500 V864 - is this even theoretically possible? - Page 5
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Page 5 of 5 FirstFirst 1 2 3 4 5
Results 61 to 71 of 71
500, 472, 425, 368 Discussion, 500 V864 - is this even theoretically possible? in Cadillac Engine Technical Discussion; Originally Posted by The Ape Man All the factory intakes will not behave properly in the 4 cylinder mode except ...
  1. #61
    BluEyes's Avatar
    BluEyes is offline Cadillac Owners Enthusiast
    Automobile(s): 1970 Sedan deVille hardtop
    Join Date
    Feb 2005
    Posts
    595

    Re: 500 V864 - is this even theoretically possible?

    Quote Originally Posted by The Ape Man View Post
    All the factory intakes will not behave properly in the 4 cylinder mode except for the factory 8/6/4 intake.
    My 472 intake feeds cylinders 1-6-4-7 off one 'plane' of the intake, which are the same cylinders that are running in V4 mode. Since I have not milled down the center of my intake, the venturis on the other side of the carb will not see any air flow and thus not dispense any fuel so I don't see what the problem would be. Whenever I have seen a V864 car in the junkyard, the intake looks like a dual plane TBI intake, so if you have some special knowledge about "secret passages" that GM cast down in there please share!

  2. #62
    The Ape Man's Avatar
    The Ape Man is offline Cadillac Owners Connoisseur
    Automobile(s): '80 Fleetwood Coupe, 1994 and 1995 Mercedes 140 Coupe
    Join Date
    Feb 2005
    Location
    Southern NJ
    Age
    52
    Posts
    2,096

    Re: 500 V864 - is this even theoretically possible?

    The factory 8/6/4 intake is designed to feed 4 cylinders and be fuel stingy. The 500 is designed to feed 8 with cruising economy. Not too much rocket science needed. You cannot simply drop draw to half the cylinders and expect the best design to look the same. It looks the same in at the junkyard? Well it isn't.
    The 368 intake ports are much smaller. Have you ever seen the inside of a 368 exhaust manifold? Those are quite a bit different than the 425/472/500 also. The theme is keep flow velocity up at lower flow rate. As I said, the FI 368 intake makes a lousy performance part on a 500. The whole idea here is to start out with a large engine and cut it back for gas mileage. In doing so the performance will be severly degraded is using a 368 injected intake. The 4 cylinder economy will be lost is using a 500 intake.
    Maybe someone will actually get one up and running and post results. I'm not holding my breath. This thread is almost 2 years old, not the first one on the subject and nobody has one on the road yet.
    Maybe someone can actually prove me wrong by building instead of typing.

  3. #63
    BluEyes's Avatar
    BluEyes is offline Cadillac Owners Enthusiast
    Automobile(s): 1970 Sedan deVille hardtop
    Join Date
    Feb 2005
    Posts
    595

    Re: 500 V864 - is this even theoretically possible?

    Disagree on your reasons. The 368 intake and exhaust has to have smaller runners whether it uses a V864 system or not. It is simply a (much!) smaller motor and using the 472/500ci intake in a stock application would diminish throttle response and low end torque.

    The beauty of shutting down cylinders is that the draw is NOT reduced it is INCREASED, and this is why economy is increased. A 500 (or 368) cruising down the highway only needs to make a very few hp to keep the car rolling. To make so little power out of such a huge engine takes alot of throttling which means that the actual pressure inside each cylinder is very low. This hurts efficiency tremendously. When you cut 1/2 the cylinders completely out of the picture you have to *increase* the throttle opening to maintain the same total power output. In fact, I'd say that the power produced *per cylinder* from the operational cylinders should roughly have to double. This means less throttling on the operational cylinders, higher cylinder pressures and more efficient combustion leading to your economy gain. What this means on the intake side is that the runners which are still being used will see more airflow than they usually would while cruising.
    No, I wouldn't expect four cylinder economy out of a 250ci because 4.1L is more the size of a large V6 and equal to alot of modern V8's. But, if I could gain even 1-2mpg that is a big gain when I get 10-15mpg right now. No, I don't expect it to pay for itself, but that's not the point. If I cared about cars paying for themselves, I wouldn't have fixed the AC, added Guidematic headlight controll, fixed the cracked taillight lens or switched to a leather interior - I'd be driving a 15 year old Metro that I bought at an impound auction. This is a hobby for me and I want V864 on the car because it would be cool and it would be even cooler to have a beautiful car like this that hits 25mpg on the highway one day so this is just one piece of the final goal.

