LT1 swap question
Thread Starter
Burning Brakes
Joined: Mar 2012
Posts: 871
Likes: 73
From: Memphis Tennessee
LT1 swap question
Anyone do this swap and use f-body accessories? I had to notch the accessorie bracket to get it in. This removed one of the mounting holes for the A/C compressor. Problem is that the hole is needed for the A/C delete pulley.
Think I can run the pulley with 2/3 bolts installed? Alternatives to that would be a custom idler pulley, or a custom bracket to make the idler work.
Think I can run the pulley with 2/3 bolts installed? Alternatives to that would be a custom idler pulley, or a custom bracket to make the idler work.
Race Director
Joined: Apr 2007
Posts: 11,150
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From: South Western Ontario
That AC delete pulley is smaller than the AC compressor pulley, yet it uses the same belt. So, it mounted down and out compared to the center of the AC compressor to take up the extra belt length due to the smaller pulley size. I would not expect it to work without the pulley and/or the belt getting into the control arm.
I think you're looking at a custom bracket mount and a shorter belt, if you have enough clearance to get the belt through there at all. A more direct on picture with the PS pump bolted up would certainly help.
I put a LT1 into my 65 Impala last summer. It was rebuilt with a hot cam and head porting and sitting on a stand in my garage for 4 or 5 years when a lobe in the Impala's 350 went flat so I figured why not. Let me know if you have any questions on the wiring or install. I just might be able to help.
I think you're looking at a custom bracket mount and a shorter belt, if you have enough clearance to get the belt through there at all. A more direct on picture with the PS pump bolted up would certainly help.
I put a LT1 into my 65 Impala last summer. It was rebuilt with a hot cam and head porting and sitting on a stand in my garage for 4 or 5 years when a lobe in the Impala's 350 went flat so I figured why not. Let me know if you have any questions on the wiring or install. I just might be able to help.
Thread Starter
Burning Brakes
Joined: Mar 2012
Posts: 871
Likes: 73
From: Memphis Tennessee
Thanks for the advice. I spent some time looking at pictures of A/C Delete pulleys installed, and it doesn't look like it'll fit. I guess I'm going to have to get creative. The main reason for using the LT1 was low price, and if I have to buy aftermarket accessories or find a corvette accessorie drive then that just goes out the window.
And how do you like the hotcam? That was the one mod I did internally. Other than that it's a stock semi high milage motor.
And how do you like the hotcam? That was the one mod I did internally. Other than that it's a stock semi high milage motor.
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
I'm thinking you have to mount an idler above the control arm assuming you can get the belt to pass between the PS pulley and the arm OK with some clearance. Not that big a deal. you can buy idler pulleys for about $20 I think.
The hot cam is good. I think it could do with a little more cam I suppose and I've read the hot cam lobe profiles really aren't that great but I don't know if that's true. Never driven with the stock cam so I don't know how much difference it made. You did the kit with the rockers too, correct?
The hot cam is good. I think it could do with a little more cam I suppose and I've read the hot cam lobe profiles really aren't that great but I don't know if that's true. Never driven with the stock cam so I don't know how much difference it made. You did the kit with the rockers too, correct?
Thread Starter
Burning Brakes
Joined: Mar 2012
Posts: 871
Likes: 73
From: Memphis Tennessee
Ok, I bolted on the accessories and used some masking tape to mock up the belt routing. There is just not enought room between the p/s pulley and the control arm cross shaft. I'm thinking I need a smaller pulley.
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
That back a-arm bolt is in the way? Can you cut the bolt to get enough clearance? Looks very doubtful but just maybe. You might be driving the pump too fast by the time you get a small enough pulley on it to have belt clearance with that bolt in the way. Maybe cut the bolt and get something like a 1/2 smaller pulley as well.
The B-car drive is similar to the F-body so I doubt it would be any better. I don't think the Corvette bracket would be any better either. It puts the PS pump in a very similar location on the opposite side of the engine so you'd just have clearance problems to the A-arm on the opposite side.
Someone must have done the swap before and know how to make it work.
The B-car drive is similar to the F-body so I doubt it would be any better. I don't think the Corvette bracket would be any better either. It puts the PS pump in a very similar location on the opposite side of the engine so you'd just have clearance problems to the A-arm on the opposite side.
Someone must have done the swap before and know how to make it work.
Thread Starter
Burning Brakes
Joined: Mar 2012
Posts: 871
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From: Memphis Tennessee
Clearance problem is with the cross shaft, and I don't want to cut that... There has to be a straight shot between the alternator and the a/c delete pulley. There are a few other swaps, but they all seem to use the Covette accessories. If I can find a small P/S pulley I can always use an underdrive crank pulley to even things out.
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Race Director
Joined: Apr 2007
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From: South Western Ontario
Make a bracket to mount the idler above the control arm instead of down low where the AC was. The belt can go from the tensioner at an angle between the shaft and the PS pulley to this new pulley.
Thread Starter
Burning Brakes
Joined: Mar 2012
Posts: 871
Likes: 73
From: Memphis Tennessee
Something like this?
I just went out and eyeballed it, and I think this will work. I'll just have to get creative with the bracket.
I just went out and eyeballed it, and I think this will work. I'll just have to get creative with the bracket.
