Author Topic: 1968 cadillac 472 fuel injection  (Read 2080 times)

Offline cadman56

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1968 cadillac 472 fuel injection
« on: February 05, 2013, 07:35:39 PM »
Any thoughts from all of you about installing the MSD 4BBL fuel injection unit on the 1968 472?
Thank you,  Larry
Larry Blanchard CLC #5820

Offline "Cadillac Kid" Greg Surfas 15364

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Re: 1968 cadillac 472 fuel injection
« Reply #1 on: February 05, 2013, 08:05:14 PM »
Sounds like an interesting project.  If the motor is stock and in good shape you should pick up a couple of MPG once the system is "dialed in".  Since the Quadrajet carb that came on this motor was specifically tuned for the engine's power curve, I would be surprised if there would be much of an improvement.  Let us know.
Greg Surfas
Cadillac Kid-Greg Surfas
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Offline TJ Hopland

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Re: 1968 cadillac 472 fuel injection
« Reply #2 on: February 06, 2013, 07:26:21 AM »
I have an EFI on my 73.   Its been on for several years now.  Before I did it I spent a few years reading and planning.  At the time there were very few options.  Now there appears to be a lot more options but I have not really kept up with things, it does appear to be changing fast. 

What is your primary reason for thinking about this?    My reasons were sick of vapor lock issues and I think EFI and technology is cool.  Vapor lock is no longer a problem and overall I think its still cool so in my case mission accomplished.   If you are looking for more power I dont think you are going to get it.   If you are looking for more efficiency unless you are planning to regularly drive cross country I doubt you will save enough in fuel to pay for the system.

Another question is are you installing this yourself?  Are you looking for one of the self tuning ones where you just set some basic parameters then follow some basic driving instructions to let the system learn the basic operation then it constantly tweaks itself after that?   Or are you interested in a more hands on tuning where you will actually learn and understand what is going on?   If you are willing to learn you can get by pretty cheap and sort of throw your own system together with a mix of new and used parts and it can constantly grow and evolve if you want it to.  From what I can tell the self learning systems are much more expensive out of the box and for the most part don't have many options to grow and evolve.   I also have concerns about service parts for some of those systems.  At least if you built one out of junkyard parts you would know that you need this sensor off this model and this one off this model.   WIth the complete kits you may be at the mercy of that kit company to support it and supply parts.  Megasquirt is what I used for my ECU and its a totally open source platform so its not like one company going out of business or changing directions is going to leave me stranded.  Downside is its not a simple plug and play.   They do apparently have self learning software now.  When I did mine you had to get it dialed in pretty close before you could turn on the 'auto tune'.  The little reading I have done since then they have refined the auto tune software now so it works fairly well.  In the end I did learn a lot about tuning and now have completely different ideas on things I am going to do with my next engine / car / system build.   

 
StPaul/Mpls, MN USA

73 Eldo convert w/aftermarket EFI
75 Eldo rusty but trusty
80 Eldo Diesel
And other assorted stuff I keep buying for some reason

Offline cadman56

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Re: 1968 cadillac 472 fuel injection
« Reply #3 on: February 06, 2013, 08:01:08 PM »
I have been planning on doing a resto-mod from the bare frame up using an overdrive camshaft & overdrive trans.  With the lower rpm at cruise speeds the carburetor will not work well & run rich.  I grew up around and worked on fuel injected & turbocharged natural gas compressor engines (yes different but with same principles) and am not new to old cars, etc., but I do have an extremely knowledgeable Cadillac service manager working with me on Saturdays.  He & I restore middle 50's through 60's Cadillacs as correctly & authentically as possible.
He has installed the new MSD unit on one of his customer's cars & now the car, fuel injected before, performs better than when new.
He is also suggesting I include the new MSD ignition unit with this change.
Yes, expensive and my concern would be parts availability as you suggest.  I haven't done it yet.  Better mileage would be a plus, but you only get so much out of a gallon of gas.  And, these cars are heavy.
Thank you for your response.  I will definitely advise the outcome if I do it.
Larry
Larry Blanchard CLC #5820

Offline Scot Minesinger

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Re: 1968 cadillac 472 fuel injection
« Reply #4 on: February 07, 2013, 05:02:18 PM »
I have a 1970 Cadillac with a 472 engine since 2005 and have driven it just under 30k miles.  Also, I own two other 1970 Cadillacs with the 472 engine.  Unless you are going to change valve sizes, cams, and maybe intake, you are not going to see much of an improvement, plus the downside risk is considerable.  The points and condenser Caddy runs about the same as MSD (not noticeable).  I have tried a lot of different things over the years, and original has been hard to improve upon, except for of course tires and shocks.  I'm not a nut for original at all, just being honest that it has been hard to beat.  Probably be easier to get an improved set of heads and cam from Maximum Torque than to change to fuel injection.

