Looking good Brian! Glad you're making progress AND DDing it! Cool guys DD first gens, just saying 
CK5
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71K5 - BP71K5's Just for fun build
- Thread starter bp71k5
- Start date
bp71k5
3/4 ton status
Thanks, got a few good photos of the kids sitting up on the top bars watching fireworks tonight, will post later.
Nice work like always Brian.... 
-G
-G
bp71k5
3/4 ton status
Update 07/13/2013
It's a milestone today. The original start of this build thread started with my stereo system modification, and today the stereo has been removed. Something has gone wrong internally with all the input signals and was makig the sound cut in and out frequently. Maybe a broken wire or trace inside?
Here it is:
And here's what went in its place:
Its the retrosound "zuma" and comes with the GM faceplate and knobs. The sound fidelity isn't quite as good as the pioneer, but its decent enough.
I also discovered a super helpful use for the doubler gearing. Extra extra low makes sitting in stop and go traffic much more tolerable since I can just crawl along the freeway and use the brake to modulate my speed between 1 and 3 mph.
One other update on the cooling system problem I had when the engine was running "too cool".
I replaced the thermostat ( a new 195) and flushed the cooling system and hooked up the laptop to read sensor data. When the engine is warmed up for a bit, the temp gauge on the dash reads 165( sender in the driver side head), but the ECM is seeing 195 (and running in closed loop) my cooling fans also seem to be cycling as they should so that sender looks ok too and matches the ECM. It looks like either the sender in the head is reading low, or the water in the head is actually cooler than it is at the intake manifold ports for the other two sensors. Any ideas?
I also calculated my mpg... 9 on the freeway. Could a a bbc 496 get worse mileage than I'm getting now?
It's a milestone today. The original start of this build thread started with my stereo system modification, and today the stereo has been removed. Something has gone wrong internally with all the input signals and was makig the sound cut in and out frequently. Maybe a broken wire or trace inside?
Here it is:
And here's what went in its place:
Its the retrosound "zuma" and comes with the GM faceplate and knobs. The sound fidelity isn't quite as good as the pioneer, but its decent enough.
I also discovered a super helpful use for the doubler gearing. Extra extra low makes sitting in stop and go traffic much more tolerable since I can just crawl along the freeway and use the brake to modulate my speed between 1 and 3 mph.
One other update on the cooling system problem I had when the engine was running "too cool".
I replaced the thermostat ( a new 195) and flushed the cooling system and hooked up the laptop to read sensor data. When the engine is warmed up for a bit, the temp gauge on the dash reads 165( sender in the driver side head), but the ECM is seeing 195 (and running in closed loop) my cooling fans also seem to be cycling as they should so that sender looks ok too and matches the ECM. It looks like either the sender in the head is reading low, or the water in the head is actually cooler than it is at the intake manifold ports for the other two sensors. Any ideas?
I also calculated my mpg... 9 on the freeway.
Could a a bbc 496 get worse mileage than I'm getting now?
bp71k5
3/4 ton status
Update 07/25/2913
New radiator is leaking like the last one after two weeks of freeway driving. Talked to Griffin and so far the plan is to send this one back too (another $70 in shipping) to have it warrentied again. If these things really are so fragile I'm not sure I can trust the quality on a third one. Anyone else had better luck with this stuff? Anyone else using their radiators and happy with them?
New radiator is leaking like the last one after two weeks of freeway driving. Talked to Griffin and so far the plan is to send this one back too (another $70 in shipping) to have it warrentied again. If these things really are so fragile I'm not sure I can trust the quality on a third one. Anyone else had better luck with this stuff? Anyone else using their radiators and happy with them?
bp71k5
3/4 ton status
Update: 09/10/2013
Got word back from Griffin.
Evidently, the radiators were leaking because the stock mounting brackets were too tight and crushing the radiator somehow and refused to warranty it anymore, although to be fair, they offered a steep discount on another radiator. Even though the part is supposed to be designed for this application with "minimal" modification necessary, "minimal" seems to be open to interpretation. Those buying their "direct fit" models beware, the radiator is a bit taller than stock and so I guess the mounting brackets are under more stress than normal.
So rather than risk sinking more money into a part that even the manufacturer couldn't tell me how to mount properly without damaging it, I opted for a cheaper store bought copper/brass "max cooling" edition radiator for a 71 K5. As it turns out, this radiator is also a bit taller than my old "4 core" radiator. I had originally converted to a 4 core from the stock 2 core when I bought the truck. It seems there is some third sized radiator option that Griffin may be using to design against. Can any experts confirm three radiator options for a first gen?
