@pnora I also sealed off the vent where PCV goes on one of the valve covers and couldn’t feel any vacuum on the other valve cover opening.
Pig rich mixture at idle 2 x 4 Gen 2 hemi
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OK - well that takes care of the vacuum question - you have a big cam and I guess if I had gone back and re-read your first post from last week I would have remembered that. Stock carbs just aren’t calibrated to run with a cam that big. I think you are going to have to drill the carb throttle plates unless you can find some reliable way to crack the secondary plates open slightly. But I think drilling the primary plates would work better as the AVS doesn’t have an idle circuit in the secondaries like Holley. Introducing the air in the primary throats might help idle fuel movement and better mixing.
INTMD8
Well-Known Member
It shouldn't. If the air filter is big enough it will have nearly zero vacuum even at wot/high rpm so wouldn't be any measurable vacuum at idle.
Agreed I would just disconnect it now to try.
I ran dual AVS2's on my car before (no pcv) and was easily able to tune it with a very choppy cam and low compression ratio.
Sorry. Frustrating so stay with it. Another poke at it. How new is your fuel????
Fresh out of the pump. I also have 10 gallons of 100LL I could run in it.
I been thinking quite a bit on the edelbrock idle mixture screws. I know that the somewhat norm is to start with them 1 1/2 turns out from closed but in my pondering wouldn’t that be too far out when running as a dual 4 setup? It makes sense to me that you would start with them out half of 1 1/2 turns with two carbs 3/4 turn out and tune from there.
INTMD8
Well-Known Member
Doesn't really matter where you start, just get it to temp and adjust for max vacuum.
Stop chasing "rich smell". It's going to have un-burned hydrocarbons exiting the exhaust with a cam that size.
It will lean stall long before you get the exhaust to not smell like fuel.
Stop chasing "rich smell". It's going to have un-burned hydrocarbons exiting the exhaust with a cam that size.
It will lean stall long before you get the exhaust to not smell like fuel.
Thanks for the advice I appreciate it! Right now I’m looking more at the plugs and the fuel getting in the crankcase. I finally got the plug burn looking better then before they were black
That was an accomplishment for me. Again I appreciate all the help and advice you guys have given me.
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Do the 1-1/2 turn out on both carbs for a base. More than likely you'll find that the front and rear carb will be set the same when all is tuned in. I used a vacuum guage and tach when setting mine. Did the rear for highest vacuum and rpm then the front. Went back over them again and all is well.
When initially tuning these carbs I had them setup with the progressive linkage and I noticed a high temperature with the front four cylinders. (Using a IR temp gun) This was telling me there was a lean condition with the front carb. After opening the front throttle plate just a little (using the idle stop screw) the front cylinders returned to a normal temperature. I changed the linkage to one to one and have both front and rear carb throttle plates set the same at idle.
Don't forget that having proper timing set is very important when tuning any carb whether one or two carbs. You might have to go back and forth a couple of times between the timing and carbs before it all gets dialed in. You'll get it.
Well
Thanks!
I do have them setup as 1 to 1 on the linkage I’ve also checked the temp a couple of times on each tube my readings show the outside cylinder temps to be just a few degrees cooler than the middle 2 on both banks. I have played with the timing some and have it at 18 degrees initial right now with vacuum advance unhooked I did connect to ported vacuum last night as per hemirunner’s recommendation.
Well
Fran,
What kind of pics you wanting? From Kryslerkid if so I agree! If from me I have plenty to post
Spark plugs pics, you said they were cleaner.
Been fighting same thing with my xram with Holleys. Had worn throttle shafts rebushed and opened secondaries some, helped some. To cold to play in garage with door open now.
Been fighting same thing with my xram with Holleys. Had worn throttle shafts rebushed and opened secondaries some, helped some. To cold to play in garage with door open now.
Oh yea post #111 I just battle through the cold so maybe I can get this car out of the garage in the spring
Dragon Slayer
Well-Known Member
I am waiting for this to be solved but 8" of vacuum, race type manifold and cam, 11.5 compression why do you even have dual points and a vacuum advance? None of this sounds like a street setup. With such low vacuum to signal to these carbs it is hard to believe your rich. But with fuel in oil are you sure your rings are good?
The rings are good have looked at them once during tear down inspection and once when I repaired the main seal leak. Compression numbers looked good I could do a leak down to see what it is. I have been trying to keep this build stock appearing and it’s not a daily driver by any stretch. I don’t mind not using vacuum advance and have even considered an 6 AL and trigger it with the points distributor. Think I posted compression numbers in one of the other threads I’ll see if I can post the link here.
I’m not closed to using a different ignition system if needed with this combo. Running it with the changes that you guys recommended the fuel in the oil issue has disappeared as far as I can tell and oil level is staying the same and oil doesn’t smell like gasoline. The plugs read it’s not rich like it was before at least they aren’t black I also had some voltage drop to the coil. The run ignition circuit was 4.5 volts at coil + and the start circuit was 11.4 so maybe biggest problem has been ignition related.
https://www.forbbodiesonly.com/moparforum/threads/426-hemi-compression-test-results-cold.230350/
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Fran,
What kind of pics you wanting? From Kryslerkid if so I agree! If from me I have plenty to post
It's not an Elephant
Very nice! I see you have your PCV connected to the rear carb only.
So i’ve been looking at the ignition system this evening to make sure there’s sufficient spark to the plugs. checking voltages to the primary of the coil and things and removed the distributor cap to take a look at points and I find the ground strap from the breaker plate to the housing is broke. Now this tells me the only ground path the points have is through the bearing in the breaker plate. Not good!
Just found this Bee.
My initial thoughts are : what fuel are you running?
I saw you have 100LL available, and with the cam specs posted, it would not hurt to go 50% along w/90+ octane NON ETHANOL. Depends on what you will run in final configuration (on street).
Second, ditch the points - a modified Hemi will struggle to light all that fuel with a stock system. My opinion.......
I would choose one of the well known "multiple spark" units. The manifold doesn't help, and with that combo you may well end up drilling as mentioned.
Racers input here is the best, as your setup (as beautiful as it is- jealous btw) is somewhat of a mix.
It may never stop smelling rich, but it will absolutely obliterate the tires.
My initial thoughts are : what fuel are you running?
I saw you have 100LL available, and with the cam specs posted, it would not hurt to go 50% along w/90+ octane NON ETHANOL. Depends on what you will run in final configuration (on street).
Second, ditch the points - a modified Hemi will struggle to light all that fuel with a stock system. My opinion.......
I would choose one of the well known "multiple spark" units. The manifold doesn't help, and with that combo you may well end up drilling as mentioned.
Racers input here is the best, as your setup (as beautiful as it is- jealous btw) is somewhat of a mix.
It may never stop smelling rich, but it will absolutely obliterate the tires.
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