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Taking on a somewhat intimidating job this fall on my '66 Toronado (I'll be replacing the valve seals) and I'm looking for any advice you guys could offer. Pitfalls, common issues, etc you run into and how you solved them.
I've never done this job before but I'm up for the challenge, although I'd still love your input. A couple of years ago I had to replace the valve cover gaskets because they were leaking oil like crazy and the engine made a ton of smoke when running. While I had the covers off I noticed bits of the valve seals sitting on top of the heads so they're obviously deteriorating. I didn't replace them at the time but I think now will be the right time as I'm definitely burning a bit of oil and the end of the driving season is soon upon me here.
I've got the CSM, which actually doesn't exactly tell you how to do the seals with the head on the car, but I think I can piece things together. I have a spring compressor tool that I think should work (see my picture below), and I have a new set of the Fel-Pro SS 70393 valve stem seals to throw in. I've also got a tool that can supply compressed air to the cylinder to keep the valves seated. So far I'm set up for success, I think. I won't be replacing the springs at this time. The engine only has 80k on it and was never run hard.
My questions so far (I know, I'm sorry I have lots):
Looking at the CSM, there appears to be no adjustment of the rocker arms? Do I have that right? Just put some assembly lube on the pivots and torque to 35 ft lbs? Do you guys like to do these things in the firing order or just go 1-3-5-7, 2-4-6-8?
Best practice would be to roll the engine over to TDC on the cylinder your working on and add compressed air to hold the valves closed right? If it's not bang on TDC, is there any problem with that? If the valve somehow does fall down, you're taking the head off aren't you?
The keepers, are they typically stuck? Any tricks on breaking them free? How about the seals? I've heard they can be very difficult to get over the valve stem sometimes......any tricks for that (maybe hot water?)?
I took some pictures of the heads when I had the valve covers off. I'll post them below along with the tool I bought (it was the only one I could find - hopefully it works).
Just do the valve guide seals by the firing order 1, 8, 4, 3, 6, 5, 7, 2 when each cylinder is at TDC. You can watch the lifters and pushrods and stop close enough to TDC.
If you aren't married to using an air attachment you can use a length of nylon rope. Feed it into the cylinder and then rock the engine back so the rope is compressed against the valves. This will keep them from falling into the cylinder.
Just do the valve guide seals by the firing order 1, 8, 4, 3, 6, 5, 7, 2 when each cylinder is at TDC. You can watch the lifters and pushrods and stop close enough to TDC.
If you aren't married to using an air attachment you can use a length of nylon rope. Feed it into the cylinder and then rock the engine back so the rope is compressed against the valves. This will keep them from falling into the cylinder.
The one time I used a rope it got tangled inside and I ended up having to pull the head to get it out.
25 ft/lbs torque on those rocker bridge bolts; 35 is for the 1965 "A"casting cylinder head studs. The hard plastic replacement valve stem seals are very difficult to get started over the end of the valve stem. I have always done this with the heads off and on a bench. Just push the seal all the way down on the valve stem, it will find its final location once you start the motor. You may find the valve spring retainers stuck tight to the valve stem locks, a little tap on the retainer from a plastic or hard rubber mallet or hammer will jar them loose.
Last edited by 67OAI; Oct 29, 2025 at 09:18 AM.
Reason: add info
25 ft/lbs torque on those rocker bridge bolts; 35 is for the 1965 "A"casting cylinder head studs.
Right you are! Thanks for picking up on that mistake. The manual is very confusing in this section shown below. What bolts are they referring to in Installation Step 1 I wonder?
Added some more to my previous post for you. The torque specs listed above are actually for the "A" heads with studs. The studs, listed as bolts in step 1, torque to 35 and the nuts, listed as hardened flanged bolts in step 4, torque to 20. For your "B" heads with the one piece bridge, those flanged head bolts should be torqued to 25 ft/lbs as I stated in previous post. Best to do the rocker arm removal and installation with both valves in the closed position, i.e. TDC compression.
Do compression test before starting the job as soon as the plugs are out. Plug the oil return holes to prevent anything from falling in there. It isn't a tough job just time consuming, you'll be fine, by the second cylinder it'll seem repetitive.
