4.9L Oil cooler line fitting size (Page 2/3)
Johns 4.9 APR 23, 03:20 PM
Good luck on your mod, Dennis.
olejoedad APR 23, 04:11 PM
FYI Dennis, I've run 87 octane in the car for the last 100,000 miles, not an issue. Engine has over 200,000, still runs great.
Dennis LaGrua APR 23, 08:44 PM

quote
Originally posted by olejoedad:

FYI Dennis, I've run 87 octane in the car for the last 100,000 miles, not an issue. Engine has over 200,000, still runs great.


I can believe that. Those Cadillac engines were well built and designed to last. It was last dedicated Cadillac engine that GM made and they did a good job on it ,designing it for loads of torque at a light weight. IIRC in the owners manual, GM specified running premium gas. If it works on regular that's a plus but perhaps on premium you can tune for more power. Superchips developed a performance chip that claimed a boost in power to 300HP but that chip came and went long ago. I will try to add a bit more timing to see if I can replicate what they did but first need to finish the improved cooler setup. Thank you for the comments

------------------
" 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 APR 23, 09:55 PM

quote
Originally posted by Spadesluck:

In all honesty does the 4.9 even need an oil cooler on a Fiero?




Weeelll...

The 4.9 base idle is very low. Like 600 RPM, or something like that. At that idle speed, the 4.9 does not develop enough oil pressure to satisfy the "low oil pressure" warning light on the Fiero aux gauge pod. I have to believe that an oil cooler might help a bit in that regard. (Cooler oil maybe not thinning out as much.)
(My solution? I "gimmicked" my gauge so that it reads a bit higher, and doesn't turn the light on, under normal conditions. I also bumped up my idle speed to 900+, in the program.)
J Gunsett APR 24, 08:51 AM
Did you get my email?
Dennis LaGrua APR 24, 10:36 AM

quote
Originally posted by J Gunsett:

Did you get my email?



Yes. Thank you. The answer was in the post that showed the picture of the oil cooler that I will use. Read a few posts above

"Thanks for forwarding the webpage info but those parker fitting numbers don't come up anywhere?"

J Gunsett APR 25, 09:40 AM
That part number is from about 15 years ago, may have changed the part number.

Jack
Dennis LaGrua APR 25, 11:12 AM

quote
Originally posted by J Gunsett:

That part number is from about 15 years ago, may have changed the part number.

Jack



Even so thanks for trying to help. If the M18 x 1.5 o ring AN6 fittings work I'll let everyone know.
Dennis LaGrua APR 25, 06:42 PM
Final outcome: OK please ignore all of the wrong info that I've posted on this thread. Finally figured it out.
The Cadillac 4.9L oil cooler hose fitting threads on the oil filter housing are M20 x 1.5. I will go with an adapter to a #8AN male end that will accept female hose ends and use a #8 AN hose to the oil cooler. Now this means using a straight adapter that will give up the O ring tube feature but with sealant on the threads and perhaps an O ring on the fitting the sealing will most likely hold.
Here is why I upsized to a #8AN oil cooler line and a suitable oil cooler. All of the engine oil to the engine when hot is sent through the cooler. I thought that using a #6 AN line would hinder the oil flow so went with #8AN to be sure.
Some other useful tips for anyone considering this swap
1. The stock Fiero throttle cable can be used. Its long enough. Just cut the metal Fiero tip off and use a cable crimp to form an O at the end of the cable. This throttle cable will clip on to the Cadillac throttle body pulley and will work but you may have to modify the cable bracket.
2. For the auto swap, the Cadillac 4.9L 4T60e transmission mounts can be used . You just need to remove the rubber pads from them and use Fiero trans mounts. The front engine mount can easily be made from the stock 2.8L Fiero mount.
3. The exhaust can in fact be designed to fit with no trunk cutting and without removing the heat shield. If you use the 13" Spintech Crossflow 2 1/2"/dual 2" out muffler with a modified U bend head pipe, the exhaust noise will be deep not be loud. You can easily hear the radio and while cruisingit sounds like you family car.
There are many more tips in the archives
The engine design is dated (I had mine in oil fogged storage for 7 years), but while the 4.5L/4.9L engines are no longer popular Fiero swaps; IMO, they are easy to do and still make the lightest (327 lb) cost effective performance per dollar spent. If you can find one thats low mileage it can last a very long time.

[This message has been edited by Dennis LaGrua (edited 04-26-2020).]

Will APR 27, 09:52 AM
AN-6 sounds pretty small for a full flow engine oil cooler... I built my Northstar oil cooler with -12, although I haven't run it yet. The stock fittings were -10, the threads in the oil filter adapter being M20x1.5 for Saginaw fittings.

[This message has been edited by Will (edited 04-27-2020).]