Author Topic: How to shave a second? 440  (Read 6676 times)

Offline The Cuda Guy

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Re: How to shave a second? 440
« Reply #15 on: November 06, 2010 - 01:01:39 AM »
I've already got that eldebrock performer RPM intake actually, engine sounds like it might have a cam already. Running on a 670 CFM carburetor, I know I need atleast a 750 CFM, should I get a double pumper or is vacuum secondary going to be any different?

What do I need to do to up the compression, and where do I want it to be?

And you said that the thin shim type head gasket would help? Does Summit racing offer those and how do they increase compression exactly?


Here are the shim gaskets that mopar offers, mr. gasket offers some too:
http://www.summitracing.com/parts/DCC-5155237/

The comp bump comes from thiner gasket thus bringing your combuston chamber lower towards the piston and lowering the available space for the air/fuel mixture to be compressed in thus raising your comp ratio. 

You could also have your heads shaved to increase the comp ratio, but I dont know if you want to go that far into the process.

I think the rule of thumb for Iron Heads and pump gas is 9.5:1 comp ratio max.  If you go higher you will need to run higher than pump 91-93 octaine  eg. race gas.

I would say you need at least a 850 carb.  340's came factory with I think 800 or 850 cfm carbs. 

Unless you know what your cam is, I would still look at getting one like the one I listed previously. 

If my facts are off someone please chime in and correct me.

Good luck!

Don

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Offline Cooter

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Re: How to shave a second? 440
« Reply #16 on: November 08, 2010 - 06:42:16 AM »
Steel shim gaskets and closed chamber heads are only good for around 1 point of compression jump..You'll have to go into the engine if you want it to perform..Too many opt for the cheaper and less desirable later 440 engines over the $1000-$1500.00 '66-'70 440 "HP" engines and do not reallize this until AFTER they get the engine in the car and it isn't the mighty 440 they've read about....Still the same engine, but it would be the same as taking the blower off a blower motor and trying to drag race it Normally aspirated..It just won't work..

There is a reason eveyrbody asks big $$ for the earlier 440 engines if you are looking to just drop one in and run it, Just like they did back in the day...
1958 plymouth Belvedere 2dr hd top "Christine" [OO)====V====(OO]
1969 dodge Charger "General Lee"         [___|______I______|___]                        
1968 Dodge Dart 2dr sedan 505" Stroker    (O]=0==========0=[O)                
1970 Challenger R/T Clone "Kowalski Special"   (OO) [___________] (OO)

Offline boxfox

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Re: How to shave a second? 440
« Reply #17 on: November 08, 2010 - 02:39:38 PM »
So would I be better off with just buying a 66-'70 440 engine instead of trying to modify my current 1977 440 engine?

Offline Cooter

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Re: How to shave a second? 440
« Reply #18 on: November 08, 2010 - 07:40:38 PM »
No, not nessesarily...But, finding a runable '66-'70 440 "HP" engine is next to nill today. I mean, it is a 40 year old engine and most are either worn out, or bored out already..If your engine is a little tired and in need of a rebuild, then is the time to install the "Good" pistons and closed chamber heads with steel shim gaskets. Might even go with the Aluminum heads. A stroker crank kit might even be the ticket as well...There is no magic part you can bolt on a low comp. 440 that will bring your '77 440 up to the '66-'70 "HP" 440 standard...Sure, you could swap on a set of closed chamber heads and it will help, but only about .5 a point of compression at best with steel gaskets...So, instead of a 7.7:1 440, you'd then have around an 8.2:1 440...
 
I'm just saying that most times when someone is selling a cast crank, low comp. 440 for cheap, there's a reason the earlier engines bring more if you are reusing the stock pistons..
1958 plymouth Belvedere 2dr hd top "Christine" [OO)====V====(OO]
1969 dodge Charger "General Lee"         [___|______I______|___]                        
1968 Dodge Dart 2dr sedan 505" Stroker    (O]=0==========0=[O)                
1970 Challenger R/T Clone "Kowalski Special"   (OO) [___________] (OO)

Offline moparmaniac59

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Re: How to shave a second? 440
« Reply #19 on: November 08, 2010 - 08:09:16 PM »
I would say you need at least a 850 carb.  340's came factory with I think 800 or 850 cfm carbs. 

