I just got a 3800 sc from a 2000 Grand Prix gtp. It basically came with everything wire harnes, alt, starter, fuel pump, ect. Can I use the flywheel that came with it and have it machined down to correct specs which I believe it is .840" off of the face. Or should I just get another one???

The engine is going into an 84 se...also correct me if Iam wrong. From reading the other posts the 84 transmission TH125 4 speed will work with the 3800 sc without blowing up. I just need to know because Iam gathering everything I need for the swap so when spring rolls around I can let the "fun" begin..

quote Originally posted by coxguy1: I just got a 3800 sc from a 2000 Grand Prix gtp. It basically came with everything wire harnes, alt, starter, fuel pump, ect. Can I use the flywheel that came with it and have it machined down to correct specs which I believe it is .840" off of the face. Or should I just get another one??? The engine is going into an 84 se...also correct me if Iam wrong. From reading the other posts the 84 transmission TH125 4 speed will work with the 3800 sc without blowing up. I just need to know because Iam gathering everything I need for the swap so when spring rolls around I can let the "fun" begin..

The 3800SC doest come with a flywhee-It comes with a flexplate so you will need to have a stock 3800 RWD flywheel cut down if you aree using a manuel transd. The 84 trans is a 125 3 speed and will last about 2 WOT runs behind a 3800SC. If going auto you need the 65E that come stock with the 3800SC.

Auto trans doesnt use a flywheel. If you are speaking of the flexplate I dont think the Fiero torque converter will line up to the mounting holes (could be wrong). You should get the trans that went with the 3800 4T65E-hd, you'll be happier.


TOO LATE !

[This message has been edited by Mike Gonzalez (edited 01-21-2009).]

I would be willing to bet he has a 4speed manual...

Cut the flywheel down. .840 total thickness... Read the threads in my signature.

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Losing sight of our roots in the cathode rays.
Ultimate 3800 swap thread

i have a 4 speed on my 84... I still learning the different transmissions that go into these cars so forgive me.

You will need a flywheel from a 3800 Camaro, the have it turned to .840 and balance to match the flexplate off the 3800. Or a Fiero flywheel redrilled to match the crank of the 3800.

b4 I get the flywheel machined down would it be best if I get the new stage 3 clutch and flexplate??? Or can I get the flywheel done and then get the clutch and flex plate??

You can get the clutch later. If your shooting for super performance it might be good to have the flywheel balanced with the pressure plate on, but its not needed for normal use, just high reving stuff !!

quote Originally posted by Mike Gonzalez: You will need a flywheel from a 3800 Camaro, the have it turned to .840 and balance to match the flexplate off the 3800. Or a Fiero flywheel redrilled to match the crank of the 3800.

I might be mistaken but I believe that there are two different 3800 flywheels. Supporting evidence shows that there are a few P/N's for the various years. I believe that you will need the early series II flywheel. We installed one with a guy in my club and used a 95 Camaro 3800 flywheel and with the proper machining and rebalancing (after cutting it to thickness) it seemed to work well. We did expereince a problem with the 3800 flywheel bolts that caused interference with a spec 3 clutch disc and had to go with smaller head ARP cam bolts. I would not redrill a Fiero flywheel as it really weakens the hub area with so many holes being there.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
87GT - 3.4L Turbocharged engine, modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

[This message has been edited by Dennis LaGrua (edited 01-22-2009).]

From reading other posts I was not going to use the org flywheel. I was just thinking that if I could use the flywheel from the eninge that I got and get it machined down for $40 then it would be to my benefit instead of spending 250-300 for a new one... By balancing it...would the machine shop know how to do that if I ask them?

The engine you got doesn't have a flywheel, you'll still need to get one.

quote Originally posted by coxguy1: From reading other posts I was not going to use the org flywheel. I was just thinking that if I could use the flywheel from the eninge that I got and get it machined down for $40 then it would be to my benefit instead of spending 250-300 for a new one... By balancing it...would the machine shop know how to do that if I ask them?

A: Your motor did not come with a flywheel, but a flexplate.

