IROCaholic

Alright I am getting ready to start buying stuff for my Lt1/T-56 swap and I have a few questions that I couldnt find answers to when I did a search.

1. I have all mechanical guages in my car now (oil pressure, temp, volts) Do I need to use electronic guages with correct senders to make then engine run properly or can I just run my mechanical guages?

2. Kind of the same as number 1. I have an aftermarket tach and electronic speedo that I want to run with this car instead of the stock guages, will this cause me any probs.?

3. I want the wiring to be a simple and quick as possible so I will probably go with the painless kit. I know people say to do it yourself, but I have money and no time so I really need to make it as simple as possible. Is the painless kit plug and play without any splicing of wires? does it take the place of your factory harness? Or what, could someone please give me details on it.

I appreciatte your help guys.

Klortho

The painless kit isn't plug and play, you will still have to splice in the PCM power, ignition, and grounds, plus power to the injectors. As for the gauges, the PCM relies alot on what the sending units and sensors (especially for turning the fans on and off which is a biggie to keep the car cool while idling) are saying, so you will more than likely want to use t's one for the sending unit to the PCM, the other going to the gauge. As for the Tach, you should be able to run it off of the wire coming from the PCM, and the speedo if it runs off of a 4k ppm signal just wire it up to the VSS output from the PCM as well.

Even if you used the stock gauges, there are a total of like 9-12 wires that are spliced into the existing harness and isn't bad at all to do (I can say that now since doing it and I could probably have one wired up in a couple of hours)

IROCaholic

Ok, cool thanks for the reply. I am still undecided about the wiring thats why I asked about the painless kit. I was think about doing exactly what you said about the guages aswell I just didnt want to do it if I didnt have to.This will really be the first time I have ever messed around with a computer controlled engine, So I am kind of lost. I have always messed around with carbed cars and so I ripped out all of the computer crap and threw a in a mild carbed motor the first chance I got with this car. Now I want good gas mileage and the ability to pass inspection. Thanks again for the help. If I think of any ?'s I will ask them here.

IROCaholic

I just thought of another question:
I am running a big 31x19 aluminum rad with a heavy duty 2700 cfm electric fan. Can I run this setup with the Lt1 or is there something special about the Lt1 rad and dual fans that I need?

Klortho

You can use the stock 3rd gen radiator, I opted to use the 4th gen just so I *knew* I wouldn't have any cooling problems since the car is reverse flow, I wanted to make sure and not take a chance on overheating. The 4th gen radiator has 5 coolant line hookups, one from the waterpump to the radiator (if you aren't running the oil cooler, then it would go from the waterpump to the oil cooler and the return line on the oil cooler back to the spot on the radiator) of course the main lines, then one from the coolant line from the back of the heads and then the overflow which I would highly recommend running if you aren't now.

IROCaholic

Ok I think I will go with the 4th gen setup then. I dont feel like going through the hassle of welding in a extra spots for the other cooling lines. Plus I can probably sell my griffin rad for some extra cash.

Z28ricer

iTrader: (2)

Use your griffin, its a much better radiator. You dont need to add anything extra for fittings, if you want more details on how to route it PM me, the stock thirdgen radiator is bigger than a 4th gen radiator, so i'd use that before a stock 4th gen when given the choice, not to mention it also fits better.
You can hookup your aftermarket gauges no problem, coolant sender will replace the electrical one in the drivers side cyl head, oil pressure is same as a normal sbc, volt and fuel are obviously not changed by the engine, and the tach output is the same as any other sbc, though I would suggest you buy a matching electrical speedometer.

Trans Am#5

I had my car rough wired with the Painless kit in an hour and a half. It fired this way. They aren't bad and there certainly may be better but from my experience using the kit and a buddy and I doing a second car by splicing two harnesses, I'd use the Painless harness again by all means. If you do, get the longer wired kit. It'll be easier to move things around.

I also used an aluminum 31x19 radiator and two Perma Cool fans with hoses recommended by Markolc(sorry if misspelled).

This is what Markolc did and I copied it....works perfectly. This is copied from another post........

Quote by Markolc:

You can use your stock thirdgen radiator to make things bolt up much easier. You can IM me with questions if you'd like...My SN is Thirdgen Camaro.
About the cooling setup, It's not very difficult to figure out. You can EASILY reuse your existing radiator and fan setup...you just run your lines slightly differently. Here're the pieces you need:

'94 corvette lower radiator hose
'95 Camaro Z28 upper radiator hose
3/8" brass coupling
18" 3/8" ruber cooling line
6' 5/8" heater hose
6' 3/4" heater hose
assorted hose clamps
Two caps for about a 5/8" tube.

Here's how you need to run this using the stock radiator: use the 'vette lower radiator hose to connect the radiator to the gooseneck on the LT1 water pump. Use the Camaro upper radiator hose to connect the radiator to the LT1 water pump. (you may have to grind off a little of your existing radiator shroud, but it's very minor work). Now on the upper radiator hose, there will be a 3/8" rubber line kinda splicing off of it. What you need to do with that is take the brass coupling, put it on, and take the 3/8" extra piece of tubing you bought and connect it to the brass coupling, therefore extending the tube coming off the upper radiator hose. Now route that 3/8" hose under the throttle body so it pokes out past the TB on the passenger side. There you will snake it around and connect it straight to a metal coolant line that runs along the bolts on the passenger side of the intake all the way to the back of the heads. That will eliminate the need for you using the TB to pass coolant, and giving you the cheap TB bypass mod. Now to route the lines to the heater core. Take 6' of 3/4" coolant line and run it from the upper port on the water pump all the way to the 3/4" opening on the heater core. Since you have 6' to play with, you can route it pretty much anyway the hell you want (they sell pre cut 6' rolls of this stuff for $3.99 at the auto parts stores). Now take the 5/8" heater hose and run it from the lower port on the water pump (BTW, both the ports for the heater core on the water ppump are on the passenger side) and run it all the way to the 5/8" port on the heater core. Now you have pretty much all the lines run. This is now an optional/conditional point of the coolant routing. Are you going to be using the stock LT1 oil cooler? If you are, you will not have to buy the 2 caps for mentioned in the parts list, but you will have to buy 6 more feet of 5/8" cooling tubing. There'll be one port one the drivers side of the waterpump for the oil cooler. You run a hose from that port to the oil cooler, and a hose from the oil cooler back to the opening in your radiator (which was originally used as a return from the heater core in a stock setup). If you do not plan to use the oil cooler, just block the ports on the radiator and waterpump. You'll be all set. That's the whole cooling setup. Not too hard if you understand it, and I think I explained it fairly well.

This has been posted many many times and here it is again.

There will be no issues in using the one fan as opposed to the two the PCM normally sees. That can be adjusted by your PCM programmer. Along with those fans, the aluminum radiator and a 160 Hypertech thermostat, hot summer daytime stop and go was no problem at all. I also used Water Wetter (not sure of its impact though).

IROCaholic

WOW! Thanks for all the info guys. I think I am going to go ahead and get the painless harness and go with the cooling setup you mentioned. Now all I gotta do is get rid of my current engine/trans combo so I can get moving on this thing.

Thanks again guys.

dtsfanatic

I heard that the corvette lt1 uses a pressurized system where the overflow tank also has pressure on it, where the f-body uses a standard overflow tank and set up. Can anyone confirm this and what mods would be required using the corvette version in a 3rd gen?

Trans Am#5

I think all Lt1 cars including b-bodies had a pressurized system via the overflow tank. I am using with a regular 3rd gen tank with no problems and no mods.

Klortho

Actually F-body LT1's still had pressure on the radiator, as I am running a 4th gen radiator in mine.