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? about 440 crank in low deck #608092 02/08/10 07:17 PM 02/08/10 07:17 PM
Joined: Oct 2005 Posts: 976 ontario canada mac56 OP super stock
mac56 OP super stock Joined: Oct 2005 Posts: 976 ontario canada	Hello Everything I read seems to recommend cutting the counter weights for better fitment. What is the difference between an RB compared to a B in respect to the crank? I understand it being easier to balance but most advertisements say it is for fit. Can someone explain this to me? Thanks

Re: ? about 440 crank in low deck [Re: mac56] #608093 02/08/10 07:32 PM 02/08/10 07:32 PM
Joined: Feb 2003 Posts: 12,675 Columbia, CT M moper I Live Here
moper I Live Here M Joined: Feb 2003 Posts: 12,675 Columbia, CT	The diameter of the counterweights is different. the exact number I don't recall... But it ends up being close to .200" off it. I have also used them with no clearance issues. So "your results may vary"...lol Personally I won't use a factory crank anymore when there are cheap alternatives for a better peice that drops in. To have a factory one magged, stroke corrected, indexed, and ground/polished is $400. A 440Source B wedge main/counterweight crank is $600 or so for a new part that is much stronger. Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.

Re: ? about 440 crank in low deck [Re: mac56] #608094 02/08/10 08:41 PM 02/08/10 08:41 PM
Joined: Jan 2003 Posts: 31,049 Oregon A AndyF I Win
AndyF I Win A Joined: Jan 2003 Posts: 31,049 Oregon	The crankcase on a B engine is a little tighter so the RB crank hits. Typically a forged RB crank is too heavy for a 451 or 470 motor anyway so if you have to remove weight, and you have to gain clearance why not do both at the same time? There are legit reasons for boring out the mains in a B block to the larger RB size so that is another way to solve one issue. That doesn't solve the clearance issue or the weight issue but it does allow you to use better main bearings and to use a stronger crank. Of course the block is a little weaker and it costs some money to bore the main line.

Re: ? about 440 crank in low deck [Re: AndyF] #608095 02/08/10 08:47 PM 02/08/10 08:47 PM
Joined: Oct 2005 Posts: 976 ontario canada mac56 OP super stock
mac56 OP super stock Joined: Oct 2005 Posts: 976 ontario canada	Thanks Andy. That is where I was going with this. I did not realize there was a difference in the block other than deck height.

Re: ? about 440 crank in low deck [Re: mac56] #608096 02/08/10 09:33 PM 02/08/10 09:33 PM
Joined: Jan 2003 Posts: 16,928 NC 440Jim I Live Here
440Jim I Live Here Joined: Jan 2003 Posts: 16,928 NC	A typical RB forged steel crank has counterweight diameters around 7.50-7.55" This attachment shows what I measured on one 400 block on the inner cylinders (4,6 or 3,5). I have seen the front and rear counterweights clear at 7.5" dia. You can also grind the block, or put really oversize bevels on the counterweights to clear the block. 5792109-blockweb3dim.jpg (109 downloads)

Re: ? about 440 crank in low deck [Re: 440Jim] #608097 02/08/10 09:42 PM 02/08/10 09:42 PM
Joined: Oct 2005 Posts: 976 ontario canada mac56 OP super stock
mac56 OP super stock Joined: Oct 2005 Posts: 976 ontario canada	Thanks for the picture Jim. As they say worth 1000 words.

Re: ? about 440 crank in low deck [Re: mac56] #608098 02/08/10 11:39 PM 02/08/10 11:39 PM
Joined: Nov 2003 Posts: 2,503 Illinois CRE2004 super gas
CRE2004 super gas Joined: Nov 2003 Posts: 2,503 Illinois	Here's what it looks like after you run the CNC through it to remove that annoying area and radius it.... 5792399-BBlockClearance.jpg (129 downloads)

Re: ? about 440 crank in low deck [Re: CRE2004] #608099 02/09/10 01:22 AM 02/09/10 01:22 AM
Joined: Jul 2006 Posts: 4,319 Puyallup, WA S StealthWedge67 master
StealthWedge67 master S Joined: Jul 2006 Posts: 4,319 Puyallup, WA	commonly accepted counterweight diameter is 7-1/4". I had my machinist use this dimension, and it balanced out very easily from there. LemonWedge - Street heavy / Strip ready - 11.07 @ 120

