corvettecris

I copied this from my earlier post, as it spawned off of my original question...
What does it take to do a LS1/t56 conversion? Here is what I know so far:

With an F-Body setup...

Motor mount adapters
Tranny Xmember adapter/mod
Heater hose mod
Lower radiator hose/housing mod
Accessory drive re-arrange
electric fans
exhaust mod
conversion to hydraulic clutch
cut driveshaft down
relocate shifter

And I think that is it? I have read everything I could find on the conversion, including a site on a green or black 68, and 70 LS1's homepage. The only problem is that it always seems like the article isn't complete with follow-ups and problems/concerns. I really have been wanting to test my skills and try something like this, but in order for me to know if it is too much for me to chew, I would like a fairly precise and complete 'rodmap'. I know it's been done before, so somebody out there has this info.

I figure, to keep the car in running condition for the maximum amount of time (since I dont have an entirely 'permanent garage'), the best thing to do its to break it up in peices. Like, maybe start off by installing a electric in-tank fuel pump, regulater, and bigger return line. Then maybe the electric fans. Then the hydraulic clutch, prep n engine/tranny, and so on, until the car is just waiting on the LS1 drop. From there, most everything should be ready to hook right up. THe hardest thing should be the electronics routing.

Just curious what you thought? Anybody done this, and willing to help me do a walk through on costs and labor required?

69Myway

I am just finishing a LS1 and 4A trans in my 69 CAMARO. I went a step beyond with SLP Stage III heads/cam/injectors/big pump/2,800 stall, etc. etc. etc.

All I can tell you is the LS1 is a whole different monster. You might as well be looking at a Toyota vs. Chevy SBC when you consider there is NO comparison or cross over parts between the Gen III LS1 and any prior V8 Chevy motor.

Everything is a pain in the butt, ie, Headers, fuel line, programming, motor mounts, heater hoses..etc. etc.

However, it weighs 200 less lbs than a regular sbc, and will make plenty of power and great MPG on the highway.

A road map? Maybe you could be the one that documents every single small detail????? I am sure many others would benefit from it. The best thing to do is just jump in and swim.

There are a couple of LS1 Sharks here and I think the same guys at www.ls1tech.com

corvettecris

Thats a scarey thought. I'm afraid I will get half way through, and not be able to finish, you know?

Budman68

Well, let's see. You missed the wiring harness, but that's a no brainer. Just send the F-Body one to Speartech and they will make it stand alone. I'm using the stock lines, with no problem at all. Wrong year PCM, no problem. It's not an easy swap, but it can be done in a month of weekends. The only hang ups that slowed me down was a bad clutch and my harness being stolen.

Things you need to know:
Speedo/tach will need to be electronic or you will have to buy costly convertors.
Expect nothing to fit the first time.
Get use to the sounds of Uhhhhhh when you open the hood.
Learn to drive again, driving 300+hp vette with a lite front end can be scarey at times.

Go for it, we need some fresh members to the LS1 C-3 club.

corvettecris

How did you do your fuel system?

What kind of pump?
Tank baffles?
Return lines?
Regulators?

corvettecris

I also noticed that you used a hydraulic clutch setup. What is it off of (looks like a F-body to me)? How did it fit?

and what is this thing?

70 LS1

My fuel system consists of the stock tank gravity feeding an external Walbro 340 pump mounted on the passenger's frame rail near the tank. From there it goes to a stock 99 corvette fuel pressure regulator/ filter then through a 3/8" aluminum line up to the engine bay to a flex line to a 3/8" steel line bent to go around the back of the engine to the driver's side fuel rail. The return line is a rubber line that runs from the regulator to the return fitting on the top of the tank (about 2 ft.). Scooter 70 used a very similar setup, while Budman used an intank pump.

I can take some pictures of anything you want. Just let me know.

70 LS1

The bracket pictured is Budmans design to mount the clutch master cylinder slightly below the brake master cylinder. Since all three of us are using the T56 that came with our engines, we are all using the stock Camaro/ Trans Am clutch master cylinders feeding the hydraulic throwout bearing in the bell housing.

corvettecris

So, this bracket hods the master cylinder instead of it mounting to the firewall?

