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Cheap Low Mount Alternator Setup for Truck Accessory Drive...


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Hey guys, I thought I would share a cheap and easy solution to clearence issues with the stock hood using the truck accessory drive. This will also require a car style intake manifold in order to use a stock, unmodified hood.

 

I recently began bodywork on my S30 to get it prepped for paint. As some of you know I have/had a stock hood with a 4" fiberglass cowl installed. Well my wife is just over 5' tall and would have issues seeing over the cowl. I always planned to go back to a stock hood, but the truck accessory setup places the alternator high on the driver side and prevents the stock hood from being closed.

 

I knew of two solutions for this. One is to swap the whole accessory drive over to a '98-'02 F-Body crank pulley, tensioner, idler, alternator, water pump, and alternator brackets. The second is an aftermarket setup from several vendors and prices start at $1000 and up from there.

 

Since I didn't want to spend alot of money replacing my entire accessory drive setup, I started to think about a third option that is cheap as possible, reuse as much of the existing equipment, and still be uber reliable.

 

Anyway I bought a stock (front) piece of F-Body alternator bracket from the local dealer ($20) and confirmed that the truck alternator will work with the front F-Body bracket, but the stock F-Body rear alternator bracket won't work with the truck alternator (no mounting boss on the truck alternator). However, using the front bracket alone is plenty strong. The trouble is the bracket won't line up the alternator with the rest of the truck accessory drive since the truck accessories are placed the farthest forward. So the alternator is reused which is prob the most expensive part on the accessory drive, but will require the bracket to be spaced from the block just about 3/4" in order to work with the rest of the truck accessory drive.

 

Next I went to bolt the bracket onto my iron block to discover that one hole on the upper driver outside hole isn't drilled and tapped. So I bolted the bracket with the single lower bolt and marked the spot to drill for the undrilled/untapped hole. After marking the mark I drilled a 1/8" pilot hole, then took a 11/32" cobalt drill bit and drilled the rest out about inch into the block. Then I threaded the hole using a M10 x 1.5 tap. After using some aluminum stock scrap I made 3/4" spacers to be sandwiched between the alternator bracket and the block. I needed 2 M10 x 1.5 bolts that are 140mm long (about 5.5") and I used Allen headed bolts due to the standard large 17mm hex headed bolts were too close to the belt for my comfort.

 

Now I needed to address the idler pulley. Since the belt routing will have the belt going over the top of the idler instead of under it as it does in the stock F-Body setup, the smooth idler needs to be replaced with a ribbed one. The same type used on the stock upper tensioner ribbed pulley will work fine, so you'll need to buy one of those as well, I got mine for $10 at the local auto part store. Using a few washers on the backside is needed to get the correct belt alignment. A straight edge is very helpful for this.

 

So now I needed a belt. After a few trips to the local parts store, I figured out that a 55" x 13/16" belt is ideal. I also needed to un-loom some of the alternator harness (minor) to allow the alternator pigtail/weather-connector to reach the new (lower) alternator location. After getting the length needed I re-loomed the harness with everything looks stock again. I also noticed I have a decent amount of clearence between the positive power post on the back of the alternator and the engine tower that I have read some of had issues with their S30's using the F-Body accessories. This is due to the alternator being spaced forward in turn gave an unexpected, but not undesired bonus for the conversion using the truck accessories over using the whole F-Body accessories which would place the power post alittle too close to the engine tower for my comfort.

 

It all worked great and now my S30 is painted and a stock hood is in place.

 

It should be noted that if you haven't converted from a stock truck intake manifold to the car type intake manifold yet you will need a car manifold, car fuel rail, and car injectors. If you have a DBW (drive by wire) throttle body (like I do) you will need a car style water pump due to the upper water neck running into the throttle body. If you have a drive by cable style throttle body, all is needed is a minor tweaking or twisting of the upper water neck for throttle body clearence.

