Just wondering if anyone knows which of the valve seal PN's are correct for a 1966 Toronado 425? Just checking my parts catalog and they have a couple numbers listed and they seem to be applicable to both the intake and exhaust seals. Looking at the IPC, however, the valve seals "look" different, kinda confusing. What's the difference between these two PNs? In any case, what's everone been using for these seals? If it's working for you guys, I'll just get what everyone else has been using. Typical valve spring compressor works for this job as well? Just looking for advice. This fall I'll be replacing the seals as well as the manifold bolts when I install some Remflex gaskets (we'll see how that one goes!) on the cylinder heads.






Thanks everyone!

 

Best seals, I don't know.

Spring compressor? I prefer the arm/lever type when there is room to work it. When there isn't enough room I'd use the type with the cranking **** on top and two legs that actually compresses and retains the spring.

For the manifold bolts have patience, six point wrenches and sockets and penetrating oil. Soak the bolts on a warm engine and let it cool, do this over-and-over. When breaking the bolts loose tap them tighter first to the slightest detectable movement, soak it and tap it loose to the slightest movement.

Repeated soakings usually pays dividends.

 

Get the stock replacement Felpro umbrella valve seals, p/n: SS70393. I think that the Rock Auto site states that these are rubber seals; they are not rubber but a plastic compound. The early factory seals were rubber and deteriorated over time ending up clogging return holes, etc.. Don't recall when exactly the factory changed to a plastic type valve seal but they work fine and last longer. They can be a bear to get started on the valve stem; very snug! Push them all the way down when installing; the Felpro kit should include an installation tool. They will find their comfortable location when you start the motor. Taller seals go on the intake valves. There are a couple different ways of holding the valve up when doing this job. One way is to use a compressed air supply through the spark plug hole with appropriate adapter. Another is to feed rope in through the spark plug hole to fill the gap. Either way, you want the piston at TDC on the cylinder being worked. I also prefer the lever type valve spring compressor when doing this job on an installed cylinder head. Good luck!

 

Excellent info! Thanks so much!

 

Again, excellent advice. I will definitely use these tips when I attempt to remove the manifold bolts. Grade 5 replacement hardware the way to go?

 

Grade 5 is good. The bolts are 3/8 16 TPI and IIRC 1/1/4" long.

If the manifolds have never been off look for locking tabs on the bolts that must be bent out of the way to get a wrench or socket in place. 14mm six point is slightly smaller than 9/16". Start with 14mm tools v 9/16 if the 14mm will go completely on the bolt. The 14mm will have less chance of rounding the hex and will allow you feel the bolt twist/stretch slightly more.

Thoroughly wire brush all exposed threads in addition to the penetrating oil on the warm cooling down engine.

 

To answer the original question, as it says right in the parts book listings, 401823 is for valves that are standard stem diameter or up to 0.005" oversize ("O.S."). 401825 is for valves with stem diameters 0.010" to 0.013" oversize. The factory way to repair worn valve guides in cast iron heads was to hone oversize and use an oversize valve. The seals needed to match. This is described in the Chassis Service Manual.

 

Ahh! Oversize, (O.S). I can't believe I missed that. Back to the books I go. Thanks Joe

 

Do the heads still have 1966 springs and all other valvetrain parts? If so, now is the time to inspect for wear, and just replace the springs if they're 60 years old. Springs fatigue with use.

 

Yep, never been touched. This car was very gently used its whole life, I'll inspect as best as I can though.

 

How much mileage is on this engine?

 

81k

 

Your inspection may go very well then, springs I would replace. I have a couple '66 Toro engines and one of them had lost the internal retainer clip of the lifter, very possibly because of valve float within those heavy fat lifters and with weak springs.
Please report back with your excellent results, and good luck - hope all goes well!

 

Took a few pics back when I did the valve cover gaskets a couple years ago. Not that this shows much other than it was pretty clean inside:

 

Good day all, just as an add on to this thread I was wondering how you can tell if you're looking at an intake valve or an exhaust valve when you have the valve covers off? I did a little digging in the manuals and I can't quite tell. I only ask as I want to make sure I put the right seals on the correct valves. The images shows below do a pretty good job depicting them but I can't tell which was the engine is facing. Any tips on this? Exhaust valves are the smaller ones correct?






Drivers side valves



Passenger side valves

 

Look at the intake manifold and follow the raised runner to the intake valve, the other valve on that cylinder is the exhaust valve.

 

Looking at the intake runners, they don't look like they directly line up with the intake valves in a couple of cylinders. The air must not go straight at the valves on those cylinders. I guess you could follow the same logic using the exhaust valves? I have this picture saved ( I think it's Bob Siegrist's' cylinder head from his 1967 Toronado)

 

Follow that picture, it's the perfect example.

 

Are the cylinder heads the same for both sides? Now that I look at his picture and my car, I have no idea how to tell which side cylinder head I'm looking at in those pictures (I made the annotations to the picture earlier as I thought I was looking at the drivers side cyl head). I previously thought that the B on the heads meant it was the drivers side. I hadn't noticed before now but I see that the B on the heads is on both of the cylinder heads. One of the B's is on drivers side FWD, the other B is on passenger side AFT so it could potentially just be interchangable side to side (by looking at it at least).

 

No matter how you want to slice and dice this.
#1 The top of the head will always be top on either side. Bottom of the head will always be at the bottom on either side. Are you following me here ?

#2. Center of the cylinder head is center on either side. If you have to, count FOUR valve stems from either end THOSE are exhaust valves. The intake valves are next to them on either side and either side of center.

#3. If you need to, count two valves in from either end of the head, you have the other exhaust valves.

To simplify this, simply find the central TWO valves. Then, notice the pattern of exhaust, intake, exhaust, intake toward the ends.
I hope this helps.

 

It's so simple when you describe it this way. I should have seen that myself. Thanks for this!

 

Yes for this situation consider them interchangeable side-by-side. You could even swap them side-to-side. There could be a minute difference e.g., a date code or other stamping but no functional difference.

 

Checked the parts catalog (which I should have done earlier honestly)........same PN for both sides so they are indeed the same. Wow, learn something new every day. Appears that the Toronado and the 400 use the same heads, cool! Although, I think I recall Joe telling us that these later head PN's were different heads than the originals and not quite as good. Thanks again!

 

Sometimes the answer is right in front of us, we just don't see it. I am sure you can chuckle inside when you look at an Oldsmobile head next time. You learned something that will perhaps be passed on.

 

The heads are the same side-for-side. The only time this is not true is on most OHC engines where both heads need the cam drive at the front. On your car, the head that was born on the passenger side will have the engine unit number stamped on the front of it.

 

That's great info Joe thanks. That would be very helpful if I ever have the cylinder heads off as it would tell me which side is which.