How Much Power Can a 1600 Dual Port Make? We’re Finding Out!

[Alexander_Monday]

[BFB]

[Root_Werks]

Sort of getting back to the OT:

Turbo aside, I would think you could make a street-able 1600 produce 75-ish HP. Porsche did similar with the 356 Super 90 and that was 1600, correct?
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When I set my timing, why do I flush, then take a pee?

[oprn]

Ah yes but without opening up the case or removing the heads? That was the original premise of their experiment. It has of course morphed into more when the numbers were not high enough...
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Our cars get old, we get old but driving an old VW never gets old!

[Fun With VDubs]

Our latest episode is up on our channel! In it we have a special guest star, the engine out of our Baja Bug. We test a few different distributors. Most notably a 009 and an SVDA. The results were NOT at all what we predicted. We also see just how much power this engine makes.
FYI, at no time was this engine in danger of blowing up!


Link

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Swing on over to our YouTube channel. There we post work we're doing on our VWs, and the adventures we take them on.
@FunWithVDubs

[Zed999]

SVDA isn't for making power, it's for low throttle driveability and economy, neither of which show up at WOT on a dyno. Silly video this week drawing the wrong conclusions by testing a street engine effectively on a drag strip.

[Alstrup]

Yeah, as I noted on yt, there are so many misunderstood results this time that it almost hurts. Jeebuzx! I had decided that I would not comment more in this thread because of course should attack it the way they wanted. But the understanding of what and why here is totally lacking. I will explain tonight.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[Alstrup]

Yeah, as I noted on yt, there are so many misunderstood results this time that it almost hurts. Jeebuzz! I had decided that I would not comment more in this thread because of course they should attack it the way they wanted. But the understanding of what and why here is totally lacking. It has to be corrected for fiture reference. I will explain tonight.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[oprn]

My thoughts on this one is that the testing and comparison is woefully inadequate and really inconclusive because we were only given hints of what the individual timing curves were. All we know is initial timing and total timing, there is a whole lot going on in between those two events that we know nothing about.

This is especially true for the vacuum canister. How much advance did it give? And at what throttle setting and RPM did it occur?

Also when your Buddy talks about the vacuum canister pulling a lot of advance at idle... something is wrong! My guess is you are hooked up to a manifold vacuum port, not the proper distributor vacuum port because if you were there would be NO vacuum signal at idle.

Each distributor started out at a different initial advance setting and that alone makes the playing field unequal especially in the lower 1/2 of the RPM range where you were looking for peak torque. If you were to document that I believe you would find out where the missing torque and power was lost.

And as has already been mentioned, the drivability/off idle stumble was mentioned several times but not at all addressed in the dyno runs.

As usual it was an easy to watch, entertaining video but I would like to see more meaningful depth in the content.
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Our cars get old, we get old but driving an old VW never gets old!

[GS guy]

Does seem like the CB dist. was a bit lazy compared to the 009? Despite the adjustability, no mention made to trying to match the amount of advance and curve to the 009. It should have at least matched the 009 in performance. Also no mention of tweaking the accelerator pump to help with the flat spot (presuming it has some adjustment). That said, these videos are a fun watch - with more of a "hold my beer and watch this" attitude!
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70's vintage Deserter GS buggy - undergoing transformation to Super GS!

[Alstrup]

Soo. Where to begin.... Lets take it from the top

39 mm. Solex carburettor.
Adding that on top of a stock intake manifold will do next to no good. In fact it will almost only make your life more complicated.
Half of the potential gain will be eliminated in the adapter some people use to size it down to the manifold size. If the carb is attached directly with no adapter it is equally poor.
All 37 & 39 mm carbs DO NOT work with stock SVDA distributors. Reason is that the vacum orifice sits too low in relation to the butterfly.This leads us to the next issue.

Distributors.
First, there was no telling whether they swopped coil along with the distributors. I have to assume they did, because the same coil on all the distributors would result in even larger differences.
Now, The reason to why the 009 performed the best is pretty simple. It had the Ignitor 3 module. And what is the ”3” module? - Multispark. We will come back to that.

In this particular set up they have opted for a slightly higher than stock duration camshaft, but relatively low lift. Then they have opted for large valve heads, because large valve heads makes sense on a larger displacement, right(?) - No, not necessarilly. What happens here is that due to the rate, in lack of a better word, of the intake, the intake port velocity is fairly good at lower rpms, so the engine makes decent torque down low, but tapers off pretty soon. That is because the engine can´t breathe. The ”time area” is wrong and the intake vacum becomes is wrong in relation to the cylinderhead, so the intake port is inefficient most of the time, which again means that the fuel mix in the chamber never becomes good. And that´s where the Ignitor 3 comes into play. Due to its multispark however not especially strong it does have a significantly longer spark duration, which means that the fuel mix gets lit up better, and THAT´s where the extra torque and +2 hp peak power comes from. Not the 009 , not the carb, but the burn quality.

The SVDA dizzy. Can be a fine solution, but definitely not here.
As I already mentioned, the 39 Solex carb does not work with a normal SVDA.
Also, the overall mechanical timing curve in a stock 113 series SVDA does not match the engine. So it is a no brainer that that didnt work well. (If they did´nt swop coil at this point then there is another reason to poor running and poor power)
The CB dizzy. Well, it was obvious that the timing curve out of the box didnt match the engine´s requirements, but they apparently didnt bother playing with neither springs nor advance stops to find the sweet spot. The ”missing” 2 hp is explained above.

