: 472 compression test

04-18-04, 12:32 AM
I bought a 1967 cadillac deville convt. that im trying to restore for $950.00 it has a 1968 472 cid in it ,and I also got the original 429 in pieces. I have worked on the 472 trying to get it to run with no luck , so I ran a compression test and going from front to back on drivers side I got 50,50,40,95 and pass side going from front to back I got 64,55,40,55. I was wanting some advice on what you think about this and what I should do. I want to get max h/p and tourqe for this car. Any advice?

Dead Sled
04-18-04, 07:31 PM
whats your budget for the engine? do you want to work with what you got or take it our machine it and rebuild it and start from scratch?

04-18-04, 08:32 PM
I would like to spend about $1500 at most all cost included on engine. also does any body know if there is a gear drive set up for 472.

lux hauler
04-18-04, 11:09 PM
No gear drive. You have two choices for a timing set.....either stock or Cloyes has a really nice roller set. From what I've heard, the Cloyes is money well spent.

$1500 will probably get you a stock re-build depending on what it needs.

Performance builds on these engines can get pricey. It's not necessarily the labor or machine work but the parts. Check my thread about my 500 build. It'll give you an idea of what a mild performance build can cost. There are some places that I spent too much money. I could have saved close to 8 or 900 if I had planned things a little better.

Below is the link to the thread about my engine build.

04-20-04, 11:47 PM
Hey guys. I looked in the PAW catalog and found a racing master rebuild kit. for $ 1600.00 alot more than I wanted to spend but, if your going to do something- do it the way you want it the first time. Right? I know after machine work, head work and mis. bull$hit it will dig into my chasing the g-string at the bar budget. but she never knew my name the next day anyway. YOU GUYS ARE GREAT. thanks:worship:

04-21-04, 02:46 PM
Hey guys. I looked in the PAW catalog and found a racing master rebuild kit. for $ 1600.00 alot more than I wanted to spend but, if your going to do something- do it the way you want it the first time. Right? I know after machine work, head work and mis. bull$hit it will dig into my chasing the g-string at the bar budget. but she never knew my name the next day anyway. YOU GUYS ARE GREAT. thanks:worship:
You are exactly right that you shuold do it the way you want the first time. I've gotten stuck a couple times doing it the way that was most affordable instead of the way that I wanted it. In both cases I ended up selling the car because although it was very good it was never what I thought it could have been.

Look at the info from Lux Hauler. He has built a heck of a motor.

Steve B.

Angela Desmond
04-21-04, 05:47 PM
Try your comp. test again, this time put about 2 or 3 teaspoons of motor oil, a little heavy like 50 weight if you have it, down the spark plug hole first. If the readings stay the same you're losing comp. through the head gasket of valves. If the readings go up, it's probably piston rings.Either way, it's been my experience, that if you want a rebuild that will last you over 100k miles, spend the money on the machine shop work, it's money well spent... :thumbsup:

04-22-04, 01:20 AM
Hey guys, LIke I say you guys are great. I did check out his build and I bet it runs like a scalded cat. I will try the oil in the spark plug holes , I hope it helps. Thanks alot all your help is greatly apprecieated.:worship:

04-23-04, 11:17 PM
I put some oil in the spark plug holes and the compression raised. going from front to back on drivers side 112,90,50,100 and from front to back on pass. side 85,80,80,115. Who knows maybe if I can get to run for a while then change the oil it might come up a little more. Thanks so much. IT may run again with a little tender loving care. YOU GUYS ARE THE GREATEST. THANKS AGAIN:worship: :worship: :worship:

Angela Desmond
04-24-04, 09:43 AM
The oil you poured down creates a seal between the cylinder wall and the piston rings. So if the readings went up, you most probably have bad rings.Changing the oil will do nothing to help your problem. You need rings kid....

04-27-04, 11:19 PM
SHE'S ALIVE!!! I did a few things and it runs. I put desiel fuel in the spark plug holes to help the rings free up and and then did oil the same way, that seated the rings. still not enough compression. I always heard a weird noise when ever i turned the engine over. sounded like a boat motor. I traced the noise to valve covers, removed them and discovered a stuck valve and a bent push rod, a hammer and a new push rod -still not much compression , pulled oil filter and it was dry. primed the oil pump . tund it over untill oil pressure raised enough to work lifters ... DAM THING STARTED AND SCARED THE CRAP OUT OF ME!! I didnt expect that to happen. Thanks so much for all the help. You guys helped bring another one from the dead.:worship: :worship: :worship: :worship: :worship:

04-28-04, 04:01 AM
Great thread voodoo, it makes me wonder what kind of intresting things might happen when I finally try to fire mine up. Speaking of which, how much will vacuum affect wheter or not a 472 ('68) will start or not start. All my vacuum lines coming out of the firewall are burnt and I'm wondering if I should tackle this problem before attempting to kick it over.:rant2:

04-28-04, 11:58 PM
Im not a very good mechanic,still learning. but I do know the distrib needs vacume, it goes to front passanger side of carb. What is your project car?:)

