| Author | Message | ||
| Frank Parker (Parkerfe)
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Charles, lean it out, have the test,then set it back where it belongs until the next test is needed. | ||
| Torai Madjid (Black5000s)
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Picture of combustion in a cylinder during idle mix setting: http://groups.yahoo.com/group/lamborghini_info/message/8001 Countach intake ports and plugs are both between the cams. That is why the light from where the plug is located is visible in the darkness near the carb. | ||
| Torai Madjid (Countach83)
|
Another tip on syncing. Take the idle screws and clean the needles with carb spray. I also cleaned the seats with pointed hard wood round toothpicks (careful!). There was a lot of rather nasty black stuff there. Put the snoot on the carb spray, and blow through the holes where the idle screws go. Tried Gunson's sync tool. It does not read in absolute terms, like Kg/hr. I've seen better, but the Gunson unit is good for tight situations like the Countach with mods. The Countach has side draft carbs, which face into the sides of the engine compartment. Easy to reach with a flat hand, but not in plain sight. Gunson's tool has a flow indicator, and a hose which connects to a pickup which is shaped like the end of a doctor's stethoscope. You can put the indicator where it is plain sight, and go down the row of carbs in a few seconds by feel with the pickup. Leaves the second hand free to go after adjustment screws. Nice and fast for the last touching up, and resync when mix adjustment changes the idle speed too much. I don't do the "take 1/8 turn from each" route. Run the sync tool through afterward and you will know why. I applied the following Mickey Mouse mods to the Gunson product. - Wire tie to better affix the indicator head to its holding clip. - Longer more flexible hose - Put a 1 quart/liter plastic bottle in series with the line between the pickup and the indicator to get a less bouncy reading. I don't think it was designed for 1 carb per cylinder at low idle speeds. - Closed 2 of the 3 intakes holes with tape. Used tape to fix adjustment on the size of the remaining hole. Was not designed for 1/3 of a liter of displacement per hole. I'd use it again for the Countach, but I would use something else for more accesible situations like DCNF's with the intakes on the top. Using this and the Colortune allows sync and mix tweak for the cost of a little extra time while changing plugs. Playing a tune in the city tunnels with a well synced V12 sounds nice. These tunnels have a lot of turns and merges which give an excuse for a lot of unnecessary shifting, and noise making. Here, object is not to go fast, but to play a little song. | ||
| Warren E. Smith (Magoo)
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Hey Torai, Stick with us, your wealth of knowledge is appreciated by all. Who knows you may find a Ferrari through the Chat line. MAGOO | ||
| Torai Madjid (Countach83)
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Came close, but don't own a Ferrari. Been around them a lot since the Ferraris dominate the club events. Have Lambos, and a Maserati. Drive them a lot (well, not the ones on the other side of the pond). Came within a hair of buying a US spec 328 here in Europe, but came across too good a deal on a nice Countach. The sport exhaust is good for playing a little song in the tunnels under the city. I work in well secured areas, sit 15 feet from my car, so I can use these cars to commute. I come and go late, so I get to romp on relatively empty roads. Sneaking in and out of work is impossible. I planted the seed in my brother's mind, and he just got done sorting out the 308 he recently bought. He loves it. I found out about this site from him. I would like to drive some of the Ferraris, they must be quite different from the raw, brutal Countach. I'll get a chance to try my brother's 308 when I visit him next. Some variety like a TR instead of another Countach would have been nice, but the oppertunity did not present itself. I look young, and get branded as a tourist at a lot of dealers. Someday. Guess I'm still offically a wannabe. I really appreciate these sites, I enjoy the talk, and you all help me enormously with my cars. Lambo and Maserati information is much more scarce (much fewer cars); a lot of what is discussed here helps. | ||
| Bill Sebestyen (Bill308)
