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I believe that there should be NO barbed fittings with clamps anywhere on these engines if they have been "full flowed".

AN screw-on fittings are the only way to go, IMO.

There is simply too much pressure on the outlet side of the pump for barbed fittings to handle unless you have a pressure-limiting oil pump cover for your full flow system and even then the barbed fittings are marginal.

The photo appears to show an AN fitting was used, but transitioned to a plastic barbed connector.  Weak link?  

My experience is not under a hood, so I’m ignorant here, but I do work in a rocket engine component test lab.  We use AN exclusively in all of our permanent and temporary pressure test set-ups.  (Well, except for the real high pressures where Autoclave or similar is needed - we go up to 40,000 psig and sometimes higher).  AN fittings have limits, especially when something like a swivel fitting is used.  We proof test all of our flex hoses and inspect/test them on a periodic basis.  And in case you ask, our pressure mediums are helium, nitrogen or DI water, so not the same fluids this group deals with.

Again, I’m ignorant in this arena but my experience would have me running away from push-on connectors, especially when failure leads to nasty consequences.

Rubber hoses, when subjected to heating/cooling, eventually get hard and if you're not clamping them on the barbed fittings it's not if, but a matter of when a hose will let go.  While the ends will get hard, the rubber liner inside can swell and restrict/cut off flow and take out the engine by oil starvation as well. It doesn't happen very often, but it is a (little) known issue with rubber lined hose.  Clamps are essential, and a smart man on a budget will replace hose with new every 2-3 years.

Stainless hose with AN type fittings is, of course, much better, but remember, the inside is still rubber lined.  I have also read about these hoses swelling shut- it doesn't happen very often, but just like the cheaper hose, it does happen.

A few years ago I read about a road race team with a modified 935 that had just rebuilt the engine (I can't imagine how much that cost!) and the thing died once warmed up and after only a few minutes of practice laps.  It was taken out, checked over with new bearings and $$whatever else needed (oil pump? cylinder hone? a piston or 3? rings? a couple rods?$$) to get it up and running again. Re-installed and a few minutes into break in/practice laps it croaks again. Again it was taken apart and rebuilt.  Thing was, nobody could tell why it was dying.

Anyway- after being stuffed back in the car it dies AGAIN!  At this point they sold the engine (for pennies on the dollar) just to be rid of it.  The guy who bought it went through it, found nothing that would cause what was happening so kept on looking and found that 1 of the stainless oil hoses that came with it had swelled shut.

If you're going to buy stainless hoses spring for teflon lined- it will never break down or swell shut.  Some people claim that even rubber lined stainless is a regular replacement item and also say that with the teflon liner being slippier (vs rubber), there's less pumping loss (and more oil pressure).  You'll have to have them custom made- the ends are swaged(? swedged? I'm too lazy at the moment to look it- mind you with the time it took to type all this I probably would have come out ahead!  Anyway- you have to have the tool) on and teflon hose doesn't bend as tightly as rubber lined, but careful planning with the correct angle fittings will make it work.  I have heard of guys having stainless hoses made up considerably cheaper at hydraulic equipment shops, but hydraulic fittings typically have very small openings because they deal with strictly high pressure (and relatively little fluid movement), where engines need oil FLOW as well as reasonable pressure. Hoses and fittings that don't flow what an engine needs can WILL starve an engine of oil as well.

Hope this helps.  Al

Last edited by ALB

I used to look up "hydraulic hoses" in the Yellow Pages (remember those?) for places local to me, and found a couple of great shops near me is several states.  Now you can just Google the same search words, adding "near me".  All of those shops like working on custom stuff, especially if you drive over there after installing their work to show them the car!

Generally, they charge $10 USD per foot for stainless sheathed hose (for Teflon - Rubber inside is a bit less) and then $10 USD per end fitting.  At least that's a good rule of thumb.  I've also found that a lot of local NAPA stores can make up custom hoses, too.

You can get around the fact that Teflon hoses don't like to bend much by using angled fittings and watching the route the hose has to take.  Fittings come in straight, 22.5º, 45º and 90º angles.  

