I was helping MRX Rotary with getting to his aux port sleeves (another story all together). We got to the intake manifold oil injector removal. We no more than breathed on the injector lines (yes, both of them). They both cracked-off the banjo fittings right at the tip of the barb. Brittle. Suddenly, we had another problem to fix.

Cause of failure? My opinion - the oem tubing is marginal at best of heat toleration. Perhaps they're nylon. Not much better than 200 degrees F. material.

Ok, so, this is what I have selected to use. Both the tubing and clamps were found online at http://www.corbincorp.com which is MSC Industrial supply Co.

1) Tubing: MSC # 48701031 available in 10' lengths. Perfect length - still have about 3-4' to spare. 1/8 x 3/16 (CTL) Teflon PFA - Industrial. Translucent. 1/8" I.D., 3/16" O.D.

PFA Characteristics
• Excellent abrasion & temperature-resistance
• Low coefficient of friction for ease of flow
• UV & Gamma radiation stable, chemically inert
• Thermally superior to most plastics
• Outstanding chemical & electrical properties
• Durometer=shore D 55±5
• Temperature range: -320°F to +500°F

$1.51 per foot x 10' = $15.10

2) Clamps: MSC # 48547962. Two-Ear Clamps
Type: 2-Ear
Nominal Size: 1/4
Inner Width of Ear: 0.118 In.
Thickness: 0.0276 In.
Width: 0.236 In.
Material: Stainless Steel

$.33 ea. x 12 = $4.00 (yeah, only needed 8, but that's only if you don't booboo. I got 4 spares. Wanna buy em?)

OK, I splurged a tad here - could have gotten zinc plated @ .19 ea. Woooo!

Some pix:

So, what's wiring tool doing here? It made the perfect crimper for the clamps! Just do one side at a time. Not all at once. Just a small squeeze at a time, then the other side, back, etc. Finally, the clamp goes fully squished and is gripping the teflon tube so hard, it's hard to rotate anything anymore!

 

Okay, so here are a couple sketches of the lines in there.

I added 1" to the measured lengths. It's a thing I do when I can. Dunno why really, other than I hate being too short. Those lengths are written on the setch at the pump.

How to reclaim the banjo fittings: Patience!!!!!!

1) GRIND-OFF just enough of both ears of the clamp ring, and it will come (fall?) apart in two halves. I got a bench grinder which most would consider a toy. It was perfect.

2) Whittle-away at the plastic tubing WITHOUT MESSING-UP THE METAL BARB!!!...PATIENCE!!!!!

That's about all there was to that.

Putting the tubing onto the banjo fitting barb: Patience!!!!!!

Just push it on with steady force - NOT TOO MUCH THOUGH!!! Twisting it while pushing really does help a lot. A little spit or something is good to lubricate it some. A paper towel helped me to grip the teflon tubing, and helped to keep me from crushing it in the process...

I did 8 out of 8 without a screw-up, so it can't be that hard...

Let me just make this perfectly clear: DON'T FORGET TO SLIDE A BAND CLAMP ONTO THE TUBE BEFORE YOU PUSH THE SECOND FITTING ON!!!!

 

Some pix of the (almost) completed project. (Still waiting on a parts order for the aux. port sleeves...)

The two loose ends go to the intake manifold injectors, when they get put back on.

Note how I marked them I, II, III & IIII to coincide with my sketch numbering system.

Well, that's all I can think of. I like to write-out anything I can think of. Not trying to insult anyone's intellegence with being overly detailed. I just hate not having the info that I need AFTER I commit to a project like this!

I think I spent more time just looking for the right materials, and ordering the stuff, than the time that I spent doing the actual work.

Hopefully you know of someone like me who works at a place that regularly buys from MSC. We recieve our orders next-day from their Allanta location. Nice.

 

What kind of pressure can the tubing take? I didn't see it listed....

 

check these out, as much as the oem ones but far superior for those who dont want to make their own...

http://www.rotorsportsracing.com/per...g/OMPlines.htm

 

Useless link....

 

That tubing is pretty cool see-thru so you can see the oil and stuff. But yea, what kind of pressures can it take? braided lines can take almost anything, but cost a shitload. I spose if the see-thru ones that you have are better than the stock ones, then its all good.

 

I know. I couldn't find that number anywhere either. I was a little worried about that until I got this tubing in my hand and did this work with it.

I can say that I have more than a lot of experience with your garden variety polyethylene tubing which is used everywhere in industrial pneumatics. That stuff is rated for 125 or 150 psi. This teflon tubing seems to me to be just as capable, if not more. It's pretty tuff stuff, hard to just expand it over the barb. It takes a few minutes of steady pushing to finally push it all the way on.

Sorry not to have a number for you on that...

 

Anyway you can call them or something and find out? I'm kinda lazy and don't feel like it... .

 

Good find, mine are getting crunchy. I priced replacements the other day and nearly soiled myself. I have to agree that teflon is superior. I work in a chemical plant, and the instrument techs use it on their pressure calibrators. That o.m.p. can't put out too much pressure or mine would have already disintegrated.

 

OK.

Do you (or anybody) know what kind of operating pressure they will see? I thought I read somewhere that the pressure is like real low...

But, yeah, ok, I'll call tomorrow...

 

I searched and apparently there isn't much pressure in the lines.

