3.4 timing cover in a fiero (Page 1/2)
PAUL66 JAN 29, 11:47 PM
So I have been planning a 3.4 swap and already have the engine, spare fiero trim for it and the computer and harness. Due to a story too long to tell I am emotionally attached to that engine. I say that because I believe buying a 3.5 used that I could swap in would be cheaper than rebuilding the 3.4, buying a dawg intake converting to the obd1.5 ecu and doing all of the beadwork myself to maybe approach 180 hp. 3.5 drop in at 201 hp. I had a great conversation with ryan at sinister the other day that kind of help lean me more towards the 3.5. The. I am out in my garage and start thinking about the 3.4 again....lol. Anyway Ryan made me realize the 3.4 had two crank sensors, 1 in the block and one on the timing cover. So that brings me to my question . I have read you can not use the 3.4 timing cover on the fiero because the water pump flows in the opposite direction. I also read a post about a guy who preceded to use the 3.4 cover and just swapped the pump impeller. Can anyone confirm that the 3.4 cover can be used if the impeller is swapped? If I stay with the 3.4 it will only be if I can convert it to the Camaro ecu and SFI. If I can use the 3.4 timing cover so I don’t have to build some kind of crankshaft sensor on the balancer that would enforce me keeping it. Sorry for the long post, I may as well have told you why I am emotionally attached the the 3.4.......lol. Thanks in advance for any replies.

Paul
olejoedad JAN 30, 09:56 AM
I believe you may have misheard Ryan.
The 3.4 cam sensor hole is in the block, between the timing cover and the lower intake manifold.
fierofool JAN 30, 10:15 AM
Joe is correct. The mounting points for the crankshaft and cam sensors is about the only major difference in the 3.4 and 2.8 blocks.

Coming in the next issue of the Georgia Fieros Newsletter is an extensive article on timing covers and water pumps. It should be released shortly. You'll find it in the Club News section.
Blacktree JAN 30, 09:51 PM
IIRC the Camaro engine did have 2 crankshaft position sensors. One is on the side of the block, and reads the trigger wheel built into the crankshaft. The other is mounted to the timing cover, and reads a trigger wheel on the harmonic balancer.

The problem with the Camaro timing cover is, the mounting bracket for the ignition brick interferes with the firewall. That bracket is built into the timing cover. So you would need to modify the timing cover and relocate the ignition brick.

Another alternative would be to use a Fiero timing cover, and make a mounting bracket for the sensor.
PAUL66 JAN 30, 11:02 PM

quote
Originally posted by olejoedad:

I believe you may have misheard Ryan.
The 3.4 cam sensor hole is in the block, between the timing cover and the lower intake manifold.



I don’t think so, I verified on my engine. Definitely has two crank and one came sensor. I did verify you can’t just swap pump impellers though. Thanks for the reply.
PAUL66 JAN 30, 11:07 PM

quote
Originally posted by Blacktree:

IIRC the Camaro engine did have 2 crankshaft position sensors. One is on the side of the block, and reads the trigger wheel built into the crankshaft. The other is mounted to the timing cover, and reads a trigger wheel on the harmonic balancer.

The problem with the Camaro timing cover is, the mounting bracket for the ignition brick interferes with the firewall. That bracket is built into the timing cover. So you would need to modify the timing cover and relocate the ignition brick.

Another alternative would be to use a Fiero timing cover, and make a mounting bracket for the sensor.


I don’t follow how the brick would interfere with the firewall if it is behind the balancer. It seems like the bigger problem is the direction of waterpump rotation. I do like the prospect idea of modifying the 2.8 cover to take the brick. I will compare the two covers side by side and see if it is a possibility.
Dennis LaGrua JAN 31, 08:47 AM
The 3.4L P/R engine front (timing) cover will bolt to the Fiero 2.8L block but you must use the 3.4L oil pan or the 87-88 oil pan with it.

------------------
" 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 "

fierofool JAN 31, 11:07 AM
The 3.4 timing cover used on the Fiero will cause the coolant to try to flow backward if it will work at all. The water pump channels of the Fiero pump does not match the channels on the 3.4 CamaroBird timing cover.

The CamaroBird water pump is designed to rotate counterclockwise while the Fiero pump rotates clockwise. The 3.4 pump pulley is smooth, running on the outside of the belt. The 2.8 pump pulley is grooved, running on the inside of the belt. Even if one used the 3.4 timing cover and pump by changing the pulley, the pump wouldn't circulate the coolant because it would be running backward.

Again, I suggest one go to www.gafiero.org >Message Board >Club News >2020 Newsletters, February Edition. GTRS has done some extensive studies on this subject.
Dennis LaGrua JAN 31, 11:49 AM

quote
Originally posted by fierofool:

The 3.4 timing cover used on the Fiero will cause the coolant to try to flow backward if it will work at all. The water pump channels of the Fiero pump does not match the channels on the 3.4 CamaroBird timing cover.

The CamaroBird water pump is designed to rotate counterclockwise while the Fiero pump rotates clockwise. The 3.4 pump pulley is smooth, running on the outside of the belt. The 2.8 pump pulley is grooved, running on the inside of the belt. Even if one used the 3.4 timing cover and pump by changing the pulley, the pump wouldn't circulate the coolant because it would be running backward.

Again, I suggest one go to www.gafiero.org >Message Board >Club News >2020 Newsletters, February Edition. GTRS has done some extensive studies on this subject.



I have the 3.4L timing cover with the Fiero water pump and have experienced no problems whatsoever. Perhaps you are not taking about the 3.4L pushrod engine used on the 93-95 Camaro/Firebirds. It aligned perfectly.

------------------
" 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 02-04-2020).]

Blacktree JAN 31, 12:25 PM

quote
Originally posted by PAUL66: I don’t follow how the brick would interfere with the firewall if it is behind the balancer. It seems like the bigger problem is the direction of waterpump rotation. I do like the prospect idea of modifying the 2.8 cover to take the brick. I will compare the two covers side by side and see if it is a possibility.


I used the term "ignition brick" to refer to the ignition control module and coils.

However, I do need to make a correction. The ignition mounting bracket isn't built into the timing cover. It's built into the mounting bracket for the A/C compressor. In any case, it will not fit in the Fiero engine bay without modification. The alternator placement may give problems, as well. Plus, the 3.4 V6 intake manifold would point to the passenger side of the Fiero, whereas the Fiero intake goes to the driver side. So you'd need to make a custom air cleaner box.

That's a lot of work, just to keep the Camaro timing cover. That's also why most 3.4 V6 swaps have Fiero stuff swapped onto the 3.4 engine.