Vortec Engine to TBI Swap

[Bret]

So it's not completely GMT-400 related, but I have a 1999 5.7 Vortec I'll be swapping in my 1967 Biscayne. I'll be going carb'd initially, but I plan on going to a 1990's chevy TBI and computer later on.
Have any of you guys done a Vortec to stock TBI? Do most of the Vortec Sensors transfer over? I plan on cutting them before the harness so I can reuse them.
And a bonus question, the car has a Muncie 3 speed, would the Vortec stock flywheel work for this? I havent seen anything saying it wont.

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[454cid]

Why TBI?

 

[Schurkey]

I plan on going to a 1990's chevy TBI and computer later on.
Have any of you guys done a Vortec to stock TBI?

I'm replacing my 5.7 TBI with a Vortec short-block.

I can't help with most of your questions--but--you'll need to think about what fan/water pump/ps/alternator/AC belt system you're going to use.

If you use the '67 V-belt system, you'll need the '67 water pump, fan clutch, and fan. The stock serpentine system spins the water pump, fan and clutch backwards, AND the Vortec water pump and Vortec block don't have provisions for the coolant bypass required with the older V-belt, or TBI-era serpentine system water pump.

Depending on what you use for a drive belt system, you may need to drill the bypass hole in the front of the block. Some Vortec blocks have the hole partially-drilled, some blocks have the hole not there at all. I have one of each style of block, and I'm drilling the bypass hole in both so I can use a bypass-style water pump.

The Vortec intake manifold has a coolant bypass instead of the water pump. Unless you use the Vortec intake manifold and special thermostat, you'd need to use an older water pump and drill the block.

You'll also want to be sure to use a timing cover/timing pointer and torsional damper that go together. They're not all calibrated the same. Make sure you find TRUE TDC on #1, and that the damper and timing pointer line-up at "0". If the timing marks are straight up-and-down, you'll need to avoid the "short" water pump because there's no room to shine the timing light between the back of the water pump and the front of the block. Short water pumps require the timing pointer to be offset to the driver's side of the engine--which means the torsional damper has to have the TDC mark offset to the driver's side to match the pointer.

The Vortec blocks have two fewer bolts that hold the timing cover in place. I'm drilling and tapping the extra holes in my blocks so I can use any SBC timing cover, not just the plastic, disposable Vortec cover.

 

[Bret]

I want to do TBI for a few reasons. I like the carb, but it does get tedious to have to rebuild because I dont drive it all the time. I also want to start dabbling into FI tuning. Theres also all the obvious benefits like not worrying about the choke. The biggest part of it though is probably getting into tuning.

As far as the engine, I'll be keeping the stock serpentine belt system. There should be no problems other than maybe the alternator being a little too high output for the cars old wiring, but I have plans to rewire it shortly after the swap. A PO swapped the stock 327 for an emissions late 70's 350 thats pretty tired. .I'm going to put on a Jegs carb intake manifold, so I wont have to worry about the stock one. As for the radiator, I'd like to use the vortecs if I can fabricate something.

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[Bret]

I'm replacing my 5.7 TBI with a Vortec short-block.

I can't help with most of your questions--but--you'll need to think about what fan/water pump/ps/alternator/AC belt system you're going to use.

If you use the '67 V-belt system, you'll need the '67 water pump, fan clutch, and fan. The stock serpentine system spins the water pump, fan and clutch backwards, AND the Vortec water pump and Vortec block don't have provisions for the coolant bypass required with the older V-belt, or TBI-era serpentine system water pump.

Depending on what you use for a drive belt system, you may need to drill the bypass hole in the front of the block. Some Vortec blocks have the hole partially-drilled, some blocks have the hole not there at all. I have one of each style of block, and I'm drilling the bypass hole in both so I can use a bypass-style water pump.

The Vortec intake manifold has a coolant bypass instead of the water pump. Unless you use the Vortec intake manifold and special thermostat, you'd need to use an older water pump and drill the block.

You'll also want to be sure to use a timing cover/timing pointer and torsional damper that go together. They're not all calibrated the same. Make sure you find TRUE TDC on #1, and that the damper and timing pointer line-up at "0". If the timing marks are straight up-and-down, you'll need to avoid the "short" water pump because there's no room to shine the timing light between the back of the water pump and the front of the block. Short water pumps require the timing pointer to be offset to the driver's side of the engine--which means the torsional damper has to have the TDC mark offset to the driver's side to match the pointer.

The Vortec blocks have two fewer bolts that hold the timing cover in place. I'm drilling and tapping the extra holes in my blocks so I can use any SBC timing cover, not just the plastic, disposable Vortec cover.