So I modified my other radiator bracket to accommodate the taller size.
So far so good. The performance is no different than the aluminum one according to my measurements so far. My only complaint would be the thinner hose to tube joints compared to the thicker tube used on the aluminum. But as long as it doesn't leak, I'll be happy to only have lost $370 on this effort.
Got word back from Griffin.
Evidently, the radiators were leaking because the stock mounting brackets were too tight and crushing the radiator somehow and refused to warranty it anymore, although to be fair, they offered a steep discount on another radiator. Even though the part is supposed to be designed for this application with "minimal" modification necessary, "minimal" seems to be open to interpretation. Those buying their "direct fit" models beware, the radiator is a bit taller than stock and so I guess the mounting brackets are under more stress than normal.So rather than risk sinking more money into a part that even the manufacturer couldn't tell me how to mount properly without damaging it, I opted for a cheaper store bought copper/brass "max cooling" edition radiator for a 71 K5. As it turns out, this radiator is also a bit taller than my old "4 core" radiator. I had originally converted to a 4 core from the stock 2 core when I bought the truck. It seems there is some third sized radiator option that Griffin may be using to design against. Can any experts confirm three radiator options for a first gen?
So I modified my other radiator bracket to accommodate the taller size.
So far so good. The performance is no different than the aluminum one according to my measurements so far. My only complaint would be the thinner hose to tube joints compared to the thicker tube used on the aluminum. But as long as it doesn't leak, I'll be happy to only have lost $370 on this effort.
TDAWG1
1/2 ton status
Good to see you still pluggin away on this ole machine. Hope to see ya soon to
bp71k5
3/4 ton status
Thanks. Have fun in Moab, I hope to be there next year. You guys ok with all that water?
TDAWG1
1/2 ton status
No water over here its Duanes side thats Crazy, and its good.
bp71k5
3/4 ton status
Update 10/28/2013:
It's getting close to rainy season so I needed I get some primer over the back quarter.
After I hammered it as perfectly as I could get it, its done. I can't get to the back sides without cutting the inside of the bed out for access, so needless to say its not perfect but is requiring very little glaze to smooth it out.
Here's right before:
All the weird oil canning and flimsiness is removed and straight. You can see some of the hammer marks still there along with some minor low spots that'll fill easy enough.
Here's some with filler skimmed on and then a coat of primer until I can sand it smooth and prime the whole quarter panel in a few weeks.
And I started doing some bending and welding of some parts to tie the cage into the structure under the body a bit more but this is all I have to show until next time.
It's getting close to rainy season so I needed I get some primer over the back quarter.
After I hammered it as perfectly as I could get it, its done. I can't get to the back sides without cutting the inside of the bed out for access, so needless to say its not perfect but is requiring very little glaze to smooth it out.
Here's right before:
All the weird oil canning and flimsiness is removed and straight. You can see some of the hammer marks still there along with some minor low spots that'll fill easy enough.
Here's some with filler skimmed on and then a coat of primer until I can sand it smooth and prime the whole quarter panel in a few weeks.
And I started doing some bending and welding of some parts to tie the cage into the structure under the body a bit more but this is all I have to show until next time.
bp71k5
3/4 ton status
Update 12/22/13:
Now that the CA winter is over and back to normal temps, I found some time to use the bender and welder.
Here's the area to be worked on for reference. The steel 2x4 that replaces the rocker box is on the right and you can see the body mounts on the left.
To keep that 2x4 in place if it gets hung up on a rock, I'm adding some tube that ties the drivers side and passenger side together. If you look carefully, you can see that the tube goes right past the #3 body mount and is also right below my cage mounting plate in the bed.
Another angle showing the tubes going over the frame and under the body. The tubes are split near the center of the truck because I couldn't get them in and out with the limited space.
Now that those were in place, I needed a way to tie the bottom of the cage mounting plate, the #3 body mount, and the tube structure all together. Here's how it started.
The two parallel 1/4" legs are designed to fit under the corrugated folds under the bed. These let me solidly sandwich the bed surface under the cage mounting plate and above this bracket. Those legs have to be an exact distance apart to fit flat but the first version of the bracket shrunk after all the welding heat got to it. After reading Greg's build and how metal likes to shrink after welding, I discovered my drywall knife was a pretty handy way to shim those brackets apart enough during welding.
