Ok I am about to purchase a caddy that has a LT1 motor in it that I want to use for the new buggy. It is at a junk yard and the prob is we dont have a key for it. I need to know what I can do to bypass the anti theft in order to crank it. I dont want to spend all the money on a motor I cant crank.

Travis

Most of the street rod wiring harnesses have a bypass for the anti-theft thing in the steering column. You spend a few extra bucks up front, but you have simplyified wiring and instructions.

It appears from my search that folks arent keen on the LT1. I see something about optispark probs. Anything else to be aware of.

Travis

I almost went that route with mine. (swap in an LT-1)
Decided on a Ford Mustang 5.0 HO. I was led to believe it wasn't as complicated and had a better stand alone fuel management system.
Now I'm sure that an LT-1 fan will step up and dispute this but that's what I was led to believe.

Take it from an F-body guy (that is Camaro and Firebirds), the Optispark (ie. opticrap) SUCKS. They have a BAD habit of not mixing well with ANY MOISTURE. If you are running a buggy out in the desert, you can probably get away with it. Alambama, you are probably like me , (IL) and have lots of mud and moisture. This spells death for the opti sparks :(

Otherwise, either get a harness or get LT1Edit and you can program out the theft lock :)

Are there any issues with it being out of a caddy or are they all about the same. Also will any LT1 harness work on this motor (being from a caddy). One from painless I suppose. Is there any options for the optispark. Where is it located and what does it do (excuse my ignorance).

Travis

Now I'm sure that an LT-1 fan will step up and dispute this but that's what I was led to believe.

----------------

Hey Doctor G, Yes, I will step up and say that for power, the LT1's kicks ass. The heads and intake flow much better than the 5.0 Fords. It's too bad that GM just didn't go to DIS ignition instead of the Opticrap. There is a setup to use the LS1 DIS with the Opti as a crank trigger but that is pretty pricey and requires knowledge of both systems.

For low end torque and reliability, the TPI engines are a much better choice if he wants to retain GM powertrain.

In my opinion the 94-95 LT-1 is the motor of choice....

That is due to the fact that it is OBD-I with lots less crap to program out than the OBD-II versions...

Also, the LT-1 was GREATLY inproved in the waterproofing of the distributor in 1994.....

I run mine in wet conditions and have not had any problems nor have any of the people I run with.

From what I am told, the later LT-1's and the LS-1's are very waterproof.

On the question you had above, the Vehicle anti theft system can be programed out of your computer by any competent shop that has the software.

www.sunrayengineering.com can program your computer for you..

OK I am assuming (as per a buddies knowledge) that it is a LT1. As I said, it is in a caddy. I think late 90's maybe 2000 model fleetwood (again I think). How can I be sure that is what it is. It is not the typical looking tune port.

Travis

OK I am not sure on the vehicles year or if it is even a fleetwood. I still need to know what the motor is.

LT1 would be a great engine. Drop the optispark and go to like a MSN or what ever the big ignition set up is called. They make their peak torque at 2400 rpms. They also have a very flat torque band. They have 275-285 hp at around 4000 rpms. I would love to have that engine in my jeep. If you wanna learn a lot about them go to camaroz28.com or ls1.com. Both are great site and I frequent ls1.com quite often.

Here's the LT1 I had for my Impala SS. The opti-spark you speak off is that mustard colored plastic piece in front. It's the "distributor" on these motors. There is a way to keep them dry and running well. My car was lowered and would splash water up in the opti all the time. They are around $500 to replace so I came up with a solution. There is a top breather hole and a bottom breather hole, I drilled both out round (mine were square) and epoxied vacuum elbows in the holes. I then routed the top one with silicon hose to a small K&N I had on my valve cover. The bottom was routed to the intake box or in my case a conical K&N. While the engine was running it would draw a small amount of air thru the unit so if any moisture got in there it would be dried out with the air flow.

