: 1970 / 472 with 375hp or 240?



KimKnudsen
01-04-11, 06:18 AM
Happy new year fam :)

I'm wondering.... Originally the 472 that was delivered in 1970 Deville is a 375hp
engine right? When i look at other cars for sale, some of them have 220-240hp? Was this an option? Or have they put in a 72-75 engine production?
- How can i check my engine if it's a 375hp engine? And where are the numbers located?

- My Deville convertible also have single exhaust on the left rear side, was this original? Because many ask me if i have a double exhaust ( one pipe on both sides )

Best wishes

Kim K

drmenard
01-04-11, 09:05 PM
When they rated your motor in 1970 , it was tested with no accessories and open exhaust... you get a bit less HP with a waterpump , alt, A/C compressor and P/S pump connected .. then put a exhaust , transmission and rearend then your number goes way down... don't get me wrong they got pleanty of power...In 1971 they dropped the compression ratio and so did the HP drop... but if you want to know if you still have a 1970 motor there are a few ways to tell... 1970 did not have a air pump with a tube going from one head to the other... they used 2 different castings for the heads.. the castings that ended in 950 did not have a boss to be drilled fot the air tube..to find the casting number its under the rockerarm cover... the other I think was 902 had the boss for the air tube but was not drilled.. so if your heads are 950's its a 1970... if not drilled its a 1970... if it has plugs or a air tube in the heads its not a 1970.... Not sure when but not long after 1970 they changed how they rated HP and had to take all things in to account... If your motor has never been apart you should think about changing the timing chain and gears... they were made with a plastic coating that chipped off and made the chain sloppy... and on a small chamber motor, that you have if 1970, if it jumps timing it will bend all your valves...there are cheap chain and gears that are about $30 and there are good chain and sprockets for about $100... DON'T USE THE CHEAP ONE.... the good one has 3 keyways... so you can adjust your cam timing.... if you are not going to change your cam ,go with the +4 setting.....

YourMainParadox
01-10-11, 08:59 AM
you don't loose HP with accessories they just use some of it the engine still would be whatever hp just it won't make it to the wheels. The reason for the big change in hp over the years is emissions regulations as well as lowered compression as the years rolled on. I have a 73 472 and your compression is 10:1 mine is 8.5:1 or less I think.