Re: a few questions about big block heads
[Re: the nitro man]
#154652
11/23/08 06:19 PM
11/23/08 06:19 PM
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Joined: Jun 2008
Posts: 3,916 usa
lewtot184
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master
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Quote:
How much does it usually cost to cut a 440 crank to fit a 400 block? No offset grinding, just the mains & counter weights. a 451 seems to be the best thing I've read about so far. It seems to be a proven combo. I like the lighter weight of the rotating assembly v/s the 440.
thanks for everyone's replies. i just want to learn more (all i can) about the mighty mopar big block..
before i spent $$$ on cutting down a stock crank i'd look into a 3.90 stroker crank for 400 block. comes out to 470 cubes. parts are easy to come by and an absolute killer combo. my favorite big block combo. kinda like a hot 350 chevy on steriods.
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Re: a few questions about big block heads
[Re: lewtot184]
#154653
11/23/08 08:34 PM
11/23/08 08:34 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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I've been wondering about that 470 for my 400 block. who should I contact? EDIT & with a 400 block & rb rods what is the limit on how far it can be stroked? this is going to be a daily driver
Last edited by RapidRobert; 11/23/08 09:02 PM.
live every 24 hour block of time like it's your last day on earth
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Re: a few questions about big block heads
[Re: DaytonaTurbo]
#154655
11/23/08 09:55 PM
11/23/08 09:55 PM
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Joined: Jan 2003
Posts: 27,421 Balt. Md
383man
Too Many Posts
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Too Many Posts
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Balt. Md
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Quote:
Quote:
head wise, how can a stock type head make that kind (450-500) of power? 915 & 906 Mopar heads just do flow what a good stock small valved small block chevy head flows. I can see where the monstrous torque comes from but how can they feed a 6,000-6,500 rpm 500-550 HP 440?
Nobody here's making 500hp with stock UNPORTED heads. Take a set of stock heads, and invest the money into going with larger valves and some good quality port work and you will make them flow just as good as the eddy RPM/440source heads. You can make 500hp with those heads, because they flow decent OOTB.
Look at 383man, he's got a similar car to yours, and his 440 with ported, big valve 906's is running 11.5's in the 1/4.
You are right as I run 906 heads that I did some porting on myself. Oh and thanks for the kind words Daytona. Ron
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Re: a few questions about big block heads
[Re: RapidRobert]
#154656
11/23/08 09:56 PM
11/23/08 09:56 PM
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Joined: Jun 2008
Posts: 3,916 usa
lewtot184
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you can go 4.25 stroke. using the big block chevy rods is a plus for crankcase clearance. steel rods give a little more clearance. the 470 i used to build had an offset ground 3.75 stroke steel mopar crank, bill miller 6.8 chevy alum rods, ross 12.5 pistons, stage 6 heads, program cross bolt main caps, and a half fill block. this was strictly a race engine and had an extremly reliable bottom end. the bob weight was close to stock 350 chevy. 2 years ago the engine recieved a 4.15 eagle crank (500 cubes), 12.5 je pistons, mopar bill miller 6.76, rods and indy ez heads. the 500 doesn't run a lick better than the old 470.
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Re: a few questions about big block heads
[Re: the nitro man]
#154658
11/24/08 01:42 AM
11/24/08 01:42 AM
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Joined: Dec 2003
Posts: 5,314 Carstairs, Alberta, Canada
dave571
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Posts: 5,314
Carstairs, Alberta, Canada
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Quote:
head wise, how can a stock type head make that kind (450-500) of power? 915 & 906 Mopar heads just do flow what a good stock small valved small block chevy head flows. I can see where the monstrous torque comes from but how can they feed a 6,000-6,500 rpm 500-550 HP 440?
I realize you love mopars too, so don't take any offense to anything I mention, but I notice a lot of GM guys look at BB mopar heads, and can't believe we get any power out of them. I had a friend call mine "tractor heads" After he put twin screws on his 454 it was finally faster than my car, but that's a different story.
I guess the only answer to how is it that they perform, is that a motor isn't a flow bench.
500 hp out of an iron headed big block with very minor port work is not tough. Especially if you go with a 440 or bigger.
My 915's are still stock valve size. Port work is/was minor. I do agree with john rr's comment that you can make it worse too.
Just remember you're not trying to redesign the head, just smooth it out a little.