Also, instead of running a hardline or braided to the rear, you just ran a rubber hose for the return line? How is it working out?

I would really appreciate any pictures that you have. Do you have any problems not having baffles as far as normal street driving goes??

corvettecris

Also, (sorry for so many questions) what are the options for tranny crossmember? I currently am automatic, so it is removeable already, but what about the mount?

70 LS1

The flange on the master cylinder has a strange mounting angle as it was designed to mount nearly vertical on the F-bodies. This bracket bolts to the firewall behind the brake master cylinder and holds the clutch master cylinder.

The rubber line is fine. Like I said it is very short and since it just dumps into the top of the tank, the pressure is low. I also run a rubber line to the inlet of the pump and between the pump and the regulator. I have had no problems with fuel starvation in the last 3 years. The tank has been run down to less than 1/4 and still no issues.

You also mentioned costs in your original post. Check this out.

http://www.corvetteforum.net/c3/70lt1/costs.shtml

I'll take some pictures later today. What specifically do you want?

70 LS1

The tranny mount is going to need to be custom made. You can use original crossmember and it is good that it is removable already. Scooter70 has a template to make a mount. Mine is much simpler, but his is a lot nicer.

corvettecris

I would liike to se pics of your belt drive, especially if you had to mod it in any way. Also your 'simpler' crossmember mount, your lower radiator hose, heater hoses...

How did you hook up the throttle cable?

On the fuel system, are you saying that you used the stock return line by just running rubber hose from the engine to the frame? I thought you had to run a bigger return line than the stock one?

70 LS1

No, the regulator is mounted by the pump in the back of the car. Only one fuel line runs from the back to the front. The return line runs directly from the regulator nearly straight up to the top of the tank. I'll take some pics.

corvettecris

More questions:

What type of manifold or header did you go with?

Did you have to change the yoke on the driveshaft? To what?

corvettecris

AHHHhhh, now I understand. I thought that the high pressure had to go all the way to the fuel rails, and then a low pressure return line went from there back to the tank.

So the regulator bleeds off the excess right by the tank, and only one line goes to the engine...the stock line, right?

At what PSI does the fuel line run?

70 LS1

I am using a stock corvette manifold on the driver's side and a passenger's side F-body manifold. I have a set of pacesetter long tube headers that I am modifying to fit.

For the driveshaft I measured from the end of the trans to the yoke on the differential. I had the yoke from the T56 and tried to use that, but the u-joints were the wrong size. For $180 the driveshaft shop shortened my driveshaft, gave me a new yoke and installed 2 new u-joints.

70 LS1

58 psi. And unlike a lot of cars, that does not change with RPM or manifold pressure.

I am not using the stock fuel line. I am using a 3/8" aluminum line. The only stock part of my fuel system is the tank.

70 LS1

You're not a Jarhead are you?

Budman68

You mil-spec guys.


I'm use a 82 sending unit with a late 90's corvette fuel pump. It puts out about 60 to 65 psi. It just pops in and you have to add a pigtail to the pump. Also using the 99 fuel reg and single fuel line.

If you need the Master cylinder bracket template, I can fax it to you. I would use thicker steel, mine gives a little. You will need to fab up a small bracket for the pedal to unless you like a short throw. My pedal throw is about 3" which is close to a road race car.

As far as a crossmember, buy a kit from Jegs for under $100 and build it. It will be so much easier than trying to cut and splice. It took me a half a day to build mine out of the stock one. You'll end up saving about 20 lbs.

My driveshaft is a 88 vette alum. unit cut to fit.

I'm using stock f-body pulleys without modifications, no a/c. S & P sells a pretty inexpensive conversion kit for it. You can fab it up preety easy with plate steel, if you have the time.

Hoses are a no brainer, jsut got to Autozone and ask to go in the back and look around. I bent coat hangers and used those for bends.

Why not go with a auto and save yourself a lot of time?