Do compression test before starting the job as soon as the plugs are out. Plug the oil return holes to prevent anything from falling in there. It isn't a tough job just time consuming, you'll be fine, by the second cylinder it'll seem repetitive.
Oil all friction points upon reassembly.
Good advice and a good reminder. I saw those big oil return holes when I had the covers off and thought those would be a great spot to lose the valve keepers down! I'll be sure to plug them.
I actually just did a compression test. I got 190ish PSI on all the cylinders except for #1 & #3 which were at 210 & 205! I think the damaged valve seals are on those cylinders and the oil is getting down to the pistons, increasing the compression. I did a compression check last year and I got 185 & 187 on those two cylinders.
Added some more to my previous post for you. The torque specs listed above are actually for the "A" heads with studs. The studs, listed as bolts in step 1, torque to 35 and the nuts, listed as hardened flanged bolts in step 4, torque to 20. For your "B" heads with the one piece bridge, those flanged head bolts should be torqued to 25 ft/lbs as I stated in previous post. Best to do the rocker arm removal and installation with both valves in the closed position, i.e. TDC compression.
I don't doubt you but do you have a manual reference for that? The '66 CSM doesn't mention 25 ft/lbs on the V8 engine rockers anywhere that I have seen. I may just be missing it.
Last edited by ourkid2000; Oct 29, 2025 at 09:57 AM.
[QUOTE I actually just did a compression test. I got 190ish PSI on all the cylinders except for #1 & #3 which were at 210 & 205! I think the damaged valve seals are on those cylinders and the oil is getting down to the pistons, increasing the compression. I did a compression check last year and I got 185 & 187 on those two cylinders.[/QUOTE]
Oil sealing the rings possibly and carbon build up on top of the piston due to oil burning.
You mentioned that you got higher compression numbers on cylinders #1 & 3. Does your car start with a puff of blue smoke? This is an indicator of worn valve guide seals. You could also do another compression test and squirt oil in each cylinder before taking the reading. If all of the numbers are similar you know the #1 & 3 valve guide seals are suspect.
You mentioned that you got higher compression numbers on cylinders #1 & 3. Does your car start with a puff of blue smoke? This is an indicator of worn valve guide seals. You could also do another compression test and squirt oil in each cylinder before taking the reading. If all of the numbers are similar you know the #1 & 3 valve guide seals are suspect.
I haven't noticed too much blue smoke to be perfectly honest but I did find quite a bit of rubber valve guide seal material on the driver's side bank so it would make sense. Anyway, that's why I'm doing the seals.... they are deteriorating.
I just want to add that the tool you have will be pretty useless on an Olds engine because there are no real rocker arm studs. You will have to rig up a bolt that might work. its a little more expensive but this type of tool will work better:
Another hint. After 60 years the valve locks tend to get stuck in the retainers pretty good. After you take the rocker arms off take a small ball pein hammer and smack each retainer on one corner to **** it sideways. That will break the locks loose and make it a lot easier to compress the spring. Hers is a pic of where to hit.
I just want to add that the tool you have will be pretty useless on an Olds engine because there are no real rocker arm studs. You will have to rig up a bolt that might work. its a little more expensive but this type of tool will work better:
Another hint. After 60 years the valve locks tend to get stuck in the retainers pretty good. After you take the rocker arms off take a small ball pein hammer and smack each retainer on one corner to **** it sideways. That will break the locks loose and make it a lot easier to compress the spring. Hers is a pic of where to hit.
That's really good advice. I will keep this in mind for sure. The manual shows the tool has a bolt that helps you compress the springs. I guess I could rig up something similar, welding some threaded rod together.......or try the spring compressor you show.
The main problem with the tool you have is that it almost makes it a two person operation because you have to hold pressure on the spring while you try to get the keepers out. With the tool I showed its a lot easier by yourself. Get a small magnet too. That makes it easy to grab the keepers. If you have an automotive machine shop near by see if they will sell you set of new keepers. They are very cheap and I always replace them. I buy them in boxes of 500.
That looks like a crazy mix of valve stem seals and timing gear plastic!
Yes, my car has the air injection reactor system (K19) so you'll see the lines going into the head in my pictures.
