anyone want a 505 stroker before i throw it in the bin

[daredevil]

So what youre saying is my opinion is like an asshole.Ok dont listen. Do what the old timer says. I see how far its got you. Does the old timer even know what a ch28 is. I,m thru.You didnt need my advice anyhow.I,d bet money damons dead on. Hes been tuning and racing mopars for 20 years or more. Maybe you will see the show most expensive rides in the world one day. Watch the part about Ronn motor cars Scorpion. Check out the pro driver. Damon Kuhn. Helped in developing the Hydrogen assisted motor. I think he was even an engineer for Comp cams at one time. But that old timer probably who you want to listen to.

 

[benno440]

whoa mate,
you misread, i was referring to the 10 different companies i have asked the same question and got 10 different answers. your infor has been very helpful.

 

[daredevil]

Sorry I took it wrong.I just know without Damons advice I would probably just have a cobbled together bunch of parts. His technical expertise is amazing. I usually dont cheer for anybody but he has impressed me.

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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.

Benno ,
buy an in car AF meter unit . At least then you know what is happening , and buy 2 eddy strip kits and mark them to front and rear carb. If you get 1HP/ci you have a mighty fine motor and this is easily achieved - you should be there by now easily . But once you get over 1.1/1.15 HP/ci you are getting to a point of less street friendly manners and the trade offs that go with it . The magazine numbers I take with a grain of salt .
hang in there ,

Tex

If you dont want to spring for a meter just buy a few sets of plugs and swap a couple in everytime you make a jet change and then read them to see which way youre going.

 

[benno440]

i am using alot of damons advice and his tuning articles, but he told me to use at least 2 x 625cfm carbs, everyone else said this is too big, i am surei can get the 500's to work, i CAN get a hold of 2 street demons (625cfm) to see how they go, which i guess i might try.

yeh i am on my 4th set of plugs now, the plugs seem to look pretty spot on, except the back 4 cylinders (5, 6, 7 & 8) are a tad moist, the front 4 are dry but still tad rich.

 

[Meep-Meep]

Benno, there is something else I want to bring up. Your CH28 is a dual plane like a performer but for dual quads and the images I found show it to be a divided plenum. What may help you a lot is cutting a notch in the dividers. If you are running progressive linkage then cut a notch under the primary carb. Or before you cut get a couple of 1/2" spacers and see if your idle improves. A spacer (or notch) might also help with your monster cam. For notch dimensions see the Performer RPM single 4 or the old CH4B / DP4B.

 

[benno440]

meep, I was replacing the lifters tonite, and noticed a few things.

* I bought 2 x HV 2" supersuckers which don't even fit on my intake which I a pissed off about as I was told that that's the part number I need to buy but anyway.

I was actually talking to a mate of mine about removing some of the divider in between the plenums .
also we flipped both carbs and carb gaskets upside down and both gaskets about the middle of each one it looks like it hadn't sealed completely from carb to intake as the rest of the gasket showed indentations from being torqued down, so I wiped a bit of grease on intake then sat carb on to see what the seal was like and I am not sure if you have seen underneath an edelbrock carb before but right next to the sealing surface it has a recessed groove that is blank and seems to have no apparent effect but looks like it might be causing a vacuum leak, which I don't get as these carbs are suited to this intake. I will have to get a pic to explain properly

 

[Hemirunner]

Benno, there is something else I want to bring up. Your CH28 is a dual plane like a performer but for dual quads and the images I found show it to be a divided plenum. What may help you a lot is cutting a notch in the dividers. If you are running progressive linkage then cut a notch under the primary carb. Or before you cut get a couple of 1/2" spacers and see if your idle improves. A spacer (or notch) might also help with your monster cam. For notch dimensions see the Performer RPM single 4 or the old CH4B / DP4B.

Good point Meep, the notch will help but that intake is an issue on big inch engines. Besides the fact that it's a dual plane intake, which isn't a good thing on a big stroke engine, it also has no plenum volume to draw from. An Indy mod-man intake with a dual quad top would give it all you need, but if you change that, you might as well go to some bigger 650cfm Thunder series edelbrock carbs. Hell, while we're at it, dual quad EFI would solve some issues too, LOL. That CH28 will choke off most well built 440 inch engines, let alone a big stroker.

 

[67Satty]

Benno,

You should think about ordering Don Dulmage's book "Old Reliable" since he uses the same CH28 intake as you and runs mid-11s in a 4000 pound Charger with a stock stroke 440.

