3.8 SC in a 91' Z34 5spd?

[HayesPerformance]

Hey everyone,


I was wondering if its possible to match a Getrag 284 to a 3.8 SC series II or III?
Which flywheel would I need?

Will the 3.8 Series II SC bolt into my engine bay?

What mods would need to be done to make it work, aside from exhaust, and the general stuff.

Would the 3.8 ECM work everthing else correctly?

I'm just trying to deside weather I want to stay with the 3.4 dohc or go 3.8 SC....

I wouldn't mind having an engine that can give me good MPG when cruising and still be able to make into a fun car.

THANKS.

[SappySE107]

They both suck for MPG so how about an option that doesn't make me want to beat puppies.

[HayesPerformance]

Can you match a getrag 284 to a 3.8 SC?

[bszopi]

Think about it... Does a 4T65E bolt up to a 3800? Does it bolt up to a 3400? Does a 4T60E bolt up to a 3400? Does it bolt up to a 3.4DOHC? Does a 284 bolt up to a 3.4DOHC? Does it bolt up to a 3800?

[Emc209i]

WTF people! How hard would it be to type "yes" and post send. Three letters and two clicks.

The answer is yes, any series 3800 will bolt onto your getrag.

You will need the 96+ Camaro/Firebird NA 3800 flywheel. It will have to be machined down to .840". That's a substantial amount of material to take off, so make sure you take it to a shop with a large lathe. It cost me $100 to buy a flywheel and also have it machined. You can order the flywheel bolts from GM --which I did -- but be warned they are incredibly expensive; $65 for 10 bolts - they come in bags of 5 (you need 8 ). I was able to knock the price down to $30 with a friends discount.

As for mods required:
-Being you'll likely retain the power steering pump with the W-body, you'll not have to mess with the belt setup, which makes everything much easier.
-I'm not sure what you'd be able to do for the front mount. The GTP uses a single mount at the center of the engine. Check into the Regal mounts, I know they look similar to the Z34 stock mounts.
-You'll need to wire a computer. I'm using the OBD 1 '94 Bonneville computer which is absolute cakework with my manual tranny. OBD II is slightly more technical, but I don't see why you'd need to deviate from OBD I with a 91 Lumina.
-You may have to rewire your cruise control, if you have one --or update to electronic cruise--. Otherwise, as long as you wire power and gauges into the cabin, everything should work fine.

I anticipate higher MPG averages then my DOHC was getting
In 1995, the GTP was rated 19city/28hwy. This is the SFI motor.
In 1999, the GTP was rated 21city/29hwy.
Being that your '91 Z34 is batch fire, I can guarantee that you'll see better gas consumption.

I also chose to upgrade from my dohc because of reliability issues, you can read my Fiero horror stories at pennocks if you want. 3800's are extremely well built, and its very very hard to break one if you keep good oil in it. People always rag on them because of their low hp numbers. But consider this, at the stock 240 hp, you are making more than 20 hp over the DOHC. You also get 60 ft/lbs more torque, all from a motor that is smaller than the dohc. Of course, a pulley and cam upgrade has put the motor at well over 300+ crank hp.

The only downside to swapping will be that the 3800 will never sound as good as the 60*V6 does.

So, go fast or sound good?

[bszopi]

Since its a 3800 topic, its more fun to not post a direct answer. We could have just closed the thread, I guess....

[Emc209i]

Sounds like a personal problem to me.

[bszopi]

Sounds like a site problem to me. No reason to discuss a 90V6 on a 60V6 forum.

Here, I'll be more helpful - www.l67swap.com

[SappySE107]

ill be more helpful too. closed.