What do you think a 500 crate engine would get MPG wise?

What vehicle, what rear-end?

Brian

Stick it in a CRX and you could see 20 city, stick it in a 76 hearse and you'd be lucky to see 10.

Oh yeah. I forgot the vehicle. A 1977 Deville.

Assuming all stock including drivetrain and optimum tuning: around town = dismal 10-12 MPG.
Steady highway 65 MPH = 14-15 MPG. An overdrive would help out.
Steady highway 55-60 MPH = 17-19 MPG.


The later flat top piston open chamber head engines were always easier to set spark advance curves on compared to the dished piston engines. Dunno why but have noticed this several times.

It would be all stock. I'm looking to sell my 1977 Coupe that had the engine rebuilt with a new camkit, bored out, new pushrods, valves, etc. and buy another 1977-1979. The only reason is being that there are too many small things I don't want to keep worrying about. Oh, it also had the tranny rebuilt with a shift kit. Anyway, I'm looking to sell it and start all over and drop an engine in it that will get good gas mileage. I remember reading something about a deville that got about 25 mpg with some work done to it. What would it take to get something like that?

Realistically... buying a northstar powered Deville.

Realistically... buying a northstar powered Deville.

Or a Honda....but you know how those BIG CAD engines are. Right now I'm getting something along the lines of 13-15 mi. a gallon from my 425. I really just want to start all over and rebuild a 472/500 and drop that in another 1977-79 coupe. I just don't know whether to get one with low compression and use a mild camkit from MTS, or put some 76cc heads on a 500 and get a higher compression and use a little bit beefier cam. I would like to get something along the lines of 18 mpg. Most of my driving is for work (about 30 min. away) and it's almost like highway driving. I stop twice and then hit a small town, but that's it. Just looking for some opinions. Right now I have a 71 sitting with the 472 in it. I was thinking about just pulling that out and using that for the 77-79, and then getting another 472 and making that my "ultimate engine" for the 71. Just wondering what the experts think on here.:)

Another thing that I've been wondering about. Is there a place where I can order ALL the hardware for a 472/500 engine? I mean, all the bolts and things like that in a kit or something?

If you want low compression, the '76 500 had 8.25:1.

Does low compression give better gas mileage, or does higher compression? It's gonna be a daily driver so I don't want to go higher than 10:1.

Well, the time has come already. I found a good deal on a very CLEAN 1976 Coupe Deville d'Elegance. Oh my god, this thing is sweet. Now I have to sell my 1977 coupe, and possibly the 71 also.:( Hopefully not the 71. First thing I'm gonna do is put the edelbrock intake on it. Will this swap perfectly or will I have to mess the A/C, carb, etc...?

Higher compression gives more power but doesn't burn more fuel/air mix. So I'd assume it giver better mileage. If you want you can look into propane, as it gets a tiny bit worse mileage on a stock engine than gas would, but it's a hell of a lot cheaper. You could also run 76cc heads on a later model 500 and make up for the loss.

The stock A/C compressor won't fit on the Edelbrock intake.

What year did the 76cc heads come off of?I can't remember. I won't be doing that swap with this car anytime soon though. Doesn't the compression jump from like, 8.25:1 to 12:1? Well, I will do it in the future though to another toy.:D

What would I have to do to make my A/C work with the Edelbrock intake? This is going to be my daily driver for awhile and want to do everything I can to get better gas mileage, without tearing apart the engine and for a cheap price. I'll probably go ahead and get a carb and have it rebuilt in the near future. But like I said, I don't want to go messing with the lower end.....yet.:)

Another thing that I've been wondering about. Is there a place where I can order ALL the hardware for a 472/500 engine? I mean, all the bolts and things like that in a kit or something?

on ebay. they have complete bolt sets for 20 - 30 bucks.

I love ebay

OK, well, the car is mine. It just has to be shipped from Nevada. Here are the first things I'm gonna do to it
*Headers with 3in(?) dual exhaust to open it up a bit
*Aluminum intake-most likely edelbrock
.....I heard there was some bracket or a compressor that would fit on this????
*Rebuilt Q-Jet
After all this is done, it'll probably be awhile for me to mess with the lower end. I'd prefer to get an engine core and work on that in the garage for my '71. What size heads came on the '71 472? Just wondering. Here are some pics of the 1976 I just bought. What a beauty....

71 engine will have 76cc heads. Might want to consider modifying the stock intake before you spend $250 on an Edelbrock. Beautiful car. :)

Great looking car. Isn't there some way you can get an A/C compressor on the Edelbrock? Some small one with a custom back bracket or something like that? I am almost certain it was discussed on here nto too long ago. I'm just curious. In my opinion you should definitly modify the stock intake.

Great looking car. Isn't there some way you can get an A/C compressor on the Edelbrock? Some small one with a custom back bracket or something like that?

You might try looking at the later 368ci Caddies. They had a newer style compressor that is MUCH shorter (a bit bigger around though) and looks like it might be able to be fit if one had the desire.

I know I've heard of it before- someone fitting one of those short compressors on it. Maybe it was on the MTS forums.

Either way, I would go for modifying the stocker. Cheaper, just about as much performance, and your A/C compressor fits.

I've thought about modifying the stock, but I'd rather just buy the Edelbrock. I don't have any tools and have no idea on how to cut the center of the original intake. And I also thought I heard something about a compressor fitting the Edelbrock. What size pipes should I run on the stock 500? I was thinking of just going 3in duals, but is that too much on a stock motor? Oh, and I'll throw on some headers with the exhaust...

I would just take the stocker to a machine shop to do it for you. That is a huge ass thick piece of case iron we are talking about.

What do I ask them to do? Any measurements?

Print off these pictures (taken from the 500caddy.us site), and show them to them. They might be familiar with it. Either way, they will know what you are talking about.

3" duals is a bit much for a stock engine. Unfortunately the BBC Monte Carlo headers that are probably the easiest/cheapest option for headers on these cars are way too big (either 2 or 2 1/8" primaries, 3 1/2" collectors) for the stock engine. This just gives me an excuse to squeeze more power out of the engine though...

I would go with 2.5" dual exhaust on a stock engine.