DS Pump

[Wally]

Originally Posted by verbeekb

Porsche published a tech bulletin for the connecting rods, they should be notched for additional cooling/lubrication of pistons and wrist pin. I can see how this becomes even more problematic in a dry sump set-up.

Why do you think so?

This engine does not have a mechanical fuel pump or distributor drive, but those could be possible problems for others who are dry sumping with those parts in place.

Again, why do you think this is the case?

I know a type 1 with additional sump will run considerably hotter (no exact data) when ran with an oil level upto about the original oil pick up vs. stock configuration.

That seems very odd? again I don't understand this or heard of anybody with the same problem

I am also leaning towards wet sump in this case. This is a non track driven Bus.
Brian

I agree on the latter tho I don't see the 'need' for DS in his application either.
In general, I think you 'overthink' the whole thing too much. From others experience, the DS - even with that pump - works very well as is imho ;-)

Best of luck with the build,
Walter

[verbeekb]

Hi Walter, how are you? I was thinking of giving you a call on this one, but this works just as well

I don't -think- Porsche published a tech bulletin about notching both sides of the connecting rods in 914-4 engines, it's a fact. VW came with a similar bulletin about 12 years later I think. I have the original Porsche bulletin in my archive (twice) but as you know it's somewhat hard to get to The VW version of the bulletin also covers a change in P&C clearance and the elimination of the paper and alloy gaskets on the cylinders for all later model Baywindows and all type 4 powered Vanagons. I think they even came with a spacer to restore CR. The notches -three per conn. rod side- are needed for additional piston cooling, according to the bulletins of both Porsche and Volkswagen.

As far as the distributor drive and original mechanical fuel pump (which we are not using) are concerned: I am only saying that there -could/might- be problems in a dry sump set-up, lubrication problems obviously. I just don't believe that the addition of a dry sump pump and a tank is a complete and well thought out way of doing this, there must be more to the story. If no additional modifications are required then I would like to learn about that as well. There seem to be plenty of mods required in non VW engines that are converted to dry sump and we have very little room to do so (not easy to alter crank case dimensions, not easy to install additional oilers for pistons and cam lobes), but that does not automatically mean we can get away with it. One solution might be to modify the scavenge pick up so there will be more oil in the sump at all times.

The temperature difference between stock type 1 configuration VS Gene Berg additional sump, both running approx. same amount of oil, gave me higher temps in a few rough field tests, again, no accurate data, just an observation, this translates very easily to a dry sump set up, not a conclusion, just something to think about.

So far the only advantages of dry sumping I can think about is the constant supply of oil under -severe- driving conditions (if the tank is narrow/high enough), and the additional oil quantity. Assuming we will go for true full flow filtering and and external cooler, there are realy no other benefits (ok, windage issues perhaps, but that is of little importance in this case).

Overthinking the issue, yeah, you may be right on that one, but see, this is not a low budget project, it deserves the right attention and it is not my engine, I have to be more than just sure. This engine needs to be torquey, ultra reliable and will stay in that Bus pretty much forever, it's not a test bed.

Cheers,

Brian

www.karrera.net

Originally Posted by Wally

I agree on the latter tho I don't see the 'need' for DS in his application either.
In general, I think you 'overthink' the whole thing too much. From others experience, the DS - even with that
pump - works very well as is imho ;-)

Hi Walter,

Thanks for your reply.
We are trying to find out what is the best solution for my type 4. DS in my situation is not needed. I agree on that,
but is DS the best solution or not, and if yes, which part are the best and should we use? That's what is important to us.

Funny to read from your hand that Brian and I ‘over think’ it to much. If there is one person who will not affiliate anything
without hard evidence, it’s you. Others experience with DS and the Schadek pump is just not enough for us this time. We
want to know for sure. Let us just this one time.

