed, possibly mill for positive seals, and mill to get to 8.5-9.0 CR. The only porter I know of in Colorado is Colorado Cylinder Head, but the old guy who knew Mopars has retired I hear.
Thoughts?
Thoughts?
Last edited:
slantsixdan
=..=
slantsixdan
=..=
Not on my planet! That could be a function of the planet, rather than the task or the candidate methods.
I like the rope method because…erm…it's easier and quicker. Quieter, too.
I knew a gal that did a good rope trick once.
Don't overthink it. I changed all of them with air pressure and a cheap Harbor Freight valve compressor in an hour or two. I'm sure rope works just as well, and as Dan said above, it will be quieter than having your 15-year-old Craftsman oilless air compressor rattling away in the background.
Charrlie_S
Well-Known Member
My 2 cents worth. I would use the rope. Why? Because the 198 and 225 slant six engines have the piston down in the bore at top dead center. If using air, you need to make sure the piston is exactly at TDC or the air pressure will push the piston down. Also if you break the air pressure seal (like when removing or installing the keepers) the valve can drop to a point where you cannot grab it to pull it up (even if the piston is at TDC). Don't have that problem using the rope.
EDIT: Depending on your budget and ambition, and what you want from the car.
I would consider removing the head and having the guides checked (and repaired if needed) freshening up the valve job, and milling the head to get a HONEST (by measuring) 8.2-8.5 compression ratio.
EDIT: Depending on your budget and ambition, and what you want from the car.
I would consider removing the head and having the guides checked (and repaired if needed) freshening up the valve job, and milling the head to get a HONEST (by measuring) 8.2-8.5 compression ratio.
Last edited:
Mopar44134
Well-Known Member
Overhead valve spring compressor is the biggest pain in the *** of the job, especially by the blower motor.
with compressed air you will hear blow by, possibly air through the carb or exhaust if the valves dont seal 100%. Once the spring is compressed I tap the retainer with a hammer to losen, before I remove the keepers I tap the top of the valve to make sure its seated. I’ve smacked the valve pretty hard to see if will jar loose, never had one fall. The sound it makes with 100+ psi is actually reassuring.
the pressure is on once the keepers are removed. I add grease to the keepers to keep them on the valve.
Rope method seems less stressful.
bottom line, it’s up to you, me compressed air seems easier/faster.
with compressed air you will hear blow by, possibly air through the carb or exhaust if the valves dont seal 100%. Once the spring is compressed I tap the retainer with a hammer to losen, before I remove the keepers I tap the top of the valve to make sure its seated. I’ve smacked the valve pretty hard to see if will jar loose, never had one fall. The sound it makes with 100+ psi is actually reassuring.
the pressure is on once the keepers are removed. I add grease to the keepers to keep them on the valve.
Rope method seems less stressful.
bottom line, it’s up to you, me compressed air seems easier/faster.
I've heard of it often but have never done it by stuffing a rope down there. Ive done the air compressor and the "pull the head" each many times. With that low of miles id definitely try the air first, with the head on the car/ usually that cuts the oil consumption from where it starts out to somewhere between "tolerable" and "almost none". At least that's been my experience. Unless you have further reasons to suspect a valve problem. If the car 's only gone 88k in 52 years about any reduction in oil usage would be noticable, and besides even if you still use a little bit, on something driven so little, a little top end lube won't hurt anything.
I've seen them go from 1qt in 500-650 miles down to 1/2 a quart of oil used in 4k miles (4k is when I change my oil) and the pack of valve guide seals themselves are quite cheap. So even if it didn't work, you got a new experience and aren't out much.
And just because you pull the valve spring and see that "oh that valve still has its seal, it hasn't fallen apart and gotten into the pan yet" don't let that fool ya into thinking the seal is still"good". They harden up, lose their pliability and Don't work any more.
I've seen them go from 1qt in 500-650 miles down to 1/2 a quart of oil used in 4k miles (4k is when I change my oil) and the pack of valve guide seals themselves are quite cheap. So even if it didn't work, you got a new experience and aren't out much.
And just because you pull the valve spring and see that "oh that valve still has its seal, it hasn't fallen apart and gotten into the pan yet" don't let that fool ya into thinking the seal is still"good". They harden up, lose their pliability and Don't work any more.
I finally got around to doing this today. Went with the rope a dope method. Works like a charm, wow it’s amazing how much rope 1 cylinder can swallow! It’s also amazing how hard 53 year old rubber seals are too!
-
