Been away for awhile but nearing the completion of the unit. After disassembly and further inspection the unit was actually built for 1958. In the manifold to air meter flange is stamped 1958 unit #4. This appears to be 4th of potential 5 units built.
Rochester Fuel Injection Production Summary
13,289 57-59 Passenger cars and 57-65 Corvettes
544 57-65 Service and training
447 57 Pontiac Bonneville
511 58 Pontiac all models
5 ? Cadillac
? Oldsmobile (patents filed
? Buick (patents filed)
14,791 Total
The distributor and the drive cable have been cleaned up as well as the air meter shown attached in the photo. The only item remaining is the rebuilding of the fuel meter and reinstallation.
So is the basic unit the same as any of the others, just mounted on a special Cadillac specific manifold?
That's a very rare thing indeed. Do you plan to install and use it on your car? And was it originally on your car? If not, where did you ever find it?
Very nice! I'd be interested in hearing how it works if you try it. Good luck with it. That's so cool!
Rick
Rick,
The manifold is basically the same as a Pontiac unit that has the Cadillac flanges. I don't plan on installing it on anything because I am really a Chevrolet Corvette guy and have no Cadillacs. I inherited these part from the lead development engineer for Cadillac on fuel systems along with a trove of other pieces. He is still around and I talk to him frequently.
This unit was an engineering piece that was run a vehicle and stored for the past 60+ years. I have seen one picture of a show car that had FI emblems on the rear quarter. I have attached a few pictures of the unit before I began working on the restoration. You are more than welcome to contact me if you like and can share as much as I know.
Bruce WItherspoon
517 749-4840
An interesting piece, and using the distributor drive for injector timing?
Bruce. >:D
I believe the systems are constant flow. They are not synchronized like modernen simultaneous double fire which fires on both the exhaust and intake stroke while modern sequential injection is timed to fire on the intake stroke only. Sequential requires both crank and cam position while SDF only needs crank position. The constant flow requires neither.
So, is the drive unit for the fuel pump?
Bruce. >:D
If I understand you question correctly, the distributor drives the fuel meter.
Here is a cut away of a Chevrolet unit
Just did a search, and the distributor drive is for the fuel pump, providing up to 200 Psi.
It would be an interesting piece to put onto a 390. But hood clearance might be a problem in a '59 or '60.
The one you show looks completely different to the other GM ones that I have seen.
Bruce. >:D
Here is a picture of a 1957 Pontiac units for sale on EBAY. If you go out and look at a 1957 Pontiac FI it will have a cover over the top. Here is a link to the cast 1958 Pontiac unit.
https://www.ebay.com/itm/Rare-Complete-1958-Pontiac-Rochester-Injection-w-Distributor-Turkey-Roaster-/223566736837
By the way the units were built in some development vehicles. I put tis next to a tripower manifold with the air cleaner and it is no taller than it.
Yes, very interesting Bruce, and Bruce. It doesn't look like the typical Rochester injection units that I've seen either.
I've never really looked into how they operated before. A constant flow to each cylinder sounds like a little too much though. I wonder how well it would run. It would be interesting indeed to see it working.
So what are your plans for it? A display piece maybe? If it's for sale, you can count me out, I doubt I could afford it.
I do have another question, why are there two distributors?
Rick
A carb is constant flow as well using the vacuum signal to pull the fuel through a jet in a carb upstream of the intake manifold. THe problem. THe fuel does not stay atomized as it travels through the intake runner. The fuel that is not atomized falls out of the air/fuel mixture at low velocity areas of the runner and is no longer used in that combustion stroke. Eventually that raw fuel will make its way to that cylinder causing a rich mixture.
The constant flow systems are metered to deliver the correct fuel in the port atomized as close to a correct air/fuel ratio as possible at the higher pressure to insure that the fuel is actually a vapor and not a drip.
Forgot there is only one distributor. the other is a spare.
Here is a shot of the Eldorado Brougham development that Al Haas gave me. It looks like it could have been a similar unit and this would have been '55 or '56 as it was before the car was released.
