4.9 build question (Page 1/3)
P.O.L. Mafia JAN 15, 11:20 AM
So, I have an 86 GT with a V-6 and four speed. I’m pulling the turd V-6 and putting in the 4.9, and I know before you say it, I’m starting off carbed and later I am going fuel injected. Im waiting because I intend to end up with coil on plug fly by wire but its going to take some time to get all that squared away. Anyway, I want to keep the AC and I don’t have a bracket for the compressor. To my knowledge the V-6 compressor will work on the 4.9 but I don’t think the brackets will work. I’ve searched ebay and the webs and can find a ac delete but not the bracketry. Anyone have any info on this? I can fabricate anything, I have good welding and fabrication skills, but I don’t want to reinvent the wheel if not needed.

Thanks in advance

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Mike T
CCWorks
http://www.ccworks.org
Choppers and Fiero's RUUUULLLLEEEEE
michael.tullock@ccworks.net

Neils88 JAN 15, 04:05 PM
Why bother going carb first? The build is much easier using the oem fuel injection system.
olejoedad JAN 15, 04:46 PM
What are you planning to use to trigger coil on plug ignition.

The OEM 4.9 is very reliable and makes great torque as it is.

The brackets should be available at most wrecking yards.

[This message has been edited by olejoedad (edited 01-15-2019).]

P.O.L. Mafia JAN 16, 07:36 AM
going carb first cause I already have everything and I don't want to use the Cadillac brain. I intend to use the brain out of a 2000 Silverado 5.3 I just have to get the firing order of the spark and injectors tweaked to match 18436572. I did miss type, not fly by wire, but fly by cable, with the option of fly by wire at a later date. going to use a holly external trigger wheel for crank sig and the guts from a vortec disy for cam sig. I was hoping someone had the brackets laying around cause taking it off the car in the junkyard (pull-a-part) is a pain in the crack. Yes I have read about the torque and I love torque, getting set back in the seat is a great feeling, I'll take cubic inches over SC v-6 any day. I'm using a Spec 4 clutch with solid six puck disk cause everything I've read shows the springs blowing out of the disk. I'm having an adapter plate made to match the Holley 650 to the two barrel intake and radiusing the intake just under the carb plate to keep fuel from being stripped off as it makes that sharp turn. also removing the EGR tubes and plugging the holes. any suggestions on muffler?

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Mike T
CCWorks
http://www.ccworks.org
Choppers and Fiero's RUUUULLLLEEEEE
michael.tullock@ccworks.net

[This message has been edited by P.O.L. Mafia (edited 01-16-2019).]

olejoedad JAN 16, 08:03 AM
Seems like a ton of work for little gain.

Everyone has a dream.

Go for it.
P.O.L. Mafia JAN 16, 08:09 AM

quote
Originally posted by olejoedad:

Seems like a ton of work for little gain.

Everyone has a dream.

Go for it.



yes it is, but everyone with a 4.9 FI uses the caddy brain, I like to be different. I'm in the middle of building my 77 Camaro, 305 with 400 crank and rods gm TPI with 2000 Silverado brain rewired for 18436572 mated to a Muncie four. I don't have anything that's not modified different from everyone else. everyone dogs me out for stroking the 305, but i'll be the only one with it.
olejoedad JAN 16, 09:59 AM
FYI, I have a 4.9/4t60e Formula with over 130k on the swap.
Runs great, very reliable; if it does break down, easy to fix.
Dennis LaGrua JAN 16, 11:17 AM

quote
Originally posted by P.O.L. Mafia:


yes it is, but everyone with a 4.9 FI uses the caddy brain, I like to be different. I'm in the middle of building my 77 Camaro, 305 with 400 crank and rods gm TPI with 2000 Silverado brain rewired for 18436572 mated to a Muncie four. I don't have anything that's not modified different from everyone else. everyone dogs me out for stroking the 305, but i'll be the only one with it.



There are many obstacles to overcome by using a different ECM on the Cadillac 4.9L. For instance you will require a way to control the idle. The Caddy 4.9L uses a throttle body with an idle air control motor that few other common ECM's will control. IMO there is nothing wrong with matching your engine to the ECM that came with it. That computer is tunable and the code is designed especially for your engine. This engine doesn't take all that well to mods so the best idea might be to leave it stock and use it as is. Great performance can be achieved with the right gearing.

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" 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 "

Spadesluck JAN 16, 01:54 PM
I assume you have HPtuners then which is why you want to use that ECM?
Dennis LaGrua JAN 16, 03:23 PM

quote
Originally posted by Spadesluck:

I assume you have HP tuners then which is why you want to use that ECM?



We have HP Tuners here but unfortunately it can only tune flash based PCM's based upon OBD II. The Cadillac ECM is OBD 1.5 and we use Tunnercat with the proper definition file to make program changes . Fastchips makes a chip for $159.00 that CLAIMS to increase power but we've never see dyno tests with it.. The Cadillac guys say that it works though. Cadillac 4.9L Performance Chip Just click on the 93 model year.
If there was a way to simply change over to OBD II I might consider it but it comes down to risk vs reward. I don't see changes to an OBDII system resulting in more horsepower.

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" 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 "

[This message has been edited by Dennis LaGrua (edited 01-16-2019).]