Luuk

[Wally]

Originally Posted by skywalker

We are trying to find out what is the best solution for my type 4. DS in my situation is not needed. I agree on that,
but is DS the best solution or not,

IMHO, DS is always best. There are several reasons why you don't often see it tho. Complexity and cost are one and wet sump being 'enough' in most applications is another.
Funny thing is, the one reason Brian mentioned as a minor one: windage advantages of DS, is a pretty major one for me. IMO, the bigger the engine and the higher the rpm's, the more windage becomes an issue that DS can help with. I think the windage advantages of DS will give a few hp's extra as an end result (the extra gears cost hp first..)

and if yes, which part are the best and should we use? That's what is important to us.

Well, a rough guide is 'you get what you pay for'. Cost of different DS pump I have adressed in the earlier posts as you may have read

Funny to read from your hand that Brian and I ‘over think’ it to much. If there is one person who will not affiliate anything without hard evidence, it’s you.

Well, then that should tell you something No, but seriously, its just my opinion on an internet forum. For real info, ask a professional who's business is it to warrent his engines and backed up by hundreds of builds. I am just as a hobbyist.

Others experience with DS and the Schadek pump is just not enough for us this time.

Thats too bad. I regard others experience very highly, depending of course who's it is, but in general, I think theory is highly overrated and real life experiences of actual users count for everything in my book...
Therefore, I take for instance Sandeep's descriptions of his experiences very serieus and regard them as highly valuable, especially since fellow hobbyists like Sandeep have NO alternative motives (commercial ones for instance) to make up story's or tell it any other way than as it really is.

We want to know for sure.

Sorry, no guarentees when you build something yourself. Also, there are too many variables to be sure of anything when you are tuning at this level with some of these unique parts.

We both know what the person who designed your engine does for a living and what his experience and skills are. Then ask yourself this: when the person designing this combo chose these exact parts, you can either trust his judgement or don't and alter parts of the combo. If you choose the latter option, thats fine also but the question of wanting to be sure gets a little academic then in my book

Regardless, it will probably be an awesome engine anyways
Best regards,
Walter

Thanks again Walter for your comment.

Porsche and VW published a tech bulletin about notching both sides of the connecting rods in 914-4 engines as Brian mentioned. That’s in wet sump conditions! Is there enough oil in dry-sump set-up for i.g. the additional piston cooling? That’s what worries us too.

Originally Posted by Wally

... its just my opinion on an internet forum. For real info, ask a professional who's business is it to warrent his engines and backed up by hundreds of builds. I am just as a hobbyist.

We will, as a fact I already did. We will continue that conversation face to face on short notice. Anyway, we are also interested in the opinion of others, especially if they are hobbyists like you.

Originally Posted by Wally

We both know what the person who designed your engine does for a living and what his experience and skills are. Then ask yourself this: when the person designing this combo chose these exact parts, you can either trust his judgement or don't and alter parts of the combo. If you choose the latter option, thats fine also but the question of wanting to be sure gets a little academic then in my book

True. I know and you know that designing an engine like he did does not stop when start building. Designing goes on when building. If one of us is an hobbyist, I am. So I am very glad the help Brian gives me and I asked him to do the designing part. I am only paying and learning a lot these days.

Also, don’t forget the engine was designed for a beetle, not a heavy split bus. We both know the designer works a lot for customers related to race and cross. That’s his strength. My bus -when finished- would be happy on a race track I know for sure, but the chance the bus is going to see a race track is minor. It’s no wonder we look at the engine a little different then he did.

About being sure, you are right. There are no guarantees. Maybe I was not clear enough; I mend we want to be sure dry-sump is the best for my engine and my situation. That means we have to do some search and ask others at experiences. Like Brian mentioned he never build an engine with dry sump on it. For me that is a big advantage. Maybe weird to say so, but he is ‘clean’ in the way he is thinking and not going to let his course be influent by experiences in the past. (Experience are old solutions for new problems).

There will be a lot of opinions about DS is the best or not. For now –in my situation– I am not pretty sure it is, not even now after you typing “IMHO, DS is always best.” Sorry, I might be as stubborn as you sometimes can be. I appreciate you are sharing your honest opinion with us, but again it’s just not enough.

Originally Posted by Wally

Regardless, it will probably be an awesome engine anyways

And that’s what it is going to be! DS or not…

Cheers,
Luuk

[Wally]

Originally Posted by skywalker

Thanks again Walter for your comment.