Quoting from his book:

"We have tried several intakes with this car and the results might surprise you. Our best ET's have all been run with an Edelbrock CH28 dual four, dual plane manifold. The center divider has been milled down to 3/8" under both carbs and it runs a pair of old AFB Marine carbs (about 500 CFM). The air valve weights have been trimmed for quicker response and the carbs have been jetted up four sizes all around. The response is lighting fast and it has never needed attention. We run a direct 1 to 1 linkage to the carb as recommended by Vic Edelbrock."

I hope this helps you. If you throw enough scientific method at it, trying one experiment at a time and noting the results you'll get it sorted out soon enough.

 

[benno440]

got an update

lifters in, timing at 20* initial 38* total
carb currently:
900rpm idle
orange springs in the metering rods
A/F 1 3/4 turns out
.83 jets in primaries

car starts perfectly, and no more overrun
it still seems low on power
it surges badly at low rpm (car jumps like its on hydraulics have to put clutch in to stop it )

I had a fuel pressure gauge on the "racepumps" regulator and it was jumping erratically so I put a new gauge on. the pressure goes between 1-3 psi no matter what rpm I am doing, I checked all lines and filter all perfect.
maybe I need a better regulator.

my mate lent me 2 of the new 625 street demons for a tryout to see how they go, I have not tried them yet but supposedly a very good carb, I see some guy with a 409 chevy stroker using 2 of these and reckons best carbs ever. http://www.summitracing.com/parts/dem-1900

let me know what you think.

 

[Meep-Meep]

Good point Meep, the notch will help but that intake is an issue on big inch engines. Besides the fact that it's a dual plane intake, which isn't a good thing on a big stroke engine, it also has no plenum volume to draw from. An Indy mod-man intake with a dual quad top would give it all you need, but if you change that, you might as well go to some bigger 650cfm Thunder series edelbrock carbs. Hell, while we're at it, dual quad EFI would solve some issues too, LOL. That CH28 will choke off most well built 440 inch engines, let alone a big stroker.

I'm sure what you suggest will work great, but I have to think that 528 hemis have done well with the stock dual quad intake, which is the same design as the CH28, so the 505 might do well also. The hemi intake has more runner volume and that makes a difference, but I still think that 505 can run well (maybe not optimum) with the 500's on the modified CH28. What about the 440 6 BBL on big inch motors? Again, the intake is very similar to the hemi and CH28. All I'm saying is that CH28 might not be the kiss of death but it sure seems like it can use some working over.

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Benno, 1 - 3 PSI of fuel pressure?? Please explain. At idle you should have in the neighborhood of 5 PSI maybe more. Proper fuel pressure at the carb is required to maintain a proper fuel level in the bowls, so as the level drops due to low pressure, the engine can lean out. My Holley mech pump puts out 7.5 PSI on a single AFB but I can see that number dropping a little with dual quads. But 1 - 3 seems too low.

Also it seems like you found and fixed a vacuum leak at the base. Excellent! Little by little we'll get this thing going.

 

[benno440]

i don't know what else to say i have checked everything with the PSI everything seems to be working fine, i am thinking maybe this regulator does not work well with anything but the same brand fuel pump as it says when you buy there fuel pump you must use there regulator, I sold that pump and bought a clay smith pump but kept the regulator. maybe it just doesn't match. but i can turn the pressure screw up and down all the way and the pressure does not change at no matter what rpm it is doing and i have tried 2 gauges.

yeh it is definetly running a lot better, i went for a drive today, got out on the open highway, opened her up in the OD gear and holy crap went from 80mph-150mph in no time, it has got a lot of top end, and i was only sitting on about 4000rpm and still wanted to go.

still surges a little at low rpm, what would be causing this? the regulator?

 

[Tex013]

still surges a little at low rpm, what would be causing this? the regulator?

Benno , this normally will indicate a lean mixture . Using your Eddy instruction book , jetting increase graph , step your cruise mixture up .
Good to see you getting closer , I don't see the carbs as the biggest issue if at all you do have a potential 1000cfm . I do have a mildy modified Modman setup which I still believe is suited to stroker motors more so than stock cube motors - BIG plenum , just over 5 litres . Probably find your head intake port is the biggest cork , then your intake .A stroker needs a LOT of intake plenum and hence port flow/volume to fill it to best potential .You may find you are simply not able to get sufficient fuel into the motor , when you go to a very rich jetting combination it will possibly still show lean due to fuel falling out of the airstream . That's my 2 cents worth from the work I have done .