 

Anyway, if you have a DBW throttle body you have a few options. First is some truck water pumps (usually pre '04) use the same casting as the car water pump and allow you to drill the correct size hole in the water pump boss and pipe tap and plug the stock truck hole after the neck is removed.

 

The second option is to buy a car water pump, have the stock pulleys removed from both the car and truck pumps by a machinist with the correct tools and skill and have the truck pulley pressed onto the car pump.

 

The third option is what I did. I found an uber rare early Corvette (Y-Body) water pump that has the pump pulley bolted on like an older SBC/BBC. I removed the pulley and spaced it out about 3/4" (outward/forward) to align with crank pulley using spacers and longer bolts. My pump came from a '97 Y-Body that I picked up from a guy on LS1Tech.com for $40. I tried finding one at the parts stores, but every pump I found had the pressed on pulley instead of the bolt-on pulley which interchanges on the Y-Body setup.

 

I am sure I forgot some minor details, so if you have questions, feel free to ask. I just hope some other guys here can use this as a cheaper alternative to pricey aftermarket or swapping entire factory accessory drive.

 

Take care!!

post-778-024904300 1285284338_thumb.jpg

Edited by Cable
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This setup makes the use of truck engines much more affordable.

I calculated the cost to make a LQ9 compatible with the S30.

Oil pan-150

Intake/Injectors-200

Accessory drive swap -200ish

Basically $550 to make it an LS1

 

LQ9-900

LS1-2000

 

Your mod cuts it the difference to about $800.

 

It makes it more justifiable to use the vortec engines now.

Thanks!

 

Still going LS1 though , want to make it light as possible.

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  • 3 months later...

Hey guys, I thought I would share a cheap and easy solution to clearence issues with the stock hood using the truck accessory drive. This will also require a car style intake manifold in order to use a stock, unmodified hood.

 

I recently began bodywork on my S30 to get it prepped for paint. As some of you know I have/had a stock hood with a 4" fiberglass cowl installed. Well my wife is just over 5' tall and would have issues seeing over the cowl. I always planned to go back to a stock hood, but the truck accessory setup places the alternator high on the driver side and prevents the stock hood from being closed.

 

I knew of two solutions for this. One is to swap the whole accessory drive over to a '98-'02 F-Body crank pulley, tensioner, idler, alternator, water pump, and alternator brackets. The second is an aftermarket setup from several vendors and prices start at $1000 and up from there.

 

Since I didn't want to spend alot of money replacing my entire accessory drive setup, I started to think about a third option that is cheap as possible, reuse as much of the existing equipment, and still be uber reliable.

 

Anyway I bought a stock (front) piece of F-Body alternator bracket from the local dealer ($20) and confirmed that the truck alternator will work with the front F-Body bracket, but the stock F-Body rear alternator bracket won't work with the truck alternator (no mounting boss on the truck alternator). However, using the front bracket alone is plenty strong. The trouble is the bracket won't line up the alternator with the rest of the truck accessory drive since the truck accessories are placed the farthest forward. So the alternator is reused which is prob the most expensive part on the accessory drive, but will require the bracket to be spaced from the block just about 3/4" in order to work with the rest of the truck accessory drive.

 

Next I went to bolt the bracket onto my iron block to discover that one hole on the upper driver outside hole isn't drilled and tapped. So I bolted the bracket with the single lower bolt and marked the spot to drill for the undrilled/untapped hole. After marking the mark I drilled a 1/8" pilot hole, then took a 11/32" cobalt drill bit and drilled the rest out about inch into the block. Then I threaded the hole using a M10 x 1.5 tap. After using some aluminum stock scrap I made 3/4" spacers to be sandwiched between the alternator bracket and the block. I needed 2 M10 x 1.5 bolts that are 140mm long (about 5.5") and I used Allen headed bolts due to the standard large 17mm hex headed bolts were too close to the belt for my comfort.

