Re: 383/400 stroker - 3.90, 3.91 or 3.92 crank?
[Re: YYZ]
#1304025
09/15/12 08:49 AM
09/15/12 08:49 AM
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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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You have no intentions of decking or correcting the block deck?
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: 383/400 stroker - 3.90, 3.91 or 3.92 crank?
[Re: CompWedgeEngines]
#1304026
09/15/12 09:04 AM
09/15/12 09:04 AM
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Joined: Feb 2008
Posts: 715 Central TEXAS!!!!
sr4440
super stock
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super stock
Joined: Feb 2008
Posts: 715
Central TEXAS!!!!
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Without all the info, how do you expect to make an informed decision? Get the block corrected, then you will have your answer.
Joe
Without Data, you’re just another guy with an opinion.
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Re: 383/400 stroker - 3.90, 3.91 or 3.92 crank?
[Re: sr4440]
#1304027
09/15/12 09:36 AM
09/15/12 09:36 AM
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Joined: Jan 2003
Posts: 10,011 Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
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I Live Here
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Posts: 10,011
Frostbitefalls MN (Rocky&Bullw...
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Quote:
Without all the info, how do you expect to make an informed decision? Get the block corrected, then you will have your answer.
Joe
If you are expecting a good level of performance and anti knock resistance from this build, measuring and doing it right is the only way. If you are running flt top pistons and will not have any quench, then you can figure compression with a deck of 9.98 and your compression should be close or less than calculated and if you chose you can live with what you get. If it is still a little high you can band aid it with a thicker gasket. There are large bore gaskets in .040 and .051.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: 383/400 stroker - 3.90, 3.91 or 3.92 crank?
[Re: YYZ]
#1304028
09/15/12 10:01 AM
09/15/12 10:01 AM
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Joined: Jan 2003
Posts: 1,022 Andrews,In. U.S.of A.
67_Satellite
super stock
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super stock
Joined: Jan 2003
Posts: 1,022
Andrews,In. U.S.of A.
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Since you're asking "what the crank should be ground at", I'll assume you're using a factory crank. When I had mine done,due to the indexing of the factory crank I started with, 3.908 was all the machinist could get without going to a .010" U.S. B.B.C. bearing. Could have gotten more stroke with an undersize bearing,but I thought material left for future machining/freshening was more important than a few thou, extra stroke.Your particular crank may allow more or less depending on what it was originally ground at. Whatever stroke you end up with, machine the block to set the deck height to the desired level after a mock-up and measure session. The factory didn't always hold the decks equal side to side or end to end back in the day.
Last edited by 67_Satellite; 09/15/12 10:05 AM.
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Re: 383/400 stroker - 3.90, 3.91 or 3.92 crank?
[Re: YYZ]
#1304029
09/15/12 10:56 AM
09/15/12 10:56 AM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Have a shop check the deck first... that will give you a idea what you have and the decision will be alot easier... you would be suprized how bad some of the decks are
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Re: 383/400 stroker - 3.90, 3.91 or 3.92 crank?
[Re: CompWedgeEngines]
#1304033
09/15/12 01:28 PM
09/15/12 01:28 PM
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Joined: Jan 2003
Posts: 75,070 U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,070
U.S.S.A.
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Quote:
You have no intentions of decking or correcting the block deck?
DING DING DING ... WINNER .
Vlad, my crank is 3.895 stroke with that rod and piston CH combo, but that was for other reasons .
Get the block squared first , find out what the deck is and cut the crank to put the piston somewhere between 0 and .005 in the hole .
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Re: 383/400 stroker - 3.90, 3.91 or 3.92 crank?
[Re: YYZ]
#1304034
09/16/12 12:42 AM
09/16/12 12:42 AM
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Joined: Aug 2003
Posts: 43,237 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,237
Bend,OR USA
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With iron heads and pump gas I would shoot for 9.5 to 1 or less compression ratio With aluminum heads I'll settle for 10.5 or less on pump gas with 10 to 15 % Ethanol The 3.90, 3.910 strokers like to rev, in a B or RB motor, the last one I built had a set of B1-BS heads with CNC porting to M.W. sizes, it made 720 HP at 7000 RPM and was still climbing in HP at 7000 the ciustomer siad to stop the pulls at 7000 RPM because he is a bracket racer and wanted to keep the revs. under 7000 RPM Check your cylinder heads CC and go from there I have another stock Mopar 440 crank offset ground to 3.90 stroke for another 440 mild pump gas street build with a set of large valve ported 452 heads, I'm shooting for 9.5 to 1 on it I'm going to use a 7.100 long BB Chevy type rod with Icon # IC-838 pistons, looking for 9.5 to 1 comp. ratio with decent quench
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: 383/400 stroker - 3.90, 3.91 or 3.92 crank?
