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1985 Cadillac Eldorado Biarritz

Started by CAD57@2816, December 14, 2019, 03:45:37 PM

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CAD57@2816

I received an email regarding the engine in the 85 Biarritz, (maybe every model) that the engine in the 85 model year was improved during the block casting process to produce a stronger engine.  There was no detail other than that.  Does anyone have an idea what this means?

e.kempton

GM did improve the 4.1 engine after VIN # FE 623772 in the Eldorado and after FE 812094 in the Seville's. in the 1985  models. Keep away from the 1982 to 1984's. 

TJ Hopland

I would not call it a great engine in 85 but given the choice between an 82 and and 85 I would for sure take the 85.   The customers did a lot of testing for them and they learned a lot the first few years.    Better than an 85 would maybe be a "Goodwrench" replacement engine from the early 90's.   Those would be as good as they were ever going to get.  Still had some weak points but much improved over the originals.

If you don't know the engines history they started working on it in the late 70's knowing they had to do something drastic to meet upcoming mileage and emissions standards.  The 8-6-4 that came out in 81 was supposed to be the 'big car' engine through the 80's along side the diesel.   The engine that became the HT4100 was intended for the much smaller transverse FWD cars (along side a V6 diesel) that were supposed to come out in several GM lines around 83-84.  Production of those cars was delayed due to transmission issues, they did eventually come out in mid 85.

Here is how I imagine it went, here is Cadillac likely in late 80 or early 81...
   
-The 8-6-4's are selling but people don't like em.   
-Diesels are still selling well but not well enough to meet upcoming requirements. 
-We got the Buick V-6 but people don't like that because its a buick and not a v8 and its not that much better on gas or emissions so really doesn't help much.
-The 'full size' transverse transmission isn't even close to being ready. 
-Oh and someone just shot John Lennon.   

Hmm what do we have? 
-We got the basically prototype test engine for the upcoming but delayed smaller cars that isn't built like any engine before it on a prototype assembly line using technology never before tried in this industry or even never been tried before period.   

I know we told you that we were not going to need this transverse engine till 83 at the earliest but now we need them in 6 months.   Oh ya and its got to be longitudinal.   Oh ya and its going to be the standard engine for all models so we are gonna need a bunch of em.   What?  Heavier less aerodynamic car?  Incomplete testing?  Just get me those engines.......
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

35-709

"I would not call it a great engine in 85 but given the choice between an 82 and and 85 I would for sure take the 85" --- a bicycle.
::)

:)
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 - Sold
1950 Packard 2dr. Club Sedan
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2

bcroe

Quote from: TJ Hopland
I know we told you that we were not going to need this transverse engine till 83 at the earliest but now we need them in 6 months.   Oh ya and its got to be longitudinal.   Oh ya and its going to be the standard engine for all models so we are gonna need a bunch of em.   What?  Heavier less aerodynamic car?  Incomplete testing?  Just get me those engines....... 

They could have used the super reliable Olds engine, as Buick did. 
Bruce Roe

TJ Hopland

You do kinda have to wonder why they didn't do that.  A DEFI 307 would have been better than the 4100 for the big cars.  The DEFI on the olds could have still been a Cadillac exclusive.   I can't imagine that the 4100 in the big cars was that much better for emissions and mpg than even the 368 but it must have been or you would think they would have just kept going with those without the 8-6-4.    It was likely one of those illogical things about the way the government rules worked.
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

bcroe

Logic prevailed when they finally started putting Vette engines in
big cars. 

I think it was culture thing.  Early leaders brought innovation like
electric starter, automatic trans, and front wheel drive.  By the 70s
all the mechanical were pretty much the same across the Generals
brands.  Aside from a fancy body well equipped with non essential
gadgets, about all Cad could claim was their own engine.  They
insisted on a Cad engine no matter what.  Bruce Roe

James Landi

My understanding about the 4-6-8 was that it would stall under load, and that people died trying to merge into traffic...  please refute this claim as I am unsure about the origin of the source..     James

TJ Hopland

I don't know about people actually being killed and never drove one myself back when they were fairly new but I had heard that the 'transition' was one of the big problem areas.    If sequential multiport had been practical at the time it would have likely been a different story.   

Think about the literal turbulent storm going on in that intake as cylinders activated and deactivated.  Valve is operating so you got a ok flow going on throughout the intake like it was optimized for.   Now you close a 1/4 or 1/2 the valves you got this wave of air and fuel that suddenly slams into a wall likely knocking at least some of the fuel out of suspension and disrupting pretty much all the rest of the flow in the intake.   Mixtures and flow are going to be far from optimum.   Now kick em back on you may be getting extra fuel that came out of suspension in some cylinders while others are disrupted from the flow change...   doesn't sound like it would work very well. 

In the 2000's when it came back it worked great with long dry intake runners and fast computers doing sequential multiport injection.   Cylinder shuts down fuel shuts down and the long runners there is minimal upsetting of the airflow.   I'm not positive but I think all the engines that did that may have also been 'fly by wire' so the computer was in charge of the throttle which gives the computer even more control over things compared to the original Cadillac system.
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