Jump to content

Competition Oiling-Draft


Recommended Posts

Competiton Oiling fundamentals

 

 

 

Pressure and volume is fundamental but just the beginning.

 

 

 

Rule of thumb has it that 10 PSI per 1000 RPM is adequate for a racing engine. That is clearly based on the assumption that all clearances are correct and oil is not being dumped indiscriminately at the cam bearings, mains or bypasses.

 

 

 

If for example, any of these are at their wear limits the oil will dump to the easiest path and starve critical dimensions. At the other extreme a restriction will keep the oil pressure artificially high with little volume reaching the bearings.

 

 

 

 

Back in the day, Kas and Jimmy Coan did an experiment where they put a rotary union on the front of the crank and measured the oil pressure inside the crank during a dyno pull. They found the oil pressure dropping to zero during the high RPM’s essentially starving the front bearings. The cast in oil galley is too restrictive to provide adequate feed. The distributor guide bushing further restricts oil moving from the rear to the front of the engine. Beyond that many studies have been done on the centrifugal effects contributing to starvation at higher RPM’s.

 

 

 

The original and classic solution is the Kastner “Octopus“ where the galley is fed externally thru the 1/8 NPT pipe plugs closing the bearing galley drillings. -3 or -4 AN hose is typically used for this off of a manifold. There’s been talk of Cosworth? feeding their oil thru a crank mounted rotary union but I’ve not seen it.

 

 

Picture 1

Oilpictures005text.jpg

 

 

 

 

 

 

 

In addition to the octopus I’ve made it a practice to drill all of the block passages oversize to facilitate oil flow. This started when I found a bearing passage that hadn’t been drilled thru properly at the factory resulting in a massive restriction to oil flow. Pressure was great however!

 

 

 

Picture 2

 

Oversizeoilholes004.jpg

 

Picture 3

 

Oversizeoilholes003.jpg

 

Picture 4

 

Oversizeoilholes001.jpg

 

 

 

This is a 5/16†aircraft drill which is the largest that will fit thru the plugged holes.

 

Original drillings were .275 inch while the new ones are.312 increasing the cross sectional area by 23%. That also happens to be the size of the bearing oil hole so flow is maximized. A substantial improvement.

 

 

 

Back in Picture 1 Note the external oil filter and the blanking plate eliminating the stock filter housing. The ports for supply and return are in theblock already, one has an aluminum plug

 

 

 

The blanking plate is a turned piece of ½†thick alloy with a rim to simulate the outside steel housing effecting that seal and then an internal O-ring groove to seal the two internal passages from each other. I’m not aware of anyone that sells them commercially.

 

The ports for the oil are in the block. One is simply plugged while the other has a hammered in alloy plug which must be carefully drilled. Tap them both to ½ NPT.

 

 

 

The one above the filter will be for the Accusump if you are using the octopus. Without the octopus it’ll be filtered and cooled oil feeding the galley.

 

 

 

Oilpicturestext3.jpg

 

 

 

Early on when RPM’s started to climb above factory levels I started seeing damage to the oil pump which I finally figured out to be from cavitation. I put it down to a poorly designed pickup but may have been exacerbated by aerated oil.

 

 

 

I went so far as to build an “oil pump dyno†with a five gallon aquarium and a heavy Lexan lid to test different pump layouts. By putting this into the Bridgeportmill I was able to run the pump at different speeds measuring volumes and pressures and watch for aeration in the returning oil.

 

 

 

I was using the latest model oil pump with a square cut inside the crimped on filter. I cut the filter screen off of one oil tube leaving the sheet metal flange intact. I then flared the pickup like a velocity stack to smooth oil pickup into the pump. Next I cut the oil screen with flange from an old pump and pop riveted the two flanges together to restore the screened pickup. Long term plans were to go to a flat Chevy style pickup but never got around to that experiment.

 

 

 

From these tests I was satisfied with the pickup mods and eliminated the pitting on the pump rotor surfaces.

 

 

 

Sadly all of the data has been lost in computer crashes but I do recall the pump taking about 3 HP to run it based on motor amps on the milling machine.