Re: ? about 440 crank in low deck [Re: mac56] #608100 02/09/10 02:21 AM 02/09/10 02:21 AM
Joined: Jul 2004 Posts: 19,318 State of confusion T Thumperdart I Live Here
Thumperdart I Live Here T Joined: Jul 2004 Posts: 19,318 State of confusion	I`m running a 413 crank w/the counter weights cut down and w/6.385 chevy rod and JE pistons, my bob weight is around 2230 grams,spins to 7000+ with ease and has been doing so for 10 years in two different combos. I don`t buy the strength bs(or lack there of)w/a stock crank as guys are runnin 8`s w/turbos using em. Don`t remember exactly how much was removed but it balanced out very nicely and was cheap. 72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....

Re: ? about 440 crank in low deck [Re: CRE2004] #608101 02/09/10 06:47 AM 02/09/10 06:47 AM
Joined: Oct 2005 Posts: 976 ontario canada mac56 OP super stock
mac56 OP super stock Joined: Oct 2005 Posts: 976 ontario canada	Quote: Here's what it looks like after you run the CNC through it to remove that annoying area and radius it.... Nice work, but then you have a reputation for nice work. Was this done so the counter weight didn't have to be cut or were there other facts?

Re: ? about 440 crank in low deck [Re: mac56] #608102 02/09/10 08:43 AM 02/09/10 08:43 AM
Joined: Feb 2003 Posts: 12,675 Columbia, CT M moper I Live Here
moper I Live Here M Joined: Feb 2003 Posts: 12,675 Columbia, CT	I had a stock RB crank that dropped in with a minor amount of clearancing where Jim noted in the picture. This is why I say some do fit... Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.

Re: ? about 440 crank in low deck [Re: moper] #608103 02/09/10 11:05 AM 02/09/10 11:05 AM
Joined: Jul 2006 Posts: 4,319 Puyallup, WA S StealthWedge67 master
StealthWedge67 master S Joined: Jul 2006 Posts: 4,319 Puyallup, WA	but even if it fits, what sort of swiss cheese does it look like after balancing it?? The counterweights are not only too large, they're too heavy for the 451 / 470 combo. Cutting them down helps both issues, probobly also helps reduce windage. Just seems like the right way to do it.?? LemonWedge - Street heavy / Strip ready - 11.07 @ 120

Re: ? about 440 crank in low deck [Re: StealthWedge67] #608104 02/09/10 11:36 AM 02/09/10 11:36 AM
Joined: Feb 2004 Posts: 3,441 Mo. S supercomp master
supercomp master S Joined: Feb 2004 Posts: 3,441 Mo.	Quote: but even if it fits, what sort of swiss cheese does it look like after balancing it?? The counterweights are not only too large, they're too heavy for the 451 / 470 combo. Cutting them down helps both issues, probobly also helps reduce windage. Just seems like the right way to do it.??

Re: ? about 440 crank in low deck [Re: supercomp] #608105 02/09/10 12:31 PM 02/09/10 12:31 PM
Joined: Feb 2003 Posts: 12,675 Columbia, CT M moper I Live Here
moper I Live Here M Joined: Feb 2003 Posts: 12,675 Columbia, CT	I used H-beams and J&Es with the one that dropped it. The rods were not light but the crank still had a few 1" holes in it. Not that I consider that a big deal. But it did make for a bit of work when balancing it. Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.

Re: ? about 440 crank in low deck [Re: moper] #608106 02/09/10 06:31 PM 02/09/10 06:31 PM
Joined: Oct 2005 Posts: 976 ontario canada mac56 OP super stock
mac56 OP super stock Joined: Oct 2005 Posts: 976 ontario canada	So then there is no trick to cutting the counter weights is there? Just put in a big a$$ lathe.

Re: ? about 440 crank in low deck [Re: mac56] #608107 02/09/10 07:07 PM 02/09/10 07:07 PM
Joined: Jul 2004 Posts: 19,318 State of confusion T Thumperdart I Live Here
Thumperdart I Live Here T Joined: Jul 2004 Posts: 19,318 State of confusion	Pretty much............ 72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....

