Chevy Tri Five Forum banner

(Probably) dumb LS engine questions

4.2K views 11 replies 8 participants last post by  Russell@NerdRods  
#1 ·
My knowledge of the LS engines isn't that great, can anyone help ?

LS2 engines are known as 4th gen, am I right in saying all LSx engines have the same bellhousing pattern and that this is different from the LT engines ? or do 3rd gen engines have different bellhousing patterns ?

LS2 is fly by wire throttle, i.e. no cable - is there a throttle body you can change out to revert to a cable operated throttle ? This will obviously call for a different ECM, which one ?

If you wanted an auto trans to go behind an LS2 I assume its a 480LE ? I guess the correct trans would be one with its own ECM (for shift points etc)

Thanks!
 
#2 ·
Yes the LS2 is 4th Gen. The LS2 is electronic throttle controlled, but don't be afraid to use them, the gas pedal is easy to transplant and in the end it's easier to plug in wires than run pull cables etc. Then there's the ECM which can remain standard, along with cruise etc.
You could use a 4L80E but depending on your driving style, a 4L60E after 2003 would be ok, they strengthened it to be actually a 4L65E after 03. If you want to use something like a TH200R4 or TH700R4, the bellhousing fits but for the missing bolt on the LS engine, and you would need the spacer kit to bring the converter position right because the LS engines have a difference to the crank flange to trans flange compared to 1st and 2nd Gen engines.
 
#3 ·
ls engines/transmisions

crafty,the ls engine is know as gen 3, original small block gen 1 and lt1 is gen 2. lots of info published on this new gen3 and one is gm's performance catalog,p/n 19202324(any gm dealer). as far as trans goes,if you have over 400 hp and want a direct bolt in, find a 4l70e from a 05 and newer pickup or suv. same trans as 4l60e but beefier internal(300mm torque converter,7 plate 3-4 clutch assy,5 pinion reaction carrier,etc...).i have plenty of knowledge on the ls engines as a gm technician/shop foreman for 29 years but very little in the process of putting one in a trifive. will be calling on everyones help later as i install ls in my 57. need helpin technical questions, let me know,thanks chuckyb
 
#5 ·
Cruise control should work beautifully with the electronic pedal. Everything is there to do it already, no additional hardware needed except the on/off and set switch(es). What I'm talking about is the factory cruise control for the throttle by wire engine. I guess the only other deal is whether the cruise switches are routed through the body control module for the donor. I'd hope they are in the throttle module.

With a cable operated throttle, you'll need a separate servo unit and cable. That won't work on the electronic one.
 
#6 ·
Yeah I guess I'm thinking about the actual O/D switch talking to the ECM that holds the Cruise control functions.

I couldn't use an Fbody or Vette turn signal stalk and I have never seen anyone making a compatible aftermarket O/D switch that would wire into a BCM or ECM?

Am I on the correct train of thought?

Dan
 
#7 ·
Ron Francis' Wire Works and Watson's StreetWorks both have switches for turn signal stalks for GM columns as well as for Ididit and Flaming River. Watson's has them for the tilt lever too.

I'm using a Watson's switch for my dimmer switch, along with their relay. They have them in both normal on/off and momentary.
 
#8 ·
cruise control on LS engine

austinbelair,the cruise control on a fly by wire actually works very simple.the tac (throttle actuation control)module looks for a monentary high signal (12 volts) on certain circuits for on, off, speed up, and speed down.whatever the vehicle you use for a doner, just use th 4 inputs for your cruise switch.