New VW Solex intake

[Papee]

EDIT:
I am starting to get orders for this intake. Please keep in mind that your results may vary from mine but this carb setup is the best I've seen. My boat has tuned headers and exhaust, my exhaust is set up like an expansion chamber. I have on Harley Davidson Bullet style mufflers that I removed the guts then welded in washers to tune the back pressure of the exhaust. These motors do like some back pressure to run right. I've also adjusted my magneto to it's optimum setting for my setup. I did mine while on the trailer. I loosened the mag just enough to be able to move it while the motor was running, started it up and adjusted it to the best RPM. Then made sure it still started easily. My boat is also running direct drive. We should have results here soon from one of the guys running a reduction drive.

I finished up the starter project and it was too late to go to the river to do some fishing. I went down to the river to see how muddy it was an got to thinking. I was revisiting this VW carb setup. Everyone that has put one on has had good luck with it. I just didn't like the big square box plenum they were putting on to make it work. With the box there were just too many corners to trap the gas in and flowed terrible.

So I put my thinking cap on and came up with a better solution. I just happened to have a VW carb here left over from my Score Buggy. It's no good but I was able to use it for a template to make the intake. I took a look at the intake and it had some webbing in the middle which surely affected the flow so I did a little work to the inside of the intake before I got started. This is what you are looking at in the first photo, I didn't take a before pic.

I cut off the carb mount then welded a plug over the hole. I reworked this piece so it fit over the intake then made an opening in the top of the intake to accept the new configuration. Then I added material to the carb deck to accept the new carb bolt pattern and clearanced the sides to clear the rods on the Solex carb. This will certainly flow much better than what I've seen. Here's the photos.

Anyone considering a purchase of the intake from me I will need your intake in exchange. The intakes are in short supply, I think Mark said he only has 15 or so left. I'm going to go grab a few more but its best that I get a core so I have plenty here.

The price for the intake is $100 with core exchange plus shipping.
Without the core exchange it is $125 plus shipping.
PM me for details.

[aerokirk]

Interesting concept .... I'm still debating what to do about eliminating the original carb and I was also following the Solex conversions. I almost bought one on EBay recently but changed my mind before bidding. Is the throat diameter of the intake you modified the same as the output throat of the Solex?

[Papee]

The stock intake is the same size as the Solex. I would have liked to kept the carb closer to the intake but the carb uses the studs and one of them you couldn't get to if you wanted to take them out. The carb is also designed to sit sideways so the throttle linkage would be tough to do. So I rotated the carb so it works with the linkage and raised it to allow room to bolt it on. I didn't use any other materials all was made from the stock intake. Oh I did have to add an aluminum bracket on to bolt it to the stud that stabilizes the intake.

[Papee]

I went out on the river this morning to give the new starter setup a workout and everything is fine there. I had some time this afternoon so I tore the Slolex apart and the acellerator pump was good so I finished taking it apart and gave it a good cleaning. I put it back together and put some gas in the bowl to bench test it. Everything seemed to work fine so I put it on. I'm getting around 600-700 more rpm than I had been and the engine is real smooth from idle to full throttle. There is no stumbling or catching up in the motor at all. I'm going out in the morning to see how it does. I may be able to put my other prop on and put some more pitch in it if I run over 3100 rpm with the stick prop.

[aerokirk]

Very encouraging results! Did you re-jet the solex for the test or is it stock? Are you using the Solex/Brosol H30/31 or the Brokar 30PICT-1 carb?

[Papee]

Just getting ready to leave for the river. The carb is stock and the accelerator pump is set in the middle position.

[Papee]

I'm on the river now, it is working perfectly. It is pretty windy out today but I can really tell the difference. My oil temp has not been over 160 even after running the twelve miles to my fishing spot. The carb is a Slolex 34 pict-3.

[Doozit20]

im surprised of those results as well papee. Im using the 30/31 and I cant seem to get it much past the stock rpms. I measure mine with a tach that you point through the prop on the trailer for more accurate rpm readings. Might have to switch to the 34 if thats the numbers your getting. Keep us posted papee

steve

[Papee]

It worked great but it is an old worn out carb. It has no choke on it. I can't seem to get the idle down below 1200 rpm but that's not really a big deal its nice for idling around. I'm sure it's just because the carb is just plain wore out. Other than that it worked great. I am not getting quite the full throttle swing out of it either. I mounted my cable lower and drilled antother hole in the carb arm but still can't get it. I can't really run the prop faster any way. I'm at 3100 rpm now. It wasn't a real good day for testing because of the wind running up river. Going with the wind I got 33mph but that was a good tail wind.


steve your problems could be in the intake or intake design. I'm sure the work I did on the inside of the intake helped.