Tex

 

[benno440]

do you have a link for this intake? is it a dual quad? i am definetly willing to go to a bigger plenum intake as your not the only one to recommend.
and i plan on going some bigger heads maybe in a year.

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sorry tex i really dont undertsand that jetting graph.
i can tell you what i have in carb now and go from there i guess, or if someone could explain the graph to me would be nice, whether i understand afterwards is another story all together haha.

i have the .83 jets in primaries and .96 in secondaries
metering rods .65 x .52
and the orange springs (5"hg)
the pump arm is connected to the lowest hole on the pump arm

 

[MarPar]

here ya go Benno...

http://indyheads.com/modman.html

 

[benno440]

thanks Mar, had a quick look at there site earlier it looked like they made them for everything but the RB engine

 

[747mopar]

I think I'd definetly focus on that pressure issue until you figure that out, like Meep said more in the 5-7 psi range. Can you temporarily put pressure gauge ahead of the regulator to see what the pump is doing. 150 mph "holy ****" I'd be afraid of taking flight at that speed, you got bigger balls than me.

 

[Tex013]

do you have a link for this intake? is it a dual quad? i am definetly willing to go to a bigger plenum intake as your not the only one to recommend.
and i plan on going some bigger heads maybe in a year.

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sorry tex i really dont undertsand that jetting graph.
i can tell you what i have in carb now and go from there i guess, or if someone could explain the graph to me would be nice, whether i understand afterwards is another story all together haha.

i have the .83 jets in primaries and .96 in secondaries
metering rods .65 x .52
and the orange springs (5"hg)
the pump arm is connected to the lowest hole on the pump arm

open plenum pic shows insert fitted
to sort jetting using graph don't worry about springs initially .
OK . Your primary jetting ( .83 jet/6552 rod ) shows at ref #11 which would indicate 2 stages leaner than stock calibration on cruise mode . Stock setting is 0.086 jet with 6552 rod , so I would put the 0.086 jet back in to start with in both carbs , this will richen up cruise and should reduce or remove surge .
0.096 is 1/1000 bigger than stock in secondaries , leave it for the moment . Get your cruise right first .
Once cruise is right then you will need to adjust rear jetting if required .
The reference chart is for primary only , OOTB calibration is #1 . Move around the chart up , richer , or down , leaner when setting cruise . Move left , leaner , or right richer for power . This is when you lean on throttle off cruise going to pass or going up a hill not total full throttle

Tex

 

[benno440]

the car feels more stable at that speed than it does down low, the suspension uogrades are amazing i can take my hands off the wheel at that speed and feel confident.

i think i might try a different regulator as everything else seems to be working.

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View attachment 128839View attachment 128840

open plenum pic shows insert fitted
to sort jetting using graph don't worry about springs initially .
OK . Your primary jetting ( .83 jet/6552 rod ) shows at ref #11 which would indicate 2 stages leaner than stock calibration on cruise mode . Stock setting is 0.086 jet with 6552 rod , so I would put the 0.086 jet back in to start with in both carbs , this will richen up cruise and should reduce or remove surge .
0.096 is 1/1000 bigger than stock in secondaries , leave it for the moment . Get your cruise right first .
Once cruise is right then you will need to adjust rear jetting if required .
The reference chart is for primary only , OOTB calibration is #1 . Move around the chart up , richer , or down , leaner when setting cruise . Move left , leaner , or right richer for power . This is when you lean on throttle off cruise going to pass or going up a hill not total full throttle

Tex

i will give it a go, i put those jets in as i was way too rich, fouling plugs etc.

do you have the carbs bolted straight onto that open plenum? or does the top plate go on, is the angle welded in for better flow?
is the only place to get the modman from indy? and i have read other places that when people have put the modman on they lost power, is this true?

 

[Meep-Meep]

Benno, like 747 says, check the fuel pump pressure right out of the pump. Just tee in a gauge before the regulator. You really need to solve the fuel pressure and fuel level in the float bowls before you start diddling with jetting. Since you have two carbs with a total of four needle and seat assemblies, you will expect a little lower pressure because of the added flow during demand, but as long as the pump can keep up you will be OK. At idle the demand is pretty low so the pressure should be close to advertized numbers. High pressure = low flow and vice-versa. On my single AFB at idle I get the advertized pump pressure at 7.5 PSI and at WOT I get about 3 PSI.

 

[benno440]

yeh will check this, this weekend, some guy I was talking to told me that sometimes the diaphragms go on these regulators so I will check it all and get back to you guys