71K5 - BP71K5's Just for fun build

[bp71k5]

Tapping the pump inlet to fit a #10 AN requires 7/8"-14. The drill size for that thread is 13/16" which is just slightly larger than the pump bore and still leaves enough "meat" for threads. I could have bought a 13/16" drill bit, but I needed it to be flat at the tip so that I didn't cut any deeper than required. I was also worried that a big sharp bit might wobble around and not cut straight in such a shallow hole. I decided instead to cut down a uni-bit that has a 13/16" portion and use that instead.



And here's a shot after test drilling about 1/8". Seems to work fine and not wobble while cutting only a little material at a time.




So I went for it and had some success. I purchased a nice 7/8-14 bottom tape and was able to make some nice threads that should seal well. This picture also shows the o-ring I plan to modify to seal against.

 

[bp71k5]

Here's what screws into that intake port. I chose the one on the right since it has a tube diameter that matches the reservoir I will use.





The reservoir is from a 98 trans am. Once this part was figured out, I diverted back to bracket design to figure out where everything else needed to be located. Here's a shot of the barb fitting in the pump along with the reservoir and a sneak preview of the brackets in metal.

 

[bp71k5]

Next up was lots of bracket revisions. I wish I could say I had some genius plan, but I just cut lots of wood versions of brackets and kept testing fitting components to try and match the belt diagram I posted earlier.



Here's a shot of my final chosen layout including the alternator, crank pulley in position, and an idler pulley which is tucked neatly down below where its not very visible from the engine compartment. This pulley is needed to give me the 90 degrees of contact between the pump pulley and the crank pulley. I choose this option to make the upper portion of the motor not have any of the extra visual stuff thats normally on serpentine systems. I want the performance of a serpentine system, but the visual style of a early 70s engine bay. As much as possible at least.


Then I transferred all my marks to some 1/4" and 3/16" steel and cut out the shapes to match. The different thickness of steel plates allowed me to use some standard sized 3/8" spacers from McMaster Carr to replace the cut up body mount spacers I initially made. GM was nice enough to make things easy in this case.

 

[AJs72K5]

Looks good Brian. What're you using to cut your brackets with?

 

[bp71k5]

Looks good Brian. What're you using to cut your brackets with?

Mostly using a 4-1/2" cutoff wheel, but I have some more pictures coming later today (I've been sandbagging this one a little) where I used a jig saw with a thick metal cutting blade to cut some inside radius curves for the alternator. It works really well. I mark the outlines with blue sharpie and then scribe through the ink so I have lines that don't rub off, cut really close to the scribe marks, and then clean them up on a disc sander.

 

[bp71k5]

More progress:

The alternator sits on top and can't really move around much because the cs144 is deeper than my old si12 and can't sit in front of the valve covers. It also can't move to far over to the drivers side because that would decrease the belt contact on the power steering pump. You can also see the custom power steering pressure hose I'll need to use.


Here's a shot after adding the idler pulley. You can see the metal spacers I used to make the "bracket sandwich" structural enough. The little spacers at the bottom are 1-1/2" long and 3/4" diameter and sized for a 3/8" bolt.



Here's what that part looks like temporarily bolted onto the engine. The pivot axis of the alternator is fastened with the bracket, but the other side is just clamped in with my stock SI bracket mount so I could take belt length measurements.



Another couple to show how it still sorta looks like a vbelt setup, but I still have the tensioner pulley not shown.



A view looking in from under the radiator.

 

[bp71k5]

Update: serpentine tensioner

Since I'm using the belt routing from a late model camaro, I also chose to use a tensioner from the same model so I could be sure it rotated the correct direction and because it's packaged pretty small and has a small rotating arm that isn't visible from the top of the engine bay. Tensioner at the top and some brackets below which support the tensioner along with the big curved bracket which will hold the alternator at the correct angle.


These brackets look like a mess right now, but will get finessed a lot once I'm sure everything works correctly. I'm using the one head bolt that already exists along with one intake bolt and then a third bolt and support will come up from down below next to the crank pulley. It won't be very visible.



On to the alternator:
Here's that curved bracket bolted temporarily in place to show the orientation of all the parts.




I had to weld a small tab to be able to have a flange that this bracket could bolt onto the big assembly with.


And obligatory weld close up for helpful criticism.



And there it is in the engine with the belt installed. Still need to work on some loose ends before actually trying to start it. Pump plumbing is up next after that.