Turned my engine upside down today and wow how much of this stuff it was in the oilscreen , much more than earlier pic
And there are more pieces in there than shows on the pic.
Turned my engine upside down today and wow how much of this stuff it was in the oilscreen , much more than earlier pic
And there are more pieces in there than shows on the pic.
That is wild! That would turn your oil pressure light on would it not?
Have not seen the oil pressure light come on when
the engine running. Have oil pressure gauge also and have always had oil pressure. Should remove
the oilpump and clean all parts.
I suppose if all those bits of nylon timing gear & valve guide seals completely blocked the oil pump pick up it would effect your oil pressure.
The engine in my 71 98 is the OE engine with over 90k miles. I've seen the oil pressure light from time-to-time and hear a bit of valve train noise. I just use 20W50 to mask the noise. Would I put in a new cam and timing set without doing anything to the bottom end? I doubt it. I already replaced the head gaskets, so now I'll just keep driving it.
Quote:
Originally Posted by 67OAI
Added some more to my previous post for you. The torque specs listed above are actually for the "A" heads with studs. The studs, listed as bolts in step 1, torque to 35 and the nuts, listed as hardened flanged bolts in step 4, torque to 20. For your "B" heads with the one piece bridge, those flanged head bolts should be torqued to 25 ft/lbs as I stated in previous post. Best to do the rocker arm removal and installation with both valves in the closed position, i.e. TDC compression.
I don't doubt you but do you have a manual reference for that? The '66 CSM doesn't mention 25 ft/lbs on the V8 engine rockers anywhere that I have seen. I may just be missing it.
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1966 Oldsmobile Toronado DeluxeLast edited by ourkid2000; Oct 29, 2025 at 12:57 PM.
I don't have the 1966 CSM; the torque info I supplied comes from the engine torque chart in the last pages of the V8 engine section of the 1967 CSM. You can verify that the flange head bolts specified for the 1966 V8 engine is the same part number as that specified for later V8 engines thus torque value is the same. Scan of page attached.
I've seen timing chain bits cause the oil pressure switch to activate, it does happen. The oil light activates at approx 5psi, no light means better than 5psi nothing more.
Quote:
Originally Posted by 67OAI
Added some more to my previous post for you. The torque specs listed above are actually for the "A" heads with studs. The studs, listed as bolts in step 1, torque to 35 and the nuts, listed as hardened flanged bolts in step 4, torque to 20. For your "B" heads with the one piece bridge, those flanged head bolts should be torqued to 25 ft/lbs as I stated in previous post. Best to do the rocker arm removal and installation with both valves in the closed position, i.e. TDC compression.
I don't doubt you but do you have a manual reference for that? The '66 CSM doesn't mention 25 ft/lbs on the V8 engine rockers anywhere that I have seen. I may just be missing it.
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1966 Oldsmobile Toronado DeluxeLast edited by ourkid2000; Oct 29, 2025 at 12:57 PM.
I don't have the 1966 CSM; the torque info I supplied comes from the engine torque chart in the last pages of the V8 engine section of the 1967 CSM. You can verify that the flange head bolts specified for the 1966 V8 engine is the same part number as that specified for later V8 engines thus torque value is the same. Scan of page attached.
Thanks so much! Looks like you and I found yet another problem in the 1966 CSM as it doesn't show the TQ specs for the Toronado rocker arm pivot bolts. Before anyone says to check the Toro Engine section, I did. There's no TQ values listed for those parts, only specifications. According to the '66 CSM, all V8's had rocker arm studs.
Since you'll have to rotate the engine so the cam closes both your valves, you can go ahead and torque down the rocker bridges after replacing the valve guide seals.
I used nylon rope, it worked great. You don’t have to be at a perfect tdc as long as you have the rope tight against the head. To me, using air was intimidating as I have a decent compressor but it has a small reserve tank, I knew with the rope, that nothing odd was going to happen with me hitting the hose or plug of compressor that led to a head removal. Plus, I could leave for an hour and not have to worry about the compressor running.