04-29-04, 05:37 AM
I didn't know the distributor needed vacuum, I was wondering what that vaccum spigot on the carb was for. The project car is a 1968 Sedan Deville Hardtop. The story: The man I bought the car from had pulled the original engine because there was some type of fire in the engine bay. He didn't know the cause of the fire and therefore neither do I. He lowered in another one from a '68 coupe de ville, but hadn't hooked anything up when he got involoved in other projects. Come spring he needed the room on his property so he put it up for sale. I bought it as is. So far I've hooked up most of the usual stuff that gets un-hooked for an engine swap. The last two things on my list before I attempt to start it are electrical (old wiring harness was burnt) and vacuum lines. The electrical is pretty daunting on it's own so if I didn't have to worry about the vacuum stuff too much that would be nice. If you're anything like me there are most likely times where you wish you were working on a car with it's original engine, but hey a convertible's a convertible right. And $950 is a good chunk of change less than the $1200 I paid for mine. Thanks again for the post.

Angela Desmond
04-29-04, 09:21 AM
A lot of racers don't bother with vacuum advance at all. I ran a Mallory Unilite with only mechanical advance for years on a chevy small block, but you don't get as good gas milage at cruise speeds. You can start the car without the vacuum advance, just bump up the timing about 4 or 5 degrees and it should idle fine. Just remember to plug up the vacuum source or you'll have a leak.

04-30-04, 11:07 PM
Hey Canadiankid . Im still trying to put wires and vacume lines back :banghead: hope I can get it all right. Im sure glad to have guys like Lux and Angela to ask questions, those guys know there caddys. Mine wouldnt be running yet without them. I also put a manual choke 750 cfm Edelbrock carb on, this dosnt help vacume line hunting. I also have a electrical device on the drivers side of transmission that I cant find a wire for? Im going for the first test drive tomarrow probally wont shift? Who knows. Anyway we have great taste in classic cars . Good Luck with your classic machine. :)

05-01-04, 12:54 AM
Thanks voodoo, same to you. And remember, Cadillac ownership is an instant liscence to use the word "FUGEDDABAWDIT" all the time.

Angela Desmond
05-01-04, 08:38 AM
Sorry to disappoint you,I'm not a "guy"...Unless you call everyone "Guy"...And I grew up and lived most of my life in Brooklyn N.Y. ,where EVERYBODY says " FUGGETABOWDIT"..(I'm still guilty of saying it) :rolleyes:

05-02-04, 01:31 AM
Sorry Angela, I guess I just assumed you were a guy. I really feel like an ass. I hope your not mad. I really appreciate all the help you gave me. I took the caddy for a test drive today, the engine ran like a champ- but the car haddent been driven in so long the front wheel locked up. went through the tire and the spair. Going to buy all new brake parts as soon as my funds come together. I also have a leeking power steering hose. But it felt great to go out in wind even with all the little problems. P.S. are you hot!!:D

Angela Desmond
05-02-04, 11:27 AM
Not mad at all...Hot, I guess, but married...look like an old Goldie Hawn; that fixes cars.. :p

lux hauler
05-02-04, 12:56 PM
Not mad at all...Hot, I guess, but married...look like an old Goldie Hawn; that fixes cars.. :pand a former pro-boxer:want:

05-04-04, 12:25 AM
Angela- hey your hot , look like Goldie Hawn, can fix cars, like caddys, and can kick ass as a boxer. You Are The Greatest Women In The World! To bad your married. I used to box a little here in Indianapolis- wasnt a pro-but it was alot of fun= when I won. :worship: HELL YA!! U THE GREATEST.

Angela Desmond
05-05-04, 02:44 PM
thanks guys... :bouncy:

05-05-04, 04:53 PM
By the way, just a silly question, but I don't know the answer for sure: what is the compression number being searched?:hmm:

I've allways heard of different values, but never have I actually read or hear anyone say "XX is the correct compression for such an engine"...:confused:

Angela Desmond
05-05-04, 06:41 PM
That's a damn good question; in this case, I think if it's in the 115 range it should be OK. I believe it's more important that they are all in the same area, as long as it's not stupid low, like 70PSI or something. If they were all 70PSI I'd guess it was a blown head gasket....Naturally, if the comp. ratio is high, the PSI will be high, but I don't know if there is a mathimatical equation for figuring PSI from the comp. ratio. :hmm: I'll e-mail someone I know that's a whiz with auto-math and see if there is one.

05-05-04, 11:49 PM
I was going to put a picture of my car on here, does anyone know how to do this? I know you most likely dont give a dam what my car looks like, but im prowd of it.

Angela Desmond
05-06-04, 01:46 PM
I can't help Voodoo with the pics, I'm computer illiterate, but i did get an answer for Catman. There is no exact formula because there are too many variables, like cranking speed of the engine, oil pressure at cranking speed, cam duration, etc... Generally, stock motors are around 100PSI, slightly modified 110 to 140, all out motors can be over 140 and I was told it's been seen as high as 240PSI...So it's more important That they be fairly even between cylinders and nothing more than 10 or 20PSI different in a cylinder from the other cylinders, which is pretty much what I thought in the first place. Hope that helps you a little :)