[Papee]

Just to make a few things clear, my oil temps before ran around 200 when I ran hard and now are down to 160 now matter how long I run. As for my rpm gain, I gained around 600 rpm over the Tilliotson and about 300-400 over the stock carb. More importantly is the engine runs cooler, smoother through all rpm ranges and just seems like a different motor. As I said above, I am not getting a full throttle swing out of the linkage so there is more to be had there. I really don't need it for this prop as I am turning it at max rpm now. This is something I will revisit once I replace the carb with a new one possibly allowing me to run a bigger prop or more pitch. It will most likely be a longer prop if possible rather than a pitch change.

[aerokirk]

Really good news. I ordered a second spider from Saturn so I can experiment with it. Are you planning on another Solex 34 pict-3 then? I've been watching eBay but there's not a great assortment right now unless you want a chinese (EMPI) version which I don't think I do. Sounds like you'll have to bodger up another bellcrank setup like you did on your first airboat so you get full range on your throttle linkage

Not a bad power increase for the $$$ output !!! Thanks for sharing info.

[Doozit20]

I was able to get a full throttle swing with the setup that I am using. I have a cable fed rig that goes in a sleeve much like a bike brake. It works pretty good. I did notice an increase in the overall throttle response with the 30/31 over the stock carb. Im still working on jetting but so far im only able to spin a 59x10 ultra up to about 2750. Im thinking I may go down to 9 pitch to see if its better. I was noticing however with the solex that the rpms stop going up at about 3/4 throttle but I can still open the throttle more with no increase in rpms. Maybe a larger main jet will help??? Any thoughts.

those are great results your getting with your setup papee. Gives us all hope lol

[krwsr]

Wow Papee! Great innovation with the intake. I'm with aerokirk, am ordering a manifold to play with, and I was able to find a carb on eBay. I have heard of a lot of success stories with this carb.
Kenneth

[aerokirk]

OK ... now I'm a bit confused ... Doozit mentions a lack of throttle response after 3/4 throttle. According to what I've read from Chuck and others, this would signify too much carburetor and the remedy would be to go down a size, but I suppose it could also just be a jetting issue. Papee ... I'm curious as to whether you will get the same results with the pict-34 when you get your linkage figured out. As they say ... you're right on the bleeding edge of technology !!

[Papee]

I'll pull the linkage off some time this week and see what happens. I think the big difference is the intake design. Have you seen the intakes that these past carbs were on? I was out this morning and put my small KN filter on that I was using. It didn't like that, the throttle response was not as good and I lost rpm. I ordered a new carb so I don't want to do too much experimenting with this old carb because I'm sure it's not up to snuff. Also, these carbs have and adjustable accelerator pump so I'll be experimenting with that adjustment when I get the new carb.

[aerokirk]

By looking at your posted picture it looks as though there were baffles in the spider, is that correct? I wonder if it was to swirl the airflow? I would imagine that opening it up made a really big difference in the power output. Did you order another Solex 34 pict-3 then?

[Papee]

I wish I had taken before photos of the intake. The one I am using was new old stock an never on an engine. I'm not sure about the design. It looks like there is supposed to be webbing there but on the one I modified it had a hole in it. Not a designed hole but one left by maybe the material not flowing in the mould right. I'm getting ready to modify another intake for the green boat so I'll be sure to get before photos of it.

I am sure that this design flows much better than the boxed plentums types I've seen. The modifications I've made to the inside can only help that's for sure. I did order the same carb I have on now.

Edit: I ordered the empi, I had one on my score buggy and it worked fine. It replaced the carb I am using now.

[Papee]

Welding on these intakes is not easy. Some of you may have experience welding cast aluminum and its not pretty. The impurities make the welding tough to get a good weld. I ground the intake good the used the brush on each piece but the impurities still caused the weld to be contaminated.

I'm not sure if the cleaners will help with this or not. I didn't bother grinding and re welding, I just got the best weld I could get on it and left it alone. I didn't try to make the welds nice by going over them. I brushed the welds and looked carefully for any spots I thought would leak and found none so I just threw on some paint just in case to help seal it. I never did get the bracket on mine to attach to the original post but the carb doesn't really move around. I will take the time to put it on the green boat since its not mine.

[Papee]

I decided to go out and cut my spare intake apart for photos. This one doesn't look near as bad as the one I used. I will still take the air grinder to this one grinding out as much of the center as possible and not messing with the strength of the intake.

You are looking into the hole where the stock carb would be. Seeing this like it is I can see why the two cylinders next to the prop run hotter than the others. With this web in there I'm sure those two cylinders aren't getting as much gas as the front two causing them to run lean and making them run hotter.

[Corky]

Interesting...I'm trying to figure out the reasoning for the stock baffle configuration....For anyone that cares I checked ebay and amazon...Amazon has the EMPI 34 pict 3 for $110.00 free shipping...