And here's the bracket in place. Notice that the bracket has a plate that goes under the body mounting surface but above the rubber body mount.
I missed a closeup photo of how the tube connects to the bracket, but you can see some gussets and a hole for a 1/2" bolt along with some paint. I also drilled out the body mount to accept 1/2" grade 8 bolts instead of the stock 3/8" grade 5. The other cage mounting plate is one the left. It'll get a tie-in too a little later.
Back to the tubes...adding in some tubes to tie the two longer ones together as added some pilot holes in the 2x4 to mount them. The plan is to weld in some 3/8" nuts flush with the 2x4 to fix those tube structure down to it.
And a parting shot of the tube structure after some flapdisc work to clean up the welds. It was really tough welding upside down under the truck and there's much more sloppy welds than even I can tolerate. Ive been grinding lots of it down and redoing some beads. You can see at the right some plate that meets up with the plate on the body-mount bracket. It'll get plated in even more. The tube is also cut a bit shorter than before. I found that there isn't space to connect these two structures together with a single joint in the middle of the truck. I'll need to make a couple intermediate lengths of tube to join the driver and passenger side structures together.
That's all for now. I need to keep it drivable for a few weeks and so finishing up these structures and adding another tie-in to the other b-pillar cage mount will have to wait until after the holidays. I did do the quarterly drive up the freeway to get all the dust to fly out. My son enjoys any little jaunt he can get in "daddy's big truck".
Now that the CA winter is over and back to normal temps, I found some time to use the bender and welder.
Here's the area to be worked on for reference. The steel 2x4 that replaces the rocker box is on the right and you can see the body mounts on the left.
To keep that 2x4 in place if it gets hung up on a rock, I'm adding some tube that ties the drivers side and passenger side together. If you look carefully, you can see that the tube goes right past the #3 body mount and is also right below my cage mounting plate in the bed.
Another angle showing the tubes going over the frame and under the body. The tubes are split near the center of the truck because I couldn't get them in and out with the limited space.
Now that those were in place, I needed a way to tie the bottom of the cage mounting plate, the #3 body mount, and the tube structure all together. Here's how it started.
The two parallel 1/4" legs are designed to fit under the corrugated folds under the bed. These let me solidly sandwich the bed surface under the cage mounting plate and above this bracket. Those legs have to be an exact distance apart to fit flat but the first version of the bracket shrunk after all the welding heat got to it. After reading Greg's build and how metal likes to shrink after welding, I discovered my drywall knife was a pretty handy way to shim those brackets apart enough during welding.
And here's the bracket in place. Notice that the bracket has a plate that goes under the body mounting surface but above the rubber body mount.
I missed a closeup photo of how the tube connects to the bracket, but you can see some gussets and a hole for a 1/2" bolt along with some paint. I also drilled out the body mount to accept 1/2" grade 8 bolts instead of the stock 3/8" grade 5. The other cage mounting plate is one the left. It'll get a tie-in too a little later.
Back to the tubes...adding in some tubes to tie the two longer ones together as added some pilot holes in the 2x4 to mount them. The plan is to weld in some 3/8" nuts flush with the 2x4 to fix those tube structure down to it.
And a parting shot of the tube structure after some flapdisc work to clean up the welds. It was really tough welding upside down under the truck and there's much more sloppy welds than even I can tolerate. Ive been grinding lots of it down and redoing some beads. You can see at the right some plate that meets up with the plate on the body-mount bracket. It'll get plated in even more. The tube is also cut a bit shorter than before. I found that there isn't space to connect these two structures together with a single joint in the middle of the truck. I'll need to make a couple intermediate lengths of tube to join the driver and passenger side structures together.
That's all for now. I need to keep it drivable for a few weeks and so finishing up these structures and adding another tie-in to the other b-pillar cage mount will have to wait until after the holidays. I did do the quarterly drive up the freeway to get all the dust to fly out. My son enjoys any little jaunt he can get in "daddy's big truck".
Last edited:
bp71k5
3/4 ton status
Update 4/6/2014:
Wow, been a while since last update but only because not much was changed until recently. I had been hauling stuff for my kids school musical and when I parked it last week, I found there was a bit more oil around the engine bay than I like so I did some degreaser and sprayed it down. Big mistake...
The solvent ate through the water pump gasket and water started leaking out badly.
