tmcorvette

Hi All,

I have a question about changing the engine in C4 to LS1.

My friend would like build in an LS1 engine together with the transmission to his 'Vette from a Camaro (99). So we are looking for conversion kits to fix the engine and transmission into a C4.

Any idea where can we find conversion kits for this?

Thank You.

vettedan

I’m not aware of any specific kit to drop in an LS1 into a C4. This conversion should be a breeze compared to putting one into a C2 or C3 Vette. The LS1 engine mount boss location is different from any other Generation small block. You will need to buy or fabricate a LS1/6 engine mount adapter and use the LS1 PCM. I assume the fuel pump can be changed out with the LT1 pump. It’s possible the LT1 pump might work. The TACH signal will need to be converted, since its signal is similar to a 4 cylinder output. All the other gauges should work with the LS1. After the installation, you might need to lower the front end due to the decrease in weight of the block. Overall this conversion should be straight forward for a C4 Vette. We will be selling our own LS1/6 mount adapter in a few weeks.
Dan
www.vetteworksonline.com

tmcorvette

Thank You very much.

jburnett

I've been doing LS1 swaps in different vehicles since early 2000; several first gen F-bodies, a G-body, several trucks and hot rods, and currently a 9C1 B-body (cop Caprice). I designed several mounting systems for them as well. The LS uses a different block mount that does a conventional small block Chevy. Street and Performance in Mena, AR. (well known for their pioneering in EFI and engine swaps) builds a billet aluminum adaptor mount so you can adapt the factory Gen 1 SBC motor mounts to the LS family of engines. It makes the swap very simple. I've worked with them very closely for a long time and have just given them my design for the Caprice mounts; they will be the best source for the adaptors. Retail on the adaptors is about $100.00 for the natural and $125.00 for the fully polished.

As for the tranny, it's the same as the 700R4 only electronically controlled. Take a C4 tailhousing off a 700R4 and swap it onto the 4L60E. For control an aftermarket harness is your best bet. You can obtain that through S&P, or Painless Wiring, or Howell, or I have a company here in Little Rock that's owned by a lady that used to work for S&P Electronics here in L.R. before they sold their operation to Comp Cams; Superior Harness. I've used several of Rita's harnesses and can recommend them as well.

I have yet to do an LS swap into a C4 but am intending on doing so relatively soon.
-Jeb

ninetyfivevette

Dan-

Any intensions on selling a T56 adapter as well? LS1 swap is one of my winter project possibilities.

bogus

Oh, yes! This is great information!!!

Thanks!

vettedan

It's possible if we get a C4 Vette in the shop for this conversion. There might be a trans adapter available now. Do a search on Google. I think this conversion will become popular as it is with the C3 Vettes. Like I said, this conversion will be pretty easy in a C4 and it will definitely put new life into your C4 especially if you currently have a L98. We have our LS1 Adapter now available.
Dan
http://www.vetteworksonline.com/catalog/
Heres a pic of C3 LT1 we did a while back.

bogus

Questions:

1) LS1 installs in a 1984-1989, what about the digi-dash?

2) LS1 installs in 1990-1996, what about the CCM? What about the EBCM? Instruments?

Thanks!!!!

-=Jeff=-

Slalom4me

A few tales from the crypt:

June/05 "l98 converted to a ls1?"

June/03 "Turnkey C4 LS1 Swaps"

.

bogus

I have read/posted in those... and my questions regarding the electronics integration hasn't been addressed yet...

I would LOVE to install that combo in bastet44s 87 coupe. An LS1 with a 4L60E would get 30mpg on the hi-way.

and have 350hp.

The emissions updates are insane - the car is now an OBDII compliant vehicle, so passing even CARB is easy! Lighter weight (200 LESS lbs on the front end) and better weight distribution. It's the best thing yet...

I need to do more research.

Slalom4me

What about ditching the Digi-Dash for an Autometer combo?
I believe I've seen molded replacement guage panels available.

Happen to know what became of TracerX? Comes up as a
bad User Name in Advanced Search. Did he cross swords
w/ folks too many times?

(Edit: I see he signed on as LS1C4 three times in Apr-May/05)

Ditto with LS1Tuner, the name works but he appears to
have dropped off the map in '03. Sure provided a lot of
info in his various posts before he split.

