swap 4.1 to a 4.5 or 4.9 in 85 Seville?
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
Results 1 to 7 of 7
HT4100 4.1, 4.5, 4.9 Discussion, swap 4.1 to a 4.5 or 4.9 in 85 Seville? in Cadillac Engine Technical Discussion; OK, I posted this in the Seville section, but thought this might be a better spot for it. I know ...
  1. #1
    cadmat's Avatar
    cadmat is offline Cadillac Owners Fanatic
    Automobile(s): 1988 Allante.
    Join Date
    Feb 2005
    Location
    vista, california
    Posts
    188

    swap 4.1 to a 4.5 or 4.9 in 85 Seville?

    OK, I posted this in the Seville section, but thought this might be a better spot for it. I know this is kind of an odd question, especially since so few of us seem to care about this model ..but I'm thinking about getting a bustleback Seville, I know the 80 is the best for engine, but I prefer the looks and equipment of the 82- 85, plus, of the few I see that are still around, I see most of those years.. here's my question.. is it an easy swap to put a 4.5 or 4.9 engine into this car? , particularly an Allante 4.5? ( 89 to 92) or just a seville or eldo engine from the late 80'S ? my thinking is the added horsepower and the fact that most of the bugs were worked out by this time would make this engine a good upgrade..What do you think?

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    ehall's Avatar
    ehall is online now Cadillac Owners Connoisseur
    Automobile(s): 1985 Sedan DeVille
    Join Date
    Aug 2007
    Location
    Southern Maryland
    Posts
    1,500

    Re: swap 4.1 to a 4.5 or 4.9 in 85 Seville?

    From what I understand (which is probably wrong) the 4.5 can go into any transverse mount 4.1, but those only started in 85.

  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: swap 4.1 to a 4.5 or 4.9 in 85 Seville?

    The 85 seville is a longitundinally-mounted FWD car. Swapping in a 4.5 or 4.9 really isn't feasible. Too many transverse engine differences, and you'd need a new computer and wiring harness. What would be feasbile is for you to find a 6.0L from a 1980 or 1981 Seville, a 5.7L Olds FI V8 from a 1979 Eldorado, or just a plain, old Olds 350 V-8 engine. You might even be able to swap a 425 ci or 500 ci Cadillac V-8 from an older Eldorado into your Seville using your current transmission, but you'd need to beef it up. Not sure if the 425 and 500 ci are physically bigger than the 368 ci engine, but some modifications would definitely be necessary.

  5. #4
    cadmat's Avatar
    cadmat is offline Cadillac Owners Fanatic
    Automobile(s): 1988 Allante.
    Join Date
    Feb 2005
    Location
    vista, california
    Posts
    188
    Thread Starter

    Re: swap 4.1 to a 4.5 or 4.9 in 85 Seville?

    I'm in California, if it didn't come in it when it was new, I can't do it now and use it as a regular driver legally, due to emission laws 82 to 85 only offered the lousy diesel, the 4.1 and the V6( I think)

    bummer

  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: swap 4.1 to a 4.5 or 4.9 in 85 Seville?

    Hmmm. Well, one thing you can do is advance your timing to 12 degrees. That'll give you what feels like a nice power boost. Aside from that, I guess there's not too much you can do given CA's laws.

  7. #6
    carnut is online now Cadillac Owners Master
    Automobile(s): 1988 Allante' (sold), 1984 Eldorado, 84 Sedan DeVille
    Join Date
    Feb 2003
    Location
    california
    Age
    67
    Posts
    5,990

    Re: swap 4.1 to a 4.5 or 4.9 in 85 Seville?

    4.5 and 4.9 use completely different engine block castings, wont work! You can however install the throttle body from an 81 Cadillac 8/6/4 368 cu. in. engine that has larger throttle plates, reattach your TPS switch and your injectors from the original and get the one inch spacer from JEGS speed shop for a throttle body Chevy truck engine. The spacer is required to allow the throttle blades to fully open. Then bump timing from 10 to 12. Did this mod years ago on my first 84 Eldo. It would actually chirp the front tires leaving a stop light!!

  8. #7
    Po Pimp is offline Cadillac Owners Fanatic
    Automobile(s): 92' Eldorado, 97 Catera
    Join Date
    Dec 2006
    Location
    Tennesse
    Posts
    289

    Re: swap 4.1 to a 4.5 or 4.9 in 85 Seville?

    There use to be a couple of places online that sold 4.5L that would mount in this situation. You could not use the MPFI system. This system was built with the 4T60-E in mind, which is electronic. The DFI system would have to be used and you would only see some minimual gains. Well I guess not to minimual the DFI 4.5L was rated at 150 bHP, not sure that you would see the same in a different mount. In the terms you are talking about, junkyard swapping, neither would work as just a drop in conversion.

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