4.5l Allante engine (Page 2/6)
olejoedad SEP 20, 10:33 PM
M17 is 85-86.
Pauljt SEP 20, 10:45 PM

quote
Originally posted by olejoedad:

M17 is 85-86.



Ay yi yi!!! Thank-you. I sure don't mind getting schooled on this particular playing field. I'm generally accustomed to having the answers (31 years as a millwright and 10 as a motorcycle mechanic) but I am definitely on "terra non firma" with this project that I'm hoping to get into. I'll keep doing research and asking questions here to verify.
V8 Formula OCT 02, 06:09 PM
Thank you Johns 4.9. I've decided the next swap I'm going to do will be a 4.5 Allante engine with the Getrag in my Formula. I've done a 4.9 in the past so I'm familiar with the process but that bit about the balancing is very helpful.

Also, with the ISC on the Allante, what are my options for fuel injection control? Am I relegated to the Caddy ECM?

-Rick Stewart
Johns 4.9 OCT 02, 06:53 PM
Glad I could help, Rick. You don't want to use an aluminum flywheel with the 4.5 engine. Not enough material mass to remove to balance the engine. My engine balancer/machinist had to add Tungsten to the rear crankshaft weights to get it to balance. It was worth it and my customers 4.5 Stage III with the aluminum flywheel just screams!
I can't help you out with your fuel injection. Just not my thing, 90's fuel injection. But there are several guy on this forum that are very good with the Allante FI.
Radar is very helpful and others.
Cheers
V8 Formula OCT 02, 09:22 PM
Thanks John.
Reallybig OCT 03, 12:20 AM
If you're going manual for sure, avoid the isuzu 5spd from the 87&88 4cyl cars. I was told I'd kill mine, and I did. 2nd gear is a weak spot and unfortunately the most fun gear to lean into. I documented my swap to try and help others doing the caddy 4.9 swap here; http://www.fiero.nl/forum/Forum2/HTML/122389.html

Being allante and 84, there will be differences, but hopefully the rest might be useful to you
Johns 4.9 OCT 03, 12:25 PM
Reallybig,
I must be the luckiest guy in the world. I have had 4 SBCs and one Cadillac 4.9 in my Fiero all using the same 1985 Isuzu transmission. I have never had a problem in over twenty years. Is there a difference between early Isuzu 5 speeds and later model ones? Thanks
Cheers
Dennis LaGrua OCT 04, 04:00 PM

quote
Originally posted by V8 Formula:

Thank you Johns 4.9. I've decided the next swap I'm going to do will be a 4.5 Allante engine with the Getrag in my Formula. I've done a 4.9 in the past so I'm familiar with the process but that bit about the balancing is very helpful.

Also, with the ISC on the Allante, what are my options for fuel injection control? Am I relegated to the Caddy ECM?

-Rick Stewart


The ISC's on both th 4.9L and 4.5L Allante engines are the same. As you've seen on your 4.9L they are actually idle speed motors and the only ECM's that can control them are the specific Cadillac ECM's. I could be wrong, but I doubt that the popular Chevy GM's like the 730 are capable of controlling them. On the plus side I see nothing wrong with the Cadillac ECM's as they can be programmed almost as easily as most other GM ECM's. With the Allante ECM you should be fine.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Raydar OCT 04, 05:35 PM
The only PCM that will work the Caddy ISC is the Caddy PCM.
I've got a 7730, that I'm planning to adapt to my 4.9, but it will require a different throttle body. I'm thinking 3800SC or Northstar.
Keep in mind that the Allante intake has a 2 barrel "staged" throttle body (like half of a quadrajet), that orients one port above the other. You will need an adapter to mount any kind of "round" throttle body to the intake. (Or a dual blade 305 or 350 TPI throttle body may work. The adapter should be much less complicated.)
Will OCT 07, 08:35 AM
You could also keep the Caddy throttle, ditch the ISM and run a remote mounted IAC into a large vacuum port.