Re: ? about 440 crank in low deck [Re: Thumperdart] #608108 02/09/10 07:19 PM 02/09/10 07:19 PM
Joined: Oct 2005 Posts: 976 ontario canada mac56 OP super stock
mac56 OP super stock Joined: Oct 2005 Posts: 976 ontario canada	Thanks Thumper

Re: ? about 440 crank in low deck [Re: mac56] #608109 02/09/10 07:34 PM 02/09/10 07:34 PM
Joined: Jan 2003 Posts: 31,049 Oregon A AndyF I Win
AndyF I Win A Joined: Jan 2003 Posts: 31,049 Oregon	Quote: So then there is no trick to cutting the counter weights is there? Just put in a big a$$ lathe. There are several tricks to cutting down the counterweights. First off you need to know what dimension to cut it to. Then you need the right fixture to bolt to the crank flange so the lathe can hold the crank. It also works better if you have the right tool to center the nose of the crank. And the last trick is to have the correct type of cutting tool.

Re: ? about 440 crank in low deck [Re: AndyF] #608110 02/09/10 07:51 PM 02/09/10 07:51 PM
Joined: Jul 2004 Posts: 19,318 State of confusion T Thumperdart I Live Here
Thumperdart I Live Here T Joined: Jul 2004 Posts: 19,318 State of confusion	Let me re-phrese that(4 u Andy)it`s no problem for the machine shops that I deal with. How`s that? 72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....

Re: ? about 440 crank in low deck [Re: CRE2004] #608111 02/09/10 08:38 PM 02/09/10 08:38 PM
Joined: Jan 2003 Posts: 16,928 NC 440Jim I Live Here
440Jim I Live Here Joined: Jan 2003 Posts: 16,928 NC	Quote: Here's what it looks like after you run the CNC through it to remove that annoying area and radius it.... That is nice looking.

Re: ? about 440 crank in low deck [Re: mac56] #608112 02/09/10 08:58 PM 02/09/10 08:58 PM
Joined: Nov 2003 Posts: 2,503 Illinois CRE2004 super gas
CRE2004 super gas Joined: Nov 2003 Posts: 2,503 Illinois	Quote: Quote: Here's what it looks like after you run the CNC through it to remove that annoying area and radius it.... Nice work, but then you have a reputation for nice work. Was this done so the counter weight didn't have to be cut or were there other facts? I've always wanted to do it, so I did I've spent the time going from the lathe to mock up and still having fitment issues so I thought I'd eliminate the real problem. Now I don't have to put a half inch wide chamfer on a crank to keep it from hitting that spot nor do I have to whack the OD unless I want to do a "no holes" balance job. I've also turned the cranks down on some 4.375 combos and had to add a piece of heavy metal which I wouldn't have had to do if I had cut the block rather than the crank. Now If it's a combo that needs clearance at BDC, I only have to turn the crank(or cam cut the counterweight) enough to clear at BDC.

Re: ? about 440 crank in low deck [Re: 440Jim] #608113 02/09/10 08:59 PM 02/09/10 08:59 PM
Joined: Nov 2003 Posts: 2,503 Illinois CRE2004 super gas
CRE2004 super gas Joined: Nov 2003 Posts: 2,503 Illinois	Quote: Quote: Here's what it looks like after you run the CNC through it to remove that annoying area and radius it.... That is nice looking. Thank you.

Re: ? about 440 crank in low deck [Re: CRE2004] #608114 02/10/10 06:38 AM 02/10/10 06:38 AM
Joined: Oct 2005 Posts: 976 ontario canada mac56 OP super stock
mac56 OP super stock Joined: Oct 2005 Posts: 976 ontario canada	Thanks for the pics and info guys. Very helpful.

Re: ? about 440 crank in low deck [Re: mac56] #608115 02/10/10 06:01 PM 02/10/10 06:01 PM
Joined: Jul 2009 Posts: 413 Norway (old world) Oyvind Mopar mopar
Oyvind Mopar mopar Joined: Jul 2009 Posts: 413 Norway (old world)	There is at least one advantage in keeping the stock crank diameter; it puts the mass out to where it does the best job of balancing against the crankpin forces. To benefit from this advantage you need to cut the corners off the throws, which in total will make a lighter crank, than if it is just turned down. Look at recent Nascar cranks, they are made like this, they even put numbers of mallory metal in the slim counterweight, to save on mass in total. (But it makes no sense if you then bolt a heavy steel flywheel to the crank!) The question is if the machine shop will put the extra effort in the balancing, but it should be possible for a little extra fee to get the holes drilled out in the corners first for balancing the overweight crank. I am luck enough to have my own crank balancing machine!

