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Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: clarkent5477 on March 31, 2018, 01:41:18 AM

Title: 1967 429 Sticky valves
Post by: clarkent5477 on March 31, 2018, 01:41:18 AM
Hello,

I've got a 1967 429 in my 66 Fleetwood that's got sticky valves. So much so that the rocker arm supports have all busted. I expect this is from running it after it hadn't been run for a very long time. I also suspect that the lack of the valve returning quick enough and the resulting misalignment in the valvetrain cause enough slop to cause the supports to break. Any recommendations on how to free the valves up? Or is it just best to rip the heads off and give it a valve job?

Many many thanks in advance!

Clark
Title: Re: 1967 429 Sticky valves
Post by: Julien Abrahams on March 31, 2018, 03:44:22 AM
In my view, if that muvh damage has already been done, then it also a possibility thsf the valves have hit the pistons, causing more damage. I would completely disassemble the engine just to see how bad things are. Worst casescenariomyou need to rebuild the engine.
Good luck
Title: Re: 1967 429 Sticky valves
Post by: 35-709 on March 31, 2018, 09:29:50 AM
Agreed.  Firing up an engine that has long been idle requires great care and preparation.
Title: Re: 1967 429 Sticky valves
Post by: Scot Minesinger on March 31, 2018, 10:16:11 AM
Agree with Julian and Geoff, dissemble and inspect - probably at a minimum valve job and timing chain are required.  Then you get into all the might as wells; reseal trans, new rear main seal, wiring, detail engine bay and etc.
Title: Re: 1967 429 Sticky valves
Post by: clarkent5477 on April 01, 2018, 04:45:32 PM
Thanks everyone. Yeah the guy I got it from pulled it out of a barn. Evidently the thing hadn't been registered (and I assume run) since the early 90s. Had I known it hadn't been run that long I would've stopped him.
Title: Re: 1967 429 Sticky valves
Post by: clarkent5477 on April 01, 2018, 04:53:29 PM
Since a rebuild is in order, do you all have recommendations on rebuild kits? Which do you prefer? A buddy of mine mentioned getting Stellite seats to make it easier to run with unleaded fuel. Any recommendations greatly appreciated!
Title: Re: 1967 429 Sticky valves
Post by: clarkent5477 on January 03, 2019, 09:08:04 PM
Just an update.. So I replaced the rocker supports and lubed and tapped the valves and started it. It clunked a little at first, but after it warmed up and got fresh new fuel running through it, it ran like a champ. No rebuild... (yet)  :)
Title: Re: 1967 429 Sticky valves
Post by: rajeevx7 on January 03, 2019, 09:24:14 PM
That clunk was prob a knock. Either way, glad it’s running for you! Aren’t we all just on a timeline towards a full teardown and rebuild anyway >:D
Title: Re: 1967 429 Sticky valves
Post by: Julien Abrahams on January 04, 2019, 03:07:21 AM
Glad you got it running 😉
Title: Re: 1967 429 Sticky valves
Post by: spolij on January 08, 2019, 08:19:21 AM
 rajeevx7----------Aren’t we all just on a timeline towards a full tear down and rebuild anyway >:D
So true so true LOL
Title: Re: 1967 429 Sticky valves
Post by: Jeff Rosansky CLC #28373 on January 08, 2019, 02:25:17 PM
If the valves were gunked up other things probably are too.  Everybody has their snake oil theories. Here is mine-- A little Marvel's does wonders. It may be worth a try. Don't use too much because it may free things up and all that crap ends up in your oil system. Not everyone agrees with this, but I think most will agree it won't hurt anything to try
Jeff
Title: Re: 1967 429 Sticky valves
Post by: clarkent5477 on February 14, 2019, 09:16:13 PM
Thanks everyone. Yeah, I ran some Marvel in gas tank as well as some Rislone in the crank case after I changed the oil. So far so good. Now sorting out transmission stuff. It works in all gears, but the rear seal needs to be replaced. I'll do U-joints as well, since there's vibrations at certain highway speeds (actually gets pretty disturbing if I let it go for too long..like the car is going to shake apart).
Title: Re: 1967 429 Sticky valves
Post by: clarkent5477 on February 14, 2019, 09:37:32 PM
Quote from: rajeevx7 on January 03, 2019, 09:24:14 PM
That clunk was prob a knock. Either way, glad it’s running for you! Aren’t we all just on a timeline towards a full teardown and rebuild anyway >:D

Your Fleetwood 75 is gorgeous!
Title: Re: 1967 429 Sticky valves
Post by: Maynard Krebs on March 03, 2019, 10:59:25 PM
Quote from: clarkent5477 on February 14, 2019, 09:16:13 PM
I'll do U-joints as well, since there's vibrations at certain highway speeds (actually gets pretty disturbing if I let it go for too long..like the car is going to shake apart).

Clark... your Cadillac may have "constant-velocity joints" at each end of the driveshaft (assuming that yours is not a 75 Series).  What is important is to mark (with a crayon) one of the bolt locations at each end of said shaft... so that after it's properly rebuilt, you can (or they can) re-install the driveshaft in the very same original position at each end, with their respective flanges.   These driveshafts "take a set".. and will be happiest (smoothest) when re-installed in the same, original positions when new (even if you change all the "crosses", which should be done anyway).   

Doing that and all else correctly.. should solve your vibration issues.
Title: Re: 1967 429 Sticky valves
Post by: Bobby B on March 04, 2019, 07:24:12 AM
Every car I've resurrected, even though is sounded /ran fine once started, wound up needing a rebuild in a short amount of time. Nothing worse than letting an engine sit un-lubricated for any amount of time, especially in the elements. I've never had any luck with any of my "barn finds" or when the seller says "It Ran when put away", or "It started right up when I dumped some gas down the carburetor" statements........
                                                                                                           Bobby