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71K5 - BP71K5's Just for fun build

bp71k5

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Update 8/20/2017

Lots of miscellaneous progress. I keep running into a "need to order a part" work stoppage on one portion so I load up my summit cart with what's needed and then work on another part. Once I get to free shipping, order gets placed and the cycle starts over again. I'm really hoping not much more money is needed to get this running, but it's looking like a mini starter might be needed.

Let's start with transfer case, I installed it. This motorcycle jack has been handy for this kind of thing. Just needed more wood than I did when I had 33's.
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Went right in. Got a bead of "the right stuff" in between the trans and the magnum. The magnum has a thin recessed groove all the way around the input which made a nice place for a bead of sealant.

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My first "ran out of stuff" moment. Got the crossmember mounting bushings set up like I wanted but needed some square tubing so I stopped here. ORD includes a really helpful bits of steel that saved me hours of fabrication. It'll get a bit of reinforcement but it'll work well.
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You can see the little shift lever for the magnum on top with about 1/2" of clearance to the body.
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So went back to plumbing the fuel system until I can get square tubing. I was able to reuse my custom stainless tubing from inline tube and ran a hard line down the passenger side front of the motor.
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Made a small bracket to hold the lines above the blocked off carb choke port.

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Then my next stopping point was realizing the return tube is 5/16" and doesn't work with the -6 fittings I got. So I added a fitting to the summit cart and went on to the next item.

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Finished installing the accessories and adapting the tbi wiring to the 454 throttle body. Also picked up a new air cleaner housing since my old one was crashing into the firewall now that the engine is closer.
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Up next is exhaust, and re-install the cooling system. Once that is done, I can start and break in the motor. Lots of 2.5" mandrel bends and related stuff to make the exhaust work.
 

bp71k5

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Update: 7/25/2017

I have a plan for the exhaust. The back half is still in the truck, and I'll just be rebuilding the front portion that connects to the motor. I'm not sure whether it's best to build from the heads back to the tailpipe or the other way around but I'm starting here and working my way up to the heads.

3" ball and socket held in place temporarily with a pipe clamp.
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Then I need a piece to transition from the 3" tube into two 2.5" tubes. One of those needs to run under the motor to the passenger side head. Used a small section of 3" and squeezed it into an oval shape that was 2.5" thick and about 3.5" tall. The two tube on the right need to be notched together so they match the 3.5" oval'd tube. The marks were an attempt to mark the cuts using math, but it wasn't entirely successful.
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Marked the lower tube and cut it so it so it extended halfway into the 3" tube.
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Then did a bunch of flap wheeling to make them match.
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Not a bad fit.
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Here's what the notches looked like.
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Then used plyers to tweak the joint into a close replication of the oval
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Tacked in place.
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Then final welding.
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Won't win any awards with it but it should work well and flow better than the old one.

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tRustyK5

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I admire the effort, and the end result isn't terrible at all. I was going to do the same, faced with the same dual 2.5" into a 3" single on my Blazer. I found this at Summit for just under $30 though and hit the easy button instead.

https://www.summitracing.com/int/parts/mpe-10778

mpe-10778_ml.jpg
 

bp71k5

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I admire the effort, and the end result isn't terrible at all. I was going to do the same, faced with the same dual 2.5" into a 3" single on my Blazer. I found this at Summit for just under $30 though and hit the easy button instead.

https://www.summitracing.com/int/parts/mpe-10778

mpe-10778_ml.jpg

Thanks! I did see that in your thread and almost got it. My trouble was that one of my 2.5" pipes needs to be on the same centerline as the 3" otherwise I have to cut a bunch of bends to route it back to where it needs to be. I figured this way would at least let me build some skills.
 

bp71k5

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Update 8/27/2017:

Got the crossmember installed temporarily. It'll get another couple bars in the back and front, but I want to get the motor running ASAP.

2x2 square tubing got a few weld nuts installed on top so I can bolt them on from inside the frame.

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Truck is back on all 4 "normal size" tires.

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And started routing pipes for the exhaust. Work travel interferes again so it has to sit for another week.

IMG_4701.JPG
 

bp71k5

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So, my next post was going to be a video of the motor running but having a couple issues. It started on the first turn of the key, but has a couple problems:
1. Running way rich, chokes everyone around it with smoke.
2. At least one cylinder is not firing. I pulled the plugs and #7 has fuel coming out. #4 and #6 don't have any color on them, but are dry, and the rest are covered with very black soot.(obviously rich)

My most basic questions are whether the spark plugs that are not coated with black soot are the ones not firing? Would too much fuel cause them not to fire or is there fuel building up because they are not firing?

Plan is to lean out the mixture at idle and recheck the valves to make sure it's mechanically ok then try again.

Edit: valves are adjusted(they were a little on the loose side but ok), replaced the cap and rotor, and discovered one fuel injector is leaking a lot once fuel pressure builds so I'm hoping is why the motor is flooding. Swapped in my 5.7L injectors as a test to see if I can get it running.
 
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tRustyK5

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You'd think even with too small injectors it'd still be able to do more than idle. No load rev doesn't take much fuel at all.

What does it do if you try to rev it?
 

bp71k5

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You'd think even with too small injectors it'd still be able to do more than idle. No load rev doesn't take much fuel at all.

What does it do if you try to rev it?

Just stalls out. I may need to recheck the timing and data log it. For some reason I wasn't able to get any sensor data to read.
 

NorCal69

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Nice job, Brian. Great to hear her running, even if she's not dialed in perfect yet.
 

tRustyK5

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Just stalls out. I may need to recheck the timing and data log it. For some reason I wasn't able to get any sensor data to read.

Did you get any numbers at all? like fuel pressure? I'm wondering if maybe a pinched fuel line somewhere hindering supply so much that idle is all you can get?
 

bp71k5

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Did you get any numbers at all? like fuel pressure? I'm wondering if maybe a pinched fuel line somewhere hindering supply so much that idle is all you can get?

Theres some kind of error on my tablet that runs the tuning software. It was reading ok for ~20 seconds and then just hung. What data I did get was that it's really lean at idle. Since it would go more than idle, I'm assuming it's lean everywhere. Since new 80lb/hr fuel injectors appear to be pretty expensive, I found an option from AFI that will let me run more modern injectors on the throttle body. Hoping when that arrives I can use a stock 7.4L bin to program the chip with that might be closer to what this motor needs. I'm also not convinced the timing is good so I have to check that.
 
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