LT1/L83 into something eventually
Thread Starter
Staging Lane
Joined: May 2016
Posts: 90
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A lot of question have come up about the fuel system. These are the main components I am using. The Walbro 392 will move enough fuel and is capable of more that the 58 psi that the corvette ls filter/regulator delivers. It remains to see if 58 psi will be sufficient. The third item is the fuel composition sensor. I doubt I will ever use e85 but it's nice to be able to. Who knows, a turbo may be in my future. I most likely put an inline filter in before the pump as well.
I'm going a similar route it appears that with this the computer can't control or turn the pump on. I will add a switch to turn mine on when the key is on. This should work.
On The Tree
Joined: Aug 2006
Posts: 118
Likes: 4
LT1 Gen V intake vacuum port. I have installed a car LT1 intake on my L83 and like previous LS engines, it has a port in the back that can be used for vacuum. All it takes is swapping the existing close plug with part GM 12559760. For illustration the pictures below show the LS type truck intake, which has the exact same provision as the new LT1 intake (L83 and L86 intakes do not have this provision ) with and without the nipple.
Thread Starter
Staging Lane
Joined: May 2016
Posts: 90
Likes: 0
Hello. I'm the guy who posted the info on taking the purge valve off and using its port as the possible source for brake booster vacuum. To answer your question, the Gen V engines make plenty of vacuum to assist the power brake booster. The reason for the external vacuum pump is for the 4 cylinder fuel economy function. Only when the engine is at 4 cylinder mode the vacuum level may drop to the point of affecting the power brake (I doubt it. At cruising speeds who needs power brake LOL) . My programmer tells me my engine will not have the 4 cylinder shot down, so I will go with the car intake option. With my engine running I was able to test the vacuum with the purge valve off. I did not measure the vacuum but I can say that it is as strong as with LS engines. I think this is a good source of vacuum for power brakes with the L83s and L86s intakes.
I have installed a car LT1 intake on my L83 and like previous LS engines, it has a port in the back that can be used for vacuum. All it takes is swapping the existing close plug with part GM 12559760. For illustration the pictures below show the LS type truck intake, which has the exact same provision as the new LT1 intake (L83 and L86 intakes do not have this provision ) with and without the nipple.
I have installed a car LT1 intake on my L83 and like previous LS engines, it has a port in the back that can be used for vacuum. All it takes is swapping the existing close plug with part GM 12559760. For illustration the pictures below show the LS type truck intake, which has the exact same provision as the new LT1 intake (L83 and L86 intakes do not have this provision ) with and without the nipple.
Thanks you for this information. I noticed the port and had blocked it with a plug. I'm happy to have a verified answer that the engine vacuum is ample for the brakes.
Now I can use the electric vacuum pump on my Isuzu 4BD2TC diesel powered Jeep Liberty when I upgrade the alternator. This engine uses a relatively low output alternator that has an integral vacuum pump on it. The 70 amp alternator can't keep up with the electric cooling fans and the AC on high during city driving on these HOT South Alabama summer days.
Thanks again!
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Staging Lane
Joined: May 2016
Posts: 90
Likes: 0
I decided that the 1980 Trans Am will be the proud recipient of the LT1 engine. I've been stripping everything off and out of it for the past couple weeks. Too bad it is not in as good of shape as it looks. What looked like some minor metal patch repairs in the floors is now full pan replacement on both sides.
Spent yesterday cleaning the underside, removing ball joints and control arm bushings and preparing control arms and other front end components for paint. My budget does not include tubular arms but stockers will go back together with all poly bushings. My "splurge" purchase on the front suspension will be QA1 adjustable coil overs with 400 lb springs. I will use 2" lowering leafs on the back. Hopefully will end up with an improved stance and excellent handling.
I will post some pictures when I get a minute. For now back to the thankless task of replacing floors.
Spent yesterday cleaning the underside, removing ball joints and control arm bushings and preparing control arms and other front end components for paint. My budget does not include tubular arms but stockers will go back together with all poly bushings. My "splurge" purchase on the front suspension will be QA1 adjustable coil overs with 400 lb springs. I will use 2" lowering leafs on the back. Hopefully will end up with an improved stance and excellent handling.
I will post some pictures when I get a minute. For now back to the thankless task of replacing floors.
On The Tree
Joined: Sep 2004
Posts: 113
Likes: 0
I decided that the 1980 Trans Am will be the proud recipient of the LT1 engine. I've been stripping everything off and out of it for the past couple weeks. Too bad it is not in as good of shape as it looks. What looked like some minor metal patch repairs in the floors is now full pan replacement on both sides.
Spent yesterday cleaning the underside, removing ball joints and control arm bushings and preparing control arms and other front end components for paint. My budget does not include tubular arms but stockers will go back together with all poly bushings. My "splurge" purchase on the front suspension will be QA1 adjustable coil overs with 400 lb springs. I will use 2" lowering leafs on the back. Hopefully will end up with an improved stance and excellent handling.
