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1971 Head(s) redo

Started by elanmike, February 17, 2021, 08:45:02 PM

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elanmike

I have a 1971 SDV with 33k miles. The car was stolen over the summer and as the expression goes "they drove it like they stole it". Scoped the motor and the pistons are fine but I have some bent valves and it is time to pull the heads and off to the machine shop. Who is a good source of valve-train hardware for early 70's Cadillacs? I am assuming much will have to be replaced parts wise. It is my understanding that the seats are already hardened in 71 for the low lead/unleaded that was becoming available. Any other thoughts are appreciated. I was going to use Tom at Cylinder Head Services Inc in Minneapolis for the machine work. Thanks in advance

"Cadillac Kid" Greg Surfas 15364

This post sounds very familiar. Does anyone remember it or am I just having a senior moment
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Cadman-iac

Quote from: "Cadillac Kid"  Greg Surfas 15364 on February 17, 2021, 09:24:35 PM
This post sounds very familiar. Does anyone remember it or am I just having a senior moment
Greg Surfas
Not sure Greg,  is it possible to share a senior moment?  Lol!
I remember the story about it being stolen,  but haven't heard much since then.

Rick
CLC# 32373
1956 Coupe Deville A/C car "Norma Jean"

Bob Hoffmann CLC#96

1968 Eldorado slick top ,white/red interior
2015 Holden Ute HSV Maloo red/black interior.
             
Too much fun is more than you can have.

chrisntam

Quote from: Cadman-iac on February 17, 2021, 09:57:22 PM

I remember the story about it being stolen,  but haven't heard much since then.

Rick
1970 Deville Convertible 
Dallas, Texas

TJ Hopland

Does your machine shop want you to get the parts?   As far as I know there isn't anything too special or difficult about valve parts for these engines so if the shop's regular sources have them I would think that would be the best route. 

IF the shop can't get or doesn't like what their usual suppliers have then I think I would consider CadCo (cad500parts.com) a shot.  I have not used them before but given the choices today I think it would be worth at least a call. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

elanmike

This is a refresh of the post from a while ago. Since I asked about parts (and any thoughts about while the heads were off) in the previous post and didnt get a response to those questions I thought I would put it out there again. I know all parts aren't created equal. The machinist doesn't specialize in Cadillacs, though he has a great reputation as a machinist.

The Tassie Devil(le)

Don't worry if he is not a specialist in Cadillacs, especially the one you have, as these are just basic engines, and nothing special.   Just that the parts are bigger, and therefore easier to work with, and get ones' hands inside.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

TJ Hopland

The only head things I can think of for these and I don't remember the technical details or names but its common to change the guide seal type.   Cadillac used what I think is called an umbrella seal that has plastic parts and wasn't typical for engines of the era.   As far as I know they still make them and come in a full engine gasket set.    What many people choose to do is change them to a different style that I think is called a positive seal that was more common.    To do this I think they machine the height of the guides down a bit.   

You can ask the shop about it.  I don't think its something you need specific details for.   The shops deal with that sort of thing all the time for performance builds where they need more lift so more clearance so its not like it takes tools or processes they are not used to.   Mine was done that way and I can't remember if that was something I read or something they asked me if I wanted done.   For a lightly driven classic I don't know if it really makes a lot of difference.   The umbrellas eventually crack and fall off and the positive seals get hard and quit sealing so either way in another 20 years someone may have to replace either one. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

"Cadillac Kid" Greg Surfas 15364

I thought this sounded familiar.  If I am not mistaken there were some responses suggesting that if they were able to float the valves you might just check on the condition of your timing chain.  All that rattling around is a good way to destroy even a good Nylon coated cam sprocket.
In regards to the heads themselves, a good machine shop will magniflux them to check for any cracks and check the valve guides for wear.
I myself use the positive Viton seals.  They are positive seals and although they require some machine work on the valve guides, they are good.  I have posted a shot of the type of seals I am referring to.  These are not specific for your car, just as an example of the type.

https://www.summitracing.com/parts/hrs-93360?rrec=true

I also would take a second look at the pistons for damage.  It is hard to imagine the valves hitting the pistons hard enough to bend them without doing damage to the pistons themselves
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

elanmike

#10
Just an update. Pulled the heads and all that goes with that and figured out what was going on. The brand new carb had its choke blow out. Since we had everything dialed in just months before the car was stolen we didn't notice this until we started diving into it. The engine was so coked up that it caused the bad readings on the leak-down test. Regardless, the intake manifold was pulled and found to be damaged, the timing chain was in dear need of replacement, figured out that the weird random leak in the radiator was a totally failed core, and both exhaust manifolds were cracked. So we redid the heads anyway (real hardened seats, new valves...) since they were off anyway. Hopefully will fire up in the next couple of days. Fingers crossed

Update: Running great, waiting for the new muffler and resonator and charging the AC Friday. Now for the little things:)