Build Thread Harley Orange, a 1969 camper van build

Pontus

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Following up on my post here, my BRE/Bosal 079-4097 arrived today, and I am both very pleased and a tad disappointed. Before I start another EPA legal discussion, keep in mind that the ONLY reason I bought this was for the stainless downpipes and hopefully a decent crossover pipe with an O2 bung, and this is going into a 1969 van (in case you missed the title). So the fact that this set came with 2 cats is awesome because that's $300 off the $460 I paid when I recycle them (unless someone here wants them?). Unfortunately it didn't come as pictured on the BRE site and instead came as Rock Auto did with only a dinky H pipe and no precat O2. But with some creative hacking, I can fix that with the post cat pipe. The downpipes are 2" so that should easily adapt to a good quality dual 2.25" exhaust system I've been building in my Summit cart.
IMG_20210817_181438704.jpg
I'm sure you're all thinking, why not just take it to a shop, but 1) I couldn't find any places doing custom work nearby, 2) they might not even work on this for legal reasons or whatever (or the fact that it's too tall), and 3) I don't trust them to do what I want how I want without me standing there the whole time. So I figured I'd just go this direction, get it all mocked up myself, and pay a welder to come and do it right (or maybe just buy one and start learning!). I suppose I coulda bought the pieces to weld up instead, but that would've been janky and more work. This way I just need the resonator, muffler, and pipes to weld together without any bending or complicated cuts/welds. But maybe I'm just being stupid. In any case, the only custom shop I did find (now closed) quoted me $1200 for a dual system, so that's my budget and it looks like it'll be more like $600 or so.
 

BigBlue94

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Following up on my post here, my BRE/Bosal 079-4097 arrived today, and I am both very pleased and a tad disappointed. Before I start another EPA legal discussion, keep in mind that the ONLY reason I bought this was for the stainless downpipes and hopefully a decent crossover pipe with an O2 bung, and this is going into a 1969 van (in case you missed the title). So the fact that this set came with 2 cats is awesome because that's $300 off the $460 I paid when I recycle them (unless someone here wants them?). Unfortunately it didn't come as pictured on the BRE site and instead came as Rock Auto did with only a dinky H pipe and no precat O2. But with some creative hacking, I can fix that with the post cat pipe. The downpipes are 2" so that should easily adapt to a good quality dual 2.25" exhaust system I've been building in my Summit cart.
View attachment 8077
I'm sure you're all thinking, why not just take it to a shop, but 1) I couldn't find any places doing custom work nearby, 2) they might not even work on this for legal reasons or whatever (or the fact that it's too tall), and 3) I don't trust them to do what I want how I want without me standing there the whole time. So I figured I'd just go this direction, get it all mocked up myself, and pay a welder to come and do it right (or maybe just buy one and start learning!). I suppose I coulda bought the pieces to weld up instead, but that would've been janky and more work. This way I just need the resonator, muffler, and pipes to weld together without any bending or complicated cuts/welds. But maybe I'm just being stupid. In any case, the only custom shop I did find (now closed) quoted me $1200 for a dual system, so that's my budget and it looks like it'll be more like $600 or so.
Ive built a couple full exhausts from header back and I find it to be very rewarding work. Ive done em all with a MIG welder
 

Pontus

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Supporter 2021
Quick question; Where would be the best place for a wideband O2 sensor in a full but shared dual system? My plan is to get the pipe separately out and under the deck into a dual in/out resonator/muffler as close as possible to the engine, but that doesn't leave me anywhere to get a shared exhaust sampling. And it's recommended to keep it 24" from the collector, so getting it after the rez isn't advised. Innovate also says specifically NOT to put it in the middle of an H or X pipe. So I'm thinking of welding it onto one of the down pipes, but which one runs the leanest, front or back? The V8 guys recommend drivers side which always runs leaner, but not sure how that would apply here.
 

pmuller9

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So I'm thinking of welding it onto one of the down pipes, but which one runs the leanest, front or back? The V8 guys recommend drivers side which always runs leaner, but not sure how that would apply here.
The front runs leaner with a carburetor because of the slight engine slant to the back.
 

Pontus

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Why does it always run leaner?
Idk, just what I was reading in a few google search results on the topic of wideband O2 placement. I'd imagine it's for the same reason the front of our engines run lean, maybe #1 is the front most drvr side, or it's only under heavy torque as the driver's side rotates up? Just a wild guess tho.
 

BigBlue94

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Hate to say it, but you should probably have one in each pipe.

Speed density EFI fords had their one sensor in a small "H" pipe right before the cat.
 

guhfluh

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I can see the pre-cat o2 bung in the picture, in the first cat.

I run my o2 where Magnaflow put it in their EFI merge piping, which is maybe a foot after the merge, but many trucks came with the o2 exactly in the middle of a H piping between the two exhaust pipes. I see no reason not to run it in an H near where the factory puts it.
 

Pontus

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To build, or not to build? That is the question—Whether 'tis nobler in the mind to suffer the slings and arrows of outrageous fortune (live with the shame of having my machinist build it for $550), or to take arms against a sea of troubles, and, by opposing, end them (build it myself with the potential for royally screwing it up and having to fight to fix it)? Odd how well that Shakespeare quote applies without much modification, lol.

Seriously tho, I've read here some of you saying that this is the perfect motor for a first time builder. And I'm very thorough and meticulous. I'm confident I could handle it... as long as I don't miss anything important.

But, I could easily screw it up. My machinist said that, since I bought the parts, if he builds it, he'll only guarantee that it runs and doesn't leak. but then it'll just be done right without me having to find and take time and risk to do it.

What do you think?

