Author Topic: Cadillacs with Newer GM V8s  (Read 1069 times)

Offline jdemerson

  • 1952 Cadillac 6219X Vermont -- Emerson
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  • Name: John D Emerson
Cadillacs with Newer GM V8s
« on: August 27, 2017, 07:47:48 AM »
I was at a small regional car show yesterday. There were three Cadillacs: 1965 Sedan DeVille, 1971 Eldorado Convertible, and 1983  DeVille 2-door. All were quite nice. The '83 was in beautiful condition and originally had the V6. But this had been replaced by a recent Chevrolet truck V8 with transmission, drive shaft and differential (according to owner). It appeared to be a very neat and professional installation, but I wonder about the computer controls.

I recently looked over a beautiful 1949 fastback coupe that the owner, an older lifelong owner of a car shop who has done extensive mechanical work and body work. The drive train has a new very large GM V8 crate engine, and the car has modern air conditioning, cruise, power everything, and so on. In effect is it a 2016 car with a 1949 body and exterior. I was amazed at how much of the original look was maintained in the interior, given the extensive modifications.

I'm not a fan of these types of modified cars, but I do have to marvel at how skillfully they are done in some cases. The owners point out that they can comfortably drive from northern New England to Florida and back in these cars. Is there a significant trend in this direction?  Were there cars like these at the Grand National earlier this month?

John Emerson
1952 Cadillac Sedan 6219X
Middlebury, Vermont
John Emerson
Middlebury, Vermont
CLC member #26790
1952 Series 6219X
http://bit.ly/21AGnvn

Offline 35-709

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Re: Cadillacs with Newer GM V8s
« Reply #1 on: August 27, 2017, 09:39:13 AM »
Yes, there were several cars like this at the Cadillac GN, mine, pictured below, was one of about 10 or so in my modified class.  Yes, I do believe there is a trend in this direction, one reason that for the first time at this year's GN modified Cadillacs were judged in 4 (5?) different modified classes.  My car (Big Red) took 2nd in class M2 at the GN this year.
 
We have driven B.R. over 26,000 miles since his completion in January 2011.  He has been driven to the St. Augustine, Boston, Lake George, and Washington DC GNs from our home in Florida.  He has also been driven to upstate New York on 4 different occasions (I am originally from upstate NY), and Indianapolis --- from Florida.  He is modified with all of the modern safety and power conveniences, including AC, 4 wheel disc brakes, etc., etc.  He is powered by a 1971 Cadillac 472 and we cruise at turnpike speeds.

My biggest objection to many of  these modified cars is that they use (on most occasions) a Chevrolet engine for no good reason that I can see other than that they are simpler and cheaper.  The SBCs don't have enough bottom end torque to really make these heavy cars get going --- Cadillac engines are built for bottom end torque.  Chevy or "GM corporate engines" may be OK for today's Cadillacs that are much lighter and smaller.  IMO, using a SBC or BBC denigrates the car taking away much of its class. 
« Last Edit: August 27, 2017, 10:14:41 AM by 35-709 »
1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold - but still in the family
1950 Jaguar Mark V Saloon resto-mod - Sold
1942 Cadillac 6269 - Sold
1968 Pontiac Bonneville Convertible
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2

Offline TJ Hopland

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Re: Cadillacs with Newer GM V8s
« Reply #2 on: August 27, 2017, 11:24:55 AM »
I agree a classic small block Chev is not a good fit for many Cadillacs for many reasons except maybe in the case of the early 80's were the engine options not the best but even there it a fair amount of work for minimal gains.    Big blocks are as expensive to build as 472-500-425 so why bother there too.

The LS engines which are now 20 years old I think could be a different story.   The LS engines along with their 4-6 speed transmissions make a pretty powerful yet efficient package.  Aftermarket has really got behind the LS engines over the last few years so you can pretty much take a junkyard stock truck motor and build it beyond Corvette specs if you want or as time and budget allow.   Aftermarket also makes kits for popular cars that include mounts and harnesses that make it a bolt in swap.   There is a little more work involved if you don't have a popular car but there are universal mounts and harnesses that help get things moving.