B: If you think that you can get .84o out of a flexplate and re-install it, after being told numerous times that you cant, you should step away from the swap and get someone else to do it.

mcaanda.... I just asked a simple question and it got answered. So the end result is Iam going to get a new flywheel for the swap.

Does anyone have the part number for the proper ARP FLYWHEEL bolts that people are using for the modified camaro flywheel?

I'm currently using David Kerr bolts but I'm about to put a new clutch in. I don't want to reuse the ones I have now after having the flywheel resurfaced.

if i could figure out how to post a past discussion on the bolts I would...if you go to the search "3800 flywheel" and then I believe it is topic #10 and the title is "3800 flywheel bolt recomendations" it is 2 pages long

quote Originally posted by coxguy1: From reading other posts I was not going to use the org flywheel. I was just thinking that if I could use the flywheel from the eninge that I got and get it machined down for $40 then it would be to my benefit instead of spending 250-300 for a new one... By balancing it...would the machine shop know how to do that if I ask them?

Hey coxguy1,
Congrats on your new motor, you will love it and it's not that difficult of a swap but it's gonna cost you lots of time and probably around $1000 to $1500 to do it yourself with no frills.
Here's the low down on your flywheel situation. Your gonna need a flywheel from a 3.8 SFI OHV Camaro Vin K. The years are 1995 through 2002. The cheapest one at autozone is $57.99 with a $50 core charge. The part number is 6533 for all of those years named above. You take off your Fiero flywheel and use it as the core despite what all of the warnings say about switching flywheel cores on the box.
Now you take your new Camaro flywheel and the flexplate off of your L67 to a machinist. Not any old shop will be able to balance. I had to find one that blueprints and balances motors. You then (this is important) ask the machinist to cut the flywheel down to .840 overall thickness. This means from where the crank meets the flywheel to the clutch disk mating surface. (get it? not just the outside edge thickness but the entire flywheel thickness) You then ask the machinist to match balance your L67 flexplate to your newly cut flywheel. This cost me $190.00 and the average is around $150.00.
Ok now that's done. Regarding your bolts.
You order from a GM dealer part GM#24505092 These are the torque to yield bolts for the 3.8 camaro. They run about $5 each and come in packs of 5 from the GM dealer.
Torque on these bolts is: 11 ft/lbs first pass. Then 50deg additional turn. You will need a torque angle meter to do this (auto parts stores should have one).
You apply red loctite to each bolt and make sure your crank holes for the bolts are good and clean.

Then you can order your Spec 3 if you like and just make sure you get the correct release (throwout) bearing for your transmission.
I ordered mine from www.treperformance.com and the shipping was fast.
Good luck!

keep in mind, in 1984 about 95% of the 4 speed manual trans fiero's used the 4:10 gearing, at 70MPH your probably 3500 RPM, thats very high RPM's for the 3800 s/c to be turning, the 84 model transmissions are also alot weaker than any other manual trans from a fiero.

your best option is to convert to a 85-86 4 speed manual (all your brackets, mounts and shifter will work on it) or convert to a different transmission.

the isuzu's have a weak 2nd gear with the torque from the 3800, the 4:10 and 3:32 4 speeds from the 1984 fiero's have weak cases, and the getrags 5 speeds, and 3:65 4 speeds had weaker syncronizers.

its a gamble with any of them, but ive had the most durability from the 3:65 4 speeds from the 85-86 v6 fiero's

matthew

quote Originally posted by Bubbajuju: Regarding your bolts. You order from a GM dealer part GM#24505092 These are the torque to yield bolts for the 3.8 camaro. They run about $5 each and come in packs of 5 from the GM dealer. Torque on these bolts is: 11 ft/lbs first pass. Then 50deg additional turn. You will need a torque angle meter to do this (auto parts stores should have one). You apply red loctite to each bolt and make sure your crank holes for the bolts are good and clean. Then you can order your Spec 3 if you like and just make sure you get the correct release (throwout) bearing for your transmission. Good luck!

