bgmcl60 Build

[Corky]

Nice looking set-up...What's making the casting shatter like that ??? Was the first carb cracked also near the mounting bolt/venturi area or is that casting flash showing up in the pic ???

[bgmcl60]

I think the alloy this carb was made of was too brittal someone must of dropped it hard. It spider webbed all over the bowl even up toward the top of carb. I sent the seller a picture and he refunded my money. I found another new one for 25 dollars less and bought it $89.00. The 32/36 was around 140.

[bgmcl60]

well after receiving my new 40 idle jets it still ran rich at idle around 10 to 1% about as good as i could get it and the high side with the 140 main jets it goes to 17 to 1%. not good at all tried different things with air jets and emulsifier tubes and nothing fixed the carb. my conclusion too many cfm's for 084. this one was 390 and i think 300 would be max. only my opinion. it could be fixed to work but too much time to block of passages and drill other ones.

[Corky]

Yeah, 390CFM is quite a bit for the 084...But at least you tried it...With all those other good choices it doesn't make sense to spend that kind of time on the carb..

[bgmcl60]

after failing to jet the 38 38 to run rich enough it wouldn't burn a pistion i decided to put the weber 32 36 back on and retune it. well to my surprise it was running a bit rich at idle and mixture straightened that right up. now i let it warm up completely and at 2000 rpm it was running mid 13 % and at wide open 3600 it was showing 14.7 %. wow i never seen that reading before without a lag at low rpm. the only thing different i did was to welded the upper part of the 4 to 1 adapter to the 084 intake. using the adapter with the original intake modified sit the carb higher than i liked. i cut the top half off the adapter and welded it to the 084 intake and i think this must have made a difference. just set the idle mixture and left the jets in i ended up with. bart had shown a picture where he had modified an 084 intake this way. thats what gave me the idea and with a new mig welder with spool gun it was easy. thanks again bart. this is his photo.

[Bart]

It is good to hear that something i posted is helping you out. ,
when i put it together last year, my first idea was to cut the flange off the bottom. and weld it to the top of the 084 intake, but my friend didn't want to attempt welding the to pieces together. so i ended up putting a flange to join them instead, but after hearing about your success, this minor mod might be one of the first things i do with this intake, I really don't like having an extra joint, and having it sit up so high. but below is a side view of how it is at the moment. I have blacked out what I will remove. i did not take off the front of the 084 intake, because i was wanting to use the factory mounting tap to help keep it stable with the extra weight of the carb.

[bgmcl60]

yea thats the way i did mine and still high enough for the linkage turned toward the bottom without hitting the intake tubes. i don't think leaving the original connector on will matter.. just block it off.

[Bart]

i have been thinking about, and looking at a few of the intake mods that have been posted over the last few years, and one of the biggest similarities that has been given many of us problems in tuning, has been having to much dead air space below or behind the carb. and maybe that VW adapter was just on the big side of to much space. looking back at a few of my ideas. i built a baffle that would fit in the neck of the original intake. so i wouldn't have that empty space, for air or fuel sit around in. and where i had put some weld beads on the bottom of the intake, so i could hone it out just a little more, now i am hoping that i didn't go to far overboard on cleaning it up. as for putting the plug in, the intake necks down, and the plug comes to a rest just at the edge where the intake divides up. i will have to dig around and find that plug now. and get some better pictures. at least now i am starting to see quite a few similarities, that many have had when modifying the intake manifold.
just something to think about.
in the one picture i had drilled a hole in the end of the plug. my thoughts on this was, when installed i would have another hole drilled to line up with the 1/4" threaded plug. so if i ever wanted to hook up a vacuum gauge, it would be simple to do. now i am wondering, exactly how big of hole do i really need to read the vacuum, and minimize any of the dead air space. maybe i will change this out to a solid aluminum plug, and drill an 1/8" hole that will line up with the external plug on the intake.
here is the link that shows how much i cleaned out the inside of the intake. there is always something new to learn. go to the last posting of pictures on this page.
http://miniairboatassoc.com/forum/sh...Thoughts/page2

[Papee]

I cut that end off and use it for the carb mount. I just remove the old hardware and add some material then drill new holes. The threaded bung is still there. Those intakes surely did not have much quality control. I've seen some with only about a 3/4" opening because of the flash.

[yamahaulerG1]

When I had my 0-84 it was set up by some local PPG flyers that uses them direct drive. I believe that's all he did was cut the end and weld it back on top then the 28mm solex bolted right to it. Although I don't know if at the higher rpms it is still enough but at 3000 rpms the 28mm works great. I even tried the 32mm and i lost rpms but I didn't try to re-jet the 32 I just went back to the 28. I also compared it to the stock carb and it would turn the same rpms but it would stall if you hit the gas to hard. The two barrel carb you are using does it open both sides at once or does the secondary open when the vacuum gets strong enough like a 4brl?

[bgmcl60]

they do both.the 38/38 i tried opened both barrels at the same time. the 32/36 was a progressive type that opens the front barrel and then a link opens the second barrel. only has 1 idle circuit and 300 cfm. the 38/38 had 2 idle circuits each working together. at 390 cfm i gave up on trying to bring it down to 13-14 % on wide band gauge. with 150 main jets i would have thought it would be running a lot richer. but not the case. there is a lot i don't know about this carb. mainly why they would use the same air jet as the 32/36 and also the exact same emulsifier tubes.