 

 

 

 

 

 

 

With the mention of aerated oil let me say I believe this to be a big problem in a Triumph engine. The crankshaft whipping above the agitated oil literally whips the oil into a froth. Kas related cutting a hole in a block and adding a plexiglass window to watch. He said after a couple thousand RPM you couldn’t see ANYTHING in the oil storm!

 

 

 

Hence the windage tray so common in High Performanceengines.

 

 

 

First classic step toward resolution is to deepen the oilpan by cutting it horizontally and welding a 1†strip in. Find a good welder cuz they will be grumpywhen you come back. This is also a good time to add some kickouts to the sides to increase the oil volume. And don’t forget to extend the pickup tube aswell. ½†EMT conduit works well for this.

 

 

 

Then add baffles to control oil surge during cornering and braking. A simple vertical divider coming just above the oil level will work wonders with compartments and trapdoors developing as you get more fancy.

 

 

 

Fill the pan with water and walk around the garden a bit watching how the water behaves. Really hot water helps focus the mind during these trials.

 

 

 

This dirty old thing was the one I retired when I went to dry sump. Note the simple hinged baffle to keep oil in the rear during braking. There are many different ideas for this, the example below is very simple and can surely be improved upon.

 

 

 

oldoilpan002.jpg

 

 

 

 

oldoilpan003.jpg

 

 

 

 

 

 

 

 

 

 

Link to a cross drilling treatise

 

 

 

 

 

http://www.datsun.or...eEngineMods.htm

  • Like 1
Link to post
Share on other sites
  • Replies 51
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

Competiton Oiling fundamentals       Pressure and volume is fundamental but just the beginning.       Rule of thumb has it that 10 PSI per 1000 RPM is adequate for a racing engine. That is cl

Posted Images

Hi Steve,

 

Nice article, you wrote!

 

 

Isn't 10 psi per 1000rpm seems a bit high, or is this specifically for the Triumph engines?

 

 

I always wondered if it would be possible to extrude hone the oil galleries, do you know anything about this?

 

 

Tried to find a picture of the octopus to complement your story, but couldn't find one. :(

 

 

 

Frederick

Edited by spitNL
Link to post
Share on other sites

Hi Frederick, 10 per thou is a generic hotrodding axiom on this side of the pond. It sounds right to me but maybe that's cuz I've heard it all my life.rolleyes.gif I fixed the octopus pic, any other critiques are very welcome.

 

The thing I like about extrude-honing is rounding the sharp edges at the drillings which would have to help. One time I saw a system to round those edges on some machist site and I've never been able to find it again!pinch.gif I think that would help a lot with the oil flow. I wonder if anyone in Vegas does extrude hone?

 

Hi Steve,

 

Nice article, you wrote!

 

 

Isn't 10 psi per 1000rpm seems a bit high, or is this specifically for the Triumph engines?

 

 

I always wondered if it would be possible to extrude hone the oil galleries, do you know anything about this?

 

 

Tried to find a picture of the octopus to complement your story, but couldn't find one. :(

 

 

 

Frederick

 

 

 

Link to post
Share on other sites

wonder if anyone in Vegas does extrude hone?

 

I'm sure they know on talking speed ;)

 

 

Steve, one thing I missed was that you shouldn't use right angle adapters in the oil system, cause they're so restrictive.

8a5fd726-d69b-41ba-bb4e-f47879a8fae2-800.jpg

 

10 per thou is a generic hotrodding axiom on this side of the pond. It sounds right to me but maybe that's cuz I've heard it all my life

Or I don't know what I'm talking about. blush2.gif:lol:

It just seemed high for engines that run more than 10k rpm, but of course they've got much better oil systems; the v10 F1 engines ran just 30psi apparently.

 

 

I thought about measuring the oil pressure inside the crank, would it be possible to drill a hole from the front and putting a wireless sensor in?

 

 

 

Frederick

Edited by spitNL
Link to post
Share on other sites

Thnak you, Steve, for sharing your research with us!

In return, may I share my approach?

 

Kastner's problem, to which the Octopus was his solution, was that the oil supply to the front main bearing dried up at high revs. The reason may be crankshaft harmonics or that the dizzy shaft is between the oil return from the filter to the main gallery and the front of the engine. I can't do anything about the first, and I don't think that KK's solution did either, but I can improve the oil supply to the front bearing. I've run an external supply from the gallery at the back, right forward to the front bearing drilling. See the pic. Should allow the pressure at front and back to equalise.