If my facts are off someone please chime in and correct me.

Good luck!

That's even more carb than came stock on a 440. Folks tend to go overboard on carburetors often thinking the bigger the carb, the faster the car will go. Too much carb will just bog it down. I had a 750 on my midly modified 360. It was too much and bogged down. I switched to a 650 and it's perfect. Better throttle response and no bog. I have a 1000 cfm on my 543 stroker motor and that's perfect. I think an 850 would be WAY too much for a 340. Maybe a 650 unless it's modified needs more fuel flow!!

Matt B.
Matt

Offline Cooter

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Re: How to shave a second? 440
« Reply #20 on: November 08, 2010 - 08:23:08 PM »
CFM of the carburetor is relative. Yes, a 650 CFM carb will perform great on a 440 at low RPM's, but when you get that big engine wound out, it won't be enough. An 850 on a stock 440 will be a pig on low RPM, but when you get that sucker wound out, it's great...EFI guys don't have to worry bout this, but us carb guys do...

BTW: I beleive the '74-'78 440's used an 850 CFM T-uad carb..Dimes in the front for throttle response and Q balls in the rear for performance. Some believe in these carbs and some hate 'em..The 340 Engines used a 750 T-Quad carb I believe. Talk about over carb'd, how bout the 340 "Six Pack"?  or the 440 "Six Pack"? 1350 CFM's on a stock 390 HP 440? OR how bout the Dual quad Max Wedge cars? Long ram cars? Short ram Cars?

All of 'em were obercarb'd back in the day for top end performance when fuel was cheap and they didn't care how much was running out the tailpipe...
1958 plymouth Belvedere 2dr hd top "Christine" [OO)====V====(OO]
1969 dodge Charger "General Lee"         [___|______I______|___]                        
1968 Dodge Dart 2dr sedan 505" Stroker    (O]=0==========0=[O)                
1970 Challenger R/T Clone "Kowalski Special"   (OO) [___________] (OO)

Offline boxfox

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Re: How to shave a second? 440
« Reply #21 on: November 09, 2010 - 01:43:49 AM »
With my current 670 CFM carburetor on the 440 engine it seems to almost always be running rich and if its not running rich then its not running healthy either, I've only got the idle mixture screws turned out about 4 turns right now, is that an indication that maybe the carburetor size is good for the engine as is for now?

What really set the 440 engine apart in the years?

I mean if I just take it down to the block...better pistons, better heads...will it be just the same as a 66-70 440 engine?

Thanks for the info so far guys, its been real helpful.

Offline The Cuda Guy

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Re: How to shave a second? 440
« Reply #22 on: November 09, 2010 - 04:18:28 AM »
With my current 670 CFM carburetor on the 440 engine it seems to almost always be running rich and if its not running rich then its not running healthy either, I've only got the idle mixture screws turned out about 4 turns right now, is that an indication that maybe the carburetor size is good for the engine as is for now?

What really set the 440 engine apart in the years?

I mean if I just take it down to the block...better pistons, better heads...will it be just the same as a 66-70 440 engine?

Thanks for the info so far guys, its been real helpful.

1966-1967 HP 440 were rated at 375hp and had closed champer heads
1968-1970 HP 440 were rated at 375hp or 390hp with six pack, both engines had open champer heads

1971 and later engines were lower in compression and did not have nearly as much HP.

You can meet your goals by doing the following:

- Larger Carb
- Shim Head Gaskets
- Larger Cam
- Headers
- High Flow Mufflers

This can all be done without removing the engine. 

Hope this helps you.

Don
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Offline Cooter

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Re: How to shave a second? 440
« Reply #23 on: November 09, 2010 - 06:57:17 AM »
With my current 670 CFM carburetor on the 440 engine it seems to almost always be running rich and if its not running rich then its not running healthy either, I've only got the idle mixture screws turned out about 4 turns right now, is that an indication that maybe the carburetor size is good for the engine as is for now?

