What's the issue with the aux oil line?

[piman]

Hello Bryan,

"Any extra oil you take to the head is oil you take away from the bottom end."

That would be true except for the pressure relief valve, as excess pressure is bled off. Volume drop is also a pressure loss so if the pressure remains constant then the relief valve must be controlling the pressure.

Incidentally, I had another look at the engine from Le Taxi, and that has an oil feed to the head.

Alec

 

[Opa]

Piman Keep in mind that when Kas raced the 2.0 and 2.5 litre engine they where not exactly stock. I seem to remember that he was getting upwards of 200+ hp out of them and 8000+ RPM.Also keep in mind that the engine was probably tore down after every race and inspected and refurbished as required.If it burned a little oil during the race,no a big deal.
If top end oiling was a major issue with these Standard engines I think Standard would have improved on it themselves.The six cylinder engine was not exactly new to the industry when Triumph used them.

 

[bunzil]

Any extra oil you take to the head is oil you take away from the bottom end. [/quote]


Correct me if I'm wrong, but the line of reasoning I see here is assuming the oil feed line is consuming an undesirable amount of oil. Yet no one has really demonstrated same thus far. Let's remember that oil pressure is being maintained which in this case, should be the result of the small diameter of the oil line. That diameter is providing enough back pressure to keep the flow in check and thus, maintain sufficient oil down below.

I can't be far off the mark here or we would have heard of catastrophic failures by now. The fact that most of us are speculating whether the oil line is worthwhile or not, points to a general lack of real information on the topic. It seems so far, that all we really know is that it can create issues for non-baffled valve covers, and potential consumption issues at the valve stems - especially worn ones.

 

[TR6oldtimer]

Geez, why is it that I am starting to like questions like "What color should I paint my car?" more and more. I am starting to get a headache.

Glad you are up to this, and just what color should I paint the bottom of my car? :smirk:

 

[TR3driver]

The hole there is needed to drill out the oil passage. After the passage was drilled, the plugged it with a bolt. That was the "convenient" way of solving a production problem.

Otherwise, it's really tough to drill that hole around two corners inside the head.

 

[swift6]

The hole there is needed to drill out the oil passage. After the passage was drilled, the plugged it with a bolt. That was the "convenient" way of solving a production problem.

Otherwise, it's really tough to drill that hole around two corners inside the head.

Then why go the extra step with tapping the hole for a bolt when they could have simply plugged it like the rear of the oil gallery on the block?

 

[swift6]

If top end oiling was a major issue with these Standard engines I think Standard would have improved on it themselves.The six cylinder engine was not exactly new to the industry when Triumph used them.

That would be more like solving a problem that they didn't really see as a problem. In the corporate world that's called a waste of time and resources, both of which equals money.

If the engines could break 100,000 miles with proper servicing and 95% of the consumers never had an issue with upper-end oiling during that time on their stock engines. Why would they have bothered with the expense of improving the engine. Their coffers weren't overflowing with cash. The reason the TR6 was outdated when new was because of cost saving measures. The cars, and the engines, were never meant to be around this long.

A well cared for stock engine shouldn't need any extra oil to the upper-end as long as the oil passages stay open. That being said, my old stock engine had one on it from about the 100,000 mile mark to near 150,000 miles when I pulled it to install my high performance engine. I looked at all the lower-end bearings when I pulled the stock engine. While worn, but still perfectly serviceable, they showed zero signs of oil starvation. Those 50k with the oil line were not pampered either. Many a track day with long durations of revs past 4k rpm.

Start changing things on that upper-end and it may need more oil than the stock passages can deliver. My roller rockers are much happier with the extra oil.

 

[BobSands]

Was just over on the Kastner website, and he says that for Spitfire's, he NEVER used the external oil feed, and never had any rocker wear.
Seems like he covered this for the 2 liter, and 2.5, in one of his books, that he was not a fan of the upper oiling procedure. I'll check this evening when I get home.
Take care Bob

 

[Rickc]

Well this is becoming interesting.

This baffle issue has nothing to do with weather or not to install the extra oil feed line I have the alloy valve cover and you simply install a very simple baffle and no more oil to the carbs. Besides, I do not think the extra oil line is the main reason for oil down the carbs.
I can appreciate on a tired engine with low oil pressure that this is probable a bad idea. But with an engine that is just rebuilt along with a new oil pump that has oil pressure almost at the scary high end then I can not see that I am staving the lower end. Yes, I am probable dumping a little more oil down the valve stems of 5 and 6.

