I was wondering for the swap what needs to be done to the flywheel, does it need to be machined in anyway or what?.... (i am using the 5spd getrag) also if it does need to be modified does anyone have the exact measurements for what needs to be done.
You need a manual transmission flywheel from a 1996-02 Camaro/Firebird 3800 Series 2 N/A 5-speed application to start.
You can buy new replacement flywheels for this application from almost any auto parts store but I have encountered issues with several aftermarket brands. Specifically: casting voids that appear during the machining process that must be done before you can use it in a Fiero swap (the casting voids are the result of poor casting quality). I haven't had this issue with any GM-made flywheel, but the only place you are going to find one of these today is a junkyard.
Whichever flywheel you end up with needs to be machined down to 0.810-0.840" overall thickness to work with the Fiero manual transmissions.
After you have it machined down, it really should be balance-matched to the specs of the stock 3800 Series 2 SC auto trans flexplate you took off the engine because the N/A flywheel is balanced to a different external weight spec than the SC engine requires. Failure to do this could result in a vibration problem which can shorten the life of the engine's main bearings, depending on how bad the imbalance is. A good machine shop should be able to mount the flywheel and flexplate you give them on their machine without your crankshaft. But not all machine shops will have the ability to do this. There used to be a guy on this forum who said he could do it for people but I don't know if he is still offering this service.
A good machine shop can mount the flexplate and spin it up on their crank balancing machine to get a reading of the amount of imbalance there is in it and where that imbalance is in relation to how it mounts on the crank; and then they should be able to match the flywheel's balance to that spec by drilling new holes in it.
You will need 8 new GM flywheel to crankshaft mounting bolts, p/n: 24505092. Torque to 11 ft/lbs + 50 deg turn. If you buy bolts other than these to use to mount your flywheel to the crankshaft, DO NOT use these torque specs because these torque specs are only valid for the GM bolts. To my knowledge, ARP does NOT and NEVER HAS made 3800 flywheel to crankshaft mounting bolts. They do make a generic bolt that some people have used for this purpose, but you cannot use the GM torque specs when installing them. I do NOT recommend using anything other than the genuine GM bolts for this application.
The bolt pattern on the crankshaft where the flywheel/flexplate mounts is an irregularly spaced bolt pattern - which means all 8 holes will only line up when the flywheel/flexplate is installed in the properly clocked position. Start all 8 bolts by hand and insure you can install and turn all of them in (at least a couple of turns) BY HAND without any binding up due to some holes being misaligned.
-ryan
------------------ OVERKILL IS UNDERRATED Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com
[This message has been edited by Darth Fiero (edited 12-08-2014).]
So im getting my engine outta a 2003 grand prix so the flex plate on that will be not use to me.... is there any way i can make the 2.8L flywheel work in my swap... im trying to do the most cost affective solution.
So im getting my engine outta a 2003 grand prix so the flex plate on that will be not use to me.... is there any way i can make the 2.8L flywheel work in my swap... im trying to do the most cost affective solution.
The stock 2.8L Flywheel will NOT work on a 3800 engine, period.
quote
Originally posted by Kfa171:
so im getting a 3800sc so i probably should get a 3800sc flywheel right, or is there no difference.
The 3800 SC engine was NEVER used with a manual transmission in a factory application. The only manual transmission ever put on a 3800 engine from the factory was the 3800 Series 2 N/A engine in the 1996-02 Camaro and Firebird. That's it.
These engines are externally balanced which means there is a counterweight cast into the harmonic balancer and into the flywheel (auto transmission flexplates have weights welded to them). The amount of counterweight is different from SC to N/A versions of these engines, hence the requirement for the balance-match.
Try contacting forum member fierorog He sells machined and balanced flywheels for the 3800sc for use in fiero swaps. I got mine from him and it has been working fine.
Hey Ryan, I bought flywheel bolts, p/n 24501365, came in a bag of 8, supposed to be for a '00 Pontiac model H, I told the parts guy it was for a SC engine. Are these the same bolts, just a different quantity?
Hey Ryan, I bought flywheel bolts, p/n 24501365, came in a bag of 8, supposed to be for a '00 Pontiac model H, I told the parts guy it was for a SC engine. Are these the same bolts, just a different quantity?