Thanks for that information on the bolts. I'm going to get them from ARP in hopes that they'll be a bit stronger due to the amount of power I'm trying to produce. My spec 3 was good for a few years but I've moved onto something custom that I've been working with spec on for about the past two weeks.

quote Originally posted by Jncomutt: Thanks for that information on the bolts. I'm going to get them from ARP in hopes that they'll be a bit stronger due to the amount of power I'm trying to produce. My spec 3 was good for a few years but I've moved onto something custom that I've been working with spec on for about the past two weeks.

You bet, with a smaller pulley installed now I wish my Spec 3 was a Spec 4 plus (little bit of slip punching it in second gear). You'll have to post up on your progress with the custom clutch.

(oh and the credit for the flywheel bolt info goes to Ryan at Sinister Performance)

[This message has been edited by Bubbajuju (edited 01-22-2009).]

thanks for the info... Now i just need the cash to go do everything I probably won't start till spring since it is a little chilly up here and the wife likes her garage

What if you don't balance the flywheel? would you only have vibration at high rpm or through out the rpm band?

Any vibration is probably going to cause your crankshaft bearings to fail prematurely.

Rear crank bearings will fail prematurely due to vibration from a mis-balanced flywheel. It's not a matter of if, it's a matter of how soon.

Saving a few dollars here will cost you an engine rebuild and maybe even a new crank in the future.

JazzMan

Can crank bolts be reused?

For the $15 paid for new L9 bolts, why risk it?

The GM ones CANNOT be reused. They are TTY bolts and are designed to stretch with that additional 50* of turn.

One question on top of this:
So, get a firebird 3800 flywheel, machine to .840" from crank mating surface to friction surface, then rebalance. For info, I'm using the 3800NA motor, do I still need rebalance since that flywheel originally came off a 3800NA?

Also, will the fiero clutch pressure plates bolt to the firebird flywheel, or do I need to redrill and tap for fiero clutch pressure plate?

I'm still kind of lost why you'd need to rebalance the flywheel unless the SC motors had different balancing than the NA motors did.. If you remove material from the pressure plate side, the balanced side (that faces the blcok) would still have the same net balance, no?

West Coast Fieros sells the flywheel already machined.

http://www.westcoastfiero.c...rsion_flywheels.html

Thanks!

To answer the overall question there: No, you don't have to rebalance it if you are using a NA 3800. The NA 3800 was internally balanced where the 3800SC was externally balanced. Your flexplate should also have a neutral balance, where my SC flexplate has a weight on it.

That's great news, because the thought of spending $350 plus shipping for a flywheel makes me want to upchuck in my mouth.

So make it at a local machine shop?

Yeah, planning to. I think the camaro ones run around ~$70 here, and I can't imagine spending more than about an hour of shop time to get it turned down to .840".. I figure it will set me back a total of $160.

When I posted yesterday, I was just mainly trying to figure out why people would have to re-balance the camaro flywheel.. Makes sense if the 3800SC had different balancing than the NA.

Can anybody answer the second question though? That being: Do the fiero pressure plates bolt up to the Camaro 3800NA flywheels when they're turned town?

[This message has been edited by aaronkoch (edited 07-07-2009).]

quote Originally posted by aaronkoch: Do the fiero pressure plates bolt up to the Camaro 3800NA flywheels when they're turned down?

Are you asking if the Fiero pressure plates bolt up to the 1995-2002 3.8 SFI OHV Camaro Vin K flywheels when they're turned down?
If so then yes. You use a Fiero clutch and pressure plate. They are all the same. Just make sure your release (throwout) bearing is specific to your transmission.

[This message has been edited by Bubbajuju (edited 07-07-2009).]

I love you guys, no really, I do. Thanks for all the speedy responses! Plusses for you all!

i would like to add this:

if the idea of a tq angle meter is throwing you off and confusing you, dont let it. this isnt some hard to find costly tool. i just got mine from autozone and it was only $9.99. now you can do the 50* additional turn. precision is key.

[This message has been edited by americasfuture2k (edited 04-02-2011).]

Update I dumped the 84 and got a 86 notchie with the v6 and the 4 speed tranny. Hopefully by aug I should have a enough c,ash to get started on the swap. Thanks all for the advise. You guys are the best!!!!!!!!!!!