The early 80's Cadillacs don't seem to have major issues loosing their engine computers.   Within the last year there was a guy with something like an 83? CDV that put a 425 in it.   Trip computer quits,  climate control is fine, and he didn't care about cruise which I think won't work unless you find a diesel control module.  That is also easily solved with an aftermarket cruise system.   Not sure what an LS would do to that.   I would think since you have all the LS electronics it would just be a matter of hooking up the switch.   In the late 90's the GM cruise controls were still discrete switch inputs to the computer but by mid 2000's that could have changed to a more complex data stream of some sort.  Cruise is a popular option for 'hot rods' so I would imagine there is a way to do it.

There are some little details like the speedometer.   There are mechanical speedo drives available for some of the earlier 4 speed transmissions.   I don't think you can get those for the 6's so you end up with what is basically an electric motor that is driven with the digital speedo signal from the LS computer.   They are not especially cheap, maybe $400 so its all stuff you have to factor into your plan.         
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Offline James Landi

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Re: Cadillacs with Newer GM V8s
« Reply #3 on: August 27, 2017, 09:40:54 PM »
As I have noted on several occasions in the forum, I took out an '85 4100 (the fourth in that convertible) and substituted a 2 barrel Olds small block and YES --- the 4100 distributor does  fit the OLDS--- the computer does modulate to several engine management systems, and ALL of the control head functions on the dash DO WORK--- including the A/C, the CRUISE control, and other digital displays. 

Offline TC

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  • Name: Tom Stephens
Re: Cadillacs with Newer GM V8s
« Reply #4 on: August 27, 2017, 10:54:15 PM »
As I have noted on several occasions in the forum, I took out an '85 4100 (the fourth in that convertible) and substituted a 2 barrel Olds small block and YES --- the 4100 distributor does  fit the OLDS--- the computer does modulate to several engine management systems, and ALL of the control head functions on the dash DO WORK--- including the A/C, the CRUISE control, and other digital displays.

Which small block Olds engine did you choose?

Offline James Landi

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Re: Cadillacs with Newer GM V8s
« Reply #5 on: August 28, 2017, 07:52:34 AM »
Hi Tom --

We put in an Old 260 small block--- it proved to be somewhat challenging, viz:

1.  metal "sculpture" for exhaust behind the engine cross over
2.  Shift bracket
3. accelerator bracket
4. cruise control bracket
5. minor bracket adjustments for axles
 
The big surprise--- just for "grins and giggles" we dropped in the 4100 distributor-- not only did it fit PERFECTLY but it works with the computer.  We then used as many of the engine sensor pick ups that we could easily remove and install.

The 260 engine is bullet proof --- not much difference in performance and ride that we can discern... a loss of perhaps, a mile per gallon in fuel consumption. 

Offline TJ Hopland

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Re: Cadillacs with Newer GM V8s
« Reply #6 on: August 28, 2017, 11:16:35 AM »
The 260 was part of the Gen 2 Olds family that started in the early 60's.   All the Gen 2's had the same basic dimensions like bore centers mounts and such.   The 400,425,455 were tall decks so slightly taller and wider at the top.  330, 350, 260, 403, 307 were the short decks.

The 260 came out in the mid 70's.   It was a result of GM scrambling to find an economy engine since they were not sure they would be able to buy back the Buick V6 from AMC.   It used the standard short deck stroke but had a much smaller bore.  Eventually all the GM's got this treatment some less successful than others.  The olds was one of the less crappy ones.  368 Caddy was another one that wasn't that bad.   What really hurt these engines is they tended to use the standard stroke but a small bore which meant they needed tiny valves which didn't flow very well.  Also didn't help that they were not any lighter or cheaper to build than their bigger brothers.