I used one of those screw type valve compressors that uses a ratchet handle to tighten, not the goofy version that has a faucet handle at the top that you tighten by hand. Ratchet is key and this tool lets you keep the valve spring compressed while you swap the seals. You set the spring aside as you work and just pop it back on after you get the seals installed. The tool you have requires you to apply compression on spring with one hand and remove or add the keepers at the same time. That seems miserable. Also, Get yourself a strong magnet on a telescoping pole. That makes it easy to remove and replace the keepers without them dropping somewhere.
I've used the rope method a few times. It seems safer to me, but to each their own. A dab of Vaseline/grease on the keeper will also help with reassembly.
I just want to add that the tool you have will be pretty useless on an Olds engine because there are no real rocker arm studs. You will have to rig up a bolt that might work. its a little more expensive but this type of tool will work better:
Another hint. After 60 years the valve locks tend to get stuck in the retainers pretty good. After you take the rocker arms off take a small ball pein hammer and smack each retainer on one corner to **** it sideways. That will break the locks loose and make it a lot easier to compress the spring. Hers is a pic of where to hit.
‘Use Bills advice and process, you will thank him later. That flat tool isn’t a one man job very easily.. for 25 bucks why put yourself thru the aggravation?
I’ll add one more opinion/idea. Bill K noted the twisty style spring compressor. I find these easier to use by adding a 3/8 drive adapter on it. Take an old extension (cut off) or socket and weld it to the top of the hand wheel so you can use a ratchet or I guess, even a small impact gun. Quicker & easier on the fingers.
‘Use Bills advice and process, you will thank him later. That flat tool isn’t a one man job very easily.. for 25 bucks why put yourself thru the aggravation?
Like I need a reason to buy another tool, ha! I'll pick one up for sure.
I've used the rope method a few times. It seems safer to me, but to each their own. A dab of Vaseline/grease on the keeper will also help with reassembly.
So that just keeps them from flopping around right?
I've used the rope method a few times. It seems safer to me, but to each their own. A dab of Vaseline/grease on the keeper will also help with reassembly.
Same here. Roll the engine until the piston is about 3/4 of the way to the top of the bore, put some rope in there, and then roll it the rest of the way up. About a foot, maybe 18 inches is plenty.
Same here. Roll the engine until the piston is about 3/4 of the way to the top of the bore, put some rope in there, and then roll it the rest of the way up. About a foot, maybe 18 inches is plenty.
I have bad luck. If I did this, somehow that rope would get caught up in something and I'd have to take the head off.
Regarding the errors you have found in the 1966 CSM, they most probably are just left overs from the previous year CSM that weren't caught prior to publication. There should be dealer service bulletins generated to address them. I'm sure at least one of our members would have a copy.
Regarding the errors you have found in the 1966 CSM, they most probably are just left overs from the previous year CSM that weren't caught prior to publication. There should be dealer service bulletins generated to address them. I'm sure at least one of our members would have a copy.
Well would you look at that......sheesh, unreal. Good call! Not a TSB, it's in the June 1966 Service Guild:
I have bad luck. If I did this, somehow that rope would get caught up in something and I'd have to take the head off.
That EXACTLY why I prefer the rope. With my luck, my compressor would die, the house would lose power, or air hose would burst, or some other catastrophe would occur, requiring either walking away and leaving the compressor on, or resulting in losing air and having the valve fall anyway.
That EXACTLY why I prefer the rope. With my luck, my compressor would die, the house would lose power, or air hose would burst, or some other catastrophe would occur, requiring either walking away and leaving the compressor on, or resulting in losing air and having the valve fall anyway.
Ha! You're not wrong, I understand that thinking as well and I'm preparing myself for the worst. Something bad WILL happen.
The last time I messed with the engine, I was simply checking the timing marks for accuracy. Rolled the engine over by hand to TDC with a small wooden dowel touching the top of the piston so I could watch movement......yep, marks look good. Put the spark plug back in and started the engine. Engine started making noise like I had a collapsed lifter on cyl #1. WTF?? Luckily the noise went away and didn't come back but something I did there made that lifter collapse momentarily. Probably when I moved the engine backwards ever so slightly when I was lining up the timing marks and it somehow made that lifter collapse. Everyone I spoke to on here said it was purely coincidental but I dunno......that "luck" thing.