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I purchased a matched pair of Syncrometers from Superformance and believe they are the best available comercial devices for measuring flow rates. They're not as good as a bank of 8-manometers IMHO, but to use manometers, you'd have to tap into the intake manifolds down stream of the throttle plates. On a 308 this is most easily acomplished by severing the 6-vacuum taps that vent the vapor canistor and the 2-taps that are also present on the numbers 4 and 5 cylinders. Anybody know what these 2-taps are for? I haven't been able to convince myself to severe the plumbing yet as the functionality would have to be restored with rubber hoses and T-fittings when finished with the syncronization process. The advantage of manometers is that the flow to all carbs are individually measured simultaneously and with great accuracy and sensitivity. The disadvantage is that you have adulterated the factory plumbing and the choice of manometer fluid pretty much limits you to mercury. The only other available alternative is special manometer fluid with a specific gravity of about 3 (3 times as dense as water), but even with this one has to be careful of sucking the fluid into the carbs under high vacuum conditions. The Synchrometer works well and unlike Unisynch's does not have to be held in place. In practice I selected the highest flowing barrel in one carb and designated it as the control. The flow of all other barrels are adjusted up to match it. This is where the second meter comes in handy. It can be moved from barrel to barrel, except you can not use 2 meters on one carb because both won't physically won't fit, and one compares the roaming Synchrometer's reading to the control meter. Increases in engine speed are automatically accounted for with this method. I have found that at very low flow rates, say 800 rpm on a 308 with no emissions equipment loads, my 40 DCNF 72, 73, 74, and 75's are basically closed as far as possible. Even though all barrels were apparently reading the same flow rate, some were not flowing enough to sustain combustion and enable setting of the mixture. I discovered this by using the color tune mentioned in an earlier post. Well, the color of the combution gases wouldn't change on several barrels no matter what I did with the mixture screws, even though I had rebuilt all of the carbs (very labor intensive) with the exception of recentering the throttle plates on shafts. As a last resort, I increased the flow rates slightly on the offending barrels, an adjustment so small that the Synchrometer could barely detect the change, and now I was able to adjust the mixture properly. Other items that gave me hart burn were 2-loose ball studs on the throttle linkage bell crank and the technique for checking synchronization just off idle. To check off idle synchronization, one must either pull the throttle cable or rotate the bell crank slightly. Do not rotate the linkage of one of the carbs to crack the throttle or you will get false results. All barrels should flow the same all of the time but especially just off idle, say up 2000 rpm. When synchronization is right, low speed acceleration from a stop will be much improved with the added benefit of being very kind to the clutch. Caio Bill | ||
| Warren E. Smith (Magoo)
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Steve, your right about the syncrometer. I have one and it works great. Greenfield Imp. Parts has them in stock. 413-774-2819 ask for Matt. I think around $30 some dollars. | ||
| Steve Magnusson (91tr)
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Charles B. -- the best mass airflow measuring device IMHO for checking/adjusting/balancing 308 DCNF airflows is the STE Syncrometer (sometimes spelled Synchrometer):  Here's one retail source (but there are many others): http://www.racetep.com/weber.html (about 1/3 of the way down the page -- you don't need the adapter, and it's easy enough to move quickly from barrel to barrel so you only need 1). If you're truly interested in doing this yourself IMHO you should review Chapter 13 (DCNF) of the Haynes Weber Manual and/or the relevant parts of section C of the 308GT4 WSM (110/75). Good luck... | ||
| Warren E. Smith (Magoo)
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Torai, Great to have you with us. Do you have a Ferrari at present? | ||
| Charles Byrd (Vogel)
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Since some people are writing on this string again, I will ask, what tools I need exactly to sync the carbs and get them running to specs. I like the looks of the tools mentioned earlier, but I am still not exactly sure what I need. I am enjoying this car so much, and it has no problem going to reline, but I do think the carbs need to be synced. I have decided that I will no longer be able to live life without owning a Ferrari. My 308 is great, and I will probably keep it forever, but one day I want a Ruby Red 355 to match it. Thanks for all the help guys, this site is almost as cool as my 308. | ||