 

Now I needed to address the idler pulley. Since the belt routing will have the belt going over the top of the idler instead of under it as it does in the stock F-Body setup, the smooth idler needs to be replaced with a ribbed one. The same type used on the stock upper tensioner ribbed pulley will work fine, so you'll need to buy one of those as well, I got mine for $10 at the local auto part store. Using a few washers on the backside is needed to get the correct belt alignment. A straight edge is very helpful for this.

 

So now I needed a belt. After a few trips to the local parts store, I figured out that a 55" x 13/16" belt is ideal. I also needed to un-loom some of the alternator harness (minor) to allow the alternator pigtail/weather-connector to reach the new (lower) alternator location. After getting the length needed I re-loomed the harness with everything looks stock again. I also noticed I have a decent amount of clearence between the positive power post on the back of the alternator and the engine tower that I have read some of had issues with their S30's using the F-Body accessories. This is due to the alternator being spaced forward in turn gave an unexpected, but not undesired bonus for the conversion using the truck accessories over using the whole F-Body accessories which would place the power post alittle too close to the engine tower for my comfort.

 

It all worked great and now my S30 is painted and a stock hood is in place.

 

It should be noted that if you haven't converted from a stock truck intake manifold to the car type intake manifold yet you will need a car manifold, car fuel rail, and car injectors. If you have a DBW (drive by wire) throttle body (like I do) you will need a car style water pump due to the upper water neck running into the throttle body. If you have a drive by cable style throttle body, all is needed is a minor tweaking or twisting of the upper water neck for throttle body clearence.

 

Anyway, if you have a DBW throttle body you have a few options. First is some truck water pumps (usually pre '04) use the same casting as the car water pump and allow you to drill the correct size hole in the water pump boss and pipe tap and plug the stock truck hole after the neck is removed.

 

The second option is to buy a car water pump, have the stock pulleys removed from both the car and truck pumps by a machinist with the correct tools and skill and have the truck pulley pressed onto the car pump.

 

The third option is what I did. I found an uber rare early Corvette (Y-Body) water pump that has the pump pulley bolted on like an older SBC/BBC. I removed the pulley and spaced it out about 3/4" (outward/forward) to align with crank pulley using spacers and longer bolts. My pump came from a '97 Y-Body that I picked up from a guy on LS1Tech.com for $40. I tried finding one at the parts stores, but every pump I found had the pressed on pulley instead of the bolt-on pulley which interchanges on the Y-Body setup.

 

I am sure I forgot some minor details, so if you have questions, feel free to ask. I just hope some other guys here can use this as a cheaper alternative to pricey aftermarket or swapping entire factory accessory drive.

 

Take care!!

 

This works very well IF you are not using the 140 amp Delphi alternator that is common on the 6.0 and 5.3 trucks. The 140 amp alternator fits nicely in the F body mount, but it is 4.8 inches deep and 6.3 inches in diameter. There are two points of interference: 1. the power post in the back makes contact with the Datsun motor mount post and 2. the bottom of the alternator rests on the large flat adjustment "screws" on the rack.. Using the top bolt as a pivot point, the alternator will just barely clear the Datsun driver's side rail (about 1/4 inch) as it arcs down. However, the alternator bottoms out on the rack before the arc is completed. The bottom bolt holes will need about .5 inch more arc before it lines up with the tapped lower hole in the LM7 block. The cure is to use the smaller Ls1 alternator. But, I'm too cheap to buy one and I really like the idea of having 140 amps for all my planned electronic toys.

 

I think the long cure to this would be to cut a spacer /plate that would allow for the following: 1. drill the plate for the top bolt as Cable states. 2. drill the plate for the lower existing tapped hole in the truck block, but counter sink the hole in the plate allowing you to use a short allen headed screw that would be flush with the plate. This fastener will stabilize the plate. Install the alternator using the upper bolt and clock the alternator up until it clears the rack and the power post clears the Datsun motor mount post. Mark, drill, and tap the plate to use a another short allen headed screw.

 

I'll try to post photos, but I've not had much luck doing that since the program change of a year or so ago.