David
Dave,
Not likely that this is the same. The air meter on all of the units, Pontiac and Chevrolet included have horizontal flow into the meter.
Museum piece. Rarity unfortunately doesn't a;ways equate to value. But glad its in good appreciative hands.
Since U R a "Ch" guy U know the value adder they bring to period factory equipped cars.
I recall since mechanical they were a bit of a pain and therefore didn't capture the buyers. Seems to be a resurgence of resto FI 50s autos. Maybe becasue it's so common today, there's a link to the perceived past(?) Have no idea how well they function after resto with modern parts.
What's more sexy than hearing the tri-power or secondaries kick in on a period HC GM engine? Like the famous patented HD exhaust. You don't get that with FI.
ps: The Dev. Eng should be invited to write an article on early fuel development before it's lost to the ages.
I spoke to him last night and he told me to look up the patent because he appears on it. I’ll speak to him and see if I can get him to post on here. He’s a really special guy who spent a lifetime in the industry.
Did that system have aircraft origins? I thought I read that is what they were originally developing it for but for what ever reason (maybe jets?) it didn't work out so they went looking for places it worked better and people wanted it.
I can not answer the question about the initial intent of the system for automotive applications but mechanical fuel injection was definitely used on aircraft prior to jets. It was one of the reasons for a performance advantage during the 2nd World War. Some on the fighters were still carbureted which was a limiting factor in their dog fighting during high G maneuvers.
The Germans used Fuel Injection on fighter engines, there was even a
diesel aircraft engine used at extreme altitude. The Allies eventually
did the same on some engines. I see little written about it, probably
nobody was going to reveal their advantages or lack off, at the time.
Constant flow might work better on aircraft that always have a big load,
or race engines run near max most of the time. An advantage would be
the ability to run resonant intake systems, without dropping gobs of fuel
on the way from a single carb, to the cylinders. The disadvantage being,
pretty hard to get the mixture right stopped at a light. And I doubt it
could come any where near passing modern emissions regs. A Wide Band
OX sensor such as I use, might tell quite a story.
Some EFIs, including throttle body injector types here, did injection every
crank revolution to make it work. The 70s Cad system port injected every
2 crank revolutions, just after the intake valve closed. In my 79 the EFI
had far lower emissions than a carb on the same engine. Power was not
really much different, without a hot cam and resonant runners.
The basic problem with gasoline fuel injection, is matching the fuel to
the throttled air admitted, over an extreme range of conditions. It took
EFI to measure the air really accurately, while cranking in corrections for
things like temp, simultaneously adjusting spark timing, with feedback
loops and learning programs that eventually train each system for the
engine it controls. That view makes those mechanical systems look
really crude. Bruce Roe
Bruce
The greatest gains with modern fuel injection came primarily from the ability to do two things. Understanding the actual position of the piston during the combustion cycles and the mass density of the air/fuel mixture during those cycles. That said, these benefits were initially done primarily to improve combustion efficiency to make the EPA happy. What it eventually did was allow the reemergence of more volumetric efficient performance. Spending most of my career as a GM development engineer, I saw much of the progression from carburetor to direct injection.
Quote from: spoon link=topic=163139.msg485092#msg485092 date=1610888955 Spending most of my career as a GM development engineer, I saw much of the progression from carburetor to direct injection./quote]
What department(s) were you in? Something people would think of as exciting like drivetrain? Or maybe seemingly less exciting like making the fake wood look less fake or getting the headliners to stay stuck?
Worked for GM Powertrain initially and moved later moved over to platform development for BOC/LAD doing powertrain and powertrain/chassis mount development. I worked on manual drivability on several programs where I worked with the powertrain calibrators resolving drivability issues.
I have been a FAST fuel injection dealer and do calibration work for my customers and COMP referrals since 2005 . I have raced the attached fuel injection C4 Corvette since 2001 after giving up on the Q-jet that I had raced for since the 1970s.