| Torai Madjid (Countach83)
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Just a hobby. I do Aerospace stuff, but its mostly politics now, and never use my hands for work, so I get it out of my system with the cars. I like the art and the technology, and the passion behind those creations. My dad bought me a $50 Sunbeam Alpine with a 1.7l engine and a manual when I was 14. He told me I had to learn how to fix cars if I wanted to drive. By the time I was 16, it would leave a strip of rubber through 3 gears, and I was familiar with tangling with out of production old European cars. I still do that, but the cars are more expensive now. And suitable to enjoying the Autobahn to its fullest. I still remember my matchbox Countach, and the quote in the 60 minutes Lambo piece about not having to go through life without owning at least one 12 cylinder high performance car. | ||
| Warren E. Smith (Magoo)
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Sorry,typo, TORAI. | ||
| Warren E. Smith (Magoo)
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Toria, What is your claim to fame? You seem very knowledgable on various subjects here on the chat line. Are high end sport cars your profession or just a hobby? | ||
| Torai Madjid (Countach83)
|
Looks like Steve found a better source. The Gastester CO testers are a lot cheaper ($124) than Whitney ($169). Most parts stores won't have these either in the US or Europe. I called Gunson and found the Pro version in a big parts and tool store, but it was $340 instead of $199. Why fight with looking when you can have one next day mailed for ten bucks in the US. Here in Europe, you can mail order them stright from Gunson www.gunson.co.uk. They also sell small thread ones for bikes, which may be needed for some Ferraris. I left mine in the US, was in a hurry, mail in Europe is slow and expensive ($30 for 4-7 days), so I called Gunson in the UK and located one 25 miles from me. I also got their sync tool. Looks good for tight quarters like the Countach. It has an indicator which is attached to a hose, so you can put the indicator in plain sight, and grope for intakes by feel. I would get a longer more flexible hose then the one they supply. The colortune has a 5/8" hex, and a plastic 5/8-13/16 adapter. I take 6-8" of 3/8" ID (I think, the stuff here is metric) thickwall clear hose, and put it on the snout of the adapter. I drilled it through with a 2mm drill, and pinned the hose to the adapter with a piece of thick solid copper wire. The wire was a D shape with some of the straight part cut out, to pin both sides from the outside. The hose acts like a flexible driver, which allows you to screw it in deep awkward places, cable and all. The plugs on a early Countach are in a place a proctologist would love (intakes and plugs between the cams). This would help anywhere where the plug is in a deep well. I do not use a gasket, and screw it in hand tight, and limit things to an idle. It is too hard to get a gasket which falls off. If things are way rich, wait for the extra gas (orange color) to burn away, and work from the lean end. The car I was working on tonight was smoking like a locomotive rich, and it took 5-10 sec for the orange to subside. For idle work, I carefully open the gap on the colortune to about .050" with a jewelers screwdriver. | ||
| Steve Magnusson (91tr)
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Joel -- it's one word "colortune" and the manufacturer is Gunson. Here's a link with a lot of info: http://autoexpertproducts.webjump.com/ | ||
| Joel Ames (James)
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Torai, how about some more info on the device, Color Tune from JCW. I've wanted one for many years and have never seen one advertised. I looked at JCW and can't find it. People at auto stores thinks I'm crazy when I ask for one. Thanks. | ||
| Torai Madjid (Countach83)
|
I used the flow meter JC Whitney sells (german made, reads in mass flow rate (Kg/hr I think), and Color Tune, a glass sparkplug also from JCW. I used to pass a Euro 85 Maserati Quattroporte in an idle type test at 150 ppm HC and 0.8% CO. This car has a two valve 4.9 with 4 DCNF webers, an air pump, and hollowed out cats. I set the idle rather low, about 700 RPM, and balanced the flow across the carbs (1)between the barrels in each carb, and then (2)across the carbs with the idle screws, and then (3)set the linkage so each carb flow would increase with pressure, but no movement on the throttle. One rod pulls all 4 carbs open. Each carb straddles cylinder banks. I would run each idle screw in and out a few times