Yeah, so now its my turn, lol. In the last post I commented that you may not be able to tell if a cam were one tooth off. I just degreewheeled the engine in this 308, and found the rear intake cam about 24 degrees retarded according to its mark! I also found the flywheel marks 3 degrees retarded. If someone services this car in the future, they will find only one camshaft closely aligns with its factory marks, as I set the cams to lobe centers of 100 on intake and 90 on exhaust. One cam is about 3/32" off its mark! But this is the same cam that "appeared" to be off 24 degrees, so in actuality its was probably closer than that. Now its back together and ignition timed and carbs resynced. I felt that if the one cam was off some, and that I have actually retimed all four cams, I should double check the sync. Some shop replaced the original carbs with new version ones with the four screw tops. These also have built in airhorns so I cannot use the nice bell mouthed airhorns that normally hold the aircleaner on. I swapped over the jets from my other carbs, now have 60 idles, 135 mains, f36 tubes, 200 AC. That was done way back right after I got the car, so in comparison to altering valve timing it had these jets prior. Different? Yeah! Its a whole different animal now, it pulls VERY hard. Much harder than before. But I have an intermitent ignition problem now I have to trace down. It ran fine before I pulled the distributors off, so I dont know whats causing this now. Almost feels like a loose connection but I cant find one. This makes the car, which seems like its running pretty good to begin with, suddenly feels like you just opened up another set of carbs and really pushes you into the seat pretty good. Even well up in third gear, it pulls really hard. But one time it sputters at 5000, and the next time it does it at 6000. Wierd. But the carbs. I know what I know, I can figure this stuff out pretty good, but my lack of experience with multiple webers is raising its head, so I need some advice. The car will idle down okay, right down to 500 rpm if I let it before it quits. But the slightest touch of throttle sends it up to 3000 and it hovers there a bit before slowly coming back down. Obviously I need to correct the ignition first, and plan to tackle that this morning if possible before going back to play with the carbs. But any advice on what would make these cars slow to idle back down would be greatly appreciated. I am wondering outloud if the new carbs were not set up correctly to begin with. Like for example, should I turn down all the idle speed screws and only just crack them open slightly, and then set up the idle bypass screws to get it running at a base idle? I have four different books on Webers, even setup instructions, and not a one even remotely touch on the bypass screws other than one small mention of ability to balance flow between the barrels.
NGKBP5ES...no iridium, platinum, gold plated stuff required....a 7 or 8 is going way too cold on a carb car, IMO.. I have an ANSA as well, but not sure of my jetting, they were all wonky (mismatched) when I got the car and I believe JRV returned them to stock....there is a chart on where to start, as 78-79 cams are different from my 1977. Algar has a good rep as a shop, I think, as Paul has discovered, there is just no substitute for taking the time to properly degree the cams. Go with the Euro spec settings and it will perk up...... As far as sinking big money after the purchase of the best car you can find, well..... *shaking hands* "Welcome to the 308GTB Brotherhood!" LOL! I notice you seem to have reservations about leaving the car for a long period at the shop, but hard as it is to take them off the road, you will have to give ONE GOOD TECHNICIAN the time it takes to know the ins and outs of your car. That is the only way to acheive happiness, grasshopper....... Once they get tired of moving it around, they'll fix it right and you'll be on your way!
Heres a quote from Marlan Davis, Senior Technical Editor, Hot Rod Magazine, Oct. 2006, page 155: When a change is made in exhaust system efficiency, intake-port length, camshaft profile, or connecting rod length, it changes the vacuum signal at the main-circuit discharge port in the carburetors venturi, which changes the air pressure through the carburetor. And that means the amount of suction on the jets also has changed. If the amount of suction pulling on the jets changes, the amount of fuel flowing through the jets fixed orifice is no longer the same. The amount of change of fuel flow through the jets versus the change in signal [air pressure or vacuum drop] is not linear or directly proportional, so the overall air/fuel ratio will change, requiring rejetting the carburetor. Because the interplay between signal, restriction, total airflow, and charge dilution is extremely complex, it is impossible to predict in advance whether any exhaust efficiency improvement requires richening or leaning the carburetor.
Wow I had forgotten all about this thread. I'm glad you brought it back up. After a bunch of fiddeling here's where I stand now. Went up to 60 Idles and the bottom end was much better but still not running great. After talking to lots of F-car guys I went from 125 to 135 mains. Car ran pretty good, but now pretty rich down low. Not much punch. Installed NGK 6 plugs and much better, but not a lot of kick down low but the middle was fan-friggin-tastic but I fouled a plug. After much frustration and becoming an expert on the removal of the masochistic airbox I realized that I just was too rich down low and didn't know how to improve. Hotter plugs not the ticket and leaner idles made it backfire and stumble so I found the thread about the miraculous airbox secret. I was very skeptical but it made sense and seemed the only way to get more air to lean idle mixture. ( I am by no means a carb expert so don't pound me) But I thought Hell it couldn't hurt so I set about removing the stuffing from the airbox. Whoever said it was no big deal job was full of crap. A friend cut the tac welds for me but getting the grate out of the airbox inlet was a bear I had to cut it in half(the metal grate with the holes holding the stuffing) and then bend it in half. About two hours later I was spraying brake cleaner to get the attic insulation out and bolting it back together. GREAT GOD ALMIGHTY- This thing now kicks A**. It is a completely different car. I swear the first time I ever thought this car needed way better brakes. It's almost scarey and runs better then any I have ever been in. I still have a tiny almost electrical cut-out at exactle 6300 rpm which IMHO is electrical, but I'll start working on that soon.Any Ideas?? By the way the car exhibits no stumble in hard cornering about 99 percent of the time. And the sound. OH MY GOD! MANY, MANY THANKS TO ALL ON THIS CHAT SITE. WITH YOUR HELP I NOW HAVE MOVED A BUNCH OF STEPS UP THE MECHANICS LADDER TO MERELY INCOMPETANT. LOL ---THANKS
Way to go!!! The 1977s don't have that stuff in the airbox...LOL! Always good to hear positive results...I still say you could go to BP5ES around town, if needed, but also don't forget to regap them down...."out of the box" is too wide!