.

Ramanstud

Although I HAVEN'T done an LS1 Swap, I have converted from a L83 TBI crossfire to a L98 version PFI setup, and have used a converter harness to run the digidash. I then converted the digidash to full autometer guages once the dash started to go out. Cost me $500 in guages (I used the pro-comp version with two 5" guages for Speed and tach, and then the 2.x" guages for oil, water, gas.

There are many combos you can do to get plenty of guages in the C4 dash, I would just use cardboard templates and then have the faceplace machined out of 1/4" or 1/8" thick aluminum. The wiring is simple, it's just a matter of getting schematics for your year vette and splicing into them at the digidash harness. If you use a programable tach, you won't even have to worry about the Speedo signal conversion....

Slalom4me

Bogus,

Why cut up bastet44s 87 coupe??

Instead of that, two words: Road Trip !

.

bogus

Bastet's coupe has issues... mainly, a toasted tranny, a salvage title and most recently, what appears to be a POS cam. The cam that came with seems to have lost a lobe and sprayed metal into the engine.

I am still investigating... but it does not look good.

I have always wanted to do this conversion... and why not? Fbody engine/tranny combos are cheap cheap cheap, and all I need is some wire and a soldering iron (so to speak).

Bastet does not want to loose the digi-dash... but we need to talk once I have done all the investigation... it might be cheaper to go without...

I have found that the various mounting plates and stuff are not that expensive.

FD2BLK

Bogus, I did the LT1 into my 84 so i have bit of an idea of how the digi dash works and belive it or not it has almost nothing to do with the ECM so the LS1 would be a straight swap. The only function you loose is the MPG. THe only other thing that would need to be addresed for the swap mentioned would be the fact the older reluctor rings have a different PPS rate then the new ones so you may have to install two rings, One for the LS1 PCM and one for the Spedo, or find a converter and use the output of the LS1 PCM would be the other, probably simpler option.

As for the 94-96, I think the the CCM would have to go and the dash is prety straight forward as far as the gauges go, all the analog gauges have a coorisponding sensor you would just have to install into the LS1 and some of the digital, fuel gauge ect.. would be a straight plug and play type of deal. I know that it can be done because I have seen the newer interior installed in the earllier C4's. I think Jeff can chime in with this one if I remember correctly he has the newer dash in the older style C4.

STEVEN13

-=Jeff=-

Yes a newer C4 with a CCM will run without the correct ECM.. I had a 92 CCM in my car wirth a 91 ECM. the Speedo, Fuel, and Voltage are all that worked on the LCD, BUT I kept getting the flashing SYS light since the 91 ECM did not have the correct response for the 92 CCM when the CCM looked for it. I think if you kep the 92 ECM powered to feed serial data to the CCM you could run the LS1 Standalone. You would however lose the MPG Functions.

Another thought I still want to try is run the LS1 from my 91 ECM. I have a eDIST and need the crank trigger and Cam synch sensors, once I have those I should be able to make my L98 run with LS1 Coil Packs. If I can do that I think the LS1 would work the same way. This project is on hold though as I ran out of funds for the rest of the ignition components

Steve85

On the digi dash issue. I have an 85 that I put DFI in, I realized at that point that very little dash info comes from the ecm. I think mileage is it(range too by default). Oil has its own sensors, speed goes into the dash THEN to the ecm, coolant has its own sensors for the dash independant of the ecm. It won't be perfect but you will hardly notice. Assuming the earlier post about the tach signal is correct that would need to be addressed.

It would take some work to eliminate which wires from the LS1 PCM would not be needed to essentially turn it into seperate, stand alone ECM for your purpose. Probably just a few serial links and what not is my best guess.Also, I have a 6spd so I never contemplated transmission controls issues....

That is one good thing about the early C4's, each system is seperate and can modified, upgraded, elimated with little to no effect on the others. No check engine lights because the PCM didn't get a signal from the left door module telling it that it's awake .

bogus

I suspected the ECM was rather ignorant in the L98... but wasn't sure.

Here is the million dollar question, regarding the LT1 (1992+), how does the ASR continue to function without engine information?

This is the sort of info I need... I have seen dealers selling LS1s, 4L60Es and such for about $3k. That is the deal of the century!!!!

Thanks guys! I have more research to do!