 

This is for the new engine I'm building, so I can't report anything yet about its success or failure.

 

John

 

PS How do you insert full-sized pics, insted of the thumbnail that must be clicked on to see? J.

post-690-0-24109700-1315836027_thumb.jpg

Link to post
Share on other sites

John, I don't see any problem with that. As you're not running a remote oil filter or oil cooler there's not much other option is there? Please go the extra and overbore those galleys to give you're bearings every chance...

 

Thnak you, Steve, for sharing your research with us!

In return, may I share my approach?

 

Kastner's problem, to which the Octopus was his solution, was that the oil supply to the front main bearing dried up at high revs. The reason may be crankshaft harmonics or that the dizzy shaft is between the oil return from the filter to the main gallery and the front of the engine. I can't do anything about the first, and I don't think that KK's solution did either, but I can improve the oil supply to the front bearing. I've run an external supply from the gallery at the back, right forward to the front bearing drilling. See the pic. Should allow the pressure at front and back to equalise.

 

This is for the new engine I'm building, so I can't report anything yet about its success or failure.

 

John

 

PS How do you insert full-sized pics, insted of the thumbnail that must be clicked on to see? J.

 

 

 

Link to post
Share on other sites

I will run a non-return oil filter that sits on an adaptor that also feeds an oil cooler, to and from, the oil passing thence directly into the gallery. I've no criticism of your KK setup, indeed I've nothing to report. My thought was to simplify KK's idea with the same intent.

 

I'd be interested to know if he thought of this way and rejected it, and why. It's simple enough to reverse.

 

JOhn

Link to post
Share on other sites

Hello Steve

 

I'd be interested on how you think windage trays and crank scrapers contribute to the oil system flow. Having mentioned the "oil mist" at high revs, and also the potential power drain reduction, they sound like a solution to a few of the issues raised. Not a stand alone solution but appears to be a very good bolt on option to me. Worth US$300 ?

 

Pretty sure this is you :)

SteveSmithrace.jpg

 

Many thanks for the post by the way, clarified allot of my questions.

 

Nigel

Link to post
Share on other sites

Nice write-up Steve. Some good points and ideas there. I'll be investigating the oil pump drive bush and drilling the oil ways on my new build as a result :thumbsup:

 

Nick

 

 

Nigel, I'll expand that bit some if it will help. As it's a draft any discussions we have can go back in before it's saved to the Sticky site Dave controlled. As for the distributor guide Nick, I turned that thing down to just a feather width and never noticed any improvement. I'm sure it was there cuz I removed a lot of material from there. One thing I never even thought about was grinding and shaping the outer periphery for flow improvement. I only ever looked at the guide bushing. Maybe there's something there?

 

 

Link to post
Share on other sites

Hey Ed, I'm not running an Accusump any more with the dry sump but I fully support it! Don't skimp on lines, Dash-10 in my opinion. I think a lot of my problems over the years were from the dash-8 oil lines. Just too small.

 

BTW, the drilling pics in this thread are your engine....thumbsup.gif

 

Steve, are you running an Accusump as well? We installed one on the yellow car, and I'm working up a distribution system using a Peterson four way manifold.

4 way manifold

 

Ed

 

 

 

Link to post
Share on other sites

Guys, we're developing a list of additions to the original posting. I'll try to pull it all together and expand on the questions as I can. Hang on and continue critiquing.

 

Hey Ed, I'm not running an Accusump any more with the dry sump but I fully support it! Don't skimp on lines, Dash-10 in my opinion. I think a lot of my problems over the years were from the dash-8 oil lines. Just too small.

 

BTW, the drilling pics in this thread are your engine....thumbsup.gif

 

 

 

 

 

 

 

 

Link to post
Share on other sites

Hey Ed, I'm not running an Accusump any more with the dry sump but I fully support it! Don't skimp on lines, Dash-10 in my opinion. I think a lot of my problems over the years were from the dash-8 oil lines. Just too small.

