The Dodge Challenger Message Board

Hello Dave. I had my distributer rebuilt by an old friend that has a reputable repair shop. He told me I'll probably have to play with it to get it running right. I told him about my situation about not knowing what exactly my camshaft was. He said I need an advanced curve distributer. The distributer I had only had, I think four degree's advanced curve. He made it a heck of a lot better to suit any cam I had. I haven't talked with him for a while but, I'm sure he made it more of a 1969-71 spec dizzy, without worrying about all the smog gagging stuff wich I don't have anyway. So, I know it's an advanced curve but, haven't messed with it internally. I think your right because, it never pinged before the dist. rebuild. I saw some of those other thread's on changing spring's and some kind of adjustment in the vacuum canister but, am affraid of making it worse. I'll read those again tonight when I get some more time. Thank's again, Dave! I alway's need and enjoy your input, Pat

I was looking on previous thread's about this topic. I know that I saw something more specific about tuning the advanced curve here before. I can't find it. I don't think I have a vacuum canister on the dizzy that I can adjust with an allen wrench. Super small hole. Short of taking it back to the shop, what can I do? In adjusting it to 8 degree's, I did have the vacuum disconnected and plugged off. Help! Thank's, Pat

Pat do you have a vacum advance canister on your dizzy? If so, some where adjustable by inserting a small allem wrench inside the opening, you can feel it "catch" onto the fastener inside. The advance "arm" will have a number stamped onto it. This is the vacum advance the unit is capable of. I have an N.O.S. vacum Chrysler unit if you want it. It's stamped 8.5 degrees advance. It's technically for a six dizzy but should fit all dizzys, let me know if interested. Eddie

patrick wrote:I had only had, I think four degree's advanced curve. He made it a heck of a lot better to suit any cam I had. I haven't talked with him for a while but, I'm sure he made it more of a 1969-71 spec dizzy, without worrying about all the smog gagging stuff wich I don't have anyway. So, I know it's an advanced curve but, haven't messed with it internally.

Non of this sounds right to me.

Leave the vacuum dissconnected and plugged at the carb until you sort this out.

Use a "dial back" timing light to find out what the timing is at idle. Then increase the engine speed in 500rpm increments until it either stops advancing or you get to 4000rpm (don't rev above this).

Then tell us what the results are.

You should produce something like this for us.

800rpm (or whatever your idle speed is) = (degrees advance)

1000rpm =

1500rpm =

2000rpm =

2500rpm =

3000rpm =

3500rpm =

4000rpm = (only if timing has not stopped advancing)

This can be made into a chart to form your "Advance curve". A performance advance curve starts at around 14 degrees advance at idle and has around 34 degrees max advance at 3000-3500rpm with half of it in by 2000-2300rpm.

Thank's Dave. I'm going to plug it off and I'll let you know what I find. Family and I are going on Vacation this week so, I probably won't get a whole bunch done with it until... next week is booked too I'll get back to you. Thank's, Pat

Today, I got the new 670 Street Avenger in the mail from Summit Racing. I forgot that I had a spreadbore mannifold. Therfore I,m going after some more part's. The adapter as well as the nice looking split fuel line for the Holley. Dave, I'll be talking to Bob, the guy that rebuilt my distributer tomorrow, and see what he has to say. I don't have a dial back timing light but, I know he doe's! Hopefully I'll get everything together before the "End of the World Run" In Long Beech, Washington, the week after next. I heard last year, there was around 3000 hot rod's at the event. And a lot of them were Mopar's. Talk to you soon, Pat

Good to hear it Pat.Are you going to have enough hood clearance with the Avenger/adaptor?. You might have the same height with the RPM AirGap/Avenger. You know you want that manifold Pat! Just keep thinking 30 extra H.P.!!!!!

Your killing me Eddie! I love the thought of the extra 30 HP. But, I'm also very cheap. Not in the sense of the word but, I do count my pennies. Only because my kid's don't. I want do do a little carb change, I hear about school clothe's, ASB card's, physical's ETC... If I do any more than I have to, especially to the Mopar, I hear about the cost of sending them to college, Dorm's, food, book's.UUUUGGGGHHHH!!!! Now, if they were even "B" student's, It wouldn't be so bad, but their C+ put's them in the "You Suck Range". My wife say's that I'm way too freugal, I guess that's how it's spelled.She's with me but' prefer's to hang low. Ohhhh! The Car's. My kid's need car's! I'm sure your done raising your's. And I'm sure you remember well. I think I'm going to make a special little fund entitled "Kid's Future" A.K.A. "Daddy's Mopar!" Oh, here they come again, wondering what dad is doing on the computer. Gotta go, Pat

I hear ya Pat. I had to pay my stepsons engine rebuilding adventure before he left for the Air Force. It cost me 600.00 to pay off his Honda ATV engine. Then he gave it to his friends before he left, never thought about leaving it to 'dad'. I had to pay his debt or they 'kick you out' of the military. Anyways, keep saving those pennies,(it adds up), and get that RPM Air Gap on there someday. You wont be disappointed. Tell you what. When you do get it, if it doesnt live up to 'our' expectations I will buy it back from you for the same price you paid for it. Hows that for confidence!!

I'll keep you posted on the air gap RPM eddie. Your into my head enough now, that it won't go unexplored. In the mean time, I have all the stuff together to install the 670. I got the adapter plate, not exactly what I expected. I thought it was going to be a 1" spacer but, turned out to be 1/8" with a couple of gasket's from Edelbrock. My nephew ordered it for me. I'm going to install saturday morning, then go to one of our local car show's. I'll keep you posted. Completely Carburetor Challenged, Pat

Sounds great Pat, make sure you're fasteners are long enough, they should be with only 1/8 thickness increase. I used ARP stainless carb studs, but I understand if you are on a budget. Also make sure the linkage will 'bolt' on with the Holley, sometimes you have to get an extension on the 'throttle linkage' part of the Holley. Not difficult or hard to visualise, you'll see what I,m getting at when you do the install. I didnt have to touch a thing to mine other than the idle speed. It was 'spot on'. Keep us posted!!

Hey Pat, just a suggestion, check all of your clearances such as the butterfly, linkages, and other moving parts. I installed a heat shield/spacer kit and a fair bit of trimming was required to keep the throttle from sticking WFO. "Universal application" parts sometime need work to make em fit right.

Hope you packed your camera for the car show. We like pictures.

Hey Guy's, I got that new Holley in yesterday. It was only going to take about 15 minute's. Four hour's later we had it in and tuned. I'm still playing with some timing issue's but, pretty happy so far. Feel's pretty much the same off the line. When I get on it on the Freeway, A lot more response and a lot more pull. Still wondering what that 770 or 870 would have been like. I'm still a little confused why, when the car came with a 750 thermoquad, that a Holley 770 was too many cfm's for it. The darned thing put's me and the passenger back in our seat's. I still want more!!! I guess that would be the same if I had a HEMI power plant in there. Alway's need more. No linkage issue's, it fit's like a glove. Changed the air breather though. I took some picture's at the local car show but, my kid's messed with the camera, my space, video's etc... They deleted my cool stuff for their whatever. Anyway, loving that 670, wanting to try 770. Sold the 600 Edelbrock for $150. Not too shabby. Take Care, Pat

With quick response at Idle and great pull at high R.P.M.'s, I think I'm getting 18 M.P.G. Not that it matter's. We just got back from the coast and used 1/2 a tank. I really don't care about M.P.G. But, I think I'm getting this thing tuned where it need's to be. Still need to down tune that advance curve on the dizzy. Some pinging at high R.P.M.'s under load. I'm an Edelbrock fan, especially in my truck but, in my Challenger, and my 340 Cuda', Holley is the only way to go!(Disclaimer): (This only applie's to kick A.. vehicle's that I've owned in the last Twenty-Five year's.) I'm really rusty on all this Tech Crap but, a lot of this 1st grade tuning stuff is coming back to me. P.S. This Is Not A Commercial! Thank's, Pat

I knew you would enjoy that Holley Pat. Holley QC has improved remarkably in the past ten years!! When you get that AirGap on it she'll really wake up!!! Glad to hear your cruises are more enjoyable

O.K. Air gap might be coming in the future. But, for right now, I was thinking about one of those Phenolic 4-Hole spacer's to compliment the intake setup I already have. Heard it might give me more rev's. Any thought's?

Are you asking if it will increase the revs? Or the power/response? Carb spacers help build plenum volume and there fore may help build more power, in your case, I would'nt know Pat. It might be a waste of money and cause clearance problems with your hood. I have seen them 'work' on single planes at a certain RPM band. And of course to be utilized for linkage issues and adaptors/nitrous plates, ect..but on dual plane manifolds, doubtful,(power increase).

Why wouldn't the four hole spacer add more power and response to my dual plane. I think I understand why an open spacer wouldn't work. My goal was to use the spacer to mimic the Performer RPM without blowing another couple hundred buck's on another intake this year. I have $20.00 in Summit Buck's that's burning a hole in my pocket. I was thinking, what the heck. I'm pretty happy with it right now. Maybe I should just leave it alone. But, you know how it goe's. Tinker, Tinker, Tinker.

