Re: 440Source math problem?
[Re: Stanton]
#661957
04/05/10 10:49 PM
04/05/10 10:49 PM
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Joined: Nov 2004
Posts: 3,544 Syracuse,NY
CompWedgeEngines
master
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master
Joined: Nov 2004
Posts: 3,544
Syracuse,NY
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Thats very typical. Many combos are figured for 10.720 as to allow for a -.005 clean up cut off the decks to provide a square , clean deck surface as most old blocks need it, and to be honest, most new blocks deck surface finish is pretty poor. If you need to use Cometics or any other MLS gasket, that .005 will give you enough room to correct the RA for proper finish.
RIP Monte Smith
Your work is a reflection of yourself, autograph it with quality.
WD for Diamond Pistons,Sidewinder cylinder heads, Wiseco, K1 rods and cranks,BAM lifters, Morel lifters, Molnar Technologies, Harland Sharp, Pro Gear, Cometic, King Engine Bearings and many others.
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Re: 440Source math problem?
[Re: Stanton]
#661958
04/05/10 10:55 PM
04/05/10 10:55 PM
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Joined: Jan 2003
Posts: 4,395 The Pale Blue Dot
Skeptic
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master
Joined: Jan 2003
Posts: 4,395
The Pale Blue Dot
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I'd contact Brandon( before yet another inflammatory 440 source post) and let him know....If you really spent money with him and aren't just trolling about a math error on his website. The difference could be taken up with a cleanup deck.... Ma Mopar wasn't that careful with deck heights. Good Luck with that. BTW I checked a few other combos listed on his site, funny thing, that's the only one with a deck height error
Last edited by Busfixer; 04/05/10 10:56 PM.
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Re: 440Source math problem?
[Re: Stanton]
#661960
04/06/10 12:10 AM
04/06/10 12:10 AM
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Joined: Jan 2003
Posts: 5,875 communist bloc of new jersey
jamesc
master
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master
Joined: Jan 2003
Posts: 5,875
communist bloc of new jersey
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Quote:
What gives ... where's the .0055 gone ???
hopefully onto the table of the mill that squaring the block to where it should be. stock deck heights are all over the place. better to have is stack up a little short for clean up room then have it too tall. as mentioned i would consider this common practice not a math error.
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Re: 440Source math problem?
[Re: AndyF]
#661964
04/06/10 03:42 AM
04/06/10 03:42 AM
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Joined: Feb 2003
Posts: 21,318 Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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Quote:
What exactly is the problem? You deck the block to match the rotating assembly.
You do a mock up assembely and measure how far each piston is in the hole so you can square it and mill correctly. I would sooner do that than go off of advertised lengths.
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Re: 440Source math problem?
[Re: DaytonaTurbo]
#661965
04/06/10 05:47 AM
04/06/10 05:47 AM
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Joined: Dec 2009
Posts: 1,074 detroit, mi
POS Dakota
super stock
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super stock
Joined: Dec 2009
Posts: 1,074
detroit, mi
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Quote:
Quote:
What exactly is the problem? You deck the block to match the rotating assembly.
You do a mock up assembely and measure how far each piston is in the hole so you can square it and mill correctly. I would sooner do that than go off of advertised lengths.
I have friends who think I was crazy to have the bores done first so i could fit the oversized pistons and do a mockup assembly in order to find the true deck height I needed afterwards.
IMO taking your time and getting things right is worth the extra trip to the machine shop.
Id rather do that, than end up with the compression all wrong, or a problem I can't correct afterwards because i put my head in the sand.
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Re: 440Source math problem?
[Re: Stanton]
#661967
04/06/10 08:04 AM
04/06/10 08:04 AM
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Joined: Jul 2005
Posts: 428 wappinger falls new york
Jimi_Vignogna
mopar
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mopar
Joined: Jul 2005
Posts: 428
wappinger falls new york
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Quote:
Got a 440Source stroker kit for an RB ...
4.375 stroke crank 7.1 rods 1.423 comp. height pistons .009 deck height (down the hole) 10.725 stock 440 deck height
so... 4.375/2 = 2.1875
nominal deck on an rb is 10.720, if it was mine i would make the deck 10.700 and if the pistons are above deeck buy custom cometics in the thickness you need to make the required deck ht. square deck the block first then bore it not vice versa!!!! + 7.1 + 1.423 + .009 = 10.7195 ??? What gives ... where's the .0055 gone ???
This is critical stuff !!!
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Re: 440Source math problem?
[Re: Stanton]
#661968
04/06/10 09:50 AM
04/06/10 09:50 AM
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Joined: Oct 2004
Posts: 8,165 Left Coast
BobR
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Posts: 8,165
Left Coast
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Quote:
Got a 440Source stroker kit for an RB ...
4.375 stroke crank 7.1 rods 1.423 comp. height pistons .009 deck height (down the hole) 10.725 stock 440 deck height
so... 4.375/2 = 2.1875 + 7.1 + 1.423 + .009 = 10.7195 ??? What gives ... where's the .0055 gone ???
This is critical stuff !!!
IMO. Not that critical.
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Re: 440Source math problem?
[Re: Stanton]
#661972
04/07/10 12:36 AM
04/07/10 12:36 AM
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Joined: Feb 2003
Posts: 10,209 Someplace you aren't
SomeCarGuy
I Live Here
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I Live Here
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Posts: 10,209
Someplace you aren't
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Get the deck height correct, then order parts to fit that spec. Or cut it down to what a shelf kit needs.
Sounds like you are in the latter.
I want my fair share
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Re: 440Source math problem?
[Re: Cab_Burge]
#661974
04/07/10 07:51 AM
04/07/10 07:51 AM
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Joined: Mar 2006
Posts: 9,910 Eighty Four, PA
B G Racing
master
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master
Joined: Mar 2006
Posts: 9,910
Eighty Four, PA
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Quote:
Quote:
If you want the real(correct) math,you should install the crank,rods and pistons at all 4 corners,then make your measurments and do the machine work if necessary base on the actual numbers or if you have an accurate way of measuring the block at crank center.
I use one piston(no rings on it) and rod on all four corners, mark all the measurments down. Don't be suprised on a stock OEM motor to have taper front to back(or visea -versa) as well as a different deck hieght on one side versus the other side. OEM machine work was not even close to blueprint specs on al the Mopar motors I have blueprinted
We usually install the oil ring to make sure the piston is centered in the bore and not cocked,if not it can be off the amount of the wall clearence usually .005
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