Last edited by Learning_Curve; Jul 1, 2012 at 07:21 PM.
Thread Starter
Burning Brakes
Joined: Mar 2012
Posts: 871
Likes: 73
From: Memphis Tennessee
Well I started working on drive, but didn't really like how it was turning out. So I broke down and bought a Corvette drive off of Ebay. Only thing that it didn't come with was a crank pulley. I've heard that the Camaro hub/pulley won't work with the Vette setup, but untill I get everything mounted up, I won't know if the pulley is too short or too long...
Also started on wiring. One question I have is what circuits did you blend the LT1 harness with the stock engine harness? I know that all the guage circuits will need to be spliced, but I'm still figuring out the power circuits. I'm thinking an auxililary fuse block with B+ for the computer memory, and maybe using a relay acuated by the Vettes switched ignition wire for the rest of the circuits
Also started on wiring. One question I have is what circuits did you blend the LT1 harness with the stock engine harness? I know that all the guage circuits will need to be spliced, but I'm still figuring out the power circuits. I'm thinking an auxililary fuse block with B+ for the computer memory, and maybe using a relay acuated by the Vettes switched ignition wire for the rest of the circuits
Instructor
Joined: Mar 2010
Posts: 228
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From: Evansville WI
I LT1 swapped an earlier F-body a number of years ago. If I remember correctly, except for the tach and speedo(electronic), the gauge senders are separate from the sensors the PCM uses, so the gauge wiring was pretty straight forward. I remember that we needed to get a VATS bypass module too to bypass the PCM's built in anti-theft system(this can be turned off by a tuner if you have your PCM tuned as well).
Thread Starter
Burning Brakes
Joined: Mar 2012
Posts: 871
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From: Memphis Tennessee
I believe you're right. However, the wiring for all the sender units is part of the LT1 wiring harness, and they all terminate in a connecter. I just need to splice this with the stock engine compartment harness.
And I think a tune will be a must, since I'll be without downstream 02 sensors, smog pump, EGR, EVAP, and a bigger cam.
And I think a tune will be a must, since I'll be without downstream 02 sensors, smog pump, EGR, EVAP, and a bigger cam.
Race Director
Joined: Apr 2007
Posts: 11,150
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From: South Western Ontario
Not sure why you'd want to run without O2 sensors. Actually, I'm not even sure how reasonable or possible that is.
I used a Painless 4-circuit block for my swap to power the motor. I believe there is 1 full-time powered fuse and 3 switched fuses.
If I recall correctly, you'll have to provide switched power the coil, O2 sensors, injectors, reverse lockout solenoid, fuel pump relay, and the PCM. Constant power goes to the PCM as well. I would power the cooling fan directly from the solenoid on it's own power feed. There is other stuff that takes power, but you're not using any of it.
I used a Painless 4-circuit block for my swap to power the motor. I believe there is 1 full-time powered fuse and 3 switched fuses.
If I recall correctly, you'll have to provide switched power the coil, O2 sensors, injectors, reverse lockout solenoid, fuel pump relay, and the PCM. Constant power goes to the PCM as well. I would power the cooling fan directly from the solenoid on it's own power feed. There is other stuff that takes power, but you're not using any of it.
Team Owner
Joined: Feb 1999
Posts: 34,453
Likes: 665
From: Republic of Texas
Team Owner
Joined: Feb 1999
Posts: 34,453
Likes: 665
From: Republic of Texas
Thread Starter
Burning Brakes
Joined: Mar 2012
Posts: 871
Likes: 73
From: Memphis Tennessee
Engine is a '97, so it is OBD II. "Downstream" refers to post Cat O2 sensors, and the wires for them have been removed. I found a great resource at LT1swap.com, and it broke down all the circuits at the PCM connector. So I just started pulling any pins for unneeded cicuits, and removing the wires from the harness. Post cat o2 sensors, egr solinoid, AIR relay, Purge, A/C control have all been removed. There are four B+ circuits that I have wired to a fuse block under the hood, with another fuse block to feed the two switched ignition wires.
Top fuse block is the B+ circuits, bottom is the switched circuits.
Here are the gauge circuits, connecting the LT1 Harness to the Vette harness. I wanted to keep as much of the stock wiring as possible.
And all these connections will be covered with heat shrink once I make sure everything works. I just wanted a way to dissconnect everything without having to cut wires. Once I'm done, all the wiring will have to come out to be wrapped in wire loom. Having random wires strung throughout the engine compartment is a pet peeve of mine.
Top fuse block is the B+ circuits, bottom is the switched circuits.
Here are the gauge circuits, connecting the LT1 Harness to the Vette harness. I wanted to keep as much of the stock wiring as possible.
And all these connections will be covered with heat shrink once I make sure everything works. I just wanted a way to dissconnect everything without having to cut wires. Once I'm done, all the wiring will have to come out to be wrapped in wire loom. Having random wires strung throughout the engine compartment is a pet peeve of mine.
Last edited by Learning_Curve; Jul 23, 2012 at 05:51 PM.
Racer
Joined: May 2001
Posts: 401
Likes: 0
From: Carlsbad CA
It looks like I let my four year old son wire everything up!Good luck with your conversion. And definitely consider one of the options that lets you adjust the tune on your own without having to burn your own chip every time. Plenty of options are discussed over at thirdgen.org.