440 combo opinions

[thrillbilly]

A little back story on this.  I built this 440 over 10 years ago and put it in my 1974 Charger.  It has always ran well, I've driven it hundreds of miles at a time, never gets hot, never misses a beat, and has never been apart since it was built.  I ran it down the 1/4 several years ago with 3:23 gears and ran in the 13:80 range very consistently.  I have zero complaints, but now I'm bored with it and would like some opinions on how to get some more power out of it.  Specs as follows;

76 440 block bored .30
balanced rotating assembly
10:1 hypereutectic pistons
Edelbrock 84cc heads
Crane Gold Roller rockers
Edelbrock Performer RPM intake
Speed Demon vac secondary 750 carb
Comp Xtreme Energy 284H
.507/.510 lift, 110° LS/106°CL, 284/296, 240/246, .338/.340
Recurved stock style dist, 32 degrees all in at 2000 RPM
MSD 6AL ignition box
Hooker 1 7/8 full length headers
Coan built 727 w/manual valve body 2800-3000 stall.

I have since changed to a 3:55 gear and tuned the carb with a wide band 02. 
Runs better than ever, but I still have some issues with the carb. 
I got a great deal on a 850 Mighty Demon mechanical secondary, but I won't be able
to tinker with that until spring.  Should I step up to a larger cam also?
I am a bit concerned about breaking in another cam and have considered a roller,
but the expense is turning me off.

Sorry it's so long, but wanted to tell the whole story.
What do you think, you won't hurt my feelings!!

[cdr]

what kind of exhaust system ?  & might need a little more timing, that cam is pretty big, I dont think you need a cam change. also what is the elevation at the trac you run.  & what was the mph

[thrillbilly]

what kind of exhaust system ?  & might need a little more timing, that cam is pretty big, I dont think you need a cam change. also what is the elevation at the trac you run.

3 in with flowmasters, Northern Indiana is around 760 ft I believe.

I have played with the timing some, but I end up getting detonation if I give it much more.  I think its around 12 degrees at idle with the vacuum advance plugged.

[cdr]

what was the mph?  this is going to start a fight but get some of the welded dyno max 3 in mufflers, they are straight through design, flow masters suck in my opinion, and proof at the trac.   

[thrillbilly]

what was the mph?  this is going to start a fight but get some of the welded dyno max 3 in mufflers, they are straight through design, flow masters suck in my opinion, and proof at the trac.   

I think it was just over 100mph.  Mufflers didn't have any effect since I have electric cutouts.  I usually run around with them open 90% of the time anyway, just ask my neighbors, and their neighbors, lol.

[cdr]

have you checked to make sure when you mash the pedal the carb is at wide open ?

[heyoldguy]

What are you willing to sacrifice "to get some more power out of it."? Right now you bored but have "zero complaints".

[BSB67]

Do you know the cylinder pressure?  If not, can you measure it and get back to us?

[69wannabe]

That's a pretty nice set up looks like to me, 528 hemi would be an upgrade!!! LOL. Wish I could point you in an upward direction but what you got there seems to be a nice combo....

[RECHRGD]

I'm no expert, but if you're only hitting 100 mph in the 1/4 mile with all those parts, something is wrong.  Hell, my stock R/T back in '68 could meet or beat that.  Did you do the work?  Was the cam degreed?  Just seems that you should be at about 105 or better.  As others have asked, do you know what cylinder pressure you have?

[BSB67]

........if you're only hitting 100 mph in the 1/4 mile with all those parts, something is wrong.  Hell, my stock R/T back in '68 could meet or beat that......

A little harsh (coming from me - right  )  But I was thinking the same and thought that maybe the cylinder pressure could give us some in-site before we start going in the inevitable 500 different directions on what to fix.

[thrillbilly]

I do not know what the cylinder pressure is.  It's in storage and I'm not able to mess with it right now.  The machine shop installed the cam, but I put the rest of it together.  I think it should run better than it does too. Appreciate the help.

[thrillbilly]

That's a pretty nice set up looks like to me, 528 hemi would be an upgrade!!! LOL. Wish I could point you in an upward direction but what you got there seems to be a nice combo....