In other news, I got my exhaust in. Stainless 304 pipes, beautiful, smooth 45° mandrels, 2 Dynomax X mufflers, and 2 polished, rolled, slant edge tips that will come out about 2' in front of the rear driver's side tire.

From what I read, having a resonator bigger than the engine displacement is good for low sound without hurting performance, acting as a "pressure wave termination box" where the downpipes merge. This will allow the short, EFI manifolds to scavenge cylinders with only 3 cylinders each, nice space between pulses (better scavenging?) going into dual 2" pipes, and merge those 2 pipes in such a way as to prevent any wave bounceback that would prevent scavenging. I was going to go with the only dual in/out resonator I could find, a $300 Borla unit made for 5.0 coyote mustangs. But then I happened upon a video of someone tearing the stock resonator apart, and it was pretty much just a straight through muffler with fiber filling, which is exactly the muffler I was hoping to use. And from my work in speaker building, I know that fiber filling makes a box appear to be larger than it actually is to the speaker (or engine in this case) and helps to smooth out resonance peaks. The Dynomax X mufflers have 3" perforated X pipes inside which by my math should already be nearly 300CI of open space, so the fiber filling is just extra muff. It should appear to the engine as an open system. Then the extra muffler on the end should make things nice and quiet... I hope. The Dynomax was only $100, the pipes and tips were $20-40 each, and the downpipes will end up costing me $150, so not bad all in all. The deciding factor for me was that my BMW straight six dual system is nearly identical.

Any thoughts? I welcome any and all disagreements or conversation. Will this be too low of a restriction? FTF says there's no such thing as helpful backpressure, but I worry about a loss of low end torque. The stock downpipes are dual 2" which I'm joining into a 2.25" dual system, so it's not much bigger, but like I said, the resonator should act like an open system... which worries me. But, if my thinking is correct, the velocity created by a more restrictive exhaust should be determined by the pipe size, not the restriction/backpressure behind it, and since I'm using stock 2" down pipes, I should be good...???

IMG_20210908_181222455.jpgIMG_20210908_174650640.jpg
 

pmuller9

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The backpressure myth started a long time ago when exhaust systems parts where not stainless steel and rusted bad enough to fall off including pipes and mufflers.
When that would happen the carburetor which was jetted for the complete exhaust system in place would go lean and the engine performance would suffer.
Not realizing the real cause of performance loss the conclusion was that the engine needed backpressure to run well.
 

bubba22349

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From the projects you all ready have been doing on the 1969 Camper Van I believe your quite capable of assembleing / building your new 300 Six!
 

Frank

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Pontus- looks nice, man! I have a Dynomax on a stock log manifold single 2 1/4" pipe, with stock tailpipe (no cat), on my '79 F 100. I really like the tone, ( wife likes it too!) Plan to use them on the '90 when I do the rebuild. FWIW- a 2 1/2" pipe flows 27% more than a 2". . .
 

Pontus

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Yeah, I think I'll try it myself. I get it back next week. Thanks for the encouragement all!

In the same diy vein, instead of hiring someone to do the exhaust mockup and welding, I signed up for a basic TIG class at my local college. Always wanted to learn. Hope I'm good enough at it. I contacted the teacher and asked a few questions about what I'd need, experience, equipment, etc, and he simply said, sign up and he'd take care of me and let me learn how I want.
 

BigBlue94

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Yeah, I think I'll try it myself. I get it back next week. Thanks for the encouragement all!

In the same diy vein, instead of hiring someone to do the exhaust mockup and welding, I signed up for a basic TIG class at my local college. Always wanted to learn. Hope I'm good enough at it. I contacted the teacher and asked a few questions about what I'd need, experience, equipment, etc, and he simply said, sign up and he'd take care of me and let me learn how I want.
Why pay for someone to do the work when you can learn yourself! Pays for itself IMHO.

I went to a tech school for machining. They provided a list of the tools I would need. The TIG teacher will make sure you have the proper equipment.

From my experience, the more adult you act, the better they can teach you and award more freedom to your learning. Many of the students in these types of classes are high school kids or people just out of HS.
 

Pontus

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I'm currently in negotiations with my wife over property usage rights. I'd like to set up for the rebuild in the living room cuz my garage is packed and not exactly clean, and my usual space belongs to someone who currently needs it. Plus I'm more likely to focus on it, and the kid gets to actively see it come together into a working machine. How cool is that?! She doesn't see it that way tho. :rotfl:
 

sixtseventwo4d

Well-known member
Well how can you be so selfish? Get her an engine of her own to build so she can be right there with you. I would say let her pick the one but it will mean so much more if she is surprised by your passion and generosity. Her own tools too. (you may need to borrow one here and there anyway) and who doesn't enjoy an early Christmas! She'll come around.......
 

THE FRENCHTOWN FLYER

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Well how can you be so selfish? Get her an engine of her own to build so she can be right there with you. I would say let her pick the one but it will mean so much more if she is surprised by your passion and generosity. Her own tools too. (you may need to borrow one here and there anyway) and who doesn't enjoy an early Christmas! She'll come around.......
Bad idea.
What will you do when her engine out performs yours? Bad enough she beats you on Jeopardy and The Price Is Right.
 

Bronctopia

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Yeah, I think I'll try it myself. I get it back next week. Thanks for the encouragement all!

In the same diy vein, instead of hiring someone to do the exhaust mockup and welding, I signed up for a basic TIG class at my local college. Always wanted to learn. Hope I'm good enough at it. I contacted the teacher and asked a few questions about what I'd need, experience, equipment, etc, and he simply said, sign up and he'd take care of me and let me learn how I want.
I did the same Community College route explicitly to learn TIG for stainless.
If you already have OxyAcetylene experience you will find it very similar.
My ComCollege actually required OxyAcetylene as a prerequisite.
Cheaper learning materials and all that.
 
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