Benefits of a PICT 34-3 with 37mm throttle body?

[Chickensoup]

[modok]

I can test the ignition system on a bench, it does not have to be in the vehicle.
Compufire or TFI module will fire down to zero rpm, TFI will work down to 7 volts, but yes some systems will not.

A hall sensor itself SHOULD work at very low speed, but the thing that reads the hall sensor may need a certain speed or voltage to wake up.

Cold weather carburetor tuning on the other hand, is very unpleasant.

[oprn]

Some results from submersed glow plug. 1 cup of water at 70*F

6 volt setting - 5 minutes - 92*F, 10 minutes 108*F

12 volt setting - 2 minutes - 92*F, no further testing as the battery charger breaker keeps tripping.

So in air these things can get hot quite quickly but in a liquid it's going to take a long time to get to auto ignition temperature!

Just for interest this one draws 36.1 watts on the 6 volt setting and 78.4 watts on the 12 volt setting.

Now just to round out the picture a bit apparently the boiling point of gasoline is quite variable as different components in the gas boil at different temperatures but the majority of the components will boil between 155*F and 338*F.

[Alstrup]

[ccowx]

On the subject of glow plugs, I would suggest that the one out of a BN4 heater might be better, That is what I had in mind. It does exactly what we want. It does NOT ignite fuel and it does not even glow brightly, if at all. It's purpose is to heat the fuel and create vapor, to be lit by an actual spark plug later. Sounds both safe and perfect for the job. I am NOT trying to heat the AIR, just vaporize the fuel. I suspect they are specifically designed to NOT get any hotter than they do. Harder to find, but maybe better?

On another matter, I like Busdaddy's point about blocking the lower vacuum progression port on the 34-3, if you are boring it out. According to Alstrup, if you bore the throttle bore out you end up with vacuum on all the time. If you closed off the lower vacuum port, it would seem to me that you would have no vacuum at idle, but you would still have it at part throttle, just like always, though I understand the signal would have changed somewhat. I am mainly worried about the part throttle cruise mileage, so that is just fine with me.

Would blocking the bottom one or two progression ports solve that issue?

Thanks!

Chris

[Alstrup]

34 Solex only have one vacum orifice, so you can´t do that. If you have the cahoneys to do it you can try and block the factory one and then drill a new orifice furter up so it corresponds with the butterfly again. I have never done that, I just went to programmable instead.
Wrt ignition/distributor. You could also source a distributor, amplifier and coil from a pre 1987 WBX. That dizzy is hall effect and one of the most durable systems in the world. It can be tweaked just as type 1 units can. I would replace the amplifier with a new unit, and maybe the coil so everything is fresh. The amplifier is the "weak" point in that system. At around 100000 miles they often begin to act up. But its a $25 unit, so I simply replaced them when they came in the neighbourhood of that mileage. Also, that system will put your Winterburn against the wall, so the spark strength is actually limited by the CDI as it will not yeld more than approx 80 Mj. But that´s plenty to get a good starting capacity due to the oscillating spark.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[ccowx]

When you refer to the orifice, which one are you referring to? There is the sequential small ones that are gradually exposedas the butterfly opens and there is a large one, maybe 5-6mm around, that is farther up?

Thanks!

Chris

PS: This is why I don't mind brainstorming when things get way off topic. I am learning other things, not just what I originally asked.

[Alstrup]

You arte mixing progression holes with the vacum orifice. Don´t touch the progression holes.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[busdaddy]

[ccowx]

Mine is a 427 flange number, just like the one in your referenced thread. I am looking at it and wondering why you would move it? It looks like it will be sitting right on the edge of the butterfly, basically on the same level as the lowest of the progressive vac openings. It looks like it would be blocked at fully closed, but as soon as the throttle is cracked even a touch it will start pulling vacuum.

A larger butterfly will still sit at the same angle etc, so the relationship should be about the same. Or am I missing something here? There is mention in the thread that it is supposed to be above the plate.

Thanks guys!

Chris

[busdaddy]

I suspect the hole isn't straight on to the bore, so when material is removed from the sidewalls the hole moves to a useless spot.
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Rust NEVER sleeps and stock never goes out of style.

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Слава Україні!

[ccowx]

That makes sense. So, do I call off my machine shop from boring out an original Solex carb and buy the 37mm version from Kipa, or do I make the probably better quality Solex work? Cost is close enough, but more of a nuisance to modify the Solex. Perhaps a better result though.

Thoughts?

Chris

PS: Yes, Busdaddy, I think you called it on the hole being drilled off center and changing location if you overbore it. It lines up perfectly with the hole where the large plug in the back goes. I would guess that the hole would move downward if you drill it out larger and even .5mm would put it below the throttle plate, giving manifold vacuum instead of ported.

[busdaddy]

It depends on how you would seal up the old hole (JB weld?), and how many stabs it would take trying to aim the drill to emerge at just the right spot.
Feeling lucky?

If you know a dentist maybe they could drill the hole from the inside, tiny tools and precision is needed here.
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[ccowx]

I was thinking of using solder to plug the existing hole. Even just pushing it in cold might do it, and sand flush after.

As for drilling the hole, it is actually not that hard. OPRN is not the only model airplane builder here! I have a whole series of micro drills etc that I could use. Care in putting in a pilot hole will make all the difference, and taking into account that it is a three dimensional question, but I think it can be done. The carb was originally manufactured that way with a series of plugs and channels cast in.

Thanks!

Chris

[modok]

YES, just need to move the hole.
I prefer to use brass, make a small slightly tapered plug JUST the right size, dip in loctite, drive in the hole.....cut off excess material. Always works.

