anyone want a 505 stroker before i throw it in the bin
- Thread starter benno440
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benno440
Well-Known Member
Quick question
i have recommended by multiple people including damon from diamondback engines that my dual 500cfm carbs are too small for my intake which is making very high intake tract speeds and a narrow tuning window. he suggested dual 625cfm carbs, what do you guys think
i see demon carbs have a sweet new 625cfm carb which is similiar to the carter design with better upgrades.
should i pull the trigger and get rid of these edelbrocks
i have recommended by multiple people including damon from diamondback engines that my dual 500cfm carbs are too small for my intake which is making very high intake tract speeds and a narrow tuning window. he suggested dual 625cfm carbs, what do you guys think
i see demon carbs have a sweet new 625cfm carb which is similiar to the carter design with better upgrades.
should i pull the trigger and get rid of these edelbrocks
Since YOU asked, I think you'd be wasting your money. Again, any carburetor brand can be made to work well if it's tuned correctly. My final advice to you (remember, you asked) is to find a guy who knows how to tune performance motors and take advice from him only. If you ask 10 guys for an opinion, you're going to get 10 different answers and half (or more) of them haven't ever used the combination you have. Your fellow Aussie, Tex, seems to have a handle on his combination. Listen to him for advice and stop throwing money down the hole by changing parts left and right and not getting results. I wouldn't have said it, but again, you asked for opinions...
benno440
Well-Known Member
well its not really wasting money as i can sell the edelbrocks for the same price almost its more like swapping parts, i was just thinking the demons would be better and help my engine run a bit better
Meep-Meep
дворянин
I'm really sure the 500 and 625 have the same size primary throttle blade and main venturi so I have no idea what that guy is talking about. It is possible the low speed circuit needs to be dialed in, but for the most part the carbs should work.
Do you have a single carb like a Holley 750? or 800 and appropriate intake? Give that a shot in the name of research and post the results.
What is your idle vacuum?
Do you have a single carb like a Holley 750? or 800 and appropriate intake? Give that a shot in the name of research and post the results.
What is your idle vacuum?
Hemirunner
Well-Known Member
Put a dual channel wide band in it so you actually know what's going on. No offense intended, but just swapping parts out until something works isn't the way to tune a car. You need think through it logically.
benno440
Well-Known Member
this is copied from a msg I got from Damon at diamond back engines, he has many tech articles on tuning especially mopar engines, thought I would share what he told me to do.
"Several things here, will try to address the obvious.
First off the combo of the CH28 and small carbs is going to make for very high intake tract speeds and a narrow tuning window. You would be better off with a larger plenum intake and or larger carbs at least 625's. That said you need to tune it fully warmed up. ...properly tuned, not counting any choke action, the rise in rpm is normal which is why you cannot tune cold as the engine will be lean. I would guess a lot of your run on problems are related to throttle opening and rpm. Tune to a 850-950 hot idle speed. That cam should want 18-20 degrees of initial and about 35 degrees total. With that said, you may need to put a switch on the coil to allow mag starting ( get the engine turning on the starter and then turn on the ignition) to allow starting with the proper tune. Another option is a very light advance spring to allow starting at low timing and when the egine starts the spring expands immediately allowing proper timing. The surge could be ignition related or your metering rod springs may be a bit light allowing the metering rods to oscillate at cruise rpm going rich,lean, rich, etc. one way to test that theory is to increase cruising speed 10-15 mph and see if it smooths out, if so go up to yellow springs. Have to get busy, that should give you something to work with for a bit."
"Several things here, will try to address the obvious.
First off the combo of the CH28 and small carbs is going to make for very high intake tract speeds and a narrow tuning window. You would be better off with a larger plenum intake and or larger carbs at least 625's. That said you need to tune it fully warmed up. ...properly tuned, not counting any choke action, the rise in rpm is normal which is why you cannot tune cold as the engine will be lean. I would guess a lot of your run on problems are related to throttle opening and rpm. Tune to a 850-950 hot idle speed. That cam should want 18-20 degrees of initial and about 35 degrees total. With that said, you may need to put a switch on the coil to allow mag starting ( get the engine turning on the starter and then turn on the ignition) to allow starting with the proper tune. Another option is a very light advance spring to allow starting at low timing and when the egine starts the spring expands immediately allowing proper timing. The surge could be ignition related or your metering rod springs may be a bit light allowing the metering rods to oscillate at cruise rpm going rich,lean, rich, etc. one way to test that theory is to increase cruising speed 10-15 mph and see if it smooths out, if so go up to yellow springs. Have to get busy, that should give you something to work with for a bit."
Hemirunner
Well-Known Member
Seems to be very good advice. Locking out the distributor and putting a start retard on is the same as mag starting without the issue of the having a switch to deal with. My question is, have you tried any of it yet? He's dead on with your oscillation issue. Those blue springs won't work in this deal. I think mine has orange springs in it right now.
Tex013
Well-Known Member
Benno,
my understanding is the 500 and 600 eddies are the same carb venturi / throttle butterfly - the 500 booster cluster is different size and takes up / restricts the air flow , as you have 500's I would set them at 1:1 at least to start with though I see no reason it can't be tuned to run progressive. I have 2 x 600 eddies on the Modman . Currently I have a Victor 440 with prosystems 1000hp based carb .