I will post some pictures when I get a minute. For now back to the thankless task of replacing floors.
Spent yesterday cleaning the underside, removing ball joints and control arm bushings and preparing control arms and other front end components for paint. My budget does not include tubular arms but stockers will go back together with all poly bushings. My "splurge" purchase on the front suspension will be QA1 adjustable coil overs with 400 lb springs. I will use 2" lowering leafs on the back. Hopefully will end up with an improved stance and excellent handling.
I will post some pictures when I get a minute. For now back to the thankless task of replacing floors.
I decided that the 1980 Trans Am will be the proud recipient of the LT1 engine. I've been stripping everything off and out of it for the past couple weeks. Too bad it is not in as good of shape as it looks. What looked like some minor metal patch repairs in the floors is now full pan replacement on both sides.
Spent yesterday cleaning the underside, removing ball joints and control arm bushings and preparing control arms and other front end components for paint. My budget does not include tubular arms but stockers will go back together with all poly bushings. My "splurge" purchase on the front suspension will be QA1 adjustable coil overs with 400 lb springs. I will use 2" lowering leafs on the back. Hopefully will end up with an improved stance and excellent handling.
I will post some pictures when I get a minute. For now back to the thankless task of replacing floors.
Spent yesterday cleaning the underside, removing ball joints and control arm bushings and preparing control arms and other front end components for paint. My budget does not include tubular arms but stockers will go back together with all poly bushings. My "splurge" purchase on the front suspension will be QA1 adjustable coil overs with 400 lb springs. I will use 2" lowering leafs on the back. Hopefully will end up with an improved stance and excellent handling.
I will post some pictures when I get a minute. For now back to the thankless task of replacing floors.
Andrew
Thread Starter
Staging Lane
Joined: May 2016
Posts: 90
Likes: 0
Thread Starter
Staging Lane
Joined: May 2016
Posts: 90
Likes: 0
Funny you should bring A/C system up. I'm just about ready to pull the trigger on a vintage air system. It's too iffy to screw around with a 40 year old system.
The Vintage Air system evaporator fits under the dash and gets rid of the clunky stock unit that mounts on the firewall right up against the engine. Getting it gone and welding up the openings in the firewall will really clean the engine compartment up.
On The Tree
Joined: Sep 2004
Posts: 113
Likes: 0
Funny you should bring A/C system up. I'm just about ready to pull the trigger on a vintage air system. It's too iffy to screw around with a 40 year old system.
The Vintage Air system evaporator fits under the dash and gets rid of the clunky stock unit that mounts on the firewall right up against the engine. Getting it gone and welding up the openings in the firewall will really clean the engine compartment up.
The Vintage Air system evaporator fits under the dash and gets rid of the clunky stock unit that mounts on the firewall right up against the engine. Getting it gone and welding up the openings in the firewall will really clean the engine compartment up.
On The Tree
Joined: May 2010
Posts: 159
Likes: 1
I'll be following your build closely. Right now the L83 is going in my 72 El Camino as we speak. But my 73 Firebird is a roller in need of an engine and the the L83s are cheap enough right now that I'm going to snag another one with low miles.
I decided that the 1980 Trans Am will be the proud recipient of the LT1 engine. I've been stripping everything off and out of it for the past couple weeks. Too bad it is not in as good of shape as it looks. What looked like some minor metal patch repairs in the floors is now full pan replacement on both sides.
Spent yesterday cleaning the underside, removing ball joints and control arm bushings and preparing control arms and other front end components for paint. My budget does not include tubular arms but stockers will go back together with all poly bushings. My "splurge" purchase on the front suspension will be QA1 adjustable coil overs with 400 lb springs. I will use 2" lowering leafs on the back. Hopefully will end up with an improved stance and excellent handling.
I will post some pictures when I get a minute. For now back to the thankless task of replacing floors.
Spent yesterday cleaning the underside, removing ball joints and control arm bushings and preparing control arms and other front end components for paint. My budget does not include tubular arms but stockers will go back together with all poly bushings. My "splurge" purchase on the front suspension will be QA1 adjustable coil overs with 400 lb springs. I will use 2" lowering leafs on the back. Hopefully will end up with an improved stance and excellent handling.
I will post some pictures when I get a minute. For now back to the thankless task of replacing floors.
Banned
Joined: Feb 2013
Posts: 3,540
Likes: 207
I think I can add some further useful info here for you guys. The engine mount bosses on the LT engines stand 3/8 further away from the block centerline than the mount bosses on the LS engines do (discovered and verified in CAD program), so any swap application that has been difficult to get the front of an LS engine low enough in the frame to achieve optimized U-joint working angles is going to be even more troublesome to do so with an LT engine.
Last edited by user 4737373; Jul 30, 2016 at 12:17 PM.