Cadillac Owners Forum banner

1 - 8 of 8 Posts

·
Registered
Deville Convertible
Joined
·
22 Posts
Discussion Starter #1
Hi there.

Last year I purchased a -69 DeVille with a 472 engine.
The engine were partly overhauled, and got a new Edelbrock intake and carburator. (According to the number on the carb, its a 600CFM)
First thing I`ve noticed when I bought it, were it were quite sluggish at 50% and above throttle. It could be like it were starved, and didnt give me enough power. (First caddy, but have a -73 Lincoln with a 460 to compare with.)
The ignition had been changed with HEI. When I pulled the distributor cap and rotor, I saw the cap had some bad connections. The mechanical advance were also stuck.

This winter I`ve overhauled the distributor, with new vacuum advance, mechanical advance, electrical system, rotor and distributor.
I adjusted it by ear, and took it for a spin.
The changes were amazing. It were more like the Lincoln, and I felt it gave me more "bang for the buck".
I stopped the car for a few minutes, and when I tried to start it again it were realy slow on the starter. (I hope it is a bad ground cable, I`ll swap it tomorrow)
The starter is only a few years old, and is a "high output" starter.


Anyway, this night, I thought I`dd adjust the timing and hook up the vacuum gauge. (First time for me to use the vacuum gauge on an engine...:confused:)
I adjusted the timing to 5`BTDC. At least I believe I did. The plug wire I first thought I`d check didnt show any marking, but when I took the wire 180` from it, it looked right..
Vacuum were a bit low at aprox 17-18 inHg (I`m not sure if I trust the gauge, as its not at 0 when unplugged...), and jumping steady +- a few degrees.

I`ve also planned to check the plugs tomorrow. What should the gap be?



Messy thread, but alot of thoughts in a foreign language in my head:rolleyes:
 

·
Registered
1970 Eldorado.
Joined
·
4,023 Posts
Are we being pranked?
I am sure he means the gap of the spark plugs, i.e. what type of spark plugs he needs for his engine.

----------

Hi there.

Last year I purchased a -69 DeVille with a 472 engine.
The engine were partly overhauled, and got a new Edelbrock intake and carburator. (According to the number on the carb, its a 600CFM)
First thing I`ve noticed when I bought it, were it were quite sluggish at 50% and above throttle. It could be like it were starved, and didnt give me enough power. (First caddy, but have a -73 Lincoln with a 460 to compare with.)
The ignition had been changed with HEI. When I pulled the distributor cap and rotor, I saw the cap had some bad connections. The mechanical advance were also stuck.

This winter I`ve overhauled the distributor, with new vacuum advance, mechanical advance, electrical system, rotor and distributor.
I adjusted it by ear, and took it for a spin.
The changes were amazing. It were more like the Lincoln, and I felt it gave me more "bang for the buck".
I stopped the car for a few minutes, and when I tried to start it again it were realy slow on the starter. (I hope it is a bad ground cable, I`ll swap it tomorrow)
The starter is only a few years old, and is a "high output" starter.


Anyway, this night, I thought I`dd adjust the timing and hook up the vacuum gauge. (First time for me to use the vacuum gauge on an engine...:confused:)
I adjusted the timing to 5`BTDC. At least I believe I did. The plug wire I first thought I`d check didnt show any marking, but when I took the wire 180` from it, it looked right..
Vacuum were a bit low at aprox 17-18 inHg (I`m not sure if I trust the gauge, as its not at 0 when unplugged...), and jumping steady +- a few degrees.

I`ve also planned to check the plugs tomorrow. What should the gap be?



Messy thread, but alot of thoughts in a foreign language in my head:rolleyes:
You got yourself into a lot of work with that partly tuned engine. Without doing any tuning to the engine internals, fuel pump, headers and exhaust the Edelbrock setup will just make finetuning the engine a lot more complicated without much of performance gain than the original setup.
Anyway, you are on your way. Make sure you follow the instructions in the shop manual for your car on setting the timing, without the vacuum advance plugged. Good luck! There's a lot of knowledge with many friendly and helpful people here in the forums.
BTW, you can also ask your engine specific questions here:
http://www.cadillacforums.com/forums/500-472-425-368/

P.S. where are you located? And we would love to see pictures :highfive:
 

·
Registered
2003 Deville base, 69 Eldorado, 68 Impala, If I tell you the rest......well....
Joined
·
492 Posts
I am sure he means the gap of the spark plugs, i.e. what type of spark plugs he needs for his engine.

----------

I know, with everything he said and what he has done so far, wondering why that was asked.
 

·
Registered
2016 SRX AWD Premium 2011 DTS Platinum
Joined
·
137 Posts
I owned a 1969 Coupe de Ville with the exact problem. It turned out to be an obstruction in the exhaust that drove me nuts. The dealer finally resolved the issue by replacing the long pipe in front of the muffler. It was a double walled pipe and if you went thru water the inner wall would move away from the outer wall and block about 70% of the flow. Check out the exhaust blockage before you go further.
GOOD LUCK
 

·
Registered
1970 Eldorado.
Joined
·
4,023 Posts
I owned a 1969 Coupe de Ville with the exact problem. It turned out to be an obstruction in the exhaust that drove me nuts. The dealer finally resolved the issue by replacing the long pipe in front of the muffler. It was a double walled pipe and if you went thru water the inner wall would move away from the outer wall and block about 70% of the flow. Check out the exhaust blockage before you go further.
GOOD LUCK
Wow, I never heared of that. Thanks for sharing. Your inner pipe must've had some dent in it to act like that?
That's hard to check though.
 

·
Registered
2016 SRX AWD Premium 2011 DTS Platinum
Joined
·
137 Posts
Cold water on a very hot pipe caused the inner wall at separate on my 1969 Deville. The dealer picked up on it immediately since it occurred after some heavy rains and flooding in the area. Just start it up and place you hand by the tail pipe to see if it feels like a normal exhaust. I know how you feel. I was desperate before I decided to take it to the dealer. My 1969 coupe was one of my favorite cars!!
Good Luck
 

·
Registered
68 DVC, 96 FLTWD Brgm, 11 CTS Premium (two)
Joined
·
1,623 Posts
I am sure he means the gap of the spark plugs, i.e. what type of spark plugs he needs for his engine.

----------



You got yourself into a lot of work with that partly tuned engine. Without doing any tuning to the engine internals, fuel pump, headers and exhaust the Edelbrock setup will just make finetuning the engine a lot more complicated without much of performance gain than the original setup.
Anyway, you are on your way. Make sure you follow the instructions in the shop manual for your car on setting the timing, without the vacuum advance plugged. Good luck! There's a lot of knowledge with many friendly and helpful people here in the forums.
BTW, you can also ask your engine specific questions here:
http://www.cadillacforums.com/forums/500-472-425-368/

P.S. where are you located? And we would love to see pictures :highfive:
Especially since the original QuadraJet was rated at 650 CFM, and with that edlebrock intake seutp you have to forego Climate Control. And HEI - why bother with such blasphemy?, my P&C woks just fine has lots of reserve power at all speeds, starts in 1/10 of a sec hot or cold, etc.

The # plug on the 472 is on the passenger side. That's the one you want to put the timing light on.
 
1 - 8 of 8 Posts
Top