4.1 to 4.5
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 1 of 3 1 2 3 LastLast
Results 1 to 15 of 39
HT4100 4.1, 4.5, 4.9 Discussion, 4.1 to 4.5 in Cadillac Engine Technical Discussion; Well i got a junkyard i've used for years and recently aquired an 85 coupe with a bad engine. He ...
  1. #1
    nickh is offline Cadillac Owners Member
    Automobile(s): 90 sedan deville 87 coupe deville (project)
    Join Date
    Dec 2007
    Location
    Nebraska
    Posts
    41

    4.1 to 4.5

    Well i got a junkyard i've used for years and recently aquired an 85 coupe with a bad engine. He told me that i should be able to just drop in a 4.5 out of an 88 deville (i belive it was an 88). It has about 85k miles on it and runs good. He is giving me everything just taking off the transmission and giving it to me for $400 (stuff is cheap in nebraska). He did a couple swaps years ago and said it was pretty much a straight swap just maybe the smog pump i belive. Has anyone atemped this before? I thought i would need a 4.5 fuel pump/computer and all that suff but he says not. ANY ADVISE WOULD BE LOVELY.

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    ehall's Avatar
    ehall is offline Cadillac Owners Connoisseur
    Automobile(s): 1985 Sedan DeVille
    Join Date
    Aug 2007
    Location
    Southern Maryland
    Posts
    1,487

    Re: 4.1 to 4.5

    I talked to my mechanic about this for my 85 Sedan Deville one time (actually he tried to sell me an unfinished conversion on another car) and he said it's a direct no-hassle swap but you want a donor vehicle for small parts stuff. It also depends on the 4.5--some of them were TBI and some were MPFI.

  4. #3
    awadecki is offline Cadillac Owners Enthusiast
    Automobile(s): 76 Eldo (54k), 76 Eldo (52k), 78 Eldo (9k), 85 Deville (43k)
    Join Date
    Jun 2005
    Location
    Michigan
    Posts
    668

    Re: 4.1 to 4.5

    The 88 Deville has a 4.5 TBI motor.

  5. #4
    nickh is offline Cadillac Owners Member
    Automobile(s): 90 sedan deville 87 coupe deville (project)
    Join Date
    Dec 2007
    Location
    Nebraska
    Posts
    41

    Re: 4.1 to 4.5

    ya if it doesnt work he WILL give me some random stuff off of the 88. Just wondering if anybody has done this before. Any more input im getting the engine on wendsday so please i have 3 days with the cherry picker.

  6. #5
    awadecki is offline Cadillac Owners Enthusiast
    Automobile(s): 76 Eldo (54k), 76 Eldo (52k), 78 Eldo (9k), 85 Deville (43k)
    Join Date
    Jun 2005
    Location
    Michigan
    Posts
    668

    Re: 4.1 to 4.5

    Not sure, but you might have to use the intake and TBI off of the old 4.1, so don't throw it out. The 4.5 TBI might have a few different control system/connectors that won't interface with the 4.1's computer, or connectors may be different.

    If I had to guess, I'd say that you'd need to keep those parts to make it work.

  7. #6
    Edahall's Avatar
    Edahall is offline Cadillac Owners Enthusiast
    Automobile(s): 93 & 88 Allante, 88 Eldorado
    Join Date
    Jan 2004
    Posts
    779

    Re: 4.1 to 4.5

    Use the intake off the 4.5 if you can. It has bigger ports than the 4.1 and will breathe better. You may also need to install a adjustable FPR to dial in the extra fuel requirements of this larger displacement engine.

  8. #7
    ehall's Avatar
    ehall is offline Cadillac Owners Connoisseur
    Automobile(s): 1985 Sedan DeVille
    Join Date
    Aug 2007
    Location
    Southern Maryland
    Posts
    1,487

    Re: 4.1 to 4.5

    Quote Originally Posted by Edahall View Post
    Use the intake off the 4.5 if you can. It has bigger ports than the 4.1 and will breathe better.
    I thought that was only on the MPFI 4.5

    You may also need to install a adjustable FPR to dial in the extra fuel requirements of this larger displacement engine.
    Even if everything is off the same 4.5?

  9. #8
    Edahall's Avatar
    Edahall is offline Cadillac Owners Enthusiast
    Automobile(s): 93 & 88 Allante, 88 Eldorado
    Join Date
    Jan 2004
    Posts
    779

    Re: 4.1 to 4.5

    "I thought that was only on the MPFI 4.5":

    I believe the 88 & 89 4.5's also had intake manifolds that had larger ports. I'll have to check my sources to be exactly sure.

