Thank you all for your list of things to check on my VS 1600 stock motor. Checked valves and they were tight on all exhaust and adjusted them 0-loose just as Rascon does for moly push rods. Checked coompression and cylinder 3 at 125 psi and rest at 120. Next i'm going to check EMPI HMPX 40mm linkage and mixture setting. Put did notice the Bosch Super + WR8AC Yttrium are gapped .021-.022. Can anyone comment on this?
Thank you,
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Are you sure you have chrome-moly pushrods? Did you test them with a magnet to be sure? Just curious.....
The plug gag for WR8AC Yttrium in your engine is .028" according to Bosch, so you can open them up a bit, like .028-.030 or so depending on your gapping tool (I like the round, wire-like versions). Also, this depends on what you're using for a coil but assuming the "regular" Bosch "Blue Coil", that gap should be OK.
BEFORE YOU CHECK THE CARB MIXTURE, pop off the top of the carb and check/re-set the float level - that's the first step, THEN set the mixture at idle. You might have to get the float level procedure from someone on here, as it's unlikely that it would be the same as a stock VW Solex or Zenith carb. Setting the float level and proper setting of the mixture screws should do a bit to improve your sooty plugs. Beyond that you'll need to look at jet sizes.
The compression numbers look fine for that engine.
Hello Gordon- thank you for your reply. Rascon said builds with mild cams get chrom-moly. I verified myself with a magnet. I do have the blue Bosch coil, are you saying increase plug gap to .028-.030? Reviewing other like Samba I relieze my current gap is too small. Thank you for the float and jetting suggestions.
Thnank you Wolfgang for the link, I found this one most interesting.
Yes, open them up to .028-.030 or so.
That, alone, won't do much to clean up your sooty plugs. That cure will be in how well the carburetors are adjusted.
It's rich.
I finally went through the check list and had to; adjust all the exhaust valves, checked compression at 120 psi for 1,2,4 and 124 on 3, checked the timing- was good, checked carb synch- had to lower the idle and then adjusted all carb mix jets with resynch afterwards with timing check. Took a test drive and it ran very well, noticed less of an exhaust smell and will run it for less than 50miles and pull the plugs to see what happens. For the car to have only 1500 miles something went out of wak. thanx everyone for your help as a newbie to the madness learns from experienced folks.
WELL, not so. Finished 30 miles and pulled plugs; sooty. It has been told to me that using an EMPI HPMX dual carb I should have a pressure regulator, which I do not. Its very possible with high pressure uncessary fuel dumps into the bowel over flows in the idle jet. Suggestion was to add a regulator to maintain 2lbs. Any comments from the forum?
No, it won't "overflow the idle jet". what it will do is push excess fuel past the pilot valve into the bowl, overflowing the bowl and causing the carb to run rich. Bear in mind that a little rich (slightly sooty plug) isn't a bad thing, but REALLY rich and a plug that looks like a black wooly caterpillar is not good. You seeing any puff of black smoke immediately off-idle if you hit it quick?
Well, it won't hurt anything to add a fuel regulator and drop it to 2 pounds. Sounds a bit low to me (I like about 3.5 lbs.), but if the EMPI carbs have a weak input fuel flow circuit then excessive fuel pressure certainly can cause that. Try it out and see. If nothing changes, run it up to 3.5 and pull your idle jets and let us know what size they are. We'll all comment from there, but they should be roughly the same size as a comparable Weber.
Thank Gordon for your help. My first time pulling out the plugs, they were just as you mentioned fluffy black. Just after 30 miles on long drives at 3K rpm they are starting to soot again- should be a light tan what I hear. I'll install the regulator assuming the line just out the pump but before the T split to each carb?? Clean the plugs and run it for 30 miles and check. If no improvement then its off to the float check and jet size. I'll report the forum folks what I find. By the way anyone one out there has done float adjustments for EMPI HPMX dual carb?
Did you sync the air at idle, linkage disconnected, then set your idle mixture to peak rpm? How many turns out are your mixture screws? Mine are a little over one turn out. It does depend on the thread pitch and type of mixture screw. If they are over 2 turns your jets are way too small. Less than one turn out and they are too big.
What we really need here to help is engine size(bore/stroke), valve size(and what heads), port shape and size, CR, cam, rocker ratio, exhaust, basically full engine specs.
Also, you really need to use a fuel pressure gauge, a couple of clicks on a questionable regulator tells you NOTHING.
Float adjustments are the same as Weber, 10mm to gasket, 22.5 to 25mm on the drop.
