Bottom Dollar 4.9 Cadillac Swap Checklist (Page 2/3)
brandon8696 AUG 02, 03:08 PM

quote
Originally posted by Spadesluck:

Let me make sure I am getting this right. You currently have a caddy with the 4.5 in it correct? You are looking swapping the 4.5 out for the 4.9?



Yessir.

However, the big questions for me pertain to swapping over the Allante intake, making sure I can tune the ECM for it, and if I need to upgrade my fuel pump.

Here's what I DO know what gathering information, in case anyone from Google or whatever come across this post.

89-92 Allante intakes have the correct cooling channels and gasket match perfectly with the later 4.9 engine. Pre 89 Allante intakes have provisions for EGR though, if you really don't want to deal with tuning, you can modify the cooling channels.

However, according to this thread, FROM HERE: https://www.fiero.nl/forum/Forum2/HTML/146204.html

I can tune an ECM for EGR off, and play with the tuning a bit to accommodate the better air flow of the Allante intake.

In response to that other user asking about the gains? I honestly can't say any dyno numbers. Most of the dyno numbers I see posted on here are of heavily modified engines in Fieros.

What I can say is that the Allante intake flows more air and fuel than the TPI setup, and thus can give you a small gain over the 200hp rating of the 4.9. I also like the cleaner setup of the MPFI system, and according to several Caddy owners, it just runs cooler without the EGR system heat soaking everything.

If I can get some definitive information on self tuning, and pushing tunes to the ancient ECM, I'd then like to perhaps order a cam for the engine. That's realistically a stretch goal.

The good news is I am in no rush. My stock 4.5 is tired, but it can still handle weekend cruises without much fuss.
Spadesluck AUG 02, 04:22 PM
1. The ECM can be tuned. You can go thru the trouble to get everything yourself to do or us this guy Sinister. I used him to tune my 4.9 to run with the Allante intake. (throttle body, upper intake, and lower intake). The EGR will just be tuned out or turned off, however the tuner does it.

2. The 4.5 and the 4.9 fuel pumps are the same, no worries there.

3. With the Allante stuff, I would try and grab the rocker arm supports from the Allante car. These are stronger than the 4.9. Less prone to problems.

4. Make sure you grab the hard fuel lines with some extra hard line still attached to the fuel rail, those are impossible to find. Also the fuel pressure regulator attached to the fuel line, it is no longer made as well. Unobtanium.
Neils88 AUG 02, 07:33 PM
Unfortunately there aren't a lot of upgrade parts available. No one here has ever reported finding a cam upgrade. Also, it can be tough to find simple things like replacement head bolts, etc. This may limit some of your plans. But, as a 4.5 owner you are probably already used to this.

Supercharging or turbo charging is possible. If you go this route then you'll definitely want to invest some time in learning how to do your own tuning.
Spadesluck AUG 02, 10:32 PM

quote
Originally posted by Neils88:

Unfortunately there aren't a lot of upgrade parts available. No one here has ever reported finding a cam upgrade. Also, it can be tough to find simple things like replacement head bolts, etc. This may limit some of your plans. But, as a 4.5 owner you are probably already used to this.

Supercharging or turbo charging is possible. If you go this route then you'll definitely want to invest some time in learning how to do your own tuning.



The only thing you are incorrect on is the cam. Delta makes off the shelf camshafts for the 4.5/4.9 motors. They will also build a custom camshaft if you ask for it. I know this first hand.

Everything else you said, absolutely true.
Neils88 AUG 04, 09:13 AM
That's good to know. I'll have to look into an upgrade.
Spadesluck AUG 04, 02:22 PM

quote
Originally posted by Neils88:

That's good to know. I'll have to look into an upgrade.



Delta Cam
brandon8696 AUG 05, 10:58 AM

quote
Originally posted by Spadesluck:

1. The ECM can be tuned. You can go thru the trouble to get everything yourself to do or us this guy Sinister. I used him to tune my 4.9 to run with the Allante intake. (throttle body, upper intake, and lower intake). The EGR will just be tuned out or turned off, however the tuner does it.

2. The 4.5 and the 4.9 fuel pumps are the same, no worries there.

3. With the Allante stuff, I would try and grab the rocker arm supports from the Allante car. These are stronger than the 4.9. Less prone to problems.

4. Make sure you grab the hard fuel lines with some extra hard line still attached to the fuel rail, those are impossible to find. Also the fuel pressure regulator attached to the fuel line, it is no longer made as well. Unobtanium.



I greatly appreciate the help with this, and I think this has given me the confidence to start piecing this build together.

My only question I think I still have is in regards to the fuel system. Let's say worst case scenario I get screwed into making my own hard lines. Can I just get a fuel pressure regulator that is for the OEM operating range of the Allante? That would be like 45-50 PSI, right?

From the info I gathered, my own comfortable skill set, and my budget, I think I will ditch the idea of a cam swap, and just stick to the Allante intake on the 4.9 with an EGR delete and tune. Even if I squeeze out 215-225hp from it with my cat delete exhaust, I'd be a happy camper.

The 4.5 with only 155hp and 240ft-lbs of torque moves the little Eldorado pretty well, so I think 200+hp and 275+ ft-lbs should be zippy. Er well zippy by my extremely low standards haha.

I think next check I'll pick up the Allante parts, because I'd like to polish them before installation.

I appreciate the help, and I hope this doesn't become one of those threads that never gets a post with the finished results haha.
Spadesluck AUG 05, 11:31 AM
Unless you have the skills to make your own fuel lines you absolutely need the rails and everything that is attached to them. The injectors are not straight in the intake either, they are angled which would add difficulty making lines.

My advice it to find all the parts. But, in theory, yes you could make all your own stuff and have an aftermarket regulator. Once you see what I am talking about you will have a better idea.

I will take some pics of my stuff and show you later today.
Spadesluck AUG 05, 06:20 PM




The fuel regulator is what the purple vacuum line is attached to. The fuel inlet has the AN fitting on it. The outlet is on the regulator. The inlet is the tricky one, and I would recommend making sure you have it and the regulator.

[This message has been edited by Spadesluck (edited 08-05-2024).]

brandon8696 AUG 06, 01:27 PM

quote
Originally posted by Spadesluck:





The fuel regulator is what the purple vacuum line is attached to. The fuel inlet has the AN fitting on it. The outlet is on the regulator. The inlet is the tricky one, and I would recommend making sure you have it and the regulator.




I now understand exactly what you meant in your last comment. Sir, you are a gentleman and a scholar.

Alright, so I have a rough understanding of the fuel system needs, I have a rough understanding of the ECU tuning I'll need, and I have a rough guestimate of the mounting of it all. I suppose my last query is the EGR delete, which I'll see if I can find anywhere on this forum or the Caddy forum.

Spadesluck, do you have any firsthand experience with the EGR delete on these? Also, any weird wiring harness issues I need to worry about. I've read from several sources on here and the Caddy forums that the 4.9 PFI harness should just plug and play with the Allante connections.

I figured I may as well ask while I have you here. Hopefully this info can help other folks too.

[This message has been edited by brandon8696 (edited 08-06-2024).]