Just a thought, don't trust idiot lights. Install an oil pressure gauge and watch it as you drive. I lost an oil hose once because I didn't tighten the clamp enough after my first time changing the oil (I pumped the previous owner's oil out of the cooler hoses and replaced it with fresh 20W-50 Wolf's Head loaded with ZDDP). I noticed the pressure drop right away, long before it reached the 7 PSI setpoint of the idiot light, and shut her down. The only loss was a couple of quarts of oil on the driveway.

This discussion has taught me something. I didn't realize how high the pressure is at the back of the pump, I figured it was similar to the 60 PSI I read on the gauge when the engine is cold. I'll move replacing the rubber hoses with steel lines, stainless steel braided Teflon hoses, and AN fittings up higher on the to-do list.

Same, same but different.  A few weeks ago my brake pedal suddenly went to the floor. I could tell that there was resistance and that brake fluid must be spraying somewhere. One of my rear braided lines had suddenly failed. Apparently brake fluid burns like gasoline.  The fluid sprayed on the exhaust causing a fire. When the fir reached the engine compartment that new fire suppression gizmo deployed and prevented more serious damage to the engine.

However,  it caused $15k in other damage. 20201129_19485420210112_104934

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@PaulEllis posted:

Same, same but different.  A few weeks ago my brake pedal suddenly went to the floor. I could tell that there was resistance and that brake fluid must be spraying somewhere. One of my rear braided lines had suddenly failed. Apparently brake fluid burns like gasoline.  The fluid sprayed on the exhaust causing a fire. When the fir reached the engine compartment that new fire suppression gizmo deployed and prevented more serious damage to the engine.

However,  it caused $15k in other damage. 20201129_19485420210112_104934

WTF!!! Glad to hear your okay Paul. I hope you’re painting it yellow again. Love that color.

@JPC posted:

Competitive Engineering, Wood Street, Phoenix, put on this oil hose. Dan said didn’t need clamp..Look at pic no indent where ramp was to be..



You guys feel he should be liable?   I am not holding my breath. I had 500 miles on at most on this new hose  

What kind of mechanic would 1. not put a clamp on that assembly, and 2.  use that assembly in the first place?

I would certainly claim it was the shop's fault.

@WOLFGANG posted:

I've always seen the brass barb fitting with 4-5 actual barbs with sufficient space for a hose clamp.



The brass barbs are what I have. Along with cloth-braided rubber hose that runs through the interior of the car. It enters by the rear torsion spring on the driver's side, runs along the pan next to the box frame inboard of the rocker panel, up the driver's side door pillar, and exits into the frunk between the fuel tank and hood hinge. It runs down the edge of the frunk where it meets the fender, then into the battery well where it exits. The oil cooler and its electric fan are mounted between the front bumper brackets just forward of the battery well. I'm thinking of moving it to the void just rear of the rear torsion tube, near the transmission. It would save me a bunch of oil line. Thoughts?

@JPC posted:

Competitive Engineering, Wood Street, Phoenix, put on this oil hose. Dan said didn’t need clamp..Look at pic no indent where ramp was to be..



You guys feel he should be liable?   I am not holding my breath. I had 500 miles on at most on this new hose  

Yeah, I'd be pissed, over there demanding an explanation and what they're going to do about it...

@PaulEllis- sorry to see that.  A braided line failed- was it rubbing somewhere, or did a swedged fitting come apart?  I hope you're back on the road soon.

@Eric (McGruff)- Yeah, relocating the cooler and shortening the lines up is a good idea for several reasons.  If going to braided stainless steel, think about the teflon lined hoses.  It'll be a little more work getting the right fittings and mocking it up (use some cheaper rubber hose), but more than worth it, as you'll never have to give them a 2nd glance again.

And have a look at the fittings you're using- I've heard certain brands are more restrictive.  A while a go a guy on the Samba was saying he'd had to drill the passageway through a couple of fittings bigger to ensure proper flow.  With #8 hose I believe the minimum opening through any fitting should be 3/8"

Last edited by ALB

“I'm thinking of moving it to the void just rear of the rear torsion tube, near the transmission. It would save me a bunch of oil line. Thoughts?”

Having a shorter hose run is always good, but I am not a fan of putting an oil cooler in the void between the firewall and the rear of the back seat - the air flow turbulence just ain’t sufficient to make it efficient.

