New member here,
I was just wondering what would be needed or done to add an Edelbrock Intake Manifold, true dual exhaust, and possibly some headers to my '69 CDV...
So far I know with the manifold I'll need brackets for the A/C compressor, or do I need a whole new compressor?(The current A/C doesn't work anyway, so I have no reason to keep the current compressor.) Also, which headers would work best for the application? Are the Sanderson's really worth it or would some BB Chevy's with the flange work better? Will the Sanderson's even fit on a '69 chassis?
My main goal is to get as much fuel economy out of the engine as possible, without having to dig around inside. I don't want to lower compression, since running premium gas isn't a problem to me, I'd rather have her drinkin' the good stuff anyway... If the only way I can really milk the MPG out of her is by performing open-block surgery, I'd plan on a cam and probably swapping out the stock rods/pistons for some higher quality ones while she was open.
If any of you has any other ideas that would improve MPG (reasonably for the price), please, by all means, tell me about them ...
The Sandersen CAD600's should fit......that would be a whole lot easier than trying to fab headers for a BBC although the BBC headers may work better for higher horsepower.
The Edelbrock intake is much taller than the stock unit (3-3.5"). Make sure that you have enough room under the hood for the carb and air cleaner with that intake. The compressor IS a problem but I'm not sure what is done to remedy this.
Just my opinion but, if your not going to make any changes to the engine, I'd keep the stock manifolds and run dual exhaust off of them. Tune the carb for the little bit of extra air flow and you're good to go.
you might also run a ported stock intake manifold. I remember Cad Company did sell them for not too much. They do not have it in the catalog anymore, but I asked a while ago and they would still make one for me. Then you still have enough space under the hood to use a 1 to 2 inch 4-hole spacer AND you could still run the stock A/C compressor. I am not an expert on this, so any other input??
if i was staying where i'm living now... i'd do exactly that NIN... (minus the edelbrock carb) but since i'm planning on moving to arizona, i really think i'm gonna like that A/C...
i saw the ported stock intake on 500cid.com and noted the 40+ HP gain which caught my eye... but since weight is going to play an important role in this car, i like the idea of the aluminum manifold (along with the edelbrock name)
also, lux, how much improvement in HP/Tq would a set of good BBC headers give me?
basically, i want to get as much fuel economy as possible for the trip from here (WI) to AZ... once there, I'll be more interested in performance
First of all, putting headers on aren't going to improve gas milage. When you open up the exaust you will have to richen the fuel mixture or you'll be running a lean mixture. If you're using the Q-jet you can change metering rods and/or jets. With the edelbrock carbs you're limited to the metering rods. The Edelbrock intake (Performer), will take off a lot of engine weight and give good low end torque. There is no reason to swap out the stock rods/pistons for fuel economy because you won't be wanting to spin the engine any faster than it already does, and that's the whole reason of big buck rods is to handle high RPMs.(Unless of course your rods and pistons are so beat that they need replacement.) There are some low RPM cams out there that will give good low end torque and good gas milage and will team up perfectly with the Performer manifold. If the engine is a '69 you probably have a points type distributor and an HEI conversion kit isn't that expensive and MIGHT get a bit better gas milage due to no wear on the points so your firing will be a bit more exact.A free breathing air filter like K&N will help also, but again check the air/fuel ratio after installation
by low RPM cam, would you mean the one CompCams has in their catalog (800 - 4000 RMP working range) or do you have something else specific in mind?
Also, would running different oils in engine, tranny and rear end do any good for mileage (besides making sure its fresh oil every 3000miles)? Maybe some high mileage synthetic (Or running syn in the rear end and tranny and some other kind in the engine?)
How about using different tires? I know that in Germany you can buy tires that have a lower roll resistance and you could pump up the pressure just a little bit?
Would increasing the gap on the plugs increase mileage?