    "Even if everything is off the same 4.5?"

    Yes, unless you also swap over all the electronic modules as well. You would need the donor car to do this.

  10. #9
    ehall's Avatar
    ehall is offline Cadillac Owners Connoisseur
    Automobile(s): 1985 Sedan DeVille
    Join Date
    Aug 2007
    Location
    Southern Maryland
    Posts
    1,487

    Re: 4.1 to 4.5

    I was looking at the pics you attached to this post actually

  11. #10
    nickh is offline Cadillac Owners Member
    Automobile(s): 90 sedan deville 87 coupe deville (project)
    Join Date
    Dec 2007
    Location
    Nebraska
    Posts
    41

    Re: 4.1 to 4.5

    I went back to the yard today its an 89 deville so it is still TBI. So it sounds like it wont be to bad. I am getting EVERYTHING with this engine, he is pretty much taking off wires, hoses, exhaust and tranny. So i will try the just hook it up method and if it runs rough i would then need the adjustible fpr ( fuel pressure regulator). I will be sure to post everything that needs to be done just so some1 could rewrite it and possibly sticky it. I have been to 3 other "cadillac" forums and nobody ever agrees. Lets just hope it will work like a champ so i can take that old alum. block down to the salvage yard and pay for my new brake system . Thanks for all of the input be sure to check this OFTEN over the weekend it looks like i will be starting on friday night and be done by saturday morning :P (ya probaly late sunday).

  12. #11
    nickh is offline Cadillac Owners Member
    Automobile(s): 90 sedan deville 87 coupe deville (project)
    Join Date
    Dec 2007
    Location
    Nebraska
    Posts
    41

    Re: 4.1 to 4.5

    OMG i jsut realized i said 85. it is an 87***************. If an admin could please edit that. ass i can only edit my last post.

  13. #12
    fj12 is offline Cadillac Owners Member
    Join Date
    Apr 2005
    Posts
    25

    Re: 4.1 to 4.5

    Its a straight bolt in except for the heater hose to the thermostat housing. Instead of two 3/4" tubes on the '87, the '89 has one 1" tube. My mechanic just added 6 inches of 1" hose to a 1" to 3/4" plumbing pipe and hooked that from my thermostat to my heater hose. The pipe where the other 3/4" hose connected to, on the passenger side next to the rear valve cover, was blocked off with some hose clamps , hose, and a long wheel nut. My '87 throttle body bolted onto the '89 intake , and I kept my old air filter setup. Everything else just bolted on, with no change to the computer setup at all. Needless to say......

  14. #13
    Edahall's Avatar
    Edahall is offline Cadillac Owners Enthusiast
    Automobile(s): 93 & 88 Allante, 88 Eldorado
    Join Date
    Jan 2004
    Posts
    779

    Re: 4.1 to 4.5

    Regarding 4.1 & 88&89 4.5 intake manifolds, I checked my sources and as I pointed out they are indeed different. Here's the differences according to my source. The water outlet was different, the throttle bores were modified and the whole manifold was changed from a single plane to a dual plane design for better performance.

    It'll run better and have more performance if you install an adjustable FPR to dial in the extra fuel requirements of the larger displacement engine. The 4.1 electronics is unable to fully compensate for the higher performance engine.

  15. #14
    ehall's Avatar
    ehall is offline Cadillac Owners Connoisseur
    Automobile(s): 1985 Sedan DeVille
    Join Date
    Aug 2007
    Location
    Southern Maryland
    Posts
    1,487

    Re: 4.1 to 4.5

    So... not to hijack the thread, but should I round up a 89 4.5 TBI manifold for my project too?

  16. #15
    Edahall's Avatar
    Edahall is offline Cadillac Owners Enthusiast
    Automobile(s): 93 & 88 Allante, 88 Eldorado
    Join Date
    Jan 2004
    Posts
    779

    Re: 4.1 to 4.5

    Yes, I would round up the intake manifold that was designed to fit on this 4.5. Either an 88 or 89 4.5 intake manifold will work. I would also round up an adjustable FPR.

    Here's a FPR that works on our cars.
    http://www.aeromotiveinc.com/products.php?prod=13
    The P/N 13106 Aeromotive is the one that fits our engines. And the
    Aeromotive one will handle alcohol (aka, E85) if you should ever want
    to use it.

    Here is some info on how to properly tune your engine with a fuel
    pressure regulator:
    http://www.aeromotiveinc.com/pdf/13106.pdf

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