Right?!  Lol

[Challenger340]

76 440 block bored .30
balanced rotating assembly
10:1 hypereutectic pistons
Edelbrock 84cc heads
Crane Gold Roller rockers
Edelbrock Performer RPM intake
Speed Demon vac secondary 750 carb
Comp Xtreme Energy 284H
.507/.510 lift, 110° LS/106°CL, 284/296, 240/246, .338/.340
Recurved stock style dist, 32 degrees all in at 2000 RPM
MSD 6AL ignition box
Hooker 1 7/8 full length headers
Coan built 727 w/manual valve body 2800-3000 stall.

I am really curious about "slightly above 100 mph" in the 1/4 mile with that combination ? Unless it was about "10 mph" above 100 in the 1/4 ?
No offense intended,

But any way you could get the ACTUAL Piston Part # for that supposed "10:1 Hypereutectic" used ?

[thrillbilly]

I think it was 101 mph.  I'd have to look for the receipt, when I had it built I told the shop that is the compression ratio I wanted.  I know there are a lot of variables that go into it, but it should be somewhere close.  No offense, I'm the one that asked, lol.

[1974dodgecharger]

looks like some parts of my build Hyper pistons are probably Keith black???  and 84cc chamber heads eddy  heads RPM specifically probably since back then eddy had 2 heads 84 and 88cc.

Its probably lower than 10 to 1....

[69wannabe]

Looks like a little more initial timimg would help, maybe around 14 to 16 BTDC. I can't figure out why you can't get a little more timing out of it. Looks like you should be able to get about 34 to 36 total timing out of it with the eddy heads but I may be wrong.

[c00nhunterjoe]

That engine, even with 8:1 pistons and 30 degrees of timing should run more then 101 mph at 1000 feet air.....

[69wannabe]

I know it's crazy but I have seen some cars with built up engines that just didn't perform as intended and looked alot like this set up then you have a car built very mild that runs way better than it should. It's hard to explain really but i'm sure as car guy's most know what I am saying.

[thrillbilly]

I think they were speed pro Pistons.  I've tried messing with the timing, but I always have to back it off as I end up getting detonation.   I've just always assumed I should have went with more cam and more carb.  I remember that the pistons did come right up to the deck. 

[firefighter3931]

Looking at the combo the thing that stands out most is the 750 vac carb. If it's detonating with 10:1 and closed chamber heads the problem is more than likely a fuel delivery issue. I bet it's going waaaay lean at WOT and hurting trap speed. 



Ron

[BSB67]

Here is Doug's car - a real life, low budget deal to put your stuff in perspective:

1968 Charger
Weight w/ driver 3700
Automatic, 2400 rpm stall converter
4.10 gear
P275 60 15s
Home ported 906s
Hemi Grind cam (284/.474)
Factory stamped steel rockers
8.5:1 CR using low compression 850 g. TRW slugs
CH4B intake with a Carter 750 cfm
1 ¾" headers and 2 ½" exhaust system
12.90s at 106 with a 1.9 - 60ft.

Your stuff will be 300 or 400 lbs heavier I would guess which would shift his number 3 or 4 ths, and 3 or 4 mph closer to yours, making the numbers not that much different.  But the flip side is that you should be making considerable more power than Doug with your CR, intake, cam and heads, like 60 to 80 hp.

I picked this example because the carb is the same as yours (probably smaller in real numbers).  I have more data on a combo very similar to yours (9.5: CR, cam like yours, with 915 heads that flow 240 cfm (still less than yours) and about 4000 lbs), and he was running about 112 mph deep into the 12s, with 2.0+ 60 ft times.  He was running a 6 bbl.  If we put Your intake and carb on this car, it would still run 110 mph

[thrillbilly]

Thanks again for the input.  Wow, a whole sec quicker.  It's always ran very rich according to my wide band O2.  I leaned the primaries, and had to richen the secondaries.  But it has a big lean spot going to wot at cruise.  I think the 850 double pump will cover that, ha!

[c00nhunterjoe]

   you are talking about swapping carbs before fixing your engine... 13.8 in a 3800 lb car is about 280 flywheel hp. 101 mph in the same weight is about 300. You have a problem.

[BSB67]

  you are talking about swapping carbs before fixing your engine... 13.8 in a 3800 lb car is about 280 flywheel hp. 101 mph in the same weight is about 300. You have a problem.

Tough crowd.

At least the OP cares enough about power and performance to take the car to the track.  If he gives us cylinder pressure data, we will have more worthwhile information than we ever get here.  If he could get back to the track this spring and spend a day flogging the car there, and cylinder pressure data, we can get him well to the 12s, motor alone, I'm sure.