 

[Greg72]

Looks good Bri!!

Good templating..... I like your style!


-G

 

[bp71k5]

Looks good Bri!!

Good templating..... I like your style!


-G

Thanks. I'm not up at dykem level yet, but I think it may work better than my sharpie method so I added some to my amazon wish list in time for Father's Day. The blue sharpie starts turning black if it gets too hot so I have to clean it off before final pass on the sander.

 

[Greg72]

Thanks. I'm not up at dykem level yet, but I think it may work better than my sharpie method so I added some to my amazon wish list in time for Father's Day. The blue sharpie starts turning black if it gets too hot so I have to clean it off before final pass on the sander.

If you've been a good enough dad, maybe you'll get one of these too....

http://www.amazon.com/gp/product/B00004T7S1


What more do you want for only $8???


-G

 

[bp71k5]

Update 6/7/2014: Serpentine belt is installed.

Little bits and pieces finally coming together. Got the tensioner pulley welded up and installed. It's a sandwich of 4 plates welded up and sanded flush so it kinda looks like billet machined steel after it's painted.



With the belt installed.


If you look behind and below the pulley(next to the water pump hose), you can make out the vertical bar that runs down and bolts onto the front of the block near the crank pulley. It's pretty hard to see, but that was the idea.


After everything is running smoothly all these brackets will be disassembled and then sand blasted and powder coated before reinstalling.

And a final shot of the power steering hose I had made. This is the second version and I'm not happy with how it routes because the bend is too tight. I'll keep it for a spare. It needs a 45 degree fitting on the steering box end, but rather than buy yet another custom hose that "might" work, I just ordered some Russell "Powerflex" power steering hose and fittings from Summit to make my own. This will let me not have to guess at what will work or not.

 

[Greg72]

Your plate edges are looking nice and crisp. Do you have a disc grinder in your shop these days.....?

 

[bp71k5]

Your plate edges are looking nice and crisp. Do you have a disc grinder in your shop these days.....?

I do have a disc/belt combo machine. I use the belt 99% of the time because the plastic spark shield around the disc starts to catch fire when grinding metal. I can't seem to find any good zirconia belts in courser than 60 grit though.

 

[82355]

Very nice.

Martin

 

[jekquistk5]

Which machine do you have. I was thinking about picking up a ryobi or similar.

 

[bp71k5]

It's a 6"x48" belt harbor freight model. Not the best, but with some modifications has been working fine. The dust shield is worthless so I shouldn't have even bothered to install it.

 

[bp71k5]

Update 6/19/2104.

Hoses: I've been learning a lot about them. I had my power steering hose reworked again with a new fitting and it still wasn't good so I ended up trying the Russell Powerflex steering hose along with the matching 90 and 45 degree fitting. This gives me enough length to allow for engine vibration and still route pretty easily.



If anyone tries this stuff, I'll save you some blood and sweat. DO NOT follow their directions on how to cut the hose using a hacksaw. It just ends up in a giant tangle of prickly stainless wires that draw blood. The better way is with a thin cutoff wheel on the grinder.

For non-pressure hoses, I chose the russell pro-classic hose with full flow ends. These are easier to assemble and cut.

Here's a -10 hose and fitting parts. The collar screws over the hose and then the fitting threads into the collar.


Close up of the nylon braided hose.


The collar just threads over the hose counterclockwise. I wondered why it was so hard to get on clockwise until I read the directions. Once that's on, the fitting threads into it. The big sizes need a lot of lube to thread in easily.



Installed some -10 adapters on the reservoir and pump so it routes like this.




Removed the inner fender to get this view.


Now I'm working on mounting a cooler and plumbing it to the rest of the system.

 

[Greg72]

I like that black fabric braided hose. Looks "classic" with just a bit of bling.

I wonder how hard it will be to keep clean later on?


-G

 

[bp71k5]

Cleaning is one of my concerns, but we'll see how it does. New problem popped up:while tack welding together a radiator screen temporarily held in place in front of the radiator, I didn't think it was risky enough to dig out the welding blanket and protect the radiator from weld spatter. I lost that bet.

 

[AJs72K5]

Cleaning is one of my concerns, but we'll see how it does. New problem popped up:while tack welding together a radiator screen temporarily held in place in front of the radiator, I didn't think it was risky enough to dig out the welding blanket and protect the radiator from weld spatter. I lost that bet.

Geez. You've had enough radiator problems for all of us.