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question about GM's

09-02-2006, 09:34 PM
what is the difference between there motors, like the 3.1 and 3100, and the 3.4; 3400, 3.8;3800....ect. Iv always wonder the differences. thanks:wink:

09-02-2006, 09:46 PM
I'v not messed with the 3.1 much, but the 3.4 is a decent motor, and the 3800 is one of the best motors of all time. As far as I know no parts interchange between the 3.4 and the 3.8, and they are differnt degree blocks I think, not possative.

09-03-2006, 12:36 AM
The difference is the displacement. That's it really. But I know the 3800 is offered with a supercharger in cars like the Grand Prix GTP or Regal GS. And basically, the 3.1 makes the least power, and the 3.8 makes the most.

09-03-2006, 05:23 AM
The difference is the displacement. That's it really. But I know the 3800 is offered with a supercharger in cars like the Grand Prix GTP or Regal GS. And basically, the 3.1 makes the least power, and the 3.8 makes the most.
I agree, functionally this is about the only difference. If you mean 'difference' from a design/engineering point of view, they appear to be similar but have quite different origins.

The 3.8 is a 90 degree pushrod 2 valve per cyl engine.
It is based on a V6 originally introduced by Buick in ...1962. It has been modified and changed many times over the years where hardly any parts would fit in the 1962 engine. But it uses the same basic archetecture and manufacturing tooling.

The 3.1 and 3.4 are 60 degree pushrod 2 valve V6 engines based on the 2.8 liter V6 originally introduced by Chevrolet in 1979. They have been modified and developed extensively over the years.

09-03-2006, 01:12 PM
ok, mabye i had a poor choice of words. I was trying to ask what the differences between the motors such as the early 90's & late 80's had the 3.1 liter motor. in the mid 90's they changed it to the "3100" series motor. The question is then, why do the call the newer ones 3100 and not 3.1L? what is the differences other than years?
other examples of this happening were the 3.4L turing into the 3400 series, and the 3.8 turning into the 3800 series motor.


09-03-2006, 02:54 PM
"thirty-eight hundred cubic centimeters" sounds far more exciting than 3.8liters..... Perhaps some people have bad mental associations with 2.5 or 3.1 because of their GPA and getting punished for not having a 4.0. Oddly enough, subaru used to designate engine size by 1600 or 1800, but now it is more common to hear about a 1.8 turbo or the 2.5 RS....Nissan also has named models of the NX after its engine displacement, the NX2000 has a 2.0 liter (or 2000 cc). Perhaps CC's (in addition to being a larger number) conjures up images of sporty motorcycle engines, while liters denote soda bottles. It's likely some marketing decision either way. 3800 cc and 3.8 liter are physically, technically, and mathematically the same. It's all in how you say it.

09-03-2006, 02:55 PM
There have been some design changes (i.e. changing these engines to OBDII) but they're basically the same engine. For example, 3.8L = 3800 cc., so the numbers equal to eachother, the different numbers are just a different way of writing the displacement out.

09-03-2006, 03:17 PM
OBD generations wont change a motor, it changes the wiring and electronics, but the physical motor is still the same.

09-12-2006, 07:41 PM
the difference between the 3.1 and the 3100 was mainly in the intake manifold, but there were other electronics and design changes that made the 3100 have higher output than the 3.1, the change in names was simply branding to differentiate the new higher output motor from the older one that had the same displacement and same block.

09-14-2006, 08:26 AM
lol he said it was one of the best motors gm made? i think that prize goes to the smallblock v-8 in all of its various displacements lol... though i heard them little motors can be pepped up to very high power levels, just like import motors can be

09-14-2006, 06:49 PM
Obviously you dont understand the differnce in "best" and "powerfull" and "one of" and "the best"

09-16-2006, 05:18 PM
Im pretty sure the 3.4 and the 3400 are two completely different motors. f The 3.4 (LQ1) was a 3.1 that they decided to jury rig dual overhead cams onto and shoehorn in into the lumina z34's back in the early 90's. Cool motor, but an absolute cunt to fix pretty much anything on.

the 3400 (LA1) is much newer motor based off of the LG8 V6's. Its you're standard pushrod 60 degree V6.

The 3.8 and 3800, same motor bascially is the 90 degree v6. They basically took a v8 and lopped off two cylinders, hence why they have that funny firing order (1-6-5-4-3-space-2-space)

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