DannyP- now I realize more what the forum ment by "welcome to the madness" when I bought my car. The engine is a stock 1600cc and started at the bottom by adjusting the valves, setting the timing, adjusting the idle jets according to EMPI tech and sych'd. Just this weekend added a pressure regulator with a pressure gauge trailing it & yes the gauge really is needed for accuracy. After cleaning the plugs and running the car 50 miles then a plug check conditons have not changed. Now I thinking is purely a carb jet setting- way to rich for the engine. Looking over some EMPI youtube sites and charges, I think the idle jet which I have has a 60mm hole is way too large. I'm looking at dropping down to 50mm since I'm leaving at sea level. Since most of my drives are lone weekend runs and gas mileage is not that good I think dialing down the idle jet may help. If not then it maybe the main jet size which I believe kicks in above 2k rpm. ONE LAST Question- I pulled up a Weber IDF side view of the bowel, whats ment by 10mm to gasket and 25mm to drop?
Hi, not sure if this will help or confuse but I have the same carbs and an 1800 type 1. I had 50's in my carbs and they (when left for a while to dry out - not using the car much) left a residue in the idle jets that made the car run like s*** I took it to an aircooled specialist who said "no VW" should have less than 55's idle. He eventually settled for 60's and it runs so much better. I still have to clean the idle jets every 3 months or so but it's a different car. I think yours is adjusted too rich. The main jets don't function till around 1500-2000, idle jets all the way through (I'm no expert, so don't take it for absolute truth but that's how my car runs best now)
srblower, MOST will run with 55 or greater but it really depends on what the engine requires, not a blanket generalization. I could say that all lawyers are scumbags, but that's not really true now, is it?
An engine is an air pump, and exactly how much air it draws requires a corresponding amount of fuel. Period. If you set it correctly and size the jets right, it will be happy. The idle circuit works up to 1500 to 2500, depending on load, then you are into the progression ports which combine the idle and main circuit. Pretty much above 3000 you are wholly on the mains.
At sea level, your engine will require bigger jets than at altitude, air is denser down low, requiring more fuel. I'm not saying 60s are correct at sea level, just that the biggest jets your engine can use will be at sea level.
My engine started out with 60s and 55s work but 57.5 is the best compromise. Mains were perfect at 1.40. My engine is putting out close to 180 hp with those jets, which are smaller than some use and recommend. What I'd take from that is the engine needs what it needs.
There are tutorials online(youtube) about almost anything. But I can't find one on setting float height.
Quoted from Carey Hines: 10mm top height, measured to the gasket with the float lever arm touching the ball on the needle/seat but NOT compressing it. 22.5mm drop
In order to set the float height you need to take the carb tops off. I guess somebody or I should do a video someday....
I recommend that every new motor have an O2 sensor threaded bung installed in the exhaust. That way a wideband A/F ratio monitor can be installed(temporarily) for jetting purposes. A plug goes in the hole after you're done jetting, and then you KNOW it's done right!
Here is a video that deals with float height. Same procedure for Webers or dells really, just the measurements are different:
http://www.youtube.com/watch?v=HpleZIndmQE&list=PLOS0wPJkb5ZvYjiWp9uudqf3phzokddWL&index=7
This guy has a dune Buggy, but same powerplant.....I liked his vids on brake installation. He is a little dry but laid back and clear videos.
Hello everyone- its been a while since I posted. But have not forgotten you folks. Been working on my car taking in everyones suggestions and finally found the problem. The idle and main jets had been way off. With the purchase of the Weber manaul I self taught myself and with trial and error found the working jetting. As the manual mentions try to run just slightly rich to keep the engine cooler. I hope this will improve my gas mileage. It surely has reduced the rich smell I noticed while sitting at a stop light. Thank you all again.
Michael..... Thanks for letting us know of your success.... You just verified the need for a WEBER manual for those who don't live next door to Danny P. ( AKA: WEBER WIZARD).
As you found, its a learning curve, but doable..... Congratulations.
Congratulations, Michael, for sticking with it. I'll bet you feel like you know a lot more about your engine now, and I'm sure you'll see an improvement in the mileage. Do you remember what jetting was in the carbs when you started and what you ended up with?
The carbs had the .60 idle and .135 main. Final is .55 (tried .50 & had power loss at 2k rpm) idle and .140 main. Runs just as it did with the old arrangements, but smoother once warmed, much cleaner and feels much smoother at high speed. I was careful not to mess much with the high speed circuit since that felt really what the motor wanted- that was leave the air at what it was .200
What are you running for a distributor- mechanical only or mechanical/vacuum (svda) advance?
Currently came with the car is a mechanical 009