[ccowx]

Drilling and plugging the hole is not so bad, but care in planning the angle is going to be the key. I have drills that will do it and you can see how you would access it via the plug in the back. I even put a long wire into the hole and you can see the angle very well, so that will be a huge help in getting it right. I am thinking the key will be to have the new hole be on the edge of the butterfly, blocked at idle just like it is now. Almost any throttle movement will open it up.

I am happy that I can get the bigger bore in there but not have to use a carb of questionable quality to do it. The cost is going to be about the same either way, so for a bit more work, a better carb.

Chris

[bigbore]

Well Iam going to bring this thread back form the dead. I used to live not far from ccowx in Alaska in the town called Tok just on the Alaska side of the border the only car I had at the time was a 1963 bug all stock 6 volt 1200cc and all it never failed me even down to -50F it sat outside no power to plug it in nothing it always started I would run 200 miles one way to Fairbanks for food no problem. now at the time synthetic oil was VARY new and hard to get but thats what I had in it 0w30 that made all the difference. I now in southern Alaska and drive a 71 westy year round (ya a hard core aircooler) and Iam building a new engine a low end torquer I pull a small trailer and want some more bottom end power so I was reading this thread just now so Iam way late to the party.
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where its cold and snowy

[Lingwendil]

Low end torque what you want? Certified stump puller? Enough torque to idle your way up a telephone pole?

High lift, low duration cam, larger bore, with a bit of stroke.

Let's say, here's what I would look to as a starting point, were I to build such an engine.

-Ported 35x32 heads, or some decent 37x32 heads, like the superstocks from Steve tims, or similar froom mofoco. Intakes only, leave the exhaust alone.
-CB2280 or similar cam, tractor torque, high RPM be damned. I'm sure there are betters,this is just the first to come to mind.
-8-1 compression or so maybe a bit higher, change to accommodate cam as needed.
-74 stroke, cast crank is fine I suppose, but counterweighted would be nice.
-stock weight flywheel
-90.5 bore, matched for weight
-stock rockers, solid shaft and shims
-stock rods, matched for weight
-ported stock dual port endcastings, high flow center section from CB
-oversized 34PICT-3 carb, enlarged venturi, enlarged throttle bore.
-stock heater boxes
-header type exhaust, modified for proper heat riser crossflow. Muffler of your choice, I say hideaway as I personally think quiet paks are hideous.
-ignition depends on carb modifiactions- if you manage to make the advance signal work, use an OEM german SVDA. Modified as needed for 10 initial, 30 all in perhaps?
-OEM Oil bath aircleaner, gutted and set up to use a modern element filter. Snout cut off, and enlarged. Inlet flared slightly at snorkel. All functional preheat system intact.
-Stock preheat fittings and tin, OEM doghouse shroud.

Should make for a relatively affordable, strong engine that reuses many quality, OEM german parts that often are cheap or free. The larger bore adds room to breath around the valves, and gives a healthy bump in displacement. The longer stroke adds torque, and really helps to suck the fuel through the carb with some force. 1904cc displacement uses the stock supporting parts to about the maximum available without too much extra work.
_________________
73 super beetle thread http://www.thesamba.com/vw/forum/viewtopic.php?t=649622 Back on the Road!

Modify your Kadrons for SVDA http://www.thesamba.com/vw/forum/viewtopic.php?p=8115884#8115884

Cast iron VJU4BR8 SVDA reference thread- https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

Need replacement filters for original Kadron aircleaners? WIX #42087 is a perfect fit, as is Napa Gold #2087!

[bigbore]

ok heres what Iam working with Iam working on two engines I have two westys a 70 and a 71. right now they both have 1641s and working good but I want abit more so I have enough parts (Iam trying to use what I have) to do a 1776 and a 1904.
new case's for both
a drp 74mm crank (for the 1904) stock crank for 1776
new NOS dp heads and need to buy another set looking at new AA heads. I have toyed with using a set of sp on the 1776 (I have them) but I think dp will be better.
rods I have a set of balanced dpr rods and a set of short AA I beam rods.
cams I have are a Norris 352S and a CB 2231 I love Norris cams I have been using them sense the 70s my 71 has a Norris bus cam 329S in it now but you cant get the anymore.
carbs I have a weber 32/36 and thats a real weber with a redline intake I love them and know how to set them up. the other will be a stock solex 34 mod'ed with a 28mm venturi.
the dist I have is two 034s I also have some real germen 009s but I think the 034s are better.
Iam setting the compression at 8.3
exhaust I dont have yet but that with have the heater boxs I do live in Alaska and drive them year round so the carbs need all there carb heat also.
So what do you think of that jumble?
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where its cold and snowy

[Lingwendil]

If you still need to buy heads look at Performance Workshop- Steve and Greg Tims Superstock heads- 37x32 valves, finished in house by them. They also offer a ported version.

https://www.thesamba.com/vw/classifieds/detail.php?id=1069091/

https://www.performanceworkshop.net/cylinder-heads

I have a set on my 1776, very nice work. Great value.

_________________
73 super beetle thread http://www.thesamba.com/vw/forum/viewtopic.php?t=649622 Back on the Road!

Modify your Kadrons for SVDA http://www.thesamba.com/vw/forum/viewtopic.php?p=8115884#8115884

Cast iron VJU4BR8 SVDA reference thread- https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

Need replacement filters for original Kadron aircleaners? WIX #42087 is a perfect fit, as is Napa Gold #2087!