I just reread you're post, I'm defanitely going to research into that coolant bypass and see all the available options, I appriciate you informing me about that!

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[454cid]

I want to do TBI for a few reasons. I like the carb, but it does get tedious to have to rebuild because I dont drive it all the time. I also want to start dabbling into FI tuning.

Ok, but why TBI? Why not the stock Vortec system that's already on the engine, and then maybe swap to the marine intake eventually?

 

[Bret]

Ok, but why TBI? Why not the stock Vortec system that's already on the engine, and then maybe swap to the marine intake eventually?

I would prefer to learn on a simpler injection system, with a way cheaper modification cost. Despite being cheaper, I wouldnt want to send the ECU to get tuned because I wouldnt be learning anything that way. If I was to get into the costs needed to modify the Vortec system, I'd rather just do a Holley injection system.

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[Schurkey]

With the stock serpentine system, and and aftermarket carbed intake manifold, you'll need the TBI-style water pump that has the bypass built in, and you'll need to drill the block. The TBI water pump is also reverse rotation like the Vortec.

The Vortec water pump has no bypass, if you drill the block the water will just pour out. I don't think I have a Vortec water pump to take a photo of. I have a TBI pump, though.

I cannot immediately help you with compatibility of Vortec pulley and bracket system and the TBI pump. I don't have a Vortec pulley system to compare to, although I've got several TBI pulley-and-bracket systems lying around. For all I know, they may be identical other than the water pump casting.

The Vortec intake/TBI injection manifold is hatefully expensive, but allows you to keep the EGR for emissions and knock reduction assuming you can route exhaust gas from the exhaust manifold to the intake manifold port. GM sold a "kit" that allows you to do this, the GM stuff may be discontinued but the aftermarket still has all the parts you'd need, and at reasonable cost IF you can stand to use an iron exhaust manifold. Otherwise you'll have to have a bung welded into a header tube that will match-up with the exhaust transfer tube that leads to the intake manifold port.

 

[Bret]

With the stock serpentine system, and and aftermarket carbed intake manifold, you'll need the TBI-style water pump that has the bypass built in, and you'll need to drill the block. The TBI water pump is also reverse rotation like the Vortec.

The Vortec water pump has no bypass, if you drill the block the water will just pour out. I don't think I have a Vortec water pump to take a photo of. I have a TBI pump, though.

I cannot immediately help you with compatibility of Vortec pulley and bracket system and the TBI pump. I don't have a Vortec pulley system to compare to, although I've got several TBI pulley-and-bracket systems lying around. For all I know, they may be identical other than the water pump casting.

The Vortec intake/TBI injection manifold is hatefully expensive, but allows you to keep the EGR for emissions and knock reduction assuming you can route exhaust gas from the exhaust manifold to the intake manifold port. GM sold a "kit" that allows you to do this, the GM stuff may be discontinued but the aftermarket still has all the parts you'd need, and at reasonable cost IF you can stand to use an iron exhaust manifold. Otherwise you'll have to have a bung welded into a header tube that will match-up with the exhaust transfer tube that leads to the intake manifold port.

Looking up chevy cooling diagrams, it looks like I should be able to run a nipple in the top of the carb intake and route that to the vortec water pump heater hose nipple. If that doesnt work, I'll keep researching the issue.
As far as the intake, I'll keep the same intake for the TBI, but I'll buy a carb to tbi spacer/adapter.

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[Schurkey]

I don't think I have a Vortec water pump to take a photo of. I have a TBI pump, though.

I have both a Vortec and a TBI water pump readily available for photos. There may be other versions of either, this is what I had.

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Note that the belt is closer to the engine (lower in the photo) on the Vortec than on the TBI. The pulley attachment is different, and the fan clutch attachment is different. This could be a problem, although GM may have other variations of water pump for TBI (Camaro, Caprice, Vans, who knows what else) that could interchange dimensionally with the Vortec pump.

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This is the Vortec block I'll be using on my TBI pickup. Haven't drilled the timing cover bolt holes (2) yet.

Looking up chevy cooling diagrams, it looks like I should be able to run a nipple in the top of the carb intake and route that to the vortec water pump heater hose nipple. If that doesnt work, I'll keep researching the issue.

As long as the water pump nipple is an "inlet" and not an "outlet" that would work--and could save you some fabricating. I was going to look at the two nipples on the Vortec pump to see how they were plumbed, but I forgot.

I'm going to put on a Jegs carb intake manifold

As far as the intake, I'll keep the same intake for the TBI, but I'll buy a carb to tbi spacer/adapter.

Decide if you want to retain the EGR before buying a manifold.