Injector HP Fuel Line - How to Make?

[EngNate]

5'7, 140lb and looking forward to NZ as much as taking you fishing!

[Wotname]

Originally Posted by EngNate

..........
That's my story and I'm st-st-sticking to it. I'd bet my own money that the OP will eventually buy the OEM replacement(s).

I've bought Caterpillar injection lines and for what they cost I could not have paid myself minimum wage to make them

What was the cost for the CAT lines (rough estimate)?
The Yanmar ones in question are about $100 (AU) each, there are two of them. For the life of me, I can't see why I can't make both of them for under $50 (i.e. ~$25 each).

Originally Posted by kmacdonald

I agree. Buy OEM and be done with it. Designing an engine and rebuilding one are two different things.

I guess if he makes his own and there are issues he will know one place to look.

Why do you think I'm designing them, I am copying what is/was already there.
I will be using the same end fittings, just replacing the steel tube; like for like (i.e. OD, ID, length and similar radius bends).

[Wotname]

Originally Posted by Compass790

I'll take yr bet. How much are you willing to wager?

You might have inside knowledge . You already know how over the top the Yanmar prices are and you possibly know that my default position is DIY.

But don't start packing your bags yet and hold back on the airfares, it will probably be months away before I progress this project. I gotta finish (i.e. start and run) the YSE engine first

[EngNate]

3208 engine, #8 (a long one) about $25US for aftermarket, $45 for original.

[Compass790]

Originally Posted by Wotname

You might have inside knowledge . You already know how over the top the Yanmar prices are and you possibly know that my default position is DIY.

But don't start packing your bags yet and hold back on the airfares, it will probably be months away before I progress this project. I gotta finish (i.e. start and run) the YSE engine first

Yea Wottie was thinkn in the interests of full disclosure I have to admit I've been wrkn in piping/welding for 30+ years. BUT the pressures on you now cobber. I don't even have a passport currently & it's marginal about springing for a Vancouver airfare so I'm just joking about the pressure. Just enjoy the debate. I'm an injection line fabrication virgin tho so didn't think it was too unfair. Anyway it's fun to have a wager whilst drinkn beer!/ Engnate, hope you good at catchn salmon as we had to buy one at the docks when I was last there but i did enjoy crab, oysters & venison obtained by me & my USA ladyfriend. However back in S.F. USA I did catch a salmon on a barbless hook ( something new to me) but I had to fly out the same day. Everyone who ate it assured me it was terrific.
Here i may be able to get crays ( lobsters) snapper, (bream) pauas ( abalone), scallops oysters. But you know it's not guaranteed when you fish. Anyway that's the unthinkable position. lol

[Wotname]

If the Yanmar lines were $25, I would buy; if $45, I would probably buy. At $100 (each), I will only buy if the DIY fails.

To put it in perspective, I'm sure a CAT 3208 engine is way more expensive than a 2QM20 but the lines are way cheaper.

[Wotname]

Originally Posted by Compass790

........I don't even have a passport currently & it's marginal about springing for a Vancouver airfare so I'm just joking about the pressure. Just enjoy the debate. I'm an injection line fabrication virgin tho so didn't think it was too unfair. ........ lol

Well not only am I also a injection line fabrication virgin, I am asking how it is done - so I'm ready to take the plunge...

Better start saving Compass and EngNate, you better start getting some fishing practice in.

[Jim Cate]

Gosh, you guys better read Wottie's thread about getting the injectors out of the head... he is one determined bugger, and if he decides to fab his own injector lines, it WILL be done... count on it!

Jim

[Compass790]

Originally Posted by Jim Cate

Gosh, you guys better read Wottie's thread about getting the injectors out of the head... he is one determined bugger, and if he decides to fab his own injector lines, it WILL be done... count on it!

Jim

Yea that's wot I'm bankn on but I'm a punter. Wotty was a lot more rigid in his thinkn but I sold him some cheap aftermarket parts which worked for me & he's slowly on the turn. FYI I hope he doesn't transfer the experimental mindset to chopper work!
Hope u following te thread EngNate coz I see where Wottie is cumn frm re he is DIY guy but I talked him into a lot of it.
Yea agree with Jim Cate I based my wager On Wotties persistence but having said that I wuda cut to the chase & heated the s.... out of it early in te process.
sh.....T I enjoy CF & beer

[RaymondR]

If your old lines are badly rusted they are buggered anyway and need to be replaced and since Yanmar spares in Australia are always exorbitantly priced about the only way they are going to get replaced for a decent amount of money is make them yourself.