Good luck any way you go,

Scot
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Offline bcroe

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1968 cadillac 472 fuel injection
« Reply #5 on: February 07, 2013, 06:19:34 PM »
My comments.  A MAP based EFI is going to be a major fuel tuning project, needing things
like a wide band oxygen sensor.  The self learning may reduce this a lot.  Only a MAF based
system bolts on & works with little tuning; few add on EFIs are MAF. 

The other issue is spark advance.  Some EFIs don't even control this.  The ones that do
will need the tuning process to make any improvement over stock.  However there is
probably more bang for the buck than the fuel aspect.  I added a crank trigger ignition
system & got significant improvement.  Meanwhile the original ignition is still in place
as an alternate while tuning, and as a backup.  good luck, Bruce Roe

Offline TJ Hopland

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Re: 1968 cadillac 472 fuel injection
« Reply #6 on: February 08, 2013, 08:03:16 AM »
When I did my system I believe Megasquirt was the only option for spark control other than modifying factory systems.   I have not read in depth about current systems but I would hope that is something that is at least now an option with some of the systems.   I don't have spark control working on mine yet but I do have all the parts to do it.  One thing I could not make work was EGR.  I believe if I had control of the spark I could make it work with EGR.  Based on how much I had to change the timing and how much fuel I had to add when I disconnected it I bet there would be some possible fuel savings and performance gains to be had getting it all working.   Its so cool to have a tuning idea and just hit a few keys to try it and see the result.  If it works hit save, if not dont save it and you are back where you started.   I got to the point on mine where I kept ending up with detonation problems that were not directly fuel related so I kept having to pull out timing to the point where it was noticeably changing performance.   Messed with springs and vac but decided what I needed especially for transitional states was a non linear curve which can only be done in the digital world.  Just sitting here typing I am getting excited to get back to the project and be able to tune both the spark and fuel how ever I want it.   
StPaul/Mpls, MN USA

73 Eldo convert w/aftermarket EFI
75 Eldo rusty but trusty
80 Eldo Diesel
And other assorted stuff I keep buying for some reason

Offline bcroe

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1968 cadillac 472 fuel injection
« Reply #7 on: February 08, 2013, 09:52:29 PM »
I have yet to read anything about tuning with EGR.  Most just assume
it will be removed.  Bruce Roe

Offline cadman56

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Re: 1968 cadillac 472 fuel injection
« Reply #8 on: February 09, 2013, 07:04:37 AM »
Good morning all.  The 472 or 500 I have will be a non-EGR/non smog pum engine.  The MSD EFI & 6AL ingnition together give ignition timing.  With more voltage potential, I should be able to open up the spark plug gap also.  However, in the natural gas pipeline world where many engines use capacitive ignition multi-fire systems, I would look into that also.
I will keep you posted what I do & the good or bad results.  Please keep the ideas coming.
Thank you,
Larry Blanchard CLC #5820

Offline "Cadillac Kid" Greg Surfas 15364

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Re: 1968 cadillac 472 fuel injection
« Reply #9 on: February 09, 2013, 09:30:26 AM »
Larry,
You have me curious.  You said 1968- 472 motor in your first post.  Are you planning on using a stock (specifications such as cam and compression ratio) 68 motor?  Is it going to run on gasoline (you mentioned something about gas pipe line world)? What is your intention for improvement in going to FI? Is it power, ease of starting, fuel economy, or just an experiment?  Also, what car, transmission, rear end ratio and weight are you thinking about?  There are a lot of folks on this forum that are also on other Cadillac high performance forums.  There is a lot of available "wisdom" to be had but we need to understand what it is you want to do.
Greg Surfas
Cadillac Kid-Greg Surfas
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Offline cadman56

