Out with the 340 & in with the 410 stroker!

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You shouldn't be pinging at 36* total....what do the plugs say? You might need to go with a heavier spring combo in the distributor. I run 35* total, eddy heads, 91 octane, and the same springs you have.
 
redfastback said:
You shouldn't be pinging at 36* total....what do the plugs say? You might need to go with a heavier spring combo in the distributor. I run 35* total, eddy heads, 91 octane, and the same springs you have.
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A couple plugs [autolite 64] looked yellow/glazed with some specs, and it felt really touchy/boarderline rough at 3500 cruise well into the full advance.

Since I've lowered to 32* total, it's smooth and sounds right if you know what I mean.

My plans been to raise it a lil to maybe 34*, when all is right with cam/comp the SB wedge chamber shape dictates needing only around 30*.

What compression do you have with those aluminum heads and what chamber shape?
 
skybolt said:
How do you get those things to crank with that much initial? Why not let the distributor bring in the timing whenever you need it?
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A couple things, ONE I have no vac advance, so a high initial is compensating a lil
Two, full advance happens pretty much as I'm going releasing the clutch@2200 @ and going WOT from there=max power.

Three, The car is faster,torquier with a high initial, which helps in any combo, especially when the combo was slightly compromised by lack of gear OR the right intake design, OR too big of a carburetor OR when the carb blades are open too far to get it to idle, by raising the initial you can now close the blades more to get the slots right in relation etc.....
 
1wild&crazyguy said:
A couple plugs [autolite 64] looked yellow/glazed with some specs, and it felt really touchy/boarderline rough at 3500 cruise well into the full advance.

Since I've lowered to 32* total, it's smooth and sounds right if you know what I mean.


My plans been to raise it a lil to maybe 34*, when all is right with cam/comp the SB wedge chamber shape dictates needing only around 30*.

What compression do you have with those aluminum heads and what chamber shape?
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I am running just shy of 11:1, at about 200-205 psi per cylinder. Can't recall my chamber shape. Edelbrock says that their heads like 35* total. I myself need more cam. I am running the 274xe. Good cam, but my motor wants more.

IMO, you seem to have alot of duration/lift for the cylinder pressures you stated.
 
1wild&crazyguy said:
What trans/convertor?

Too low a stall for the cam/ or poor convertor can have that happening, it drags down the rpm/timing giving you erratic idle speeds.
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I have a 2500 stall converter in a 727 trans. I have been told by a well qualified engine builder the tight converter is causing the in gear idle issues like you say. But I have it working pretty good at this point with the timing locked. I already had the converter before I dropped the stroker in and it was low mileage so I went with it. But if I ever replace it I'd probably go a little higher on the stall.
 
redfastback said:
I am running just shy of 11:1, at about 200-205 psi per cylinder. Can't recall my chamber shape. Edelbrock says that their heads like 35* total. I myself need more cam. I am running the 274xe. Good cam, but my motor wants more.

IMO, you seem to have alot of duration/lift for the cylinder pressures you stated.
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You mean too high or too low?

Thats just what they are, the cam is in straight up almost- 109.5 installed
It is a custom grind, I had them widen the CL from 108 to 110 which in turn being a really fast ramp already left no room so the lift/adv duration was decreased & increased a lil.
Heres the original specs..
Part #: 4403-V
Grind #: KV-3
Int. 575" Ex. 575" lift changed to .573
Int. 281*" Ex. 281*" running duration changed to 284*
Int. 383" Ex. 383" lift @ lobe changed to .382
Int. 250*" Ex. 250*" @ .050 duration changed to 252*
108° lobe center/cl changed to 110*

And run w/1.6 rockers [less than ideal geometry=.560 @valve after lash] but didn't wanna go that big lift anyways, so I'm happy for now with the .560 lift, works well with the heads lift/flow range.
 
Ive got a 408 with Performer RPM and Holley 870. It dynoed 520 hp and runs great. It seems to be right size for the engine, tuning only changed one jet size. And doesn't lean out.
 
I've got RHS Magnum 360 heads w 2.02 & 1.625 valves with 10.5 cr. The cam is Hughes hydraulic roller HER3642AL with duration Int236/Exh242 and .559/521 lift. I used the original standard 5.9L magnum roller lifters with the cam.
Sorry it took a little long to reply but the Iowa - Mich State game went to final second to decide. Go Hawkeyes.
 