So I can just replace the gasket right? Of course not...the water pump is old and rusty, so I'd have to wire brush and paint it again. That's a big pain when a new water pump is only $30. Why not just get a new water pump? While I was at it, I might as well get a long water pump to make converting to serpentine easier someday. Hmm, might as well do the serpentine thing now, so get a reverse rotation pump. Hmm, while all that's apart, I might as well upgrade the alternator to a CS144 since the old one has been unable to charge with all the electronics I've added. Hmm, since I gotta fab brackets for the alternator and serpentine, I might as well do the remote power steering setup (and a cooler now) to help with the steering power.
And since I'm fooling around with all that stuff, might as well get a cold air intake setup going too. Uh, I wasn't trying to let it get out of hand, but it just does sometimes...
So I got this far.
Now I'm stuck figuring out how to get the crank pulley off to swap over the serpentine pulley I got from the wrecking yard. And before I put the pulley on, I've heard the harmonic balancer might be different between the EFI engines and the old stuff. I see some fluid dampened versions that are supposed to help prevent drivetrain noise that fools the knock sensor into retarding the timing unnecessarily. Any truth to that?
Wow, been a while since last update but only because not much was changed until recently. I had been hauling stuff for my kids school musical and when I parked it last week, I found there was a bit more oil around the engine bay than I like so I did some degreaser and sprayed it down. Big mistake...
The solvent ate through the water pump gasket and water started leaking out badly.
So I can just replace the gasket right? Of course not...the water pump is old and rusty, so I'd have to wire brush and paint it again. That's a big pain when a new water pump is only $30. Why not just get a new water pump? While I was at it, I might as well get a long water pump to make converting to serpentine easier someday. Hmm, might as well do the serpentine thing now, so get a reverse rotation pump. Hmm, while all that's apart, I might as well upgrade the alternator to a CS144 since the old one has been unable to charge with all the electronics I've added. Hmm, since I gotta fab brackets for the alternator and serpentine, I might as well do the remote power steering setup (and a cooler now) to help with the steering power.
And since I'm fooling around with all that stuff, might as well get a cold air intake setup going too. Uh, I wasn't trying to let it get out of hand, but it just does sometimes...
So I got this far.
Now I'm stuck figuring out how to get the crank pulley off to swap over the serpentine pulley I got from the wrecking yard. And before I put the pulley on, I've heard the harmonic balancer might be different between the EFI engines and the old stuff. I see some fluid dampened versions that are supposed to help prevent drivetrain noise that fools the knock sensor into retarding the timing unnecessarily. Any truth to that?
Sorry I don't know the answer but maybe a little bump to get some fresh eyes on it.
Brian,
Spend the $30 on the stock replacement pump and be on your way.....
I can appreciate the "MAW Syndrome" as well as anyone, but as a rule of thumb it generally is an escalation of a more significant repair than a water pump.
Not saying you shouldn't go with the serpentine conversion (if that's your thing) but don't let such a small repair force you to rush and gather a bunch of parts that you're not 100% sure about.... do that research and parts gathering at a more relaxed and methodical pace, and the results are sure to be better.
-G
Spend the $30 on the stock replacement pump and be on your way.....
I can appreciate the "MAW Syndrome" as well as anyone, but as a rule of thumb it generally is an escalation of a more significant repair than a water pump.
Not saying you shouldn't go with the serpentine conversion (if that's your thing) but don't let such a small repair force you to rush and gather a bunch of parts that you're not 100% sure about.... do that research and parts gathering at a more relaxed and methodical pace, and the results are sure to be better.
-G
- Joined
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Good advice right there, if not followed you may end up doing the it took 3 times to get it right but it works now, like someone else I know tends to do.Brian,
Spend the $30 on the stock replacement pump and be on your way.....
I can appreciate the "MAW Syndrome" as well as anyone, but as a rule of thumb it generally is an escalation of a more significant repair than a water pump.
Not saying you shouldn't go with the serpentine conversion (if that's your thing) but don't let such a small repair force you to rush and gather a bunch of parts that you're not 100% sure about.... do that research and parts gathering at a more relaxed and methodical pace, and the results are sure to be better.
-G
bp71k5
3/4 ton status
Yes good advice. I've already heeded some of it and have dropped the air intake and PWM fan controller for another time ( didn't mention the fans huh...)
Water pump and crank pulley is done. Just need to make brackets for the alternator and steering pump. The stock serpentine setups are kinda ugly so I'm kinda trying some ideas to make the brackets a little more subtle.