Instead, mount a fan assisted oil cooler in the driver’s side rear wheel well.  Close to the engine and gets plenty of cooling airflow.  

“I'm thinking of moving it to the void just rear of the rear torsion tube, near the transmission. It would save me a bunch of oil line. Thoughts?”

Having a shorter hose run is always good, but I am not a fan of putting an oil cooler in the void between the firewall and the rear of the back seat - the air flow turbulence just ain’t sufficient to make it efficient.

Instead, mount a fan assisted oil cooler in the driver’s side rear wheel well.  Close to the engine and gets plenty of cooling airflow.  

Thanks for the idea @Gordon Nichols. I'll have to see if I have enough room, my full-flow oil filter is already mounted in that area. If I do, it'll make for really short oil lines. 

@VSpyder posted:

@JPC

We use the same fitting on all of our builds without hose clamp. You have to use specific hose with those fittings for it to work correctly . I have been using those same fittings with the correct hose (without hose clamps)  for at least 20 yrs and have never had one come off.





Greg

Greg, when I put my first car together I used Gates Push-on hose AND fittings. I started the engine and kept the revs low for about 5 minutes. The outside air temp was about 70 and I was using 20W50 as instructed by Jake. Anyway, I revved it up a few times and BLAM one of the hoses blew off the remote oil filter mount. After cleaning up the oil everywhere, I pushed the hose back on and secured it with a WIDE hose clamp. Lesson learned.

What brand do you guys use out of curiosity?

@ALB posted:

Yeah, I'd be pissed, over there demanding an explanation and what they're going to do about it...

@PaulEllis- sorry to see that.  A braided line failed- was it rubbing somewhere, or did a swedged fitting come apart?  I hope you're back on the road soon.

@Eric (McGruff)- Yeah, relocating the cooler and shortening the lines up is a good idea for several reasons.  If going to braided stainless steel, think about the teflon lined hoses.  It'll be a little more work getting the right fittings and mocking it up (use some cheaper rubber hose), but more than worth it, as you'll never have to give them a 2nd glance again.

And have a look at the fittings you're using- I've heard certain brands are more restrictive.  A while a go a guy on the Samba was saying he'd had to drill the passageway through a couple of fittings bigger to ensure proper flow.  With #8 hose I believe the minimum opening through any fitting should be 3/8"

Everything Al said I agree with, except AN fittings are in 1/16ths of an inch. So a number 8 is 8/16" or 1/2" I.D.

Eric, definitely relocate. I wouldn't run a front cooler unless I had a dry sump AND AN-10 hose front to back.

Thanks for the idea @Gordon Nichols. I'll have to see if I have enough room, my full-flow oil filter is already mounted in that area. If I do, it'll make for really short oil lines.

There are a number of pics people have posted here of their auxiliary coolers (with fan) and full flow filters both in the left rear fenderwell; quite a few Speedster owners have their cars configured this way.  It works well and keeps the oil lines short.  Here is Gordon's-  oil cooler in fenderwell- Gordon's                                                                                                                                                           I don't know when I saved this pic of a cooler hanging off the rear torsion housing-          oil cooler shield     

It works as well; the hoses are just a bit longer.

I have used rubber oil hose and barbed fittings before on project cars with success and wouldn't hesitate to use them again if budget constraints demanded it. A couple things I have learned over the years (and I know, I'm repeating myself and other people here but it's important)- hose clamps are essential, as is replacing the hose itself every 2-3 years.

Hope this helps- Al

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@DannyP posted:

I forgot. AN fittings are full-bore, but plumbing adapters may NOT be full bore.

I've drilled out plastic elbows in my breather system, the holes were rather small, just like Albert Hall LOL!

I read what you wrote in tune without even realizing it. Here's an interesting article wherein the curators of Royal Albert Hall tried to get The Beatles to change the lyrics because they were offended that the Royal Albert Hall was being spoken about in an unflattering manner.

@Sacto Mitch posted:

.

Cool article, @Robert M .

The suggested changes to Lennon from the folks at the Albert Hall show they completely missed the meaning of his words.

I would have preferred:

Now we know how many holes it takes to lighten Al’s Vauxhall.



But both are reminders that songs, like cars, suffer when a committee tries to make them.

.

I read their suggestions and that it sounded more like a commercial than a song. Lol

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