And, also, additionally, I remember that my 1984 Coupe Deville and the 1991 Brougham I had, had a kind of spoiler in front of the engine, down, underneath the radiator, and that was done to safe fuel and make it more "aerodynamic" (Whatever thats suppossed to do on a Caddy). Could you adapt one to the 69-76 Caddies (Maybe black-painted sheet metal)
How about a lightweight hood? Maybe make one out of fiberglass, etc? I am thinking about this, as I have a guy here who claims that he can make one that looks exactly like the stock unit from the outside... Would be neat.
Hmm, thats all my fuel saving ideas. Would a MSD Multiple Spark Discharge-Unit do good for low rpm fuel mileage?
But, 69 Caddy, I feel your interest for saving fuel. I have that problem on a daily basis. The Premium I need for my daily driver is running at € 1.10 per liter now. A steady speed is there the best & only thing I can do...
Aerodynamics is always a great way to improve milage but how would we mere mortals, without the benefits of wind tunnels and such, know exactly where to place spoilers and air dams to slice through that atmosphere? Taking wild guesses may only make things worse. Removing weight with fiberglass sounds great to me, I'm planning on removing the heavy chrome bumpers on my '77 Caprice and making sheet metal and fiberglass replacements.As for the cam; I don't know manufacturers individual cams exactly, but the one you mentioned,German, is exactly in the RPM range you want to be in to improve milage and torque.Oils are a tricky subject. You have to stay with manufacturers recomendations for rear end and tranny, but motor oils, you can change viscosities, like going to a lighter oil, but, I think, if there is a lot of wear already on the engine parts, (like main bearings), it might be a bit thin for proper protection.Someone more knowledgeable than myself on oils would have to answer that one.Plug gap- you can't increase the gap without haveing an HEI or other high voltage system to jump the gap. .060 with points won't work.MSD has some nice systems, but they're pricey, and for his applications I think an HEI conversion kit will work just as well at far less cost. As for tire sizes, I think changing tire DIAMETER would change milage in much the same way as changing rear end gear ratios. A larger diameter would be like higher rear gears, less burning rubber and more highway milage.
If you figure the cost of the "fuel saving mods" into your fuel cost, I think you'll see that you'll end up spending more money on the mods then they are worth.
I'm not trying to be an @ss but......if you want a car that's good on gas, you need to buy a car gets good mileage. A 4500#+ luxo-barge is never going to do that. Can you make it a little better.....maybe. Will it be worth it.....probably not. Will it ever be good....no.
I don't know how far you are going to be traveling but just to make things easy, let's say it's 2000 miles. And for ease of figuring, let's say that the car gets 10mpg and fuel prices are $1.65 gal. Price per mile, for fuel, would be $0.165. Total fuel price to travel the whole 2000 miles would be $330 (if my math is correct).
Now, let's say you only make one change in an effort to get better mileage. Say that mod nets you an increase of 2mpg (which is a pretty good increase) but costs you $300. Now your car gets 12mpg. Fuel cost per mile is now $0.1375 taking your total fuel cost down to $275....a savings of $55.
The change that will probably be best is the HEI. It's not all that expensive and should give you a little boost in both performance and fuel economy.
also, lux, how much improvement in HP/Tq would a set of good BBC headers give me?
I've never seen any tests to show what kind of hp/tq increase is gained with headers.
I read a good article on header design. I'll see if I can find it and post it here.
Thanks for all the info people! If you've visited my cardomain site, you'll also know that I'm planning on fiberglassing as much as i possibly can... (fenders, hood, door sheet metal if possible, trunk lid...) but that will most likely come *after* the trip. Any other things to worry about with the intake manifold? I'd still like to know if I'm going to have to roast w/o any A/C, or if I'll be able to get ahold of a new compressor.
In her final form I want to have her pushing somewhere near 400+/- HP with as much torque as I can squeeze out of it... With the full package weighing in at around 3900lbs or so (think of fiberglass as Slim-Fast...)... Lofty goals...? I know it probably sounds - ...but I like to set the sights high... and plus I got plenty of time to work with...