I wish (well sort of) someone would give a definitive reason why they think (or know) that the extra oil feed line is a bad idea.
So far Shawn is the only one who has looked at an engine after 50K miles and reports no noticeable damage with the extra oil line.
I really am open to someone giving a good reason not to use one. Everyone keeps saying it starves the lower end. I dought my oil pressure would changer at all if I removed it.

Rickc

 

[RobT]

I always thought oil supply to the Triumph top-end was only an issue with the 6 cyl engine (which was basically a Herald "4" with two extra cylinders added). Oil supply to the top end was fine for the "4", but could not keep up with the extra valve gear.

Rob.

 

[tomshobby]

I have the aux line.
My oil pressure is excellent. My engine does not use oil. My carbs and intake do not have oil from the valve cover vent in them. My valve cover gasket does not leak. Before the aux line the valve train was somewhat dry in the front and now it is well oiled.
It is a good thing for my engine. The point is that is how it is for my engine, it may not be good for others.

 

[poolboy]

I guess I could go out tomorrow and have a problem due to not having an auxillary oil feed, but I've got a stock engine with 98k on it and so far so good.

 

[vrod]

I had 10,000 miles on a fresh engine rebuild with the aux oil line and dropped a valve down into the cylinder because of a broken valve spring. Parts from the valve were then sucked through the intake manifold and ended up in some of the other cylinders, scarring the cylinder wall in one so bad that it needed to be sleeved . I believe this was caused from detonation from excess oil getting past the valve stem. when the engine was torn down, I noticed some of the exhaust valves looked burned around the edge. When the new head was rebuilt I selected stainless exhaust valves. I will not be putting the aux line back on.

 

[poolboy]

I wonder how "theguyfromQuebec" is doing with his experiment, putting a valve in the line?

 

[Opa]

well spoken Tom.I don't have the aux line and haven't had.She's gone 80 thou. miles plus and all is well under the valve cover.I slide over a rocker or two every valve adjustment and shaft looks like new. I ain't gonna fix what ain't broke.
As you say.... works for me .Keep on

 

[Brosky]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]I wish (well sort of) someone would give a definitive reason why they think (or know) that the extra oil feed line is a bad idea.[/QUOTE]

Rick,

Until you develop that simple little baffle, this is what you can expect when you go from using a quart of oil every 1,100 miles to a quart every 200. Alloy valve cover with no baffle and auxiliary oil line.

Be very careful how you attach that baffle. If you weld it, you will probably damage the outside finish due to the high heat needed for aluminum. I would never attach via a fastener that could fall off inside the engine and drilling holes through the cover isn't much of an option.

And I did look at the clearance between the thick aluminum covers and the valve train where the vent pipe is located. There isn't much room in there at all.

I still have my cover sitting in the garage, so please post a fix for this when you figure it out. It was easier for me to put the chrome cover back on and take off the line than go through that hassle.

That is a small sampling of the Castrol 20W-50W that came out of the intake when I swapped my stock carbs over to tri-carbs.

 

[RonMacPherson]

Like they already mentioned. It's the volume of oil, which is a heckuva lot more important than the amount of pressure that is needed by lubricated parts.

The auxiliary line was a patchwork to "bandaid" without rebuilding your rockershaft assembly.

Machining and metallurgy have improved considerably since these engines were designed and produced better than 50 years ago. Remember the basic design goes back to a tractor motor of the late 30's.

I agree with Brosky, a good competent, up to date, machine shop will recommend(and I agree) good guides, and valve stem seals. Remember there are a lot of different "seals" available. Everything from o-rings on the stems to umbrellas, to perfect circle type machined on the guides. I do not know of any modern engine that does not come with out valve stem seals on the intakes.

So upgrading the engine design is, to me, akin to upgrading the suspension and brake design. If you can make it better by improving it, why not? As long as you are using industry standard designs and industry acceptable practices, go for it.

 

[Andrew Mace]

...Machining and metallurgy have improved considerably since these engines were designed and produced better than 50 years ago. Remember the basic design goes back to a tractor motor of the late 30's....

Yes...and no. Machining and metallurgy...and engineering (and ignition/fuel management...and a bunch of other stuff) all have improved greatly in the past 50 years. But your other chronology is off a bit. The wet-liner motor is a postwar design introduced around 1947. The six is, in turn, based on the 803cc four-cylinder introduced in the Standard 8 of 1953.

 

[swift6]

...and it was the Ferguson tractor that used a Standard engine, not a Standard that used a Ferguson engine.

 

[Opa]

yup Fergie and Standard engine. The antique engine club I am president of is in the process of restoring this 1952 Ferguson TEO