Bored and just wondering who names the LT and LS engines. We have LT1, LT4, and LT5. LS1, LS2, LS6, and LS7.

What happened to the ones in between? Sorry, crazy question of absolutely no value...but just wondering.

 

I don't think there is a real answer. Just make up something.

 

There's also an LS3 and LS4, IIRC.

 

i do

 

I quess I don't understand? If you mean a specific person, that would probably be the head (chief engineer) of the engine design team or other upper level corporate VP.
But is dictated by GM's three letter alpha/numerical RPO coding system. GM has used the first letter "L" for Chevy engines, "M" for transmission, "G" for gear ratio, etc. for some time.

 

Sorry to make this more complicated then it is. I'm not wondering who actually has the responsibility for naming the engines. Just wondering why the jump from LT1 to LT4....what happened to LT2 and LT3?

Seriously, this is just a stupid question to pass time...just a little trivia and wondering if anyone knew. I almost put this in the "lounge", but thought maybe somebody had a technical reason behind this. Maybe LT2 and LT3 were designs that just bombed or something, who knows?

 

L is used corporate wide, not just Chevy.

 

As usual, Rob hit the nail on the head. LT2 and LT3, for example, were already used by GM for a couple of 4-cylinder engines:

LT2 : ENGINE, GAS, 4 CYL, 2.OL, TBI, OHC
LT3 : ENGINE, GAS, 4 CYL, 2.OL, MFI, OHC, TURB0

 

Most of the current Engine RPO's aren't new at all they were used back in the 60's and 70's.
The LT-1 [with highfen] was originally from the 370 HP 350 used in Corvettes and Z28's
The LS1 is from the `70 Trans Am's optional 370 HP R/A IV 400 engine
LS2 is originally from the `73-74 SD455 Available in the Formula and Trans Am
LS6 is originally from the `70`454 450HP engine available in the Chevelle SS
LS5 was a 365 HP 454 engine in the `70` Chevelle and the RPO for the `71-72 455 HO available in GTO's and Firebirds.

 

The "LT-1" hyphen was never actually used in the RPO code.... only on the decals used on the cars, and in the promotional literature. The RPO was still "LT1". That engine was only 370HP in 1970, it was downgraded in 71 to 330HP and then to 255HP in 72 as a result of lower compression ratio and emissions systems, and the switch in 1972 from SAE gross to SEA net ratings.