Re: ? about 440 crank in low deck [Re: Oyvind Mopar] #608116 02/10/10 08:08 PM 02/10/10 08:08 PM
Joined: Oct 2005 Posts: 976 ontario canada mac56 OP super stock
mac56 OP super stock Joined: Oct 2005 Posts: 976 ontario canada	Quote: There is at least one advantage in keeping the stock crank diameter; it puts the mass out to where it does the best job of balancing against the crankpin forces. To benefit from this advantage you need to cut the corners off the throws, which in total will make a lighter crank, than if it is just turned down. Look at recent Nascar cranks, they are made like this, they even put numbers of mallory metal in the slim counterweight, to save on mass in total. (But it makes no sense if you then bolt a heavy steel flywheel to the crank!) The question is if the machine shop will put the extra effort in the balancing, but it should be possible for a little extra fee to get the holes drilled out in the corners first for balancing the overweight crank. I am luck enough to have my own crank balancing machine! Thanks for you opinion.

Re: ? about 440 crank in low deck [Re: Oyvind Mopar] #608117 02/11/10 12:04 AM 02/11/10 12:04 AM
Joined: Oct 2007 Posts: 4,209 New York polyspheric master
polyspheric master Joined: Oct 2007 Posts: 4,209 New York	one advantage in keeping the stock crank diameter That's also the highest inertia for the amount of weight. Boffin Emeritus

Re: ? about 440 crank in low deck [Re: mac56] #608118 02/12/10 01:01 AM 02/12/10 01:01 AM
Joined: Nov 2009 Posts: 2,177 ill D dennismopar73 top fuel
dennismopar73 top fuel D Joined: Nov 2009 Posts: 2,177 ill	i've got 2 of these cranks 1 has been in race motor for over 9 years running 9,80s 9,70s the other has just been done the shop did both the main turn down and counter weights cost 150$ for turn & $100 to turn radius on counters will not do any more to easy to call 440 source send me 500 ci stroke

Re: ? about 440 crank in low deck [Re: dennismopar73] #608119 02/12/10 07:31 AM 02/12/10 07:31 AM
Joined: Oct 2005 Posts: 976 ontario canada mac56 OP super stock
mac56 OP super stock Joined: Oct 2005 Posts: 976 ontario canada	Believe me I know about debate on just ordering 500 stroker crank. I have been struggling with it for 2 months but I have all the parts necessary for a 470 build except the crank so, not only do I have the cut a factory crank or buy aftermarket dilemma. I also have should I leave these parts on the self for more inches. (that probably won't happen) That brings us to the Canada factor. Some of the prices you guys talk about for having work done is like a dream here. Not sure why but machine work and getting new parts here comes at a substantial cost, This post did answer the real question for me. I didn't realize there was a difference in the bottom of a B block compared to an RB block.(why counter weights interfere) Sorry so long.

Re: ? about 440 crank in low deck [Re: mac56] #608120 02/12/10 06:18 PM 02/12/10 06:18 PM
Joined: Jan 2003 Posts: 17,864 S.E. Michigan ZIPPY I Live Here
ZIPPY I Live Here Joined: Jan 2003 Posts: 17,864 S.E. Michigan	I bought my crank at a swap meet, www.lsmeng.com magged ground and polished it for a reasonable price with good quality, and I worked the counterweights myself with angle grinder, sandpaper rolls, etc. I have maybe 2 1/2 or 3 hours work into it but spent alot of that time just staring at it. Thought process: factory counterweights are not even close to being round, stock 440 cranks hold up just fine at 7000 rpm even with boat anchor pistons, and I see no reason why the modified counterweights have to be perfectly round either to run the same rpm....especially with 8lbs less reciprocating weight than stock. Not much material needs to be removed to make the counterweights 7.25" diameter (plus or minus 1/16", if modifying them by hand). If you're doing a 1000hp deal ignore all this, throw away all your oem stuff and buy it all brand new. If you're doing a 550-600 deal, though, this will work great. Rich H. Esse Quam Videri

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