[Bart]

a year ago i came across an magazine by Bill Fisher, How to Hotrod Volkswagon Engines, i have referred a couple of times to information , but it had been a while. i just read through the carburetor chapter again. and he talks a lot about the theory behind the size of the venturi vrs. the fuel flow among other things. the carburetor section starts on page 24 and goes to page 43.
even though at the moment, i cant put into practice what i am reading, it is answering a lot of questions, and i am starting understand it just a little better.
How to Hotrod Volkswagen Engines - Page 24 - Google Books Result

https://books.google.com/books?isbn=0912656034

just thought this article could help out with some tuning information.

[bgmcl60]

that was some good info and explains why i couldn't tune the 38/38 weber. the ventures were too big working as a pair and not enough air velocity. now if it were a progressive type i think things would have been different. also thats why the 32/36 progressive works so good. more air velocity with smaller venturi. now it all makes sense. so i was banging my head against the wall for a reason i couldn't fix. it also may make the bug spray carburetor a little harder to tune properly because i don't beleive it a progressive type. i really can;t remember. it been like 15 years since i even had one apart.

[Bart]

glad it helped you out. i understand what it is saying, but trying to explain it is another story. it was interesting to look at the dyno chart where they compared 3 different carbs on the 1600 cc motor.
it was after reading this, that i started looking into the progressive carbs that might work for the 084. because of the hp & torque gain that it showed. when compared to the stock carb.

[bgmcl60]

i got to thinking how well the solex 34 pict carb worked and easy to jet so i started searching and found a solex 32 36 progressive carb. the price was low under 100 dollars so i said what the heck and bought it. put it on the new intake i just finished and luck would have it ran perfect no jetting to do at all. right out of the box and it ran 11 to 12% at idle and a little over 13% wide open. no hesitation and a smoothe transition circuit. it don't get any easier than this. if anyone wanted a carb with no jetting involved i think this would be the one to get. the outside looks about like a weber 32 36 but the inside is solex.float is in the bowl not on the lid. https://youtu.be/fzwztqV5O6s i changed my pitch on prop to lower rpm.

[Bart]

i like how low you got the carb sitting on the intake. i like that you have only one choke flap, on the primary side. i read about many doing that, to keep the secondary from flooding out. if my memory serves me correct.
so where did you find this solex 32/36 carb, i could sell my weber and be ahead of the game. glad you are having fun.
i have been wanting to redo my intake adapter. so it would look something similar to yours, but the wind has been a good 25 mph for the last 4 days. and welding aluminum just isn't fun in the wind. maybe later this week it will die down.

[bgmcl60]

https://www.ebay.com/itm/516-NEW-UNI...VWTKH7&vxp=mtr


it's aftermarket and not a genuine solex but it still works.

[Corky]

Hey Bobby nice alternative....Looks good and as Bart said,sits low with your intake mods...Great job.... It doesn't get any easier than just bolting it on with no tuning and having it perform like that...I might need to try this one out myself...I like the progressive arrangement...Two questions...You said the adapter is a "4 to 1" VW adapter ???? And lastly, at the end of your post you stated you needed to change the prop pitch I'm assuming this carb stepped up the RPMs it did so well ??

[bgmcl60]

i changed the pitch of the prop to bring the rpm's down. i thought 3800 was a bit much for this engine and it gets on plane just as fast. my cruiseing rpm's is 2800. before i changed the pitch it was around 3000.
be advised if you shop on ebay they have a lot of carbs claiming to be 32/36 progressive but are not. 1 was posted as 32/36 and was a 38/38 weber. so make sure you get what you want. if in doubt ask the seller to clarify description. in fact the one i bought is closer to a 34/34 than 32/36. the 4 to 1 adapter is to adapt a 4 bolt weber to a 2 bolt solex. i meant to say a 4 bolt to 2 bolt. i didn't actually cut the adapter shorter. i trimmed the 2 bolt flange off to make it round. i had a factory 084 intake i had adapted to fit a 1 barrel. cut the pipe that i had welded to intake with about 1/2 in still on intake. this gave me something i could sit the 4 bolt adapter on without having a gap in the fit. easier for me to weld that way. the adapter is a perfect fit over the pipe. just have to grind out the bore smooth.

[bgmcl60]

everyone knows the ultra prop is a good prop for direct drive. usually on a 3 blade 10% pitch blocks works good. my son has the circle s belt drive on his boat and i wanted to use the razor x on mine while testing different carbs. knowing that 14% pitch blocks was too much for the ultra direct drive but what about belt drive. well i ordered another blade and a 4 blade hub and it took 16% pitch blocks to hold his engine down to 3400. but he said it didn't get on plane as fast as the razor x did so i gave him the razor x to use and i ordered me a razor x 3 blade. i told casey if it don't work out i will build me a razor x 2 blade hub and be good to go. since i think i am finished with changing carbs it time to use the boat for what i made it for.