All of this was supposed to progress at nice slow pace, but someone went and stole my daily driver (for the second time) and so I may need to get it back to functional again soon unless my car is found in drivable condition...
Water pump and crank pulley is done. Just need to make brackets for the alternator and steering pump. The stock serpentine setups are kinda ugly so I'm kinda trying some ideas to make the brackets a little more subtle.
All of this was supposed to progress at nice slow pace, but someone went and stole my daily driver (for the second time) and so I may need to get it back to functional again soon unless my car is found in drivable condition...
Why would you have to change dampners?
Martin
Martin
bp71k5
3/4 ton status
I read somewhere that late model dampeners might be thicker and then not line up. Happily I didn't need one since it looks like both pulleys line up great.
I've done it without changing dampners.
Martin
Martin
bp71k5
3/4 ton status
Update 5/3/2014: Serpentine design
Where I last left off, I had the balancer pulley and the water pump pulley installed. These two pulleys provide a reference point for where all the other pulleys need to line up with. I decided to start with the pump:
The pump is an aluminum 1200psi TC style pump from tuff stuff performance and is for an LS1. The difference between the LS versions are the pulley shaft is a more standard 3/4" press-on style that you can readily get cheap pulleys for from any parts stores. The others have a 5/8" key way style that have plenty of pulley choices, but all the choices are high-dollar versions from March, etc. This picture is of the pump and my first cardboard template spaced up to where it needs to sit above the bracket based on where the crank pulley sits.
And this is the belt routing diagram I chose to follow.
A lot of the research tells me to make sure the belt has a minimum of 60 degrees of contact area on every pulley to make sure it doesn't slip. As some buffer, I decided that 90 degrees would be my goal for minimum. Obviously more is better though.
I constructed a wooden version of that cardboard bracket out of 1/4" pressboard and some cut down body mount bushings as spacers. This let me bolt the pump to it and confirm the spacing for the belt was correct. I used the three head bolt locations and two down near the crank.
The position of the pump is such that the inlet is aimed "uphill" and toward the drivers side where it would be easy to mount a reservoir. This brings me to one of the drawbacks of this LS pump. The inlet is designed for an attached reservoir and just has a hole for the entire reservoir to be inserted into while the reservoir is bolted to the pump itself. Since I want a remote reservoir, I need to have a hose fitting instead. Other models of tuff stuff pumps have different fittings for remote reservoirs, but those all use the smaller pulley type I didn't want.
So I decided to tap the port for an #10 AN fitting which has a hose barb. Here's a picture of the port after I jammed a rubber plug into the inlet to prevent metal chips from getting inside.
Where I last left off, I had the balancer pulley and the water pump pulley installed. These two pulleys provide a reference point for where all the other pulleys need to line up with. I decided to start with the pump:
The pump is an aluminum 1200psi TC style pump from tuff stuff performance and is for an LS1. The difference between the LS versions are the pulley shaft is a more standard 3/4" press-on style that you can readily get cheap pulleys for from any parts stores. The others have a 5/8" key way style that have plenty of pulley choices, but all the choices are high-dollar versions from March, etc. This picture is of the pump and my first cardboard template spaced up to where it needs to sit above the bracket based on where the crank pulley sits.
And this is the belt routing diagram I chose to follow.
A lot of the research tells me to make sure the belt has a minimum of 60 degrees of contact area on every pulley to make sure it doesn't slip. As some buffer, I decided that 90 degrees would be my goal for minimum. Obviously more is better though.
I constructed a wooden version of that cardboard bracket out of 1/4" pressboard and some cut down body mount bushings as spacers. This let me bolt the pump to it and confirm the spacing for the belt was correct. I used the three head bolt locations and two down near the crank.
The position of the pump is such that the inlet is aimed "uphill" and toward the drivers side where it would be easy to mount a reservoir. This brings me to one of the drawbacks of this LS pump. The inlet is designed for an attached reservoir and just has a hole for the entire reservoir to be inserted into while the reservoir is bolted to the pump itself. Since I want a remote reservoir, I need to have a hose fitting instead. Other models of tuff stuff pumps have different fittings for remote reservoirs, but those all use the smaller pulley type I didn't want.
So I decided to tap the port for an #10 AN fitting which has a hose barb. Here's a picture of the port after I jammed a rubber plug into the inlet to prevent metal chips from getting inside.