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Re: 1968 cadillac 472 fuel injection
« Reply #10 on: February 10, 2013, 04:31:58 PM »
Hey Greg,
I am planning on using the original 472 block but plan on installing a modern, mild, dual-profile cam.  Heads will be 71 or newer hard seat, with pistions that give a  8.5 - 9.5 compression ratio, single belt drive so I can use the HEI distributor, or the MSD-6AL ignition system, or the Accel spark knock control system.
The transmission will be either a 700-R4 or a 4l80E which is why I am interested in the fueil injection system since the engine will be turning slower at 75-80 mph.  The differential will be the standard 2.94:1 limited slip gear ratio that cam in the 1968 model, unless a different ratio would give better results.
I am doing all of this for driveability, fuel economy?, & performance besides the cool factor on my custom & modified 1968 Cadillac convertible. 
Other improvements will be power door locks, modern stereo, heated outside rear view mirrors, defogger rear glass, & heated seats.
If there are any questions, let me know.  I appreciate any & all help I can get. 
Larry Blanchard CLC #5820

Offline TJ Hopland

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Re: 1968 cadillac 472 fuel injection
« Reply #11 on: February 10, 2013, 08:15:55 PM »
Do any of the current aftermarket EFI systems support the 4L80e?   That would be a cool thing if they did since a lot of 'hot rod' guys want an overdrive but dont think a 700 would hold up well with abuse. 
StPaul/Mpls, MN USA

73 Eldo convert w/aftermarket EFI
75 Eldo rusty but trusty
80 Eldo Diesel
And other assorted stuff I keep buying for some reason

Offline "Cadillac Kid" Greg Surfas 15364

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Re: 1968 cadillac 472 fuel injection
« Reply #12 on: February 10, 2013, 11:37:24 PM »
Larry,
At 80 MPH it is going to "burn" close to 100 HP just for aerodynamic drag. That plus the power required for friction, etc. you are going to need at least 200 HP.  Now what you describe as a build should pull 300 HP at somewhere near 4600 RPM (if you put in valve springs to let it get there.  Wit a stock rear end of 2.94, 80 MPH and 230 x 70 x 15 inch tires (or anything with a 27.8 inch diameter) you would be running close to 3000 engine RPM.  At that speed the engine will be putting out just about enough power to keep you "at speed".
If you go to an OD, you are going to "bog" the motor and it will downshift  the trans (if it is set up correctly), so IMHO, OD for 80 MPH isn't the answer.  If in fact you were going to cruise at 60-65, the combo might work, but for the higher speeds your engine and transmission in your '68 would be fighting each other.
Just my late night thoughts.
Greg Surfas
Cadillac Kid-Greg Surfas
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Offline BReyes

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Re: 1968 cadillac 472 fuel injection
« Reply #13 on: February 14, 2013, 10:58:14 AM »
I would be happy with the stock set up. For the above named reasons, there is no better. Think my 472 had electronic ignition but yours with good tune would be great as is.

Weren't all those options you mentioned factory options on cadus?

Regards,
« Last Edit: February 14, 2013, 10:59:57 AM by BReyes »
Bernard

Offline cadillacmike68

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Re: 1968 cadillac 472 fuel injection
« Reply #14 on: March 09, 2013, 11:00:30 AM »
Even before the overhaul, my 1968 with all stock / original components had no trouble getting over 95MPH on the interstate. I kept mine about as stock as you can get (dual exhaust and a series 0 cam excepted) during the overhaul. I didn't see enough of a proposed performance benefit to changing out what has already worked nicely for years. 

If you are not going to race it, then why bother?
Regards,
"Cadillac" Mike

Offline Dave Shepherd

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Re: 1968 cadillac 472 fuel injection
« Reply #15 on: March 09, 2013, 01:24:41 PM »
What is a series 0 cam?

Offline cadillacmike68

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Re: 1968 cadillac 472 fuel injection
« Reply #16 on: March 11, 2013, 10:41:42 AM »
What is a series 0 cam?

It's the mildest performance boost camshaft you can get.  Too aggressive of a camshaft (probably too much duration)  and you get that terrible "muscle car rough idle"  which I cannot stand.  I think mine is a CompCams.
Regards,
"Cadillac" Mike

 



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