Porsche and VW published a tech bulletin about notching both sides of the connecting rods in 914-4 engines as Brian mentioned. That’s in wet sump conditions! Is there enough oil in dry-sump set-up for i.g. the additional piston cooling? That’s what worries us too.

Your welcome of course. The more detailed problems are most fun to respond to

Your fear of the notching being different in wet sump as opposed to DS is one of those things I really don't get (part of the 'overthinking')? I mean, you do know where the oil for the V-notches comes from right? How would this ever be different in a DS application? To me this is really one of those 'non-issues'

Sorry, I might be as stubborn as you sometimes can be.

Ah, I think you know me already haha!

I appreciate you are sharing your honest opinion with us, but again it’s just not enough.

Thanks! but I also don't feel the need to pursuade you of anything. In the end you will have to follow your own judgement, which is what these boards are helping us with greatly .

[verbeekb]

Originally Posted by Wally

Your fear of the notching being different in wet sump as opposed to DS is one of those things I really don't get (part of the 'overthinking')? I mean, you do know where the oil for the V-notches comes from right? How would this ever be different in a DS application? To me this is really one of those 'non-issues'

Hey Walter,

I am not thinking that the notches should be placed differently. I am sorry if I wasn't any clearer earlier.

The thing is, if these notches were deemed necessary by both Porsche and VW in wet sump conditions, then, what kind of piston cooling/wrist pin lubrication do we end up with in a dry sumped type 4? I think that captures it better.

As for windage. I am aware it "eats" energy. So does the cooling fan, so does the transmission oil. The case of Luuk's engine is mildly fishtailed, something that seems beneficial especially with the lager bores. The crankshaft is not modified to reduce windage. In a Porsche 6 the hp gain from fishtailing and knife-edging is assumed to be about 10% (!).

Cheers,

Brian

www.karrera.net

[Wally]

Originally Posted by verbeekb

The thing is, if these notches were deemed necessary by both Porsche and VW in wet sump conditions, then, what kind of piston cooling/wrist pin lubrication do we end up with in a dry sumped type 4? I think that captures it better.

Hi Brian,
No, it was clear to me before you weren't referring to the placement of the notches

I think we're getting somewhere here tho: I think that you think that the wet sump is partly responsable for lubrication of the cylinders right?
Sorry, but that is really not the case imho (think for instance windage tray in 914 2,0 application). Its the escaping oil between the rods and crank flanges that takes care of it. That's also why the rod sideplay is so important. Too much sideplay there costs oil pressure to paint the picture of what happens there.

To capture the jist of it: your wet sump does NOT lubricate the internal engine parts! Don't worry about it one second.
The rod notching was also only advised late in the seventies when there were only those really heavy brick-type T3 Vanagon busses on the market. Before there obviously never was a problem...
Those T3 transporters were so heavily abused combined with high weight and poor Cw that the engine/oil and thus also the pistons got so hot, they expanded too much and caused seizing (cheap cast pistons) in more than one occasion. Extra oil cooling was to prevent this. So, its not about lubrication, but only about cooling!! The final solution of VW was better cooling by introducing watercooling (wbx) soon after...
That is my reasoning behind the factory-advised notching thing.

I have actually never notched 2,0 liter rods in any 2 liter engine I build and I have done many many miles with them and all had way more than the factory 70 hp. Last one had twice the hp...and no ill effects of the alleged 'neccessary' notching. Most of them, I have done many miles and again, never any oiling issues of seizing of pistons... but I have always had good cooling not driving a T3 at 100 mph on the freeway also helps

Like I wrote before: I think its a 'non-issue' all together in anything else than a stock T3, but you had to let me write it all down again huh .

Now, if I would ever build a turbo type 4 on a 2 liter basis, the extra piston cooling might be very welcome since turbo's make pistons very, very hot and lean conditions are possible very easy and very fast. So I want to try this piston notching someday to see what it does or not do, but I don't worry one bit that I don't have it for now

Greets,
Walter