The 260 was never super common.   Most of them went into 75-77 X bodies like Ventura or a few A bodies like Cutlass.   I think what really wiped it out was in 77 they re designed the Buick V6 to be even fire and a few other improvements so it really took over as the big car econo option.         

Back when you could find all this stuff in junkyards you could go get all the brackets and such from a Caddy with the diesel and bolt any of the Olds engines in your 4100 RWD car.
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Offline James Landi

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Re: Cadillacs with Newer GM V8s
« Reply #7 on: August 29, 2017, 07:57:13 AM »


      "Back when you could find all this stuff in junkyards you could go get all the brackets and such from a Caddy with the diesel and bolt any of the Olds engines in your 4100 RWD car."   T.J.

Our 4100 to 260 Olds is in a 1985 Eldorado Convertible, so the front wheel geometry created a somewhat my daunting level of anxiety-- but not to worry... what didn't quite fit could be adjust to fit.  I suppose if there are lessons to be learned from our effort that was completed in 2013, they are as follows:

1.T.J. is correct regarding the availability of cross-over exhaust plumbing from other FWD G.M. cars from the 80's... I have dealt with "Action Auto Wreckers " in Massapequa (Long Island) N.Y.   Purchased three "solid" used 4100's from them starting 15 years ago... used 4100 replacements were part of their website-- no more...and parts? Occasionally they still get an old 80's Cadillac into their inventory.
2. There's a common misconception that several in car dash board features won't function with a transplant--- this is NOT true.   The 85 Eldorado Computer and related electrical and vacuum circuits work  just fine.
3. and finally, there's the miracle of the 4100 distributor in the 1978 Old's Cutless 260...

Happy day,   James 

Offline TJ Hopland

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Re: Cadillacs with Newer GM V8s
« Reply #8 on: August 29, 2017, 01:01:05 PM »
I suspect the original topic here was mostly directed at what would more or less be Chev truck motors from 87 on which was when EFI came in since those are what can be fairly easily found cheap on the used market these days.   There just were not a ton of RWD V8 cars built after the mid 80's so for the most part those don't really come up when people are considering a 'budget' swap.  Sure you can find the occasional Camaro or Crown Vic but if they are going cheap they are likely pretty beat.   I put budget in quotes because even if you get a complete donor rig with a great running motor for $500 and have a garage full of tools and a bunch of buddies with lots of skills you are still going to spend thousands before you are done.       The game is a little different if you can afford to open up the Gm performance catalog and pick out say a 6.2 liter LS6 and a 6 or 9 speed to go with it.  The nice thing about the LS platform is you can start out with a junkyard 5.3 out of say a 2001 pickup truck and build up to that LS6 as you can afford it since they are physically more or less the same.  Making it all look nice is yet another layer of skills which many don't have and doesn't come cheap if you have to pay someone to do it. 

And yes there are parts of the country where there are still classic junkyards with 80's and older stuff but there are a lot of places where between scrap values and the EPA just don't exist anymore.    The few places that still have 'good stuff' are either online and easy to find so people all over the world have easy access which usually means the good stuff sells fast for high prices or they are truly classic junkyards stuck in the 70's with no computers at all,  only a sign on the fence and an ad in the local printed phone book.   I know places like that still exist but they can be really hard to find.

With any swap the bolt in part is maybe 10% of the project.   What most people don't figure our underestimate is that other 90%.   If there is a kit or a donor car option maybe that gets you another 50% there but you still have 40% to go.    Just something simple like the fuel line was on the left and now needs to be on the right isn't usually as easy as a $4 chunk of hose and some clamps.  They guy that did the 425 swap recently was stuck for several weeks because of a throttle cable bracket.  That is a great example of a tiny little piece that may or may not exist that has about $1 of material in it that pretty much stops the whole show.   