[Re: Belvedere1]
#1304036
09/16/12 11:30 AM
09/16/12 11:30 AM
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Joined: Jan 2003
Posts: 16,928 NC
440Jim
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,928
NC
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Quote:
Be prepared to spend some extra $$ on getting that crank to balance and cutting the counterweights for clearance. I hope yours works out better than mine did.
To get clearance of the counterweights in the low deck block, there are several ways. 1) lathe turn (round) the counterweights to about 7.25" dia, keep bobweight ~2350g 2) put large bevels on the edges of the counterweights 3) grind the clearance in the block and leave the crank about 7.50" dia
The larger the bevels, the larger dia you can leave the counterweights. The front and rear (large) counterweights will fit at a larger dia than the inner (smaller) ones.
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Re: 383/400 stroker - 3.90, 3.91 or 3.92 crank?
[Re: YYZ]
#1304038
09/16/12 04:45 PM
09/16/12 04:45 PM
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Joined: Jan 2005
Posts: 3,699 Newport, Mi
Evil Spirit
master
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master
Joined: Jan 2005
Posts: 3,699
Newport, Mi
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I'm sure this will rattle a few cages - oh well. Setting the block deck height to set your quench/combustion chamber/piston clearance is important, as eliminating mechanical interference and checking compression is again, important. Decking a block solely to square it up? More important to help make the intake seal than anything else - don't waste your time or money if you think there's "magic" power there. There probably isn't 5 HP gained by decking the block just to square it up, since most blocks aren't that far off, usually in the .010 range, and cutting only .010 off a block won't change compression enough for a big power gain. You will get the same power increase by a thinner head gasket. So if you are cutting the block to set piston to deck height - whack away. Otherwise there isn't the gain there by trueing the deck to the mains that lot of people seem to believe. I've heard of a lot of people decking blocks, but not equalizing combustion chamber volumes - HUH - whats the difference? Ones just promoted better I guess.
Free advice and worth every penny... Factory trained Slinky rewinder.........
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Re: 383/400 stroker - 3.90, 3.91 or 3.92 crank?
[Re: YYZ]
#1304040
09/16/12 05:21 PM
09/16/12 05:21 PM
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Joined: Jan 2003
Posts: 75,070 U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,070
U.S.S.A.
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Quote:
The crank in question should not require further machining to fit the B-block as it was made with smaller counterweights and B-sized main journals for exactly that purpose. Plus an 8-bolt flange.
Is the crank in question a crank sold by Mopar performance in/around 2003 ? If it is have you actually tried putting it in the block ?
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Re: 383/400 stroker - 3.90, 3.91 or 3.92 crank?
[Re: RUNCHARGER]
#1304042
09/16/12 05:49 PM
09/16/12 05:49 PM
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Joined: Jan 2010
Posts: 588 Franklin, TN
23T Hemmee
mopar
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mopar
Joined: Jan 2010
Posts: 588
Franklin, TN
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Quote:
Maybe I reverse engineer stuff. I would set it up with as much stroke as you can get with that particular crank. I would then mock it up before decking and see where it was at. Then I would decide how much to deck it.
Sheldon
BINGO!!! We have a winner.....
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Re: 383/400 stroker - 3.90, 3.91 or 3.92 crank?
[Re: RUNCHARGER]
#1304043
09/16/12 06:28 PM
09/16/12 06:28 PM
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Joined: Feb 2005
Posts: 4,318 Prospect, PA
BSB67
master
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master
Joined: Feb 2005
Posts: 4,318
Prospect, PA
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Quote:
Maybe I reverse engineer stuff. I would set it up with as much stroke as you can get with that particular crank. I would then mock it up before decking and see where it was at. Then I would decide how much to deck it.
Sheldon
Me too. You'll be able to figure out if the shelving piston height will work and either move the CD around, cut the deck, or gasket it to what you want.
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