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Re: a few questions about big block heads
[Re: 2boltmain]
#154660
11/24/08 08:02 AM
11/24/08 08:02 AM
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Joined: Oct 2003
Posts: 21,345 Marysville, O-H-I-O
70Cuda383
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Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
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Quote:
Case in point though, the typical small block chevy made like 550hp stock. Then when you installed a 4bbl carb and a chrome air cleaner the power surpassed 575hp! (The same engine installed in ANY year camaro would produce close to 625hp) Dont even bring up a 3/4"cam!
whaa...did I miss something?
stock small block chevy?
common, let's try to keep it real here!
a 400 will make great power with stock parts. sure, your average iron head will max out arund 450 hp, and aluminum up to around 500-550.
the key to making a stock stroke 400 a good motor, is compression and heads. big bore allows for big valve and heavy breathing to help make torque, short stroke allows for insane revs out of a big block.
build it with aftermarket rods, pistons, etc. and save a TON of weight, you'll have a big block that makes big block power, yet revs like a small block.
my 383 is running a 440 crank, lighter rods, lighter pistons, smaller wrist pins, eddy heads. last time I did the math, I think I'm something like 7 kilos lighter on the rotating assembly over stock. 7,000 grams! that's over 14 pounds of metal off the spinning assembly!
it revs to 6500 FAST, but its making over 500 ft lbs of torque at 3,000 rpm. I don't have numbers below that because the dyno started at 3,000 rpm.
my combo maxes out at about 6200 though, because of the cam that I'm running, flat tappet hydraulic. I'm ok with that though, this is a street vehicle, not a dedicated track racer. 500 ft lbs of torque from 3,000 rpm to 5800 rpm is enough for me. I wouldn't want to sacrifice my bottom end grunt just to chase higher RPM HP that I would never be able to use on the street anyway.
**Photobucket sucks**
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Re: a few questions about big block heads
[Re: 70Cuda383]
#154661
11/24/08 08:09 AM
11/24/08 08:09 AM
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Joined: Oct 2003
Posts: 21,345 Marysville, O-H-I-O
70Cuda383
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Too Many Posts
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Posts: 21,345
Marysville, O-H-I-O
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oh, and since the Original poster is a chevy guy...I enjoy it when people ask what engine is in my Dakota...I tell them "its just an old 383" it's fun to see their eyes light up and ask "oh, a stroker motor, huh!?" I smile at them and say, "yea, like I said, just a 383" I'll let them think it's a small block chevy 350 stroked to 383 and not a Mopar 383 stroked to 438. if they can't tell the difference between a SBC block and a mopar big block...that's their loss!
**Photobucket sucks**
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Re: a few questions about big block heads
[Re: 70Cuda383]
#154662
11/24/08 08:48 AM
11/24/08 08:48 AM
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Joined: Jul 2003
Posts: 4,831 Holland MI Ottawa
2boltmain
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master
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Posts: 4,831
Holland MI Ottawa
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I was poking fun at the original posters expertise with SB chevies and lack of knowledge with mopars. He has come to the right place to gain knowledge though! Seriously though our small port big block heads do make great STREET power in stock form. Case in point: The 440 magnum at 375 rated hp was built similarly to the 454 LS-5 (Not LS-6!) 10.5 to 1 compression, hyd cam, non Holley carb ect ect. The 440 magnum ran much much stronger than the LS-5 454 (not LS-6) despite the LS-5s larger intake and exh ports and valves. Im talking stock oem motors here. The LS-5s heads will shine with more compression cam and carb but I am talking street mild stuff- the 440 was a fun no fuss no muss monster.
Keep old mopars alive.
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Re: a few questions about big block heads
[Re: RapidRobert]
#154663
11/24/08 09:54 AM
11/24/08 09:54 AM
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Joined: Jun 2008
Posts: 3,916 usa
lewtot184
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Posts: 3,916
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Quote:
Quote:
you can go 4.25 stroke.
I can use rb rods(gotta be Mopar), this much stroke increase & still have enough CH distance left to use a 400 block?
4.25 uses a big block chevy rod.
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Re: a few questions about big block heads
[Re: ZIPPY]
#154666
11/24/08 06:37 PM
11/24/08 06:37 PM
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Joined: Oct 2008
Posts: 75 greeneville, tn
the nitro man
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greeneville, tn
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Quote:
Cost me $90 to have the mains (and rods) ground and polished, $75 for zyglo/crack check, and cutting the counterweights was free because I did it myself with an angle grinder, using a cardboard template (cut 7.25" hole in cardboard, cut piece of cardboard in half). Grind to fit the template, polish it up with sandpaper rolls, and that's that. Not much material needs to be removed.
how much metal needs to be removed? .125" or less? i'm thinking about just doing the 400 with the stock stroke. what kind of abuse can a cast crank take? i know i wouldn't want to throw a 250 shot of nitrous on it, but what about just spinning it to 6,500- 7,000 rpm? will the cast crank take it? my buddy that's been in mopars all his life says a cast crank in a bb mopar wont last, him or his dad ether one won't run one in any 440 they us.
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