Ignore all the bling bling polished stuff and the S-trim Vortech. You don't need any of that! :flipoff2:

If you need to start the motor you can disable the stupid pass key BS by taking apart the steering column and following the below instructions. It will start and run for I think 60 seconds before it shuts off the fuel pump and the motor dies if you don't fix the pass key, in case you just want to check to see if it runs. :D With the VIN number you may be able to get the resistor of the chip from the dealer. I'm not sure. I know you can get a key made this way. Last time I had one made it cost me $56. :eek:

"First, Use an OHM meter and measure the resistance on the "Chip" resistor in the key itself. This is done by taking the 2 leads that come with your multimeter and placing one lead on each side if the little "chip" on the key. That will give you a number (Resistance in ohms) on your meter.
Next, write that number down and go to your local Radio Shack store. Tell them you need a resistor that matches the number you got on your meter. I personally had to use 2 resistors to get the right reading.

Then all you have to do is find the little lead that comes off of you steering column and unplug it. DO NOT UNPLUG THAT ONE THAT SAYS AIRBAG!!!!! If you do it will cost you an airbag. If I remember right it is two 22 gage wires.

After you unplug the wiring harness, use a zip tie to tie up the one that comes out of the steering column. This will no longer be used.

No take the remaining end of the harness and "BackProbe" it with the 2 ends of the resistor. One leg of the resistor in each outlet on the harness.

That should be it! Pass Key is now Disabled. "



http://www.pirate4x4.net/mstevens/uploads/lt1_vortech.jpg

Originally posted by rockcrawl
OK I am assuming (as per a buddies knowledge) that it is a LT1. As I said, it is in a caddy. I think late 90's maybe 2000 model fleetwood (again I think). How can I be sure that is what it is. It is not the typical looking tune port.

Travis


Ummm...Caddy's never had nor never will have an LT1 motor.
Cadillac tends to use Cadillac engines.

Originally posted by ForestCam
Ummm...Caddy's never had nor never will have an LT1 motor.
Cadillac tends to use Cadillac engines.

He's right. B-bodies had LT1's. This included the Buick Roadmaster. Maybe that is what he's looking at. :confused:

The last thing you want is a caddy engine! Just changing the plugs and wires on a friends 96 caddy was a huge PITA.

Originally posted by MattS


He's right. B-bodies had LT1's. This included the Buick Roadmaster. Maybe that is what he's looking at. :confused:

The last thing you want is a caddy engine! Just changing the plugs and wires on a friends 96 caddy was a huge PITA.

Don't make the same mistake someone did from here did last spring.
He was all geeked that he got an LT1 out of a Caprice untill we figured out it wasn't.
He did some checking and sure enough it was a 4.3 (V8) not a 5.7.
http://www.pirate4x4.com/forum/showthread.php?s=&threadid=34917

Just a little FYI, just because it's a SBC and it's tuned port DOES NOT make it an LT1.:D

I thought the 4.3 V8 was CPI? Not TBI. HMMM I will do some checking tomorrow. I still have all my old SS buddies E-mail addys. :D

From what my brother tells me (worked at the proving grounds for 17 yrs & he's with the Corvette group now) the 4.3 even had the optispark. The only real way to tell them is by the block number or to tear one down to find the itty bitty cylinders.:D

There are some Caddy's with LT-1's. When the high dollar caddy's in the mid-90's were running Northstar engines, the less expensive models sported LT-1 engines.

Also as said above, Buick Roadmasters, Vette's, Camaros, Firebirds, Impalla's and certain Caprice's.

What year was that engine that you vented?

I run a 96 LT-4 (96 was only year for LT-4, yes some 97 SS Camaros had LT-4's but they were still 96 engines) and haven't had any problems with it and its a full awn engine.

http://www.clearimageautomotive.com/images/TRI-Y%20install.jpg image of roughly what an LT-1 should look like that from Clear Image the maker of the Tri-Y headers that are shown on the motor. The motor is dressed up to look like Covette LT-1.