    While I agree that I can't find evidence that anyone has actually driven a Caddy with a retrofitted V864 setup, there is a member on "the other board" who has successfully mounted the 368 rocker setup to 472 heads. Last I read there he was working on EFI to go on it. Personally, I'd run it with a carb and work out EFI later but that's his choice. As for myself, I recently graduated college so I will soon be getting a real paycheck and can start affording the machine shop bills to adapt the system to my own set of heads.

    Still, sitting around writing that you don't think it will work and giving very few details on why is not the right kind of attitude to take. I've got a mechanical engineering degree, so please don't worry about confusing me with technical details. I have no problem with your opinion, but please elaborate on any problems you see so that those of us who do think it will work can overcome them.

  4. #64
    The Ape Man's Avatar
    The Ape Man is offline Cadillac Owners Connoisseur
    Automobile(s): '80 Fleetwood Coupe, 1994 and 1995 Mercedes 140 Coupe
    Join Date
    Feb 2005
    Location
    Southern NJ
    Age
    52
    Posts
    2,096

    Re: 500 V864 - is this even theoretically possible?

    Thanks for the narrative. I almost forgot about how the whole thing worked. Sorry you don't agree. If anyone ever gets one of these going then maybe someone will start looking at intake manifold designs for V engines and what would happen if 1/2 of the pulses were no longer there. Hint: This series of engines ran much better with port injection as the intake manifold runners ran a long way uphill. V engine intake manifold design includes more than getting the mixture from the carb flange to the intake ports. Balance in extremely important. Each cylinder should see similar flow velocity. As proven in engine tuning circles, flow and balance is a major factor in performance and economy. I'm saying that an intake manifold designed to work an 8 or 4 cylinders at 6 liters will not also be able to deliver reasonable performance at max throttle on an 8 liter engine and vice versa. You are pretty close on the 1 or 2 MPG figure. A good guess. That's about what the system was good for on a steady roll at 60 MPH. We can both "sit here" and pontificate for another 2 years. The answer will only be a byproduct of someone actually getting one of these working. I can design a perpetual motion machine and convince a whole bunch of people to by stock in my company. Stranger things happen every day. Too bad about that nasty conservation of energy rule.
    Congratulations on your degree. Please take it easy on some of the older, experienced engineers that you might be working with. Those guys might not seem to know anything at all for the first few years.

  5. #65
    Fleetwood472 is offline Cadillac Owners Fanatic
    Automobile(s): 78 Fleetwood w/ FI 472/ Switch pitch TH400
    Join Date
    Aug 2005
    Posts
    236

    Re: 500 V864 - is this even theoretically possible?

    Digging this back up. After years of looking i finally scored some v864 parts from an 81 cadillac i found at the junkyard today. Incase anyone hasn't seen this there is a guy in Sweeden named Peter from the cadillacowners forum that pulled this off years back. The guy is getting some pretty good gas mileage with this setup and from what I've heard it's possible to get 30mpg from a 500 with this setup and properly turned EFI. This is going on a future build of a 500 that I have but definitely the hardest part seems to be fabricating an adapter plate to get these rockers to bolt up.

    http://www.youtube.com/watch?v=YDoRk1HPoxA

  6. #66
    ferrisworld is offline Cadillac Owners Fanatic
    Automobile(s): 1979 Sedan Deville
    Join Date
    Feb 2005
    Location
    Sacramento, CA
    Posts
    364

    Re: 500 V864 - is this even theoretically possible?