to clear the dirt, put the color tune in. Starting with the screw closed, I would count turns until the cylinder started to fire - first purple intermittant lean misfire, through a bluer lean consistent firing. I would take note of the turn count, and open till I saw the sudden onset of candleflame yellow. I would put the screw about 40% of the way from lean skip to candleflame yellow. With a smog tester I would go for 250ppm HC and 1.2% (just failing without the air pump). With the air pump, it would go to about 1/2 that. I would redo the idle if it changed too much. I would do the smog test with the air pump on. After the test, I would disconnect the air pump, and then add about 1/8 turn to all the idle mix screws. The car had one cylinder about 30 lbs low on compression when I got it 10 years ago. 70,000 miles and a decade later, it's still the same. It never fouled plugs, except after a load of gas which left the plug noses an incredible bright red. Letting it sit and idle for an hour did not bother it. This would not fool a IM240 (dyno) type test. | ||
| Charles Byrd (Vogel)
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You have to get the inspection in Atlanta, or you cannot get your tags. I have called the "Green" people and explained that the car was never meant to run that lean, and I'm waiting to hear from them. Hoping, with fingers crossed, because in 6 months it will be exempt. | ||
| Neville Pugh (Nev_Pugh)
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Ha ! In the UK you have no choice, the MOT inspection is utterly mandatory .... | ||
| BretM (Bretm)
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Just drive it, I've had my car for over a year, and I haven't gotten mine inspected (even though it would definitely pass for two reasons). 1 my friend "inspects" my cars. 2 it passed in two states last year and it runs better than ever. Inspections are overrated. Don't let this prevent you from enjoying your car. | ||
| Charles Byrd (Vogel)
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The car seems to run fine, and I have no problem with the way that it runs. It is a little rich, but I don't mind a little rich, but here in Atlanta, they only allow HC to be a max of 390 ppm, and mine was 585, which from what I understand is to be about where the car should run. I have called the "Green" people and they are checking to see if I can get a waiver, which I doubt they will give me, but in six months the car will be exempt, I just cannot stand to wait that long to drive it. Thanks for the information, and I will update when I find out what I have to do. | ||
| Neville Pugh (Nev_Pugh)
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Charles, Check out http://www.r-design.net/308/techtip5.htm I synched my carbs recently, and it's actually not too difficult. However, get hold of a meter first and check them, the carbs dont tend to go out of synch on their own, and you dont want to do the job if you dont have to. Perhaps someone more knowledgable could chip in, but I doubt that the carbs being out of synch would affect the emissions that badly .... general running and performance, yes ... NOx and HC ? I doubt it .... (willing to be corrected) .. something else worn in the carb ?!? Interestingly enough I took my 308GTS carb '80 for it's M.O.T. (UK road worthyness test) recently ... when she was hooked up to the test machine the HC levels started at about 400ppm and started climbing steadily. They got all the way up to 1150 ppm (the limit for a car of that age in the UK is 1200 ppm !) then for some bizarre reason started steadily dropping !!! They got down to about 800ppm then started climing again, and the tester whipped out the test probe and said "I think we'll quit now while we're ahead !!!!" ..... I could have kissed him ! (well, no, but you know what I mean .... :-) I bought my carb synch tool, they aren't that expensive and I reconned that I'd use it enough. It cost 30GBP from www.superformance.co.uk Nev | ||
| Charles Byrd (Vogel)
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Guys, I just failed the emissions inspection here in Atlanta, too rich, but have been told by a couple of mechanics that have worked on them that it is almost, if not, impossible to get a non-cat 77 308 to pass the inspection and still run properly without burning up the valves from being too lean. I may be able to get a waiver, but I am sure that I will have to have the carbs syncronized, and I would like to do it myself, but I don't have a machine to check them, so if anyone in the Atlanta area would be willing to help me or point me in the right direction of a reputable mechanic, I would greatly appreciate it. Charles |