It still wont be as good as the performer RPM due to the smaller runners. Spacers,(4 hole), are sometimes helpful but not enough to notice it. My own personal opinion of spacers,(dual plane), are they are great for adaptors or clearance issues, linkage concerns ect.. for building power and increasing drivability, well I think that 20.00 bucks should be saved for that AirGap,(I know you're sick of hearing it), I would concentrate my efforts to your dizzy, this Pat will really help your engine. I hear you say that sometimes it pings upon cruising conditions. The engines vacum is at it's very highest at cruising. When you go Wide Open Throttle,(WOT), the vacum drops to almost zero. At cruising speed being able to hear it ping is very bad Pat. At speed it may be detonating and you cant hear it at all. This concerns me. I would take that dizzy and get a dial back timing light. Hold the revs to 2500, 3000, 3500, 4000, 4500. "see' what the timing is at those speeds. If the timing is continually raising past 3500 rpm's then something is wrong and the springs or weights should be checked out. Then you could disconnect the vacum and see what it is at those speeds again, it could be simple like the vacum canister is set to high if it's the adjustable type, either way I would get this fixed. Pinging that you can hear is bad and could cause engine damage.

I'm on it Monday. The guy that rebuilt the dizzy is going to check it out. Put it on his machine and see what this dizzys doin'. I have no adjustment in my vacuum canister. He is very good at this technical stuff. He'll be checking my handy work on my carb too. Checking my adjustment, measure the vacuum I have. All that stuff that I'm too dumb to do. I'll be chatting with him about that Air Gap too, Eddie.

Sounds great Pat. Let us know what he says about that dizzy!

Hello Eddie. I guess I didn't read your sept 17th post completely. It doesn't ping at cruising speeds, only ping's W.O.T. Not a lot of chatter but, I can definately hear it.

patrick wrote:Hello Eddie. I guess I didn't read your sept 17th post completely. It doesn't ping at cruising speeds, only ping's W.O.T. Not a lot of chatter but, I can definately hear it.

Oh, Ok it still needs to be diagnosed, at WOT the vacum drops to nearly Zero so we can rule out that vacum canister,(as I stated, the vacum is highest at cruise or part throttle thereby utilizing the vacum canister to "pull" vacum and advance the timing), it sounds like either the springs or weights are the culprit.Plug the vacum advance. I would slap a timing light on it and "see" how much the timing increases as engine speed increases. BTW, have you ever driven the car with the vacum plugged? what did it do? Did it still Ping? If NO, then you have found the problem,(vac Canister), if the same then it's the springs.

Yep. Pinged with the vacuum plugged. I'll get this figured out. I'm thinking Spring's.Or someone is going to help me get this figured out. I'll find the right combo. It's a matter of time. I have that, I think.

Noises at WOT are usually exhaust leaks. If it sounds like tappets it is the manifold gasket. if it sounds like detonation it is often an exhaust joint or hole in the pipe.

So make sure it is neither of those before going crazy on the distributor.

Good point Dave. Also I hate to say it, sometimes that ping noise is a wrist pin from the piston or a broken ring land. Is the sound the same with the engine cold or hot? I didnt want to bring this up, Pat Pat do you have mechanics stethoscope? I use a long wooden handle, this sounds crazy but actually works very well. Take a wooden hammer or old tool handle about 15" long place it on the valve cover, intake maniflod ect with the engine running, the other end against your ear, you can hear any mechanical maladies like broken rings, pistons that are "slapping" against the thrust side of the cylinder wall, flattened cam lobe ect..If the sound is only at a certain engine speed or temp. then it's probably external, if you hear it all the time with your 'tool' then it's internal and needs to be dissassembled. BTW, you can easily "load" test it. Start the engine put it in gear and "brake Torque" it, loading the converter actually, if you hear the "detonation" then it's time for some lookee see inside Pat. Post a pic of your sparkplug Pat.

I used your "Tool" to see if I could hear any funky noises. Don't know if I had the right hammer, or right stick of wood. Then I came up with a good idea. My wife's stephiscope from work. Sound's like everything is running smoothe. Hope I didn't get any grease on my wife's tool. Put it back in her bag. You see, everything in the car is, beside's the rebuild is original. Except the dizzy and stuff I haven't found yet. The dizzy, per #'s, is from a Dodge truck. When Bob told me that, I said,"screw it, let's go with a new one from Summit." He said, not so fast. It's a good one. At the time, it ony had about 2 degree's advanced curve on it. He rebuilt the dizzy with a "ADVANCED" curve and there you have it. It never pinged before but, it didn't have the curve it has now. I have faith in him. We'll just tune it down a bit. I can give you a pic of my spark plug boot's, Eddie. They are brand new Taylor's though. I'll have to wait 'til the wife or one of the kid's get back home. Don't know how to do this camera transfer yet. Thank's guy's! Pat

No exhaust leak's either.

Not the boots Pat. The end of the plug itself that screws into the chamber in the cylinder head. Did you start it and brake torque it yet?(using the stethescope). You are trying to simulate the engine under load. This will simulate the engine while under wide open conditions somewhat.