As for advancing the timing at idle, where the postulate is that if you advance it at idle you pound the main bearings.... Seldom in my life have I heard such a postulate. How should that be connected? Of course, if you advance it so much that the engine pings there is an issue, otherwise, no. That guy should take a look at the timing map on a modern engine with even a factory ECU. He will be in for a rude awakening.
With all engines, but especially engines fed by one carb or 2 sgl barrel, (or a V8 fed with a 4 barrel) you – should – set the timing where the engine likes it. To be understood like this. When you add cam duration you effectively reduce the intake mix quality from a little up to dramaticly. So what do you do to counter that ? You richen it up, right. Now, how does a rich mix burn compared to a stoich or slightly lean? … SLOW. How does a poor fuel mix burn compared to a good mix?... SLOW. Soo, in order to compensate for this you ADD timing at idle, so you can still have something like 80% burn before 20 degrees ATDC. Depending on the tune and the combo that can be anything from a couple of degrees to a full 10 degrees. (On big V8´s with way too much cam for street use I have had to go to 25 degrees idle timing before the engine would idle reasonably well)

So, at the end of the day it is fully explainable and not at all strange why the 009 with the Ignitor3 won this ”competition”. There are of course other factors, but you can generally say that the poorer the red thread in your build is, the better ignition you need. The poorer the fuel mix is, the better ignition you need. Also, another often very overlooked factor is, that the larger the bore the ”hotter” the ignition needs to be. For comparison, take a look at for instance 79-on VW type 2/4 2,0. WBX engines and similar, and see how they have made the ignition.

Getting back to the carb solution. In this case a stock 34 mm Solex with a 28 mm venturi would have been a much better choice, because then the vacuum for the SVDA would have worked and then you could have modified the timing curve – and to an extent the vacum pattern to what the engine wanted. That solution woúld most likely not even have cost torque, and definitely not peak hp because such a carb will support 95 hp easy. Also, the dreaded off idle stumble would also be easier to eliminate, even with a 009.

Then people will, once again come out and say that you can´t adjust an SVDA. Right. A few econo dizzy´s are not adjustable, but most are. I will once again link to a Ford guy who shows it well. It is the same base type distributor, so the proceedure is the same. https://www.youtube.com/watch?v=gkMLNRARGUE&t=192s On most 205´s it is even easier through the inspection hole.

I could write another essay on the 37/39 carb and intake and how to make power, but I will restrain from that since that was not the subject of that video. Also, there are some very good Baja class tuners around who can tell you even more than I can on that subject though that is of course mostly racing. Only will I say, a 39 mm Solex, prepared right, on top of the right intake will support 140 hp in street trim. Not race, street.

I hope this helps understanding the odd results from this video.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[Fun With VDubs]

[Alstrup]

I would like to stand corrected. But then you have to tell me where I am wrong
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[EVfun]

The one thing that struck me was that you timed for 30 all in without considering the effects of changing initial timing. Just driving stock engines you can tell the difference at the low end if you bump the initial timing from stock 7.5 btdc to 12.5 btdc (or 10 to 15 on a 40hp). I think that feeling was a small bump in low end torque/power.

In your last test you put the 009 back in timed 8 initial 28 all in and the results where just behind the first runs with it timed 10 initial 30 all in. This seems (to me) to be reinforced by seeing the CB unit (that you noted advanced more smoothly) had a less lumpy torque curve at the lower half.
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[rayjay]

[rayjay]

If you really want to find out what advance curve an engine combo wants you start out with a locked out distributor. Then it's pretty simple to do dyno pulls at specific rpms and adjust the timing at that rpm until the motor is making it's max and then move to the next higher increment. Once you have the timing numbers on a graph you modify the distributor you want to run so that it has the ideal curve. You really need a distributor machine to verify your work. You could do it on the engine but it would be tedious in the extreme.

[oprn]

Fun With VDubs I see you as taking the above comments not for what they are worth but as an affront your trust and confidence in your VW engine Buddy. Don't take it that way please! While you have found a fellow that is doing some good things with old air cooled VWs and that's excellent but there is NO ONE out there that is infallible. Everyone can learn something from others!

That is the basic premise of this site and I hope it is the same with your YouTube efforts. When we stop entertaining and considering other people's experience, ideas and theories we have stopped growing in our minds and in the hobby. Each and every one is good at something and the sum of the parts makes for winning results whatever your goal is.

I might add that in the begining of the VW there was a team of very competent engineers working full time for decades to take these engines to the level of drivability and dependability that we enjoyed. Today we are redesigning that same engine to try to meet modern expectations and driving conditions. It is unrealistic to expect one single person to have all the answers.
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Our cars get old, we get old but driving an old VW never gets old!

[modok]

The distributor should make no difference to the power at WOT if the timing is right.
All the distributor does is turn the coil on and off, and send the spark to the right wire. You don't need a dyno to test that.
But you can use the dyno to test what ignition timing the engine wants at each rpm, hint hint.

So something was goofed up in the tests, but it does prove something anyway, it proves that things can be goofed up.

[DesertSasquatchXploration]

^^^
Yup I just ordered the PerTronix 60130 HV Coil 60,000 Volt E-Core for my points 009 at 3700 to 4700 in a sand bowl Im 100% confident she will sing just fine and have great low end response as well. I don't want a CB china made trash distributor my 009 works great always has.
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Key is to have downward travel Preload keep both wheels on the ground at all times once you lift a tire your DONE. Guys worry about clearance instead think of the opposite you want the suspension to drop that tire in the hole and keep you going. A spider for example they keep their body low but their legs can reach pretty far so they don't (bottom out)

[petrol punk]