    I'd like to see more people doing it. I got a set of parts too, althought I don't know if I got everything I would need. All I took were the solenoid assemblies and the valve covers. I wonder how high you could go with a 425, port injection, and a super high overdrive to get the rpms down close to 1,000 - 1,200 at 65. Or maybe 55 would be better since you wouldn't want to go lower than 1,000 I would imagine. And what if you could do it with a #10 cam. Now I'm likely dreaming...

  7. #67
    deVille33 is offline Cadillac Owners Connoisseur
    Automobile(s): 1977 Coupe (blue), 1977 Coupe (yellow), 1977 Coupe (green)
    Join Date
    Mar 2006
    Location
    Western Massachusetts
    Posts
    1,390

    Re: 500 V864 - is this even theoretically possible?

    Quote Originally Posted by ferrisworld View Post
    I wonder how high you could go with a 425, port injection, and a super high overdrive to get the rpms down close to 1,000 - 1,200 at 65. Or maybe 55 would be better since you wouldn't want to go lower than 1,000 I would imagine. And what if you could do it with a #10 cam. Now I'm likely dreaming...
    These engines ( at least the 425 ) operate more efficiently at a constant between 2000 - 2500 rpm, within the "cruise" range. Engine speeds below that, and efficiently suffers because of the loads on the engine. Installing overdrive will move this engine out of it's cruise range.
    There is now another option, converting to natural gas. There is a company that makes conversion kits, but I don't know how one would adapt NG to these engines. I have seen the advantages of using LP propane in a internal combustion engine and thought that was astounding. NG would be an advantage along the same lines.

  8. #68
    ferrisworld is offline Cadillac Owners Fanatic
    Automobile(s): 1979 Sedan Deville
    Join Date
    Feb 2005
    Location
    Sacramento, CA
    Posts
    364

    Re: 500 V864 - is this even theoretically possible?

    I see a lot of people say that about the cruise range, and I understand, but then I wonder, whats the best cruise range for the car as a whole? I mean, if you're just on a flat or going down a hill, without much load, wouldn't it still use less gas at 1,200 even though it's a less efficient rpm? Even without variable cam timing, ls engines for example can cruise as low as 1,500 or 1,600 and get great mileage, and I doubt that's their peak efficiency rpm. Or maybe it is.

  9. #69
    deVille33 is offline Cadillac Owners Connoisseur
    Automobile(s): 1977 Coupe (blue), 1977 Coupe (yellow), 1977 Coupe (green)
    Join Date
    Mar 2006
    Location
    Western Massachusetts
    Posts
    1,390

    Re: 500 V864 - is this even theoretically possible?

    Never having been to Sacramento, I'm not sure what terrain you have there. Here, in the Berkshires, we have hills, so engine load is a constant variable. These engines are more efficient on I-90 where engine speeds are in the 2000 - 2600 range. When traveling on local roads, I can get better fuel efficiency on roads that allow higher engine speeds at more of a constant. I might not have to stop as often, due to intersection stop lights, on the secondary roads, but gas mileage will suffer due to pulling the car weight up small grades out of it's cruise range.

  10. #70
    The Ape Man's Avatar
    The Ape Man is offline Cadillac Owners Connoisseur
    Automobile(s): '80 Fleetwood Coupe, 1994 and 1995 Mercedes 140 Coupe
    Join Date
    Feb 2005
    Location
    Southern NJ
    Age
    52
    Posts
    2,096

    Re: 500 V864 - is this even theoretically possible?

    The 500 cruises great at 1200 RPM geared to 60 MPH.

    30 MPG out of a 500? Please. The 6 litre DEFI modulated displacement never got even close to that. Maybe in an aerodynamic 2,000 Lb vehicle.

    The guy on utube had really high compression and alternative fuel. A 500 runs really well with high compression and will idle slower than the alternator will start charging if adjusted that way.

  11. #71
    ferrisworld is offline Cadillac Owners Fanatic
    Automobile(s): 1979 Sedan Deville
    Join Date
    Feb 2005
    Location
    Sacramento, CA
    Posts
    364

    Re: 500 V864 - is this even theoretically possible?

    On his website - which is hard to find - he claims to have gotten 27 mpg on gasoline. Could have meant imperial gallons, but maybe not.

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting