Car Crafts 383 to 443 stroker build up?
HI What do you guy's think of the mopar 383 to 443 stroker article in march Car Craft? They offset grind a 440 crank to 2.2 chevy rod size and used a 6.135 Chevy truck rod and KB/Silvolite [basically stock sized] piston. It looks like a very cheap way to build a stroker. The only problem I see with it is the excessive rod side clearance. They claim no problems with oil windage as they only plan a low rpm street motor. What do you think off this? I wish someone still made a Chevy rod with Mopar sized width big end. Manley used to make these but not any more. Anyone know the old part number of those rods? Maybe it's time to get a someone interested in building these for us again! Thanks Tim
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I think they're just trying to get us to sabotage our mopars with thier short-rod chevy junk!
torch |
Isnt a 451 stroker just a 400 block with 440 crank and different rods? That block has the same deck height as a 383 right? just a bigger bore? If thats true then why not just doa 451 build up on a 383 and get like a 430 ci something. You'd avoid the Chevy parts.
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thats one way to make a rod spittin dodge! :toast:
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If you take a 383 and stroke it with a 440 crank, you can still use the MoPar rods from ethier the 383 or the 440. The piston manufacturer will have to know this. The pin size may have to be changed though. Easy for the machine shop to do.
Save money and do it right the firt time. Longer rods are better anyway. |
[ Longer rods are better anyway.[/QUOTE]
yes they are, that swhy dodge makes torque even with a short stroke :toast: |
About the article's methods and mindset... Sound like a lot of work even if you happen to have all of the components just laying around. Much more work than going on a 440 search! A 440 60 over is 452 I think, and for all the trouble and machining expense they went thru it seems a 440 rebuild would yield the same actual on-the-road results. I understand the "stealth" aspect of knowledgeables thinking it is a 383 "B" engine, but most non-MoPar people would not recognize the difference between the RB and the B engines-------plus most of them think a 383 is a stroked Chevy 350 anyway.
AND the 400/451 stroker setup is well documented and easier to reproduce. |
The method is the same whether you start with a 383 or a 400 block, the 440 crank is machined the same way, although if you offset grind the rods to 2.2" you can come up with approximately a 3.900" stroke which in a 400 block gives you 470 cubes and in a 383 gives a 443" assuming stock bore of 4.250". The mains have to be cut from 2.749" to 2.625" and counterweights have to be trimmed to around 7.25" circumference to fit the low-deck block. You can also leave the rods at the Mopar dimensions and have the 451" 400 block or 426" 383 block. The two advantages to going the low-deck stroker route is lower block weight (35-40#) and lower rotating weight since the pin height is moved up quite a bit on the stroker pistons, giving a slight power increase over a .060 hi-deck 440. If those two considerations aren't a factor, believe you would be better off cost wise to find a 440. One thing too, is the fact you could still offset grind the crank and run it in a hi-deck and come up with a 470" , although I'm not sure if anyone makes a kit for that combination, problably would need the 7.100" rods with custom pistons. You just have to decide how much effort and expense you want to put into one of these combo's.
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So you think .700 extra deck height is only 2 1/2# per side............I don't think so........... I suggest you get some real blocks and weigh them and not depend on something printed in a book.........................No way every different bore low deck or high deck block is going to weigh the same..................
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440 with main caps is 224 lbs
My 440 with main caps is 224 lbs. and is bored .030
The 400 is no way under 200 lbs. with main caps. |
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There are more reasons why the 383/400 engines are 35-40 lbs. lighter than the 440's than just a smaller block. The crank looses a lot of weight because the mains are machined much smaller and so are the counterweights. Also, everything else being equal, the the B engines use a shorter and therefore lighter piston. If underhood space is a concern, stroke a 400, you can actually get 499 cubes with readily available pistons @ 4.375" bore and a 4.15" stroke crank. However, you can't use a rod longer than a stock length 440 rod so the rod ratio is reduced to 1.63. If you use a 440 block it's easy to get 511 cubes with a 4.25" stroke and still use a 7.1" rod, resulting in a 1.67 rod ratio, and lots of room for a taller piston. So it really depends on how many cubes you want versus how much hood and header room you have. I personally would never stroke a 383 because it will cost the same to do a 400 and you will always have more cubes with the 400 block. That does not mean it won't be a good engine, and if you have a 383 block allready, why spend more to buy a 400? Another reason to stroke a 383 would be if you have say a pretty much stock 383 Road Runner and you want to blow away the competition (Flords, Chubbies) and have them throwing fits trying to figure out how you're doing it. Now that would be fun!!!!!! And you would still have your numbers matching block............djs
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DJSWWG,
Thanks for clarifiying that, I guess my advancing age and a myriad of too many numbers floating through my head for too many years had me thinking there was that big of a difference in just the block weight alone......sorry about that....my bad..... :whack: |
This is a little off-topic, but when I built my 408/360 stroker, I weighed the crank, rods, and pistons, and found that the combo was ELEVEN POUNDS lighter than the stock 360 stuff! Needless to say, I was pleasantly surprised.
torch |
Have you guys ever read the "451 Manifesto"?
Maybe someone has a link..or just search for it by name. In it, he sites all the reasons..in his opinion..why a stroked 400 is a better race engine than a 440. |
I have no problem with the 400/451 being more efficient geometrically. I had issues with how the mag crew got there, why a 383, etc. especially when the 400/451 combo is almost a purchaseable combo already with parts designed for that exact application. And the question was "What do you think of Car Craft's....".
I like all the info available now on the 400/451 combo and would not like to see it dilluted with the parts and methods Car Craft is showing. |
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http://www.arengineering.com/articles/articleframe.html |
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http://www.440source.com/blockinfo.htm |
If you want 440+ cubic inches, start with a 440, both from a longevity and economy standpoint. Unless you are racing a space limited A-body race car, making 1/4 mile passes and tearing the engine annually or bi-annually.
The following needs to be stated: The low deck B intake is inferior to the RB intake. It is physically smaller, and will not flow the air volume. There is no "ideal" intake, outside of a tunnel ram, for the engine. One guy ported an Indy 383-13? intake to max wedge size with decent results. But so much for the "economy" of the build. Mopar Stage VI heads will allow the use of the RB intake, but they are $$$. The 2.625" B crankshaft main journal is inferior to the 2.75" RB crankshaft main journal. Align bore/hone the block ($$$) to the RB size??? Which goes first in a 451, the block or the crank? Which goes first in a 440, the block or the crank? When the RB engine with it's greater displacement was designed, Chrysler's engineers increased the main journal size for a reason. One report from a drag racer from Arizona, "7 different guys used the cut down 440 cranks in 400 blocks, 5 got tired of breaking cranks, and 2 change the cranks yearly." Cut down 100,000+ mile cranks would not be the way I would go. New would = $$$. The B engine with a 440 crank puts the wrist piston so high in the piston, stability in the bore and thus longevity becomes an issue. I have read more than one report of premature oil burning (most recently a report by the owner of a Road Runner featured in a nationally publicated Mopar Magazine). Do the math, what stroke in an RB block would require the use of a 451 piston? One solution offered was a piston with 360 degree skirting, but once again, $$$. Lastly, in theory, the 400 block would appear to have less cylinder distortion, given the shorter cylinder length. In real world reality, the 400 block's cylinders distort more than the 440. Quote from a prominent engine builder from Florida, ".... the "theory" about stiffer cylinder walls is pure bologna. I've done random sampling on no less the 25 blocks and found that when removing the torque plate after honing, the lowdeck shows more cylinder distortion by more than .001 every time. typically we see the RB walls move about .0016, the low decks have moved as much as .0031. That's a huge difference. It's not a scientific test, since very few of those blocks were sonic checked, but since the head bolt pattern is the same for both, you explain the difference..." Another quote by a guy who discussed a 4.15 crank in a B block versus a RB block, in response to the quote above, "Dan Dvorak (another respected builder from the southeast) would not even build my 493" out of my nice 400 block for this very reason (distortion)." Some issues to ponder........ |
from reading that article, I got the impression that they were pretty impressed with themselves for being able to use all stock parts, ie: no custom pistons.
I was not impressed with their conclusion that the excessive rod clearance was nothing to worry about. Not being an engine builder, and not totally understanding what effects excessive side clearance can have, I was still skeptical of thier logic that since it did not blow up on the dyno, then it's all good. A street car engine, as I understand it, should last more than a few dyno pulls, no? It bothers me that they build a motor knowing one of the specs is way off and just gloss over the potential problem with what amounted to a "yada yada" |
The Manley rod was PN 14279, with 6.765 inch length, 2.20 inch journal with Mopar pin size
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But you get 12 cu in and genuine CHEVROLET rods. WOW real CHEVY rods. OH BOY REAL CHEVY RODS. And if you want to sell magazines something has to say the magic word. CHEVY RODS. They must be good. Walk the local drag strip. There are pieces everywere. Very popular.
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MOPARHOUND, I gotta cut this quote up some to address it and ask questions on it, so hang in there ....
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Thanks for being objective Rumble........usually I get some silly remarks and get flamed :flame: when I point out the flaws with the 451. :)
A major selling point for the 451 is the "economy" of it. I don't see the savings, all factors considered in balance. In the long run, starting with the 440 in the first place makes more sense. Buy a 440 short block, bolt on your 383/400 pieces and go. 1)The 2.625" B crankshaft main journal is inferior to the 2.75" RB crankshaft main journal. Bigger is better. Main journal bearing drag is what, .0001 on the time slip? When grinding down the main crank journal, strength is decreased geometrically, not summarily. I don't have the formula in front of me, but the % decrease will surprise you (33%, IIRC). 2)Which goes first in a 451, the block or the crank? Which goes first in a 440, the block or the crank? You have two chains. Which is stronger? The weakest link will break first in each chain. The 451 with the cut down crank, will break before the 440 block/crank combo in this comparison, on paper and in real world observation. Your quote, "I say no way dude. Don't do it. I don't think it's a good thing to do since the "B" block is a little more beefy down low. You would give up that advantage." I'll take the 440 crank spec. advantage, over the B blocks beef advantage. The 440 crank/block spec's are good too 650hp, before the block's main saddles become prone too cracking (per a nationally known Michigan builder, 30+ years experience.) Don't see many 650hp or even 600hp 383/400s/451s, and if you do they don't hang around long. So, if your building a street engine the crank spec. doesn't play as big a factor. But the 451 intake flow for performance, cylinder distortion issue, and piston stability longevity issue does in my book. Did you do the 451 piston in an RB block math yet? What stroke would the crank be to require this piston? Heres to bench racing. :toast: |
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I'm going to do a 451 combo on it. 500 sounds better, but I did say money issue right. (OK, just checkin) :zzz: This is the basic Idea of it. typical 451 build with Edel heads. Intake and carb are on the table. Mostly due to unknown fittment, but a Dual plane and AVS are up to bat since there a inhouse part. (Carb) Headers are Headman street tube. 727/9-1/4 rear w/3.55 cogs and 26 inch tires in a '79 Dodge magnum. For the street, I think the 400/451 combo isn't a bad deal. The focus would be moderate torque over upper HP. A high performing 451, like a brute street strip engine should still hold well though. So long as it's not abused often. I guess like anything else. I did do some research on this combo, but no longevity results turned up or was sought. Nor did piston rocking issues turn up. No math yet. Just browsing. I looked into several areas. But I did not keep anything since looking. The build is still awhile away. I'm slipping in the stock 400 first. Going back to a S/B for the Cuda, then I'll start seriously looking @ strokers for the Magnum. |
OK, I'll muddy the water now. Weight of the car you put the engine into is a factor in engine longivity. 400's making big horsepower can and do live, but htey have to be done right. Get weight down, light pistons, light rods, knife edge the crank. Cap walk is a given in a race motor, but it isn't a killer if you keep on top of it. Race motors aren't supposed to be run for 50,000 miles before being torn down and looked at.
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I've weighed a bunch of them, 383,400,440, and there is not a great deal of difference. There is a lot of variance per size but the difference usually runs 8 - 12 lbs. The RB's are taller for sure but the main bearing bores are larger which helps offset the gain at the top. Also as I understand it the smaller crank main size with a radius is very close strengthwise to the larger main size with the undercut style.
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I have asked this before. Does anyone know what they ran in nascar back in the day? 426 cu in. B? RB? Was it 74 last time they ran one of these? What ever it was it ran for 3 hours at 7000 rpm?
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1) This is the most important reason: the stroker 400 will have the same physical dimensions as the 383 that my car came with, so nobody will know that i have 70 more cubic inches under the hood. 2) The rotating assembly will be much lighter, so I can rev the hell out of it :evil: 3) Everything from my 383 switches over, without spacers and whatnot 4) Smaller engine = easier to work on 5) Lastly, 440s are expensive and the cheapest one I could find was 500 bucks and needed a full rebuild. Whereas, I bought the 400 for a 100 bucks(with a trans) and the 440 forged crank for 50 bucks and had the components to build the stroker, I didnt factor in the rotating assembly because I would be doing the same thing if I went with a 440. Now if I could have found a cheap 440 and my car didnt come with a 383, than I would have definitely went the 440 route.....actually, more likely the 496-500 route. |
I called the Ross Piston tech line and asked about any problems they are aware of with short pistons, in particular rocking in the bore and in the case of pistons whose oil rings end up in the pin bore, if excess oil consumption is a problem. Now I know the first thing that comes to mind is "ya they will say what they want to sell pistons." Anyway here's the answers I got. First, he says they use a mathematical formula (which is a ratio) of how long to make the skirt versus what the compression height is,to prevent excess piston slap and they aren't aware of any problems or they would correct the problem or stop making the piston. Second, the engine IN THEORY might tend to use more oil with the ring in the pin groove, but in reality it isn't the case as long as the bore is sized correctly for the piston and the cylinder is straight and round. There you have it.................djs
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Killer Mopar, don't forget, it's just as easy to build 499 inches with a 400 block as it is with a 440 block-you use a 4.15" stroke. The only diference is you must use a shorter rod in the 400 than the raised block, which changes rod ratio, but not much else. And yes, I've done ALL the math :thumbsup: ......djs
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Really? I never looked at the math. The longer 440 rod is a no no for a 500 cube 400 based stroker?
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Rumble, in a 400 block with a 4.15" stroke the longest rod you would be able to use is the 440 6.765" length. This leaves 1.14" for piston height. Ross makes a piston that is 1.12" long, which would leave the piston .020" down the hole if the block was the factory height of 9.98". Of course you could cut the block to increase compression if required. This is using readily available parts. Dem's da berries............djs
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okay, here's a question for all: how many of you have seen a big block mopar actually snap the crankshaft apart? i have never seen a 440 block/ crank break unless it was 'creatively' put together. i have seen one 451 combo crack right in half; the impact was so strong it broke the tranny in half at the same time. there was a split from the timing cover seal to the tailshaft seal; crazy shit.
okay, so we've come to one general conclusion ; money makes it last. so lets apply this knowledge: a 451 is built with budget parts, and it costs 3000 dollars and lasts 30,000 miles. a 451 is built with all the trick, rare-alloy parts and building processes that are known to man. it costs 10,000 dollars and lasts 100,000 miles. so in the end, the only difference is with one method, you break cheap parts quite often and possibly empty the junkyards of big block mopars at a faster rate. the other way is taking out a loan to build a motor that you will almost be worried to rev because the crank is worth more than your wife's wedding band, and there is more man hours in the block prep than the body / paint prepping. just so when it actually does break, you can watch 3 times the money come flying out from underneath your car. either way seems to have its obvious, err, perks, but i would prefer to just tear the motor apart every year before anything can happen instead of going 5 years before thinking about those main bearings 'because the shop said it could handle it' just to have a rod blast a whole through block and take out a slick and put the car in the wall or something. hah that was a little exaggerated, but you get my point |
Thanks djswwg. .020 isn't a whole lot, but workable no doubt.
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This is an interesting thread...
If you run your "street" car anything like I do, it's more of a weekend warrior than a dayly driver... with that being said... how much abuse do you think you are going to visit on the engine? There is no way in gods green earth that any of my engines in any of my "street" cars are ever going to see 30,000 miles without several teardowns to add new and improved goodies. That's the whole purpose of their existance. If I can put a 451 together for a little of nothing using existing parts or a 499 for that matter, that's what I'm going to do. which one is more bullet proof??? Don't care.. It's not going to go 10,000 let alone 30,000 miles. I know some of you guys aren't like that... but most of you are pulling wrenches on that thing all the time... if it's running flawlessly we have to dig in there and find out why... Otherwise we get bored with the car... Someone has the tag line "If it's not broke, fix it until it is" There is alot of truth to that statement for alot of us... For the money I have in the HEMI and the Ferd project, I could have 5 or 6 projects completed.... BUT my next couple projects are going to be budget jobs... I have 2 400s and 2 440s and 1 383 to play with... I'll be watching this thread to learn alittle more about just which way I'm going to go... |
A point and a question. Mighty fine small blocks out there with 2.5 inch main bearings. B blocks with 2.625 inch mains should work. And the low deck intakes are not as good? Not as available?
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The only reason stuff breaks is because it wasn't machined properly, balanced correctly, or put together right. This assumes you use decent parts. If you run stock rods with cheesy 3/8" bolts,a cast crank, and heavy old pistons it's gonna come unglued. Use quality H or I-beams with 7/16" bolts, a 4340 steel crank and light forged pistons and keep the rev limiter under 7200 or so and it'll go forever without much more than new crank bearings every 2-3 years. Change the rings and rod bolts every second tear down and that should about do it!.......djs. ps, I've never seen a forged crank break either! does someone actually have this on film???????? cause I'd really like to have a picture of one :drool:
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