Thanks- So far I have been very careful about setting the gap on all plugs at .025. I raced motorcycles most of my life and find in the box gaps to vary drastically. Maybe I'll give the 5's a try. I don't really notice any difference in the 308 between the iridium and normal NGK's, but in off-road motorcycle racing the iridium are much less prone to fouling in my experience. The iridium's make sense in theory, but like lots of things there is almost no way to scientifically test them out of a laboratory environment because there is no way to include a control. Too many variables. What I have done is buy the normal NGK's first (less then two bucks if you shop around) and if the performance change was positive I'de replace later with the irridiums ( about $5.50 at Advances Auto Parts near me)
A note on gaps. These were for points ignition and the stock coil of almost 30 years ago. Modern coils are really powerful and with electronic ignition, the car works best with a larger gap. My car also is *supposed* to be .025 but I run .038 and the car loves it. That's not too big for me, although you do want to check your plugs after some miles to make sure they're good because I have no idea on Ferraris. Similar engines though. So for you guys with carb cars but the above upgrades, I think you should run a somewhat larger gap than the manual says. Just my $.02.... Ken
I just got rid of my iridium plugs. My car was running real crappy. I read a thread here a few weeks back regarding the difference between the different styles of plug, rang NGK for some extra info and also spoke to a couple of mechanics I know. I went from the BP7IX? iridium plug to the BP6EY. It made a monumental change to the way my car runs now. According to the experts there is a suppressor in the irridium plugs for reducing radio frequency interference (RFI), this changes your spark characteristics. Modern cars run irridiums because they have computers and stuff that doesn't like RFI so the plugs need the suppressor in them, also most modern cars have big coil packs that make quality sparking happen. A carbed 308 therefore doesn't need the irridium plug and will run fine on the standard plug. I went to the EY plug too that has the little groove in the tip as opposed to the ES that has a flat tip, but I can't remember what the technical differences are in that.
Beautiful looking set of wheels. I read this whole thread and was just glad you got your car running like it should. I'm happy for you...believe me I could commiserate with you as it took me for ever to get my 308 running right. Finally like me you can now enjoy your new toy. Have fun.
Hmmmm. Both of mine do/did. I only have one airbox converted so far though so that once I have the tuning nailed down I can swap back and forth and do a more realistic comparison. Some days I feel I knew more what I was doing at 17 than I do now at 47, this stuff all seems a lil bit harder than it was back when. Maybe all those days of smelling engine exhaust are catching up on me. I needed to be reminded by Scott/SMG2, that points ignition systems dont like resistor plugs, and the owners manual specifically calls for a non-resistor plug. So if anyone is running a plug with an "R" suffix you may want to try a non resistor if your running points in a carb car and have idling issues. Crow eating time? I am not really a masochist, and I really dont want to keep pulling distributors out and monkeying with them is some half spirited sacrifice to Enzo just to say I can run points. I am very close to just putting the MSD boxes back in and saying to hell with it. I wanna drive the &^$@(*&@ thing not work on it, and its cartainly no show winner car anyway. I could just save all that pain for the other car. Maybe when I can scrounge up a distributor machine and find some room to keep it I can work on this problem more efficiently So a couple questions. 1). The car was running BPR6ES plugs with the MSD's. Do these cars need the resistor plug extensions, the "red" ones, or will it work just fine with the plain ol' black ones the way I got it? 2). I was considering running the MSD power input off the + leads to the coils, probably the yellow battery hot wire. Does anyone know if the MSD boxes draw any significant power over the standard ignition? These are MSD6A boxes if it makes any difference.
I assume you know there is a heat range difference between the irridium 7 and the regular 6. This will make a bit of difference in the way the car runs anyway. Did you try it with the normal 7's by any chance?
Yep, I knew about the change in the heat range. When I initially got my car going I had the BP7ES plugs and it ran fine but would occasionally foul depending on what fuel I used. The irridiums were suggested to me to try out and I did without researching it. They ran very well for a few weeks but then they would foul regularly and even the 'Italian tune up' wouldn't clear them properly. The BP6EY plugs have only been in a couple of weeks. So far so good, and I think it's running the best I've had it now.
so what settings are you running? 55/125/F36/200 is stock. i have yet to find 60 idle jets useful, they seem to drown the car in too much fuel, hence why i stick with 55 idles and bump the main to 135 . i am still learning the relationship between aircorrector and emulsion tube. seems the 200 AC is a happy middle, but i think a 190 would be better with a 135 to lean it out a bit in the upper range. my old red GTB seems a bit rich in the top end still ruuning the 135/200 with a better exhaust and the stick airbox with sound crap removed.( new owner doent like the indivudual air cleaners) i would love to know your carb numbers before and after.
I am running 60,135, f36 200. I was running 55 idles and 125 mains. I tried after raising my mains to 135 to step back on my idles to 55's due to lots of skeptics on 60 idles, but it was really way too lean. Popping, stumbling and no real power. Realizing I needed the 60's, but feeling they were just a tad too rich from experience, I decided to remove aircleaner stuffing for more air. The car now runs great as I said and an occasional backfire. I think I will resinc the carbs next. Make sure everything is spot on.