Here is an Impala SS Lt-1 pix with :raindow: factory covers on engine.
http://www.socalss.org/mods/ktmods.htm#brace


Go to this link http://www.fuelinjection.com/ and click on the LT-1/LT-4/Ls-1 icon and there is a good writeup on the diferences from year to year on the LT-1 motor. Years of MAP, MAS, sequential injection, OBD1, OBD2, etc.

There is another option to the Opti Spark and that is modifying the intake and installing a conventional SBC distribution at the back.
http://www.lt1intake.com/services.htm
http://www.lt1intake.com/distributor.htm

If you add GMPP LT4 "HOT" cam kit it will wake up the engine still has flat torque curve. Add LT-4 intake & heads in addition and your talking about 375 hp plus.

Buy the way I've got an extra Street & Performance harness I'd sell if your interested.

Pic of my LT-4

Damn! Got batteries?

I recently heard about an LT-1 with comp, harness and trans for $1500.00. I don't know how many miles or what year. What year, miles, etc. would this motor have to be, to be a good deal? I know I'm not giving much info but any advice is appreciated.

Well, I've had my share of Opti problems with moisture but I've come up with a solution. My motor is a '95 Camaro and it has the stock vented opti. Vented in this case means it pulls a vacuum on the opti to keep it dry. The problem is, when the opti goes under water the vacuum will pull water in through the wiring harness. Since I'm using the AC compressor as and air compressor, I pressurize the opti at around 1.5 psi. The air needs to be VERY DRY, so I have a water separator, and a dessicant drier. I purge the water separator every time I run it and I change the dessicant drier about once every three runs.

Another LT1 problem is the power steering pump on the Camaro and the Corvette LT1's. They run rack and pinion steering and there isn't enough flow for the saginaw style box. I swapped over to the Caprice setup for more flow. Aftermarket pumps will not work in the stock location because the LT1 pumps are reverse rotation.

Another little problem if you use a 168 tooth ring gear is finding a starter that will work. Stock GM starters won't fit because the exhaust manifold will interfere. I had to get one from a '96 or newer Chevy van. They have a much smaller starter and it tucks up nicely.

All this info is GREAT.............for simplicity and real world wheeling, TPI is the hot ticket.............less $$ too. No Opti-Spark to deal with either.

http://www.blazzinor.rockcrawler.com/images/tpi_406_front_view_complete.jpg

http://www.blazzinor.rockcrawler.com/images/tpi_406_cropped_on_engine_stand_small.jpg

Originally posted by wngrog
What year was that engine that you vented?

94 LT1 in my Impala SS.

Originally posted by lt1yj

Another LT1 problem is the power steering pump on the Camaro and the Corvette LT1's. They run rack and pinion steering and there isn't enough flow for the saginaw style box. I swapped over to the Caprice setup for more flow. Aftermarket pumps will not work in the stock location because the LT1 pumps are reverse rotation.

Another little problem if you use a 168 tooth ring gear is finding a starter that will work. Stock GM starters won't fit because the exhaust manifold will interfere. I had to get one from a '96 or newer Chevy van. They have a much smaller starter and it tucks up nicely.

Yeah, I know the steering sucks and I have been thinking about pump replacement I have been looking a AGR's TC pump and Howe Performance Steerings TC pump. Howe uses TC pump for ram and ram-assist steering so it must be a pretty good pump.

Can you give some more details on the Caprice box? Year?

Try some LT-4 manifolds they don't have the clearance problem. JB Conversions had a bunch of the LT-4 manifolds

Originally posted by Lowrangerider
Damn! Got batteries?

Only 2. Look closer that an OBW in the front.

I took the pump off a '95 Caprice but it's not that simple. You will also need the cast aluminum accessory bracket, AC compressor support bracket (little L shaped piece on back of AC compressor) and the harmonic balancer hub. They are spaced about 3/4" farther out than the Camaro parts.

