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Posted by: ME733 Dec 15 2009, 01:29 PM

well gang just reciently there have been some posts about carburator jets, air correction jets,jet carrier, and their location, and how to read them. My question is this. For those who have measured /verified /checked the accuracy of Jets, (both air and mains) who would you recommend , and who would you purchase them from?. I ask the question because some "new" jets I have collected are a little off. examples, 120,s were 130,s, 125,s were 135,s, 130,s were 145,s...etc., it,s easy enough to drill out a small jet and make it larger.(with jet drills) but this doesn't work in reverse naturally. So who would you recommend for new accurate Jets! or other accurately made carburator parts.

Posted by: tat2dphreak Dec 15 2009, 01:38 PM

aircooled.net

aircooled also has mid sizes like 57.5 and 52.5 and john will even help you fit a set that matches your application, if you want advise

Posted by: 9146986 Dec 15 2009, 08:52 PM

If there's any question you can check the jets with a jet reamer. Just find the reamer that fits and slide the jet down the taper and mark it with a sharpie, and then check the other jets to that mark.

The other thing I've found is that most jets are a little smaller than the appropriate jet plug gauge, if that matters.

Posted by: GeorgeRud Dec 15 2009, 09:23 PM

Don't know if he's still doing it, but Rich Paar @ PMO was always helpfull in the past when I needed parts for my 914-6.

You can fax him and he'll get back to you. I know he had the business up for sale, so maybe someone else has more current information.

Posted by: jmill Dec 15 2009, 10:30 PM

I like Pegasus. http://www.pegasusautoracing.com/group.asp?GroupID=WEBERIDFPJ

Posted by: type2man Dec 15 2009, 10:58 PM

http://www.cbperformance.com/category.asp?CategoryID=6

Posted by: jaxdream Dec 16 2009, 12:09 AM

You could also do what a guy I know used to do to Harley S&S carb jets , solder them up with solder , redrill with the jet drill size you want . Could be a easy fix in a tight spot, any who just an idea , cheap except for the jet drills.

Jaxdream

Posted by: DBCooper Dec 16 2009, 06:58 AM

Exactly what I do, and not just in tight spots. Ever notice that even with a big collection of jets you never seem to have exactly the right size? Or you can only find three? It's one of those unwritten Laws of Life things, like toast always falling jelly side down. So for me drilling is the easiest and cheapest way to jet carbs. Start small and go larger in steps until it's too rich, then lay on a layer of solder and ream it back to the right size. If you're really anal once you know the right size if you have them in your box you can put in new unsoldered jets, but I never have.

Posted by: Mark Henry Dec 16 2009, 07:10 AM

I've been tuning with a wide band and jet drills for quite a while, used a narrow band and plug method before that.
Very fast job now, no waiting or time wasting.

Posted by: sean_v8_914 Dec 16 2009, 07:25 AM

I'll second that!!! get access to a wide band. beg, borrow, steal. whatever you gotta do to get one. once you use one you will forever wonder why anyone would play around without it.

Posted by: jaxdream Dec 16 2009, 10:29 AM

I would venture to say that I am very ignorant when you guys talk about wide band tuning , i have to ass u me that you are talking about wide band oxygen sensors , just not sure how you get the data to interpret. Sounds like a very good idea , but I wolud like someone to enlighten my dumb ass . I am very curious as to the instruments / tools required to accomplish this task. Thanks be to those so inclined .

Jaxdream

Posted by: jmill Dec 16 2009, 10:38 AM

This is what I have. It's older than dirt but works great. I throw in a set of jets and go for a spin with the unit all hooked up. Find a big long hill put it in a higher gear and stomp on it. Check where your at, rich or lean. Poor mans dyno tuning.




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Posted by: jaxdream Dec 16 2009, 10:43 AM

That's great , exactly how do you hook it up ?? I have a staionary ( big ) exhaust gas analyzer , haven't messed with it yet , that sticks up the tailpipe ( proctoligist style ) . I'm interested , your's appears to be an older unit , please tell me more.

THANKS jmill

Jaxdream

Posted by: jmill Dec 16 2009, 12:18 PM

This one does the same thing. You slide the probe up the tail pipe and then hook it up to the 12v battery. There is enough wire to have the unit on the passenger seat. I duct tape the wires to the body of the car in spots so they don't get hung up and ripped out.

Posted by: charliew Dec 16 2009, 01:20 PM

I don't live in town and soldering jets always seemed to be the thing for me. I never used a jet without trying a drill in it to see what size it was before going to a different size. Course it also needed to be acid core solder that was stored away from anything you don't want rusted.

My first attempt at shade tree carb tuning was a two one barrel setup on my straight six chevy. Took it out on the hwy to check it out and it backfired and started burning (no hood or fenders). It just happened to be in front of the local airport and they saw it from about 1/4 mile away and came and put it out and I drove it back home. The only problem was I drilled too many things out and had to go to the junkyard for more carbs.

Many years later I drilled some jets on my t1 and didn't try it on the hwy and the next monday morning I had to drive about 100 miles to school and it would only go 60 in third, boy that was a long 100 miles. At lunch on monday my classmate took me to the local vw dealer and I got some new stock jets to put back in it.

Posted by: Mark Henry Dec 16 2009, 04:22 PM

Wide Band O2 meter, sensor goes in the exhaust, has a digital read out on the dash. Tells you the exact air/fuel ratio, flat spots will be seen, lean and rich readings are instant.

There are some cheap systems out there now, worth investing in, cheaper than a leaned out engine.

Posted by: jmill Dec 16 2009, 04:43 PM

My old heathkit is a narrow band and it does react slower than the newer wide band units. It's analog and you can't split hairs with it like a digital unit. It does have a few things going for it. It's cheap, no need to weld an O2 bung in the exhaust and it's portable. It's payed for itself about 20 x's over.

Posted by: jaxdream Dec 16 2009, 09:30 PM

Thanks guys , went to evil-bay , found a couple of jmill's outfit , a lot of wide band setups . Will save the pennys up for this deal , which really seems to be a great idea as far as tuning engine with carbs . Some time back i read a post from a fellow who raced , said it was the best way he could keep engine tuned good , and keep competitive . Thanks again for the info.

Jaxdream

Posted by: Mark Henry Dec 17 2009, 10:26 AM

Personally I'd pony up and get a wide band. I used to have a Haltec narrow band for ages, but it only register's around 14:1.
Our engines tend to like around 12.5-13:1 AFR for best power and cooling.

Posted by: DBCooper Dec 17 2009, 10:28 AM

+1

Posted by: DBCooper Dec 17 2009, 10:28 AM

+1

Posted by: brant Dec 17 2009, 10:54 AM

anybody willing to explain the soldering technique to me?
I want to give that a try, I've been purchasing different sizes every few weeks but want to give soldering a try.

- I assume a propane torch to heat up the jet and then a drop of solder?
- does it stick adequately to the brass
- do you have a fixture to hold the hot jet, or just pliers?
- what kind of solder is best (required) someone mentioned acid core
- I have jet measuring tools... but where do I buy jet drills
(cb, pmo I'll bet)

thanks in advance!

Posted by: jmill Dec 17 2009, 11:23 AM

Pliers are big heat sinks. Hold the jet in a vice with a wire or piece of sheet metal with a hole for the jet to drop in. Just don't sweat the threads or your holder.

I'm not a big fan of soldered jets. Too much variance between the four jets for my taste.

Posted by: Mark Henry Dec 18 2009, 06:36 AM

http://www.cip1.ca/ProductDetails.asp?ProductCode=C13-43-5715

Man $75, when I bought my set it was like $35...