A few more Olds bits for anyone interested:

RWD Olds engines for the most part used a crossover from the left side of the engine that connected to the right side manifold which then had a second connection that was the outlet to the rest of the exhaust system.   I think Buick may have also done that.  Not sure why you normally only see something like that with turbos.   Even the 'hi po' Olds cars had the dual port manifold on the right side but if they had the dual exhaust option there was a cap covering up the port that would have been the crossover. 

The FWD I suppose the transmission was in the way (on the left side) so this arrangement didn't work so those cars got a Y or T sort of arrangement which was unique to Olds equipped cars.  They were fairly common because the Toronado's almost always had Olds motors.   Caddy only had the 79's and then diesels.   Rivs tended to get V6's till the last couple years when they too got 307's.    I have never been that deep into a 4100 Eldo or Seville so I presume they had a similar but different arrangement. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Offline smokuspollutus

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  • Name: A. Molinaro
Re: Cadillacs with Newer GM V8s
« Reply #9 on: August 29, 2017, 01:50:20 PM »
As long as the distributor is in place the fuel "computer" will say something. At a comparable displacement and in good tune its guess will be pretty close to 100% accurate as it was with the original fuel injection. MAP and TPS signals being incorrect or nonexistent will work against accuracy.
1984 Eldorado Biarritz Coupe
1983 Sedan deVille

Offline James Landi

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Re: Cadillacs with Newer GM V8s
« Reply #10 on: August 29, 2017, 06:26:25 PM »
Last bit of commentary from me regarding this entire "swap 4100 project" ...T.J. is entirely correct that this is a time consuming and expensive process.  A very motivated, loving, and talented  friend and his friend who owns an independent garage did much of the work.  I paid for the parts--- they would NOT accept any compensation for labor.   I recently sold the 85 Convertible to a CLC member for a fraction of all the cash that I had in the car with just under 200,000 miles.  Was I throwing money away on a car that should have been scrapped?  Like so many of you who love their old Cadillacs, and can look past the odometer read out, the leaks on the floor, and the worn upholstery, yes, I'd do it again, with the expectation that I've added years of service to a car that may potentially bring pleasure and respect from future generations.

Offline bcroe

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Cadillacs with Newer GM V8s
« Reply #11 on: August 29, 2017, 07:43:03 PM »
A diesel FWD 79-85 Cad will supply the main parts to bolt an Olds 260/350/403
small block into a 79-85 Eldo.  But those year Riv and Toro mostly used Olds
engines and can also supply the conversion parts. 

Offline savemy67

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  • Name: Christopher Winter
Re: Cadillacs with Newer GM V8s
« Reply #12 on: August 29, 2017, 09:16:55 PM »
Hello John (and all),

The following link is to an episode of Jay Leno's Garage, wherein a '48 Cadillac has been modified with a modern Cadillac underbody, drivetrain, electronics, etc. - quite extensively.  One of the issues discussed in the video is the relationship between the computer and wire harness length.  As cars become more sophisticated electronically, it may become more difficult to accomplish swaps such as the ones described in this thread.  At some point, the 4100 distributor will not work in your preferred combination without more costly modifications.  When you watch the video, think of the expense that went into this one car.  Apparently money was no object.  It is beautiful however.

https://www.youtube.com/watch?v=IERdq9vIqQ8

As the original owner of a 1995 Impala SS, with a small block Chevy engine (350/5.7/LT1), I cannot recall a time when the 4000 pound car lacked enough torque to go from a two digit speed to a three digit speed expeditiously uphill.  That said, I like the idea of keeping your Cadillac, mostly Cadillac, as in the Leno's Garage car, and Big Red.  Since the current modified rules allow any drivetrain, we will continue to see Chevy engines, as they are relatively plentiful and affordable.  Regardless, all the modified cars at the GN were well done, and interesting to view.

Christopher Winter
Christopher Winter
1967 Sedan DeVille hardtop

 

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