G

Edited by zgeezer
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This works very well IF you are not using the 140 amp Delphi alternator that is common on the 6.0 and 5.3 trucks. The 140 amp alternator fits nicely in the F body mount, but it is 4.8 inches deep and 6.3 inches in diameter. There are two points of interference: 1. the power post in the back makes contact with the Datsun motor mount post and 2. the bottom of the alternator rests on the large flat adjustment "screws" on the rack.. Using the top bolt as a pivot point, the alternator will just barely clear the Datsun driver's side rail (about 1/4 inch) as it arcs down. However, the alternator bottoms out on the rack before the arc is completed. The bottom bolt holes will need about .5 inch more arc before it lines up with the tapped lower hole in the LM7 block. The cure is to use the smaller Ls1 alternator. But, I'm too cheap to buy one and I really like the idea of having 140 amps for all my planned electronic toys.

 

I think the long cure to this would be to cut a spacer /plate that would allow for the following: 1. drill the plate for the top bolt as Cable states. 2. drill the plate for the lower existing tapped hole in the truck block, but counter sink the hole in the plate allowing you to use a short allen headed screw that would be flush with the plate. This fastener will stabilize the plate. Install the alternator using the upper bolt and clock the alternator up until it clears the rack and the power post clears the Datsun motor mount post. Mark, drill, and tap the plate to use a another short allen headed screw.

 

I'll try to post photos, but I've not had much luck doing that since the program change of a year or so ago.

G

 

CORRECTION CORRECTION CORRECTION

 

The 130/140 amp truck alternator fits just fine with minimum and easily curable interference with the rack and pinion adjustment "screws". The key is to install the lower bolt first and, then clock the alternator and mount counterclockwise to install the top bolt. At this point the bottom of the alternator may have slight interference with the point of the large hex threaded lock ring on the rack and pinion. I just touched the one point of the hex and the body of the Alternator with an angle grinder. By "Touched", I mean a very slight cut.

 

The power post in the back of the alternator will now clear the motor mount......, but, just barely. I used the grinder to knock off the unthreaded nut guide back down to the beginning of the threads. It is now still close, but I can install a ring connection and a then nut without moving/removing the alternator.

 

I understand that a close fit for the alternator is is pretty standard for JCI LS1 kits.

 

G

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  • 10 months later...

To the OP: Looks like you have removed your power steering all together....and idea on how to create provisions to keep the PS pump?

 

Why would I want/need to keep power steering when no S30 ever came with it?

 

If someone was going to go through all the trouble of putting a power steering rack and pinion setup in their S30, then they aren't going to be worried about the cost and time involved in swapping out the truck water pump and crank pulley to the F-Body pieces and retaining the entire FEAD, including the power steering pump.

 

Take care.

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This is a great thread. When I changed to an F-body alternator, there were tons of truck alternators at the scrap yard, but only one F-body alternator, which I had to have rebuilt. Good to know that the rear bracket is not needed. That opens up lots of alternators to us. Thanks for keeping it real. I have had the same problem with a tall hood (she is 5'2"). When Rebekah drives at the track, she complains about the hood scoop. I fix it with a pillow in her seat.

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Contrary to popular belief, some people swap LS engines in to vehicles other than S30s.

 

Just a heads up...sometimes people who build other makes of cars come around to your forum to try to glean ideas from other car guys with passions for different cars. Therefore, it's best not to be a smartass ****** bag. It respresents the entire community poorly.

 

Now look, you've gone and turned me in to a smartass too! Where are my manners?

 

I guess I am still confused why you came and posted your question in a thread for S30's, yet clearly aren't working on a S30. I suggest next time taking your question to a PM instead of clouding up the thread.

 

I seriously doubt ANYONE here who knows me is going to come to your rescue, but who are you to come here and start calling names in my house?

 

Continue acting this way and the moderators will have the rest of us smelling TOAST.

 

Have a nice day.

Edited by Cable
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