GM P/N 24501365 bolts are automatic transmission flexplate bolts for the 3800 Series 2 and 3 engines. These bolts will be TOO SHORT for a manual transmission flywheel, which is much thicker than an automatic transmission flexplate.
I lnow this is an old thread amd i hate to bring it back from so long dead... but here I go.
So if i get the correct flywheel and have it machined down to the .840 size, and i also have the engine balanced. Will I still meed to have the fly wheel balanced? Or do i send it in with the engine internals and have it all balanced at the same time? I have been told the engine balence spec is 50%.
If there is someone that can help me clear this in my head please do so. I have been beatting my head aginst a wall for awhile now and not able to find a clear answer on what and how to balance all this when having the engine balanced.
I am going to say a little different then most people. I am not saying they are wrong or that my way is better but budget and other factors will make each build unique.
There is two variables to consider. One if the thickness and the other is the balancing.
The most prevalent way is what is talked about in this thread. Most don't tear the block down and when you don't the best way to get the FW balanced would be to use the flexplate to replicate the balance to the FW. Some things that I noticed is the stock balancing in these was sub par to say the least. So replicating the flexplate will still give you a poor balance. Now lets say that something happens to the FW down the road and you cant use it to balance another one. You will need to get a stock flexplate again or save your original one. Lets say you need to get it resurfaced. I see many people balance the FW by drilling holes on the face side. Now when you resurface it the balance will be off. One way to get around that is drilling on the back side. BUT if you are not taking the block down or not balancing the rotating assembly this is probably the best option.
The other popular way in this swap is to machine it down to .840 or less. The thickness of the FW after machining it down is a fraction of the stock thickness. It is required to machine it down to clear the bell housing. It's like taking off 1/4" or IIRC 40%. Now when you start getting a FW that thin you can start to have problems with warping.
The way I did it is leave the FW stock thickness which can be done with a 1/4" spacer between the bell housing and the block. I can make one for you if need be. This will let you keep the stock thickness to have less of a chance of warping, don't have to find a machine shop and pay to get it machined. And as mentioned run the risk of finding voids in the casting for after market FW.
For balancing the FW. Take the whole rotating assembly to a shop specializing in balancing engines. This is to include the crank, connecting rods, rings, pistons, wrist pins, harmonic balancer, FW, and bearings. Note you may want them to check out the crank prior to purchasing bearings as it may need to be ground down. Regardless make sure they give it a high polish. They should, but ask, balance the crank to the FW. The FW is weighted stock. Now when you may ever need to replace the FW or get it resurfaced for that mater. You will have to do no machining or balancing at all but resurface (if it needs it) it and pop it on.
If you would like more information check out my build where I have plenty of pics and more information about rebuilding the block. I have noticed that many people seem to not want to do a full engine rebuild but budgets and experience sometimes make decisions for us. 88 3800SC F23 Build
[This message has been edited by paulsobj (edited 03-05-2017).]
Thank you for the info, and i have been watching you build very closly. I was just having a problem understanding the FW balance when you were doing a complete rebuild, and balancing the rotating assembly.
If someone else has some input as i know there are many schools of thought on this, I would love to hear them. You know how it is, informed decisions and all. I am only going to get one shot at the engine this deep. The wife would kill me if I have to go back in and do it a second time.
Sorry to drag this old post out, but a quick question.
If I am mating my 88 getrag 5spd up to a 3800sc from a 98 buick that had an 4T65HD auto attached to it, can I use the flexplate that was attached to the auto flywheel with my new (machined down) Camero manual flywheel?
Sorry to drag this old post out, but a quick question.
If I am mating my 88 getrag 5spd up to a 3800sc from a 98 buick that had an 4T65HD auto attached to it, can I use the flexplate that was attached to the auto flywheel with my new (machined down) Camero manual flywheel?
A flexplate is only used with an automatic transmission. A flywheel is used with a manual application. Yo can't use both of these together. For the manual all you need is the machined 3800 flywheel and a stronger clutch. For stick applications, the flexplate that came with the 3800 is discarded.
------------------ " 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, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, 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 "