Hemirunner is right , if you are not using a oxygen sensor you should whether it be on the dyno or in your car . Just bought a Autometer from Summit for under $300 for a mates Camaro .
With the dual plane and 500 carbs I would maybe like to see a little more vacuum at idle .
What is your ultimate aim . Greg's 510 I tuned went about 440RWHP with a solid FT cam I chose , using his limits , and a sixpack , but with mild worked eddy heads ran out of cylinder head flow and could not get the AF ideal due to this . I had the same issue and went to CNC port heads whohoo what a difference I ended up with just under 430RWHP out of my 440
Tex
my understanding is the 500 and 600 eddies are the same carb venturi / throttle butterfly - the 500 booster cluster is different size and takes up / restricts the air flow , as you have 500's I would set them at 1:1 at least to start with though I see no reason it can't be tuned to run progressive. I have 2 x 600 eddies on the Modman . Currently I have a Victor 440 with prosystems 1000hp based carb .
Hemirunner is right , if you are not using a oxygen sensor you should whether it be on the dyno or in your car . Just bought a Autometer from Summit for under $300 for a mates Camaro .
With the dual plane and 500 carbs I would maybe like to see a little more vacuum at idle .
What is your ultimate aim . Greg's 510 I tuned went about 440RWHP with a solid FT cam I chose , using his limits , and a sixpack , but with mild worked eddy heads ran out of cylinder head flow and could not get the AF ideal due to this . I had the same issue and went to CNC port heads whohoo what a difference I ended up with just under 430RWHP out of my 440
Tex
daredevil
Well-Known Member
Damon knows his ****. I,m running one of his carbs on my 500. Its very common to see him tuning carbs for people at the track. I trust his advice.
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benno440
Well-Known Member
ultimate aim is to have a healthy motor that doesnt overrun etc. more of a street cruiser with a couple of circuit days and strip days a year.
i was reading moparmusclemag did a 505 build with very similiar build to mine, it had higher compression but smaller cam and it was pulling 650hp 690tq at the flywheel and was using dual 500 edelbrocks.
where i live is a mining town, there is no dynos or experienced engine tuners for 1200 km, so everything will have to be done by me with the advice of you all.
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damon was the one telling me to buy the 625 carbs and get rid of the 500cfm.
i asked ron from the winners circle who is the old time stock car tuner/racer who has been helping me so far he said replacing the carbs will still cause the same problems, but that is too big and will lose on torque and be boggy down low. it was right what previous poster said about opinions are like ********, everyone has one.
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i will wait till my lifters turn up then ill change them out, then ill reset my timing to what was recommended, add my carb spacers and play with the A/F and see what happens.
talk soon
Tex013
Well-Known Member
Meep-Meep
дворянин
2-1/4 turns out on each idle mixture screw is borderline going too far. Are your throttle blades open too far? I went over this before but you only should have about 1-1/2 turns from lightly seated on the idle speed screws, or whatever setting will bring the blade about one third up on the transfer slot.
With that low vacuum I'm not at all surprised you have carb tuning problems. You may need to open up the idle feed restrictors located in the booster clusters but you better be careful and not over do it. I can get close without an O2 sensor but hooking one up is great advice.
benno440
Well-Known Member
thanks meep, to be honest at the start I was not really clear on how to do it all, the last few days I have been researching and learning and I am confident this time around. I DO think they are open too far, this is probably my overrun problem, I will be going over everything on the carbs ( floats, transfer slot etc.)
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Hemirunner
Well-Known Member
FAST 170402 Dual channel wideband kit. Eddy strip kits are the jet/metering rod/spring kits. Read the edelbrock books from front to rear ten times and start playing with those carbs once you have the wideband installed. You will amaze yourself with what you learn.
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Get the 1465 spring loaded needle and seat assemblies as well. These will eliminate any issues with fuel during cornering or braking. Also these carbs can't take much over 5 psi of fuel pressure. Make sure you have a regulator on it.
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Get the 1465 spring loaded needle and seat assemblies as well. These will eliminate any issues with fuel during cornering or braking. Also these carbs can't take much over 5 psi of fuel pressure. Make sure you have a regulator on it.
Tex013
Well-Known Member
try this - http://www.summitracing.com/parts/atm-3370/overview/
very simple fit up , uses a bosch afr sensor - can buy replacement at Repco etc
does not come with a mount cup/bracket . Does have weld in bung and screw in plug .With a dual plane you will often find it very hard to get both banks the same AFR . Keep a hold on some of your cash as there is no need to go overboard on spending up on the biggest or flashest .
strip kits - EDL1486 covers the 500 eddys . there are kits for 600's as well , these carry bigger jets/rods
I have always run at 6 or 6.5 psi fuel pressures no worries
Tex
benno440
Well-Known Member
Tex,
thanks for the info, i already have 2 sets of the calibration kits. this is where i pulled the .86 primary jets out and put the .83 jets in then changed orange springs for the blue ones, trying to lean my mixture as i was fouling plugs.
my lifters turned up yesterday so i can get back into tuning this weekend
thanks for the info, i already have 2 sets of the calibration kits. this is where i pulled the .86 primary jets out and put the .83 jets in then changed orange springs for the blue ones, trying to lean my mixture as i was fouling plugs.
my lifters turned up yesterday so i can get back into tuning this weekend
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