MAP gas is used for refrigeration work for silver soldering small copper piping and as steel has a lot lower conductivity than copper you should get enough heat from a MAPgas torch to un-solder the end fittings if they are silver soldered. I'd have a go with a MAPgas torch first and it the end fittings come loose it's safe to assume they are silver soldered otherwise they are probably brazed and you will need an oxy torch to get enough heat. Alternatively you can just cut them off short, put them in a lathe and drill out the stub.

Hoop stress in the tubing wall is calculated as half the product of the pressure multiplied by the ID and divided by the thickness so assuming a breaking pressure for the Yanmar injector of 2,400 psi multiplied by the ID of say 5/32" and divided by 3/64 and the result divided by 2 we get a stress of about 4,000 psi. Since the yield of mild steel is about 30,000 psi 30,000/4,000 = about 7.5 so the tubing will be cyclically stressing at about 7 1/2% of it's minimum probable yield yield strength which is more than likely less than the stress where any material fatigue becomes a problem.

If you really want to go cheap, I'd go down to a wreckers and crawl under fairly late model cars until you find one with 1/4" steel tubing brake lines and chop out a bit to knock up a new set of injector lines.

[Wotname]

Originally Posted by RaymondR

.............

If you really want to go cheap, I'd go down to a wreckers and crawl under fairly late model cars until you find one with 1/4" steel tubing brake lines and chop out a bit to knock up a new set of injector lines.

I like the way you think .
Regarding sourcing suitable tube, this might become my Plan B!

[Wotname]

Originally Posted by RaymondR

.........

MAP gas is used for refrigeration work for silver soldering small copper piping and as steel has a lot lower conductivity than copper you should get enough heat from a MAPgas torch to un-solder the end fittings if they are silver soldered. I'd have a go with a MAPgas torch first and it the end fittings come loose it's safe to assume they are silver soldered otherwise they are probably brazed and you will need an oxy torch to get enough heat. Alternatively you can just cut them off short, put them in a lathe and drill out the stub.
.........

Yes this was going to be my approach for removing the existing end fitting.
Plan A - MAPP gas (already on hand)
Plan B - Oxy/Mapp gas (nearby)
Plan C - Oxy/acetylene (a bit further way)
Plan D - Lathe (an hour away)

[Wotname]

Originally Posted by RaymondR

............

Hoop stress in the tubing wall is calculated as half the product of the pressure multiplied by the ID and divided by the thickness so assuming a breaking pressure for the Yanmar injector of 2,400 psi multiplied by the ID of say 5/32" and divided by 3/64 and the result divided by 2 we get a stress of about 4,000 psi. Since the yield of mild steel is about 30,000 psi 30,000/4,000 = about 7.5 so the tubing will be cyclically stressing at about 7 1/2% of it's minimum probable yield yield strength which is more than likely less than the stress where any material fatigue becomes a problem.

.......

Thanks for the analysis, it is appreciated. I wasn't overly concerned but it is good to hear the numbers.

[Compass790]

Originally Posted by Wotname

Thanks for the analysis, it is appreciated. I wasn't overly concerned but it is good to hear the numbers.

thanks x2 for an engineer with calcs chiming in. Don't necessarily beiieve a uni grad As I made a bungy jump platform for a graduate engineer out of 250mm UB who said the shock load was so high that was required. To me it was a simple case of wood & trees. If the shock load was so high there would be a pair of ankles & feet left in the harness. Simple ( & I am) reasoning dictated that the shock cord took out the shock load, however as he got paid a lot more & his platform didn't fail he was hailed as a genius. I wuda gladly bet u cuda thrown my car off his platform ( with bungy cord attachments sized appropriately ) but I'm not rich so I cuda lost. lol

[EngNate]

It's a big advantage owning an engine of which millions and millions were made. Yanmar has you by the nuts. Pretty slick, eh, a bet that costs you more if you win! Ditto on the airfare budget. I know how and where to catch fish around here tho. Salmon, halibut, lingcod, Dungeness crab, prawns. Scallops if you dive, abalone still closed to us white folks. Here's a site where I locate a lot of parts at good prices, mostly for bigger engines, tho.


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Happy Christmas & NY!