What really set the 440 engine apart in the years?

I mean if I just take it down to the block...better pistons, better heads...will it be just the same as a 66-70 440 engine?

Thanks for the info so far guys, its been real helpful.





You cannot go by idle mixture as to how "Rich" that carb is running.. You could have the idle mixture screws backed out too far, or a blown power valve (If the carb is old enough and doesn't have the blowout protection).

To properly find out How rich the carb is running across the ENTIRE RPM range, you would need a dyno and A/F sensors. Yes, if you rebuild that '77 440, then in effect, you've made that engine an "HP" and better as we have ALOT better stuff than the factory did back in '66-'70...
This was what I was trying to get across...An "HP" Engine don't mean sh*t when you are gonna rebuild it with BETTER than "HP" stuff...
1958 plymouth Belvedere 2dr hd top "Christine" [OO)====V====(OO]
1969 dodge Charger "General Lee"         [___|______I______|___]                        
1968 Dodge Dart 2dr sedan 505" Stroker    (O]=0==========0=[O)                
1970 Challenger R/T Clone "Kowalski Special"   (OO) [___________] (OO)

Offline The Cuda Guy

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Re: How to shave a second? 440
« Reply #24 on: November 09, 2010 - 07:26:32 AM »

You cannot go by idle mixture as to how "Rich" that carb is running.. You could have the idle mixture screws backed out too far, or a blown power valve (If the carb is old enough and doesn't have the blowout protection).

To properly find out How rich the carb is running across the ENTIRE RPM range, you would need a dyno and A/F sensors. Yes, if you rebuild that '77 440, then in effect, you've made that engine an "HP" and better as we have ALOT better stuff than the factory did back in '66-'70...
This was what I was trying to get across...An "HP" Engine don't mean sh*t when you are gonna rebuild it with BETTER than "HP" stuff...

 :iagree:
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Offline moper

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Re: How to shave a second? 440
« Reply #25 on: November 09, 2010 - 11:46:42 AM »
My impression is, if you have not run the car, that you are not in the 14s now with what you have. If the engine is a good running '77 440 non HP, you have a good base, and one that can get into the high 13s with the properly matched driveline. a 2.76:1 rear axle ratio is not "propoerly matched" if your goals are 13s and you have a stock engine. 1. You dont mention the exhaust system... If you have manifolds, replace them with headers. Cheap headers are available for that car so long as you have a floor shifter. Have a good dual exh system bent up. 2 1/2 in pipes and decnt mufflers are plenty.
2. Replace or re-curve the factory distributor, if it is lean burn, get the MP electronic conversion with the vacuum advance.
3. Replace the center section with a set of 3.55s. They will allow for decent highway manners and not hurt the 1/4 mile work.
4. Install a shift kit in the transmission. I like Trans Go myself. But anything will do at this level.
5. Replace the timing set, camshaft, valve seals, and valve springs all at once. Something like the Comp XE262, or the "larger" Summit Brand cam, and a set of 911-16 or Edelbrock take off springs would be fine. The timing set from the factory has nylon gears which tend to break and shear, so ditch that too.

With those steps, done in that order, and your current intake and carb you will get the car into the high 13s provided it's tuned well and the tires are sticky. The carb's size is fine. Spend money where you need to, not where you're workable already.

You do not need to break into the engine beyond the timing chain cover if it's running well.
A similar build with a slightly larger hydraulic cam and 3.91s went 12.40s and I drove the car for two years daily. Including in the snow, with a '78 pass car 440 with 80K miles.

Offline boxfox

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Re: How to shave a second? 440
« Reply #26 on: November 09, 2010 - 02:56:07 PM »
I have headers, have a mandrel bent exhaust system with dynomax VT mufflers so its a straight through design. I have a shift kit in the transmission already I think its a B&M shift kit.
I'm looking into getting some 3.55 gears soon.
I still need to do something about the distributor, when you say re-curve what do you mean?
And what all does the timing set include?