That sounds like fun. I was sorta hoping to hear you were the guy that thought it was a good idea to have all those clips holding the hard lines that makes them rust through so I could complain and know who's name to be yelling tomorrow when I'm under the car in the cold replacing a rusted out brake line.
Sorry to disappoint ;)
Quote from: spoonBruce The greatest gains with modern fuel injection came primarily from the ability to do two things. Understanding the actual position of the piston during the combustion cycles and the mass density of the air/fuel mixture during those cycles. That said, these benefits were initially done primarily to improve combustion efficiency to make the EPA happy. What it eventually did was allow the reemergence of more volumetric efficient performance. Spending most of my career as a GM development engineer, I saw much of the progression from carburetor to direct injection.
If you were on the scene, perhaps you could describe how the development of EFI
for the Cosworth Vega (75-76) evolved into the Cad 75-79 EFI? I have never heard
anything of that development, but it is quite evident from the circuitry that they are very
closely related. The Cad advanced a lot and achieved ECU parts interchangeability,
the Cosworth ECUs were adjusted and assigned to a specific engine.
I used an Air Sensors FIRST in 1989, with analog computer coupled to their MAF sensor.
Operation was impressive, but when the car went away, the EFI went on my shelf (it is
still there). Now is AirSensors is making FAST? Bruce Roe
Bruce
Give me a call sometime. Share what I know. Not the Shell answer man with all the answers but I don’t mind sharing what I do know. My number is up above.
Quote from: spoon on January 18, 2021, 04:31:45 PM
Bruce
Give me a call sometime. Share what I know. Not the Shell answer man with all the
answers but I don’t mind sharing what I do know. My number is up above.
I see no phone number, maybe deleted? You can email it to me at bcroe@juno.com
Bruce Roe
Still making progress but its going a little slower than I would like. Some of the parts are not available like the gaskets attached. Fortunately I have the material and the tools to make them. I have attached a few pictures of the progress.
Pretty much finished here.
Now you just need that one thing that goes below it and then the thing that goes behind that and the thing those things bolt to then you can go for a drive and see if it really works.
Pretty sure it works. It last resided on a dyno on a 390 engine at Cadillac engineering 62 years ago. I have had multiple conversations about the history of this manifold with the development engineer. Some of the stories are pretty hilarious.
Not being a Cadillac guy, it won’t be me to see it run again.
To Bruce W. and all else who may have info.
Some time before 1992 a southern California RR mechanic friend bought his wife a beautiful used dark blue de Ville with a white top that he was tickled over. I didn't see anything special till he opened the hood pointed and said "its a five hundred (512?) with mechanical fuel injection." Factory mechanical fuel injection. Then he just let that sink into me.
I wanted the car bad then, but wife said not for sale. When he moved his shop out of state he sold the car in the process without telling me. I've been looking for it since. Never seen or heard of another like it.
Your discussion at least gives hope I'm not living some hallucination. I can't even find a VIN identifier digit for a mechanical fuel injected engine.
Any body here seen it or even one like it or even heard of it?
Thanks for any info you may have.
Quote from: HiRev on July 03, 2023, 01:58:14 AMTo Bruce W. and all else who may have info.
Some time before 1992 a southern California RR mechanic friend bought his wife a beautiful used dark blue de Ville with a white top that he was tickled over. I didn't see anything special till he opened the hood pointed and said "its a five hundred (512?) with mechanical fuel injection." Factory mechanical fuel injection. Then he just let that sink into me.
I wanted the car bad then, but wife said not for sale. When he moved his shop out of state he sold the car in the process without telling me. I've been looking for it since. Never seen or heard of another like it.
Your discussion at least gives hope I'm not living some hallucination. I can't even find a VIN identifier digit for a mechanical fuel injected engine.
Any body here seen it or even one like it or even heard of it?
Thanks for any info you may have.
What year was this car? And just so you know, the 500 engine was only available from 1970 thru 1976. It was available with fuel injection, but it wasn't mechanical, and offered between 1973 and 1976 if memory serves.