 

Yeah, the ones off of this engine broke so easily, it was like they were made of blown glass. LOL (wasn't funny at the time though...)

Side note: See the vacuum line above the front chamber injector - the one with a big wedgie chunk out of the end of it? Found it that way, and yes, it wasn't even connected at all!!! Good thing he was at least using MMO. He hasn't put more than 1000 miles on it snce he bought it from a guy in Charleston...

edit: Oh, never mind, I just realized I didn't post that pic.

And yeah, the primary mode of tubing failure here is heat degradation. I'll call tomorrow though, if just for kix...

 

Great pics and writeup. I'm glad theres a low-cost solution for those brittle lines. Thanks.

 

Well, OK, if you insist.

It's the vacuum line right in the middle of the pic. It was supposed to be for the front camber oil injector. It's rotated around from its position when connected. See the big missing chunk? It was laying to the side of the injector, not even close to being connected to it. It also was most likely ruining the level of vacuum in the other lines! And , yes, there was a suspicion that the vacuum system had a nasty leak before this work began. This little sucker is really hidden big-time when the engine is all-together, you know...

Also, you can see more of the teflon lines in this pic too...

Another tip I just now remembered that I didn't include above, assemble the longest lines first. That way, if you booger-up an end while trying to push the tubing onto the banjo barb, you can re-cut it to a shorter length and still use it. (Not that I had to, of course )

 

those braided steel lines are 100$ for a set, as in 2, so 200$ for braided lines that can withstand pressures of like 10000psi or some **** for a device that never puts out more than 100psi... what a waste.

I think I'll stick to that clear **** or the stock ones..

 

The vacuum in those lines actually comes directly from the engine, not the manifold. Air is sucked through the injector by vacuum in the chamber, and the "vac" lines on the oil injectors are connected to a nipple fed from in front of the throttle so that only filtered and metered air enters the engine. So that line not being connected wouldn't have affected any vac signal as much, but it would mean you were sucking a bit of unfiltered and unmetered air into the engine.

Excellent write-up BTW. It's great to see high-quality, low-cost solutions to common problems. People need to see there are often much cheaper solutions than going straight to an automotive or rotary specialist.

 

When I replace my injectors, this is something I'm definatly going to do. I don't know if my lines or my OMP is getting clogged up, but I'm definatly not burning as much oil as I should.

Is it difficult to remove the OMP and the actual injectors without messing anything up? I figure while I have my UIM off and are doing the injector work, I muight as well pull the oil injection system apart and clean the whole thing out. What would you guys suggest as a cleaning agent?

 

"PFA perfluoralkoxy
PFA was developed by DuPont as a High Temperature Teflon® with a maximum operation temperature of 500°F (260°C), while maintaining similar properties to other fluoropolymers. Of course this added temperature resistance also adds a significant increase in cost. The most common brand names include DuPont Teflon® PFA and Saint-Gobain Norton® PFA."

MSC also sells the same stuff with the Parker name. It's # 79249595 but is sold only in 50' lengths @ $56.84 (good price if you want that much).
• Chemically inert to nearly all industrial chemicals and solvents
• Translucent and flexible
• Nonstick smooth surface
• 100% Pure PFA resin used, FDA compliant
• Nonflammable
• UV and weather resistant
• Color: natural
• Sold in standard coil 50 ′ lengths only

This Parker tubing is rated at 249 psi.

The tubing that I first posted is made by Saint-Gobain Norton. Pressure rating of that particular size was not known by those present @ Norton, and the guru is out of the office roday. The 1/8 I.D., 1/4 O.D. stuff is rated @ 419 psi @ 73 degrees F. So, the thinner walled 1/8 I.D., 3/16 O.D. stuff is probably the same as the Parker tubing. Of course, pressure rating of fluoropolymer tubings go down significantly as the temperatures go up, so...

You can play with the following broshure if you want... http://www.tygon.com/Media/Documents...P-PFA-PTFE.pdf

Lots of stuff on the net about teflon pfa tubing.

 

That is the best writeup on oil metering lines ever on any of the three most popular RX forums.

I'd wager that the *pressure* in the lines is less than two psi. My goodness. Steel braided lines??? Gotta be kidding.

 

I agree.

I wish I would have known this a while back when I did mine. That seems to be the perfect material and I was impressed to see those little clamps like stock.

Kudos

 

Yeah, Racer X-8 did a good job of researching everything. He just called me up a couple days after the lines broke and filled me in (I hadn't really thought about it). But yeah I think those telflon lines are going to hold up very well.

One thing Racer X-8 didn't mention... don't lose those copper washer gasket things for the fittings! (we lost one)...

 

Just felt like shareing.
I did just like Racer X-8 when I rebuild my motor, but also bought some asbestos-tubing to cover the lines

 

That's a good idea for extra protection from abrasion & heat along the lines. Still though, the hot spot (location of failure) is at the injector fitting (heat conductance from the metal barb) and the asbestos tubing won't help there. So, still use the teflon tubing.

Nice attachment btw.

(And sig )

 

I'm still wondering how difficult it is to pull the OMP all together so I can clean it out and make sure it's going to be working properly. I plan on changing the oil when I'm pulling out my fuel injectors anyways, so it would be a good time to run maintenance on all the systems under the UIM.

I'm also looking for any tips on pull the oil injectors off for a good cleaning. They look pretty straight-forward for removal, but just want to make sure I don't fark something up.