1wild&crazyguy said:
Cause I want to be fast, and the curve is too slow.
Just try it, you'll see what I mean.
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lotsa people don't get why to lock out distributors. been doing that to mine for years and got an mpg improvement
as a bonus. IF they insist on using custom curves.. they should step up to a digital ecu. becouse analog mp units/
msd's/dated vacuum advances/mech. curves etc. just won't cut it.
 
1wild&crazyguy said:
UPDATE!
A friend of a friend gave me an 850 dbl pump demon today, so I'll be fiddling with it a lil to see if it's worth a toss.

This should be fun!
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Justin,

Is this a Mighty Demon??

I am very curious how this will work on your stroker. Don at FBO seems to believe that the 850 Mighty Demon is too big for my engine. He says it will flow close to 1000cfm compared to a Holly with same??

Keep us posted!!
 
I have been locking anything with some cam for years, and never said a word to anyone because the one time I did, at Moparchat, I was called an idiot.......
 
Mad Dart said:
Justin,

Is this a Mighty Demon??

I am very curious how this will work on your stroker. Don at FBO seems to believe that the 850 Mighty Demon is too big for my engine. He says it will flow close to 1000cfm compared to a Holly with same??

Keep us posted!!
Click to expand...

Well I took a closer look at it and it's a speed demon 750, not an 850...

But it's supposed to be more radical in calibration to what I have now=750 holley dbl pump.

The Holley came 71/80 and is at 74/83 on the 410 right now..
The speed demon stock is 76/83, s8) we'll see....
 
Mad Dart said:
Justin,

Is this a Mighty Demon??

I am very curious how this will work on your stroker. Don at FBO seems to believe that the 850 Mighty Demon is too big for my engine. He says it will flow close to 1000cfm compared to a Holly with same??

Keep us posted!!
Click to expand...

I took an 850 demon off of a 500 big block stroker it was just too big. I put on an 850 quickfuel DP and it drove so much better. Demons are for WOT only IMO. Demons=JUNK....pure junk. Never had one that drove well. They are jetted bigger due to their bigger boosters. I will run a holley, quickfuel or proform over a demon every day of the week.

Again just my opinion.
 
redfastback said:
I took an 850 demon off of a 500 big block stroker it was just too big. I put on an 850 quickfuel DP and it drove so much better. Demons are for WOT only IMO. Demons=JUNK....pure junk. Never had one that drove well. They are jetted bigger due to their bigger boosters. I will run a holley, quickfuel or proform over a demon every day of the week.

Again just my opinion.
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On my end I have had nothing but GOOD to say about the Mighty Demon carb. They have worked very well on everything I have put them on.
 
I slapped the demon on it [1st set it up per ootb]

OOTB it sucks.

Gonna lean it out a lil, it sounds a lil blubbery and doesn't pull as hard/fast as the 750 holley, but I haven't really played with it yet.

I'm gonna knock the squirter down till it sputters then bring it back up till it just stops spuddering and smoothly transitions.
Then I am gonna lean it out to 72 primary 83 secondary, I just have some trouble thinking it needs to go the other way but we;ll see.

You hear this and that about these carbs so I'm trying to be open minded with this thing, heck it's just tunning right?....lol
 
I lowered the float level, stuck a 28 shooter on there and it's better.
One thing I notice with this speed demon is the richer idle circuit, no more surge/jerk at just off idle throttle 'parking lot cruising'.

Jets are still at 76-83 for now.

oh yeah and the throttle blades are catching cause you have to by hand lower the blades back, otherwise you get another 2-300rpm higher idle...

OOTB these things need work/correcting.
 
Not the same engine, but, I tried Carters, Edelbrocks, holleys, and a buddy talked me into a 1050 Dominator and it was the best thing I ever bought. Street manners are excellent. I need to learn alot about tuning with it but I need to put the car together . (it ran great in the Roadrunner)
 
I need to work on the suspension.

It just breaks'em loose 1-2-3 at anything over 1/3-1/2 throttle.

Next I'll be correcting the pinion angle [cut n roll] and then picking up some axles for 4 1/2 bc so I can run my MT slicks and run 1/4 at fontana.

in the future....The dyno shop has 2 runs =$127 hp/tq a/f read outs.
 
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