I couldn't find a source for any after market pump that turns counter clockwise. All the aftermarket pump manufacturer's I talked to only sell standard rotation pumps.

I'm still not happy with the setup and I'm just about to modify the pressure relief vavle to improve the steering force. I still have VERY sore arms from last weekend. I'm going to install a ram assist also. Just have to get my butt busy. 39.5's just don't turn like the 32's I had on way too many years ago.

I noticed the lack of P/S pressure going from my old engine to the LT-1. That is interesting information. I have a Ram Assist and 42's and it works, but I can feel the difference.

www.westtexasoffroad.com sells an upgrade kit for Saginaw pumps that is amazing.

One guy in my club did the upgrade and his Cruiser with a Lock Right and 35's steers like a Hydro assist setup.

I am thinking about this upgrade to my existing reverse rotation pump to see if it helps.

Have you thought about using a standard pump in the slot where the A/C compressor is?

:eek: Holy cow at all the info. I really appreciate everyones help. I found out that it is a LT1. They did come in a few caddies in the mid 90's. I think that it would be an awesome motor but it seems that there are too many variables that could be problems. I can get a vortec 350 from a 96 truck. Think that may be the way to go. I wish it was tune port though. Thanks again for the info. Yall made up my mind for me. Anyone have a TPI that they want to rid of?

Travis

Originally posted by wngrog
www.westtexasoffroad.com sells an upgrade kit for Saginaw pumps that is amazing.

I am thinking about this upgrade to my existing reverse rotation pump to see if it helps.



Yep, the writeup in the tech area is how I plan to modify the pressure relief valve. The valve doesn't care if it's clockwise or counter clockwise rotation. All it sees is the pressure.



Originally posted by wngrog

Have you thought about using a standard pump in the slot where the A/C compressor is?

I'm using the AC compressor as my on board air for the lockers, airing up the tires, and to blow air through the opti. I did try several fitups on the drivers side though. I could not get anything to work. I almost ran a second pully off the crank shaft but thought I'd try the Caprice stuff first.

I did see a small difference in the steering but not enough to justify the expense.

Ram assist here I come!!!!

Originally posted by lt1yj
I'm using the AC compressor as my on board air for the lockers, airing up the tires,

How is this holding up? Any pics/info on your setup? I want to run my A/C compressor on my 4.3 as on board air but everyone I have talked to/read about has had back luck with compressors found on GM engines. Mine is pictured below. I'm not sure exactly which one it is. It's from 93 if that makes any difference.

http://www.pirate4x4.net/mstevens/uploads/ac_compressor.jpg

Just spent 10 minutes typing a reply and couldn't submit, then lost it. This will be a little shorter.

I've run it for 6 years and had my first failure late last fall. I put a couple drops of air tool oil in the inlet side every day at startup.

The LT1 compressor doesn't look anything like yours. I can't get you a pic because it's buried down low by the frame and all you'd see is little spots of aluminum.

It's easy to hook up. I used compression fittings at the inlet and outlet of the compressor and then to barbed 3/8 fittings and then to flexible air hose. On the inlet side I have a 2 1/2" filter I got from Grainger. On the outlet side I run it to a manifold I made out of aluminum. It has a quick connector, air gauge, high pressure relief valve (150 psi), pressure switch (85 on, 125 off), and 3 barbed fittings (1 air in, 2 air out).

The compressor clutch has 2 wires. 1 positive, 1 negative. Hook one up to a positive lead (switched, unless you like dead batteries) and the other to one side of the pressure switch and then run a wire on the other side of the pressue switch to ground. I also have a switch on my dash that cuts the ground so I can turn the compressor off most of the time to save wear.

If you have any specific questions drop me an email or pm.

so the only thing wrong with the lt1 is the distributor right? well frankies off road 205-594-5098 in ashville al has (with the help of street and performance) converted an lt 1 to accept a small cap hei ditributor. and it is bad ass, i'm about to do it to my lt1. and by the way lt1's rock!