On Topic - Anyone remember reading about, Type IV push rod tube mod. Options

[SpecialK]

I can't remember where I read it, and it was several years ago, but someone did a mod on their push rod tubes in an effort to keep the crankcase oil from sloshing into the heads on hard cornering. I think it had something to do with attaching the end of a Type I PR tube to the "case side" of a T4 tube which made it extend farther into the case. This supposedly prevented (to a certain extent) as much oil from entering the heads during a hard cornering, yet still allowed the heads to drain normally.

Anyone heard of, or done this?

[Bleyseng]

Damn, the heads are full of oil anyway so to keep the oil pump wet we use a tuna can to trap the oil so it doesn't slosh away. I think the problem is getting the oil to drain back fast enough thru the pushrod tubes.
Geoff

[SpecialK]

I'm no Jake, but I've heard that quite a bit of the oil that should be in the case gets thrown into the heads (long sweeper turn) that doesn't need to be there. The "tuna cans" do the trick of keeping the pick-up tube supplied, but with the debris on the roads out here (road gators, deer carcassas, mufflers, BBQ grills, etc.), I don't cherrish the idea of having something hanging off the bottom of the engine. The tube extensions don't restrict the oil flow from the heads back to the case, but kind of "dam" some of the oil from entering the head. Plus I've heard a lot of bitching about tuna can leaks (like it's not a problem everywhere else on these cars (IMG:style_emoticons/default/rolleyes.gif) ), and installation problems (possibly quality issues with the mfg.).

Sounded like a reasonable simple (and cheap) mod, and it sounds like it might have some merit........but then again, "I'm no Jake"! (IMG:style_emoticons/default/wink.gif)

Kevin

[microsa]

Isn't that what the baffle/windage tray in the sump is supposed to do?

[muddboy]

The mod on the push rod tubes was to add tubing at the end in the crankcase so that the oil had a harder time getting into the tubes. I remember seeing that mod on early type 1's along time ago, untill the factory changed the design to inlude the extra tubing.

The mod I saw that Im going to try the next time I split open a case (or assemble a new one) is to add "wings" to the pick up. Sheet metal wings welded to the pickup running along the seem of the case. With that and the factory windage tray it should control your oil. It won't stop all the oil from rushing into the one head, but will hold back a good portion from getting away from the pick up.

[SpecialK]

Isn't that what the baffle/windage tray in the sump is supposed to do?

I believe that the "windage tray" is there to prevent the oil from being whipped up into the crank by the wind created by it at high rpms. This would/will make the oil foam, and air bubbles in the oil is very bad for lubrication (think air in your brake lines).

Muddboy has the right idea about slowing down the migration of oil to the heads as is the case in hard, or long sweeping turns. It's a relative simple idea, which is what confuses me. If it is an effective mod at keeping the oil in the crankcase where it belongs, which it seems like it would, why hasn't someone made some aftermarket versions of the tubes? (IMG:style_emoticons/default/confused24.gif)

Muddboy:

"Sheet metal wings welded to the pickup running along the seem of the case. With that and the factory windage tray it should control your oil. It won't stop all the oil from rushing into the one head, but will hold back a good portion from getting away from the pick up."


I'm not pickin' up what you're layin' down here...........got any pics of this "wings" mod?


Kevin

[Brett W]

Wings welded to the windage tray don't help that much. The problem with the Windage tray is that the oil can't get back to the pick up fast enough. I ususally cut out large windows in the windage tray to help speed oil return.

The crank does not have as large a problem with windage because it is mounted above the camshaft. This tends to really help. Most engines the crank actually sits down in the oil pan so the crank tends to whip the oil into a foamy mess.

The biggest problem is pumping to much oil into the head. That is a draw back of having pressure fed shaft rockers, but they are reliable. The Tuna can helps a lot. I ran one on my daily driver and never had problems. The bottom of the can sits just above the bottom of the engine bar. Rememeber the 914 engine is between the wheels not like the beetle where it hangs out behind the wheels. So ground clearence is directly related to wheel and suspension travel, not necssarily ground travel.

[Jake Raby]

The oil doesn't slosh there... It is delivered there by the ushrods to lube the rockers and valve guides/stems..

Anything you do to the PR tube to retain slosh will also retain oil IN THE TUBES thus keeping it from the SUMP where it can be picked up again and recirculated. even the windage tray does this in stock form and thats why we either don't run it or we heavily modify it.