Posted by: ME733 Dec 18 2009, 07:06 AM

....well guys, I was sorta hoping that there would be a better response to ...WHO HAS THE MOST ACCURATE carburator jets. Apparently not many people have jet remers/ jet drill,s to check them. Some responses suggest sodering up the jet, and then drilling/reaming them out to the size needed. I have seen what results from,sodered jets- air or mains that fail. meaning the soder breaks loose, and vibrates out, or turns sideways and blocks the jet. The result is a torched cylinder. I have never used sodered jets and never will and cannot recommend this solution for getting the correct jet size,s. The discussions also brought up "wide band" ..or ..the use of exhaust gas analyzers to dial in the magic air fuel ratio. The use of this tool is normally dependant on ONE "sniffer" up the tail-pipe. This tool does not account for each cylinders Air/ Fuel ratio, but Rather gives a reading of the "average" of all cylinders. I only bring up these points, to provide Information for this group. Information about Where to purchase a cost effective JET DRILL set could be of use. thanks for the responses. murray

Posted by: Mark Henry Dec 18 2009, 11:32 AM

Man sometimes I think this guy is Alfred

Posted by: DBCooper Dec 18 2009, 11:57 AM

Hmmm... That's how I've done it for about four decades now, on my own and on customer's cars. Good to find out it doesn't work. Thanks.

Still scratching my head though. I'm aware of no way to get a more accurate hole than with a drill index. If you use the same drill in each hole how could they end up being different? And if you can't solder then of course the best advice is "don't".

The wide band tells you how the MOTOR is running, rich or lean, in different running situations, so it has to be in merged exhaust flow. You jet each throat the same, so the whole engine is in balance. You could jet each barrel individually, I suppose, but I don't know anyone who does, or why they would.

Posted by: tat2dphreak Dec 18 2009, 12:00 PM

Posted by: jmill Dec 18 2009, 02:20 PM

Working in the aircraft industry for years I can tell you that a drill bit won't drill the same size hole twice. Most drill bits create a triangle like hole anyhow. Also the run-out on most drill presses stink for accurate jet work. If you set the jet up in a mini lathe and step up the hole with reamers I'd run them. I don't have the right size reamers or a mini lathe so I just buy new.

There's folks out there who jet each barrel individually. Most use EGT not a wideband. I don't get that deep into it and run with the average of all 4. It's close enough for the girls I run with.

Posted by: DBCooper Dec 18 2009, 04:03 PM

Quibbles. Certainly you could do better with a lathe, but not enough better to matter. Have you measured those jets you're buying new to compare? That was the original complaint, variability among purchased jets from their marked size. In any case I said solder and drill until you have it jetted correctly, then, if you prefer, replace with new jets in the correct size. I've never found the need to put in new myself, and think you're just as well off or better with the jet reamers/drill index.

People who jet each barrel individually exist of course, just nobody I know. People who used to spent that much time on the dyno were serious racers who these days are all running fuel injection.

Your experience may differ, and that's fine. The important point is to know that there are different ways to do things, judge for yourself what's best for your case, and then do as you like.

Posted by: Mark Henry Dec 18 2009, 04:18 PM

My set is reamers not drill bits.
Almost all tuners agree the average AFR is good enough if the engine is in good condition,( i.e. can pass a leak down test.)

One thing I loved about SDS FI is I could change my "jets" by pushing a button on the dash. That system is now going in my bug.

Posted by: Joe Ricard Dec 18 2009, 05:30 PM

I put a straight pipe on my tangerine tubed 2316-210.
Phase 9 muff liked a idle 53 jet 145 main
2 1/2" straight pipe needs 63 ish and 155 main

Snuck up on it with my reamers. wide band meter is wonderful

Posted by: scotty b Dec 18 2009, 09:03 PM

hot glue and a sewing needle does the trick for me Murray

Posted by: ME733 Dec 19 2009, 12:36 PM

hot glue and a sewing needle does the trick for me Murray
....... scotty b........You have got to get out of the paint booth more often......a little fresh air once in a while could do you some good. murray