I'm doing some major winter projects on my '63 Coupe de Ville and one of them is to pull the motor to fix the rear main seal leak. While the motor is out, I'm thinking about pulling the heads and having hardened valve seats installed. I've had the car for a couple of years and I've put about 8,000 miles on it. I add the Motor Medic lead substitute with every fill up but that's getting expensive and I'm not quite sure how good of a job it's doing. Plus, I don't know if the previous owner used any lead substitute so I don't know the condition of the valves/seats. When I install a vacuum gauge, it fluctuates quite a bit so I believe I already have some leaking valves. I plan to do a compression test soon.

Has anyone had hardened valve seats installed in their heads? If so, I'm anxious to hear how you made out.

Views: 84

Reply to This

Replies to This Discussion

I would perform a cylinder leak down test, that will tell you which  valves are leaking by listening @ the tail pipe for exhaust valves & the carb for intake valves, also the oil fill tube for rings leaking. I have used hardened valve seats on Pontiacs , and will be on my 429 Cadillac  rebuild, they work fine.Given your cars age it could need valves, seats, and bronze wall guides and valve springs.

Thanks, Chris for the good information. I'll definitely perform a leakdown test once I find the low compression cylinder (if I find a low cylinder) but whether I find low compression or not, I still want to install hardened valve seats for any potential future issues. I 'm looking forward to someone on here chiming in regarding their experience with installing hardened valve seats on their Caddy project. 

For those who came across this thread wondering about hardened valve seats, in a nutshell, here's the deal: When our wonderful cars were built, gas was way different. It was relatively cheap, it was higher octane and it included tetraethyl lead (lead). The addition of lead helped increase the octane but, more importantly, it helped "cushion" the valves each time they slammed closed on the valve seats. Unfortunately, lead was found to be bad for the environment so it was removed and we now only have unleaded fuel. Now, without the lead to cushion the valves, the valves can get hammered into the seats which can damage the valve and the seat. This damage will stop sealing the air/gas mixture in the cylinders and cause an inefficient burn. This can lead to poor performance, a "miss", poor fuel economy and other issues.

There is a lot more to it but this is the gist of it. And, this is why I'm anxious to hear about other Caddy owners installing hardened valve seats.

Mike,

I agree with what you wrote, but a petroleum engineer once told me (and I've read the same, over the years) that lead does not increase octane. It reduces the potential for detonation. And also provides a cushion for the valve seats, as you said.  

Bring back lead!

Van

RSS

Photos

  • Add Photos
  • View All

Forum

Show Your Vintage, Antique or Personalized License Plate!

Started by Jason Edge in 1963/64 Cadillac Specific Discussion. Last reply by Michael Buonaccorso yesterday. 13 Replies

I recently brought in an original, unrestored 1963 Indiana license plate…Continue

63 and 64 engine block interchangeable?

Started by Henrik Sonne Hansen in 1963/64 Cadillac Specific Discussion. Last reply by Jason Edge on Tuesday. 2 Replies

I read the section: 1963 & 1964 Engine and Transmission Facts, but still in doubt if the engine block of a 63 and 64 are the same and interchangeable?More specifically, will I be able to use all…Continue

Stuck Throttle

Started by Logan Robb in 1963/64 Cadillac Specific Discussion. Last reply by Logan Robb on Monday. 8 Replies

While out for a Sunday cruise this afternoon, I had a small heart attack when I opened up the throttle a bit and went to let off, only to have the ol girl keep going. Luckily, I was on a straight…Continue

Recent Minor Repairs

Started by Logan Robb in 1963/64 Cadillac Specific Discussion on Monday. 0 Replies

This is a repair I had been putting off and I am not sure why as it was nothing more than tedious. When I purchased my Fleetwood, I didn't know there was no thermostat in the water pipe, but the…Continue

Blog Posts

Loud air moving sound within carb with cleaner removed

Posted by Dave Fehrle on March 23, 2024 at 3:23pm 8 Comments

While checking my Carter carb with engine running, I took the air cleaner off and there was a very loud hissing sound of air. I placed a piece of paper over the carb and it didn’t move up or down, is this normal?

Vintage Air AC

Posted by Chase on March 21, 2024 at 5:55am 0 Comments

Hey everyone, has anybody done a Vintage Air AC/Heat setup in their car? I want to bypass the old vacuum setup and go with a Vintage Air Gen 2 model. Before I get started, does anyone have any experience with this? (Which model to go with, do’s and dont’s, etc.) It looks pretty involved. Any and all info/pics would be greatly appreciated. Thanks!

accumulator dryer

Posted by CHRIS CARLSON on December 6, 2023 at 10:54am 0 Comments

Who rebuilds original AC  accumulator dryers for 1964 Cadillac? I have been on Classic auto air in Tampa FL wait list for over a year ,  There is one on Old air products web site that looks very similar to the original # 21-4214A but states it fits 1962 Gm cars, The one recommended for a 1964 Cadillac is half the length 21-4215A    What  is everyone using ? I would prefer to be as original as possible. Thanks

'63 Eldorado trumpet horn + 2 standard horns restoration

Posted by Les Eastling on November 15, 2023 at 10:34am 1 Comment

My son, unbeknownst to me, had all three of the horns on our 1963 Eldorado completely restored. We had recently added the Eldorado trumpet horn to the two standard horns and the sound was not very good... we had heard good ones so we knew something was not right... but there was not much we could do to get better sound from the 3 horns. 

There is a restoration service called The Horn Works who my son…

Continue

Videos

  • Add Videos
  • View All

© 2024   Created by Jason Edge.   Powered by

Badges  |  Report an Issue  |  Terms of Service