I make tabs that weld to the pick up tube and retain slosh and they work well. I have tubes with these welded on already if anyone wants to try one and see the differences..

On full race engines we weld up the tips of the pushrods, which eliminates oil from passing through them. This keeps them lighter as well as limits the oil getting to the rocker cobers. I then use an external oiling system that taps into the main oil galley and is pressurized to fill the valve covers and lube components. The arrangement allows me to change the amount of oil delivered to the covers easily through Solex main jets that are installed precisely to squirt oil on the valve guides...

This works better than anything else I have ever done shy of a dry sump system...

[SpecialK]

The oil doesn't slosh there... It is delivered there by the ushrods to lube the rockers and valve guides/stems..

Anything you do to the PR tube to retain slosh will also retain oil IN THE TUBES thus keeping it from the SUMP where it can be picked up again and recirculated. even the windage tray does this in stock form and thats why we either don't run it or we heavily modify it.

I make tabs that weld to the pick up tube and retain slosh and they work well. I have tubes with these welded on already if anyone wants to try one and see the differences..

I knew that oil is delivered to the head via the push rods, and returned to the sump through the tubes, and the oil doesn't really "slosh" into the heads, but rather enters the heads by the centripetal force created in a turn.



"Anything you do to the PR tube to retain slosh will also retain oil IN THE TUBES thus keeping it from the SUMP where it can be picked up again and recirculated."


"I make tabs that weld to the pick up tube and retain slosh and they work well. I have tubes with these welded on already if anyone wants to try one and see the differences.."

So, which is it Jake? (IMG:style_emoticons/default/confused24.gif)

[McMark]

"Anything you do to the PR tube to retain slosh will also retain oil IN THE TUBES thus keeping it from the SUMP where it can be picked up again and recirculated."


"I make tabs that weld to the pick up tube and retain slosh and they work well. I have tubes with these welded on already if anyone wants to try one and see the differences.."

So, which is it Jake? (IMG:style_emoticons/default/confused24.gif)

Quote #1 is referring to the Pushrod Tubes. Quote #2 is referring to the Pick Up Tube.

[Bleyseng]

Ok Jake, how about a pic of the tabs you weld on to the pickup tube to prevent slosh.I have always thought that the problem was getting the effin oil back thru the pushrod tubes quick enough so on long sweepers the oil can return to the sump.


Geoff (IMG:style_emoticons/default/biggrin.gif)

[SpecialK]

"Anything you do to the PR tube to retain slosh will also retain oil IN THE TUBES thus keeping it from the SUMP where it can be picked up again and recirculated."


"I make tabs that weld to the pick up tube and retain slosh and they work well. I have tubes with these welded on already if anyone wants to try one and see the differences.."

So, which is it Jake? (IMG:style_emoticons/default/confused24.gif)

Quote #1 is referring to the Pushrod Tubes. Quote #2 is referring to the Pick Up Tube.

Ooops.... (IMG:style_emoticons/default/slap.gif)

[Jake Raby]

Its both actually... Keeping oil out of the rocker area is one trick, getting the oil that is there back to the sump as fast as possible is the second trick. The third trick is controlling the oil that IS in the sump during cornering..

If I posted that pic I'd be shooting myself in the foot... If you want one of these trick parts I have it in stock (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/boldblue.gif)

I am also working on another wet sump modification that will work excellent with the scat wet sump addition. The way it will be set up it practically gets oil from two different areas of the sump one each for left and right turns. I'm trying it on my Hybrid headed 914 engine along with about 20 other wild and crazy mods.

[Bleyseng]

Yeah, ya could just run 1 1/2" pvc pipe from the valve covers to the tuna can to drain all that oil back faster.


Geoff

[SpecialK]

If I posted that pic I'd be shooting myself in the foot...

Show us Jake! I'll call for a Medic! (IMG:style_emoticons/default/biggrin.gif)

[Cap'n Krusty]

Never seen the tube mod on T1s, but 356s got it in the mid-late 50s, and 912s have it. Simple, cheap, and what harm could it do? Need to silver solder the extensions in place, something that might well be a challenge for a lot of us.
The Cap'n

[muddboy]

I wish i had a picture. was in an article 5 or so years ago... and I dont know if I have the magazine anymore. I can look, but dont expect to find it untill next year... but I will try to "sketch" out the idea.