I have a new long block engine coming from Accurate engines. It will be an LA1-based build. I just pulled the old 2.8 liter engine and the bay is empty, awaiting the arrival of the new 3.4. The issue I am facing is whether or not to get a new flexplate (I understand that this may be a necessity) and if so, which flexplate, by part number (like from the Fiero Store, or elsewhere) should I get. I have been told that I cannot use the old flexplate, but don't know which flexplate I should order. I am sure someone in here has done this mod before. Can you please help me out? Thanks in advance....
If it's an 88, your old flexplate should work. Otherwise, you'll need one for a 60 degree V6 (3.1, 3.4 or 3.5) from a FWD application. I wouldn't be surprised if most all of them are the same part #. Make sure it is drilled to accommodate whatever torque converter your trans uses.
Thanks for the information. I have heard, possibly mistakenly, that there can be spacing issues with the transmission. The old flexplate looks good. The ring gear teeth are in excellent condition and a visual reveals no defects. I guess I will give it a shot and see. I see no reason it shouldn't work, but I am a neophyte when it comes to swapping out anything in a Fiero. I once put a mildly massaged Datsun 280Z engine and 5-speed manual transmission in a 530! BMW that had a floor shifter automatic in it. That was not too hard, but I was using intact units to do it. I didn't have to get down to the component level. I am in no rush to get this done, so I will take my time and get it right and let others know what I learn. We all benefit from the knowledge in here, and there is a lot of it.
Have a great Thanksgiving Day, especially under the circumstances in which we find ourselves.
Thanks for the comeback. I will look for the proper replacement. Just out of curiosity, what would have happened if I used the original flexplate? Vibration???
[This message has been edited by eti engineer (edited 11-25-2020).]
Thanks. I did some reading on this and now I understand the issue. I used to teach vibration analysis and fully understand how just a little bit of imbalance can create a fairly large amount of vibration when rotated. As I recall, if one puts a 2-ounce weight at a radius of 3 feet on a perfectly balanced disc and spins it at 3600 rpm, it will exert a tangential force of over a ton. Tough on bearings and I am sure one would feel it throughout the car. I have located a source for the flywheel I need. Have a great Thanksgiving!!!
Thanks. I did some reading on this and now I understand the issue. I used to teach vibration analysis and fully understand how just a little bit of imbalance can create a fairly large amount of vibration when rotated. ... Tough on bearings and I am sure one would feel it throughout the car.
I had a friend who had an old Chevy Nova. Had a 350 and a 4 speed. Engine ended up breaking, and he replaced it with a 400 and an automatic. The 400 was (supposed to be) externally balanced, but he ended up using a 350 flex plate. It vibrated like a Home Depot paint shaker. I'm amazed it stayed together.
I am sure that it would be a bad vibration. It really doesn't take much to produce it . This is why when you lose a balance weight on a wheel, it feels like hell, and your wheel is not spinning at a high rpm when compared to the spin of the crankshaft. I was not aware of the issue with external and internal balancing. I found out about it through you and others in here. Thanks for looking out for my best interests. I would hate to have gotten the whole thing back together, just to find that I had to pull the whole engine and drivetrain cradle again!!! I am retired and in no big hurry to get this thing back together. I just want to take my time and do it right. For anyone who has been through this and who might be aware of any pitfalls I should avoid, please speak up. The Fiero configuration is one I have not dealt with before now.
Hope you had a great Thanksgiving!! Leftovers forever at or house now. It's just my wife and me, and it takes a while to eat what's left.
I am sure that it would be a bad vibration. It really doesn't take much to produce it . This is why when you lose a balance weight on a wheel, it feels like hell, and your wheel is not spinning at a high rpm when compared to the spin of the crankshaft. I was not aware of the issue with external and internal balancing. I found out about it through you and others in here. Thanks for looking out for my best interests. I would hate to have gotten the whole thing back together, just to find that I had to pull the whole engine and drivetrain cradle again!!! I am retired and in no big hurry to get this thing back together. I just want to take my time and do it right. For anyone who has been through this and who might be aware of any pitfalls I should avoid, please speak up. The Fiero configuration is one I have not dealt with before now.
Hope you had a great Thanksgiving!! Leftovers forever at or house now. It's just my wife and me, and it takes a while to eat what's left.
I heard from a friend that there is a very detailed post in here on how to relocate the starter when replacing the stock 2.8 with the 3.4. I can 't seem to find anything on this. Can someone point me in the right direction. My new engine will arrive on Monday and I plan to get right to work on it.
Thanks for the information below. The engine is due to arrive tomorrow, so we will see. I didn't know the application of the LA1 until you pointed it out. Thanks....
quote
Originally posted by pmbrunelle:
The 3.4 L LA1 comes from a FWD car/minivan.
The starter is already in the correct location; no drilling required as with the RWD donor engines.