 

BTW, the drilling pics in this thread are your engine....thumbsup.gif

Ok Steve, I'm seriously thinking about Accusump for next year. Do you recommend 4 or 6 pint and is their any advantage to electical. I was thinking tap open for competing and tap shut for road, or am I being dim and simple again?

Link to post
Share on other sites

I'll let Steve answer for himself, but in my limited experience, most of the vintage racers (wet sump)over here run an Accusump. If you get one, why not use it all the time? Most folks seem to have the electric valve, but mine is manual. The Accusump is mounted on the floor right beside me, no passenger seat in a race car. I only see six pint units, no one seems to use the four pint versions.

 

Ed

Link to post
Share on other sites

Ed beat me to it, he said it all. I had the manual valve initially and forgot to open it more than once. Thusly I went to the electric solenoid valve but found out it had a price of it's own. Twice I had the engine out of the car for rebuild and during other work switched on the ignition. Only took a microsecond to think WRONG! After that is when I learnt to plug all disconnected lines for both cleanliness and Stupidity.

 

I see no reason whatsoever to not use the Accusump whenever it's available. How many threads do we have regarding the rattle on startup with our cars? Accusump is a preoiler. Find an innocuous place in your car to hide it and plumb it in. Loads of industrial machinery has this built in as standard, called accumulators....

 

I'll let Steve answer for himself, but in my limited experience, most of the vintage racers (wet sump)over here run an Accusump. If you get one, why not use it all the time? Most folks seem to have the electric valve, but mine is manual. The Accusump is mounted on the floor right beside me, no passenger seat in a race car. I only see six pint units, no one seems to use the four pint versions.

 

Ed

Link to post
Share on other sites

I run one. Since I installed it this season I do not see the pressure diving as I did last season through the corners.

 

Its wired into the system so I open it before starting and leave it open the whole race.

 

It feeds directly into the block via a one way and a tee.

 

IMG_2038.JPG

 

IMG_2053.JPG

 

IMG_2002.JPG

Edited by AndreGT6
Link to post
Share on other sites

But Andre, you have a dry-sump, yes?

So why the dip in oil pressure "on diving into corners"?

It can't be oil sloshing in the sump, leaving the oilpump sucking air, so I'd look for another cause - is your reservoir big enough, or rather, TALL enough?

I used to get oil starvation with a wet sump, esp. when I had to brake hard and turn left - Mansfield at Cadwell was an engine killer.

Fitting a combined windage and baffle plate system cured it completely.

I still have wet sump.

 

John

post-690-0-57229800-1316209800_thumb.jpg

Link to post
Share on other sites

Hard to say. I've yet to look inside this engine. I was simply looking at the oil pressure gauge.

The light warning never went on.

I'd simply mash the go faster pedal and the pressure would go back up ;)

 

I've been told an oil scrapper would help too. Keeps the oil moving around on the bottom end.

 

With the accusump its a 2 way street.

You're protecting the engine or laying down more oil after you blow up...

 

A.

Link to post
Share on other sites

John, I don't think Andre has a dry sump????????

 

 

Hard to say. I've yet to look inside this engine. I was simply looking at the oil pressure gauge.

The light warning never went on.

I'd simply mash the go faster pedal and the pressure would go back up ;)

 

I've been told an oil scrapper would help too. Keeps the oil moving around on the bottom end.

 

With the accusump its a 2 way street.

You're protecting the engine or laying down more oil after you blow up...

 

A.

 

 

 

Link to post
Share on other sites

Steve,

Only Andre can answer that.

 

Andre,

An oil scraper fits extremely closely to the journals as they rotate. The idea is to remove the oil layer from them, reduce the weight and drag of the oil layer and get the oil back down into the sump. It stops them "moving around" with oil all over them! But it also needs skilful fitting to get a close enough fit to be effective.

 

If you don't have a dry sump and don't have a windage plate +/- baffles, I'd recommend doing that before you fit the expnsivem and complicated hi-tech stuff!

Sometimes Lo-Tech Rules!

 

John

Link to post
Share on other sites

Dry sumps are not legal in my series.

When I open the bottom end up I'll be able to to tell what the PO did with the baffles.

Like I said with the accusump in place I've not see the drops in the turns so its doing the job.

 

I'm also running a conventional oil.

 

A.

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...