Rick
My guess, it was a 76 with Electronic Fuel
Injection, or possibly a late 75. Neither
that system or the 50s mechanical had any
feedback loops, and the ignition system was
just stock. The 50s system did not even
have the advantage of an electronic air
sensor (MAP), or any sort of compensating
calculations. Bruce Roe
A Deville with a 500 would be 75 or 76 and I believe mid 75 the EFI became an option and I think was available on all the cars. The first one I saw in person was a Fleetwood so I know a few made it into other than Eldos.
The 75-80 system was electronic but didn't use any microprocessors. Their new system that came out in 80 in some models did and they made a big deal about that and called it DEFI, D for digital. The DEFI was basically the same system that GM started putting on other things in 82 but those were never known as DEFI. Cadillac actually stuck with that system on most models till 90. They did appear to drop the D from the name in the 85-88 range.
The 75-80 system was also multiport meaning there were 8 injectors which is quite different than the DEFI and most other GM systems of the 80's that had 1 or 2 injectors in the throttle body. Mopar and Ford also played with throttle body at first but quickly changed to multiport unlike GM that wasn't all multiport till 96 which was almost 10 years later than the others. A different twist on multiport was tuned port which I think was a Corvette thing around 85 that then slowly made it to other models including the Allante.
So especially back in 92 for a somewhat technical person I can see them trying to point out that having a multiport EFI system on a 75 or 76 model was unique and different than many of the other EFI systems that would have been around in 92 especially in GM circles. If you were a GM family in 92 there is a pretty good chance you still had a carb in your daily driver fleet.
I don't know that many people that were not into Cadillacs knew that Cadillac had any sort of fuel injection system back then. I don't think the average person ever heard of fuel injection other than maybe in a song till the 80's when it ended up in many models. If car enthusiasts knew about it it was most likely in the context of Corvette even though there were other models that had the same system and a couple electronic systems that were tried.
Calling it a 512 is odd but it sounds like you are not sure that was the number. 512 would be 050 overbore which is probably possible but not common on one of these engines so if someone did it I could see them bragging about it. A 030 overbore would be 507. The other number that gets thrown around a bunch is 501 and 502 since those numbers were on the underhood sticker in a fairly large font. Those numbers were just some sort of identifier for emissions and people never seemed to read the 'fine print' just below that that said either 472 or 500 cuin.
You also mentioned a white top? Convertible? If it was a convertible that would make it an Eldorado. 71-76 only the Eldo was available as a convertible from Cadillac so 500", EFI, and convert would be a 75 or 76 Eldo.
Yeah, I wasn't sure what year that Cadillac began using fuel injection. I was remembering a car that my boss had back in 1982, and for some reason I was thinking it was a 73, but I do remember that it was a Fleetwood.
Somewhere out in my collection of literature, I have a factory manual on the injection system, but I'm not sure what year it was printed. I keep thinking it's 73, but it may be 75. I'd have to dig it up to verify.
Rick
Somewhere in my stuff I have a manual dated 75 that says its a preliminary service manual for electronic fuel injection. Its been a while since I looked at it but I don't remember it saying anything about the cars it went into. Personally I have never seen any 75's other than the early 76 Sevilles that had it so maybe they were just trying to get the word out so people would order that option in their 76's? It didn't look like it was that great of a seller. If they had not made it the only/standard engine in the Seville it probably would have been a very rare system.
You could be right about that TJ. I keep thinking that my old bosses car was a 73 because I thought it had round headlights, but that was years before I got into Cadillacs.
I do remember that he never drove it because it had issues with the injection system, and that was early 80's.
Rick
In the early 70s they threw everything they had
into the system, including port injection, just
introduced integrated circuits, and an electronic
MAP. Hey its a Cadillac.
By the 80s models they had more parts suitable
for EFI, including OX feedback and the less than
a decade old micro processor. Lots of cars could
meet emissions with new digitally programmed
spark advance, and a carb with electronic modulation.
Bruce Roe