400 stroker cranks

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MidTexCuda

MidTexCuda

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Looking to build a killer street, pump gas stroker motor for a big tire light car.
Most all kits listed for the 400 seem to max out at 4.25. Has anyone crammed a 4.375 or 4.5 in a stock block?
If so how hard was it to do and was it worth it?
Was there issues with finding pistons off the shelf or issue will rod length and availability?
I have searched the internet and could not find one thread on this subject. Any help would be great.
 
Diamond has some off the shelf for the 4.250 stroke.
 
Look at a stroker and you realize the rod caps almost hit the block skirt. Even a 4.00 in a 360 mandates a little nip with a grinder. I know there is bigger but they must use different rods, ie. bolts instead of nuts. Also the piston skirts get very short as they have to clear the throws too as they are that much deeper.
 
I dont mind notching the block or external oiling. There are a lot of 4.25 kits but I want to know if a 4.375 or 4.5 will go with out huge mods. If so is there a issue getting pistons? What rod length?
 
MidTexCuda said:
I dont mind notching the block or external oiling. There are a lot of 4.25 kits but I want to know if a 4.375 or 4.5 will go with out huge mods. If so is there a issue getting pistons? What rod length?
Click to expand...

hughs, 440 source, or muscle motors .
 
440Source has nothing in the 4.5 stroke for the low deck. I think what will happen is the piston pin will get into the oil rings and the skirt will just be too short to provide adequate support. Of course, all this could be total conjecture.
 
im going to build a 400/540 this winter,ive asked your question many times and did a lot of research ,even talked to best machine,they said they never attempted to put a 4.5 crank in a 400 block,but I know it can be done but he did tell me to do a few things,is to cut the radius down and use a 6.60 rod,ohio carankshaft ,I see on there website can cut the radius down to 7.4 or 7.3,and do the 2.2 rod journals and the 400 mains size and 6 bolt or 8 bolt.i know theres many crankshaft makers out there,ohio crankshaft,moldex,bryant,callie,scat,velasco,shaftech,kryphonite,crower,so im going to try it,mine with have the radius cut down,8 bolt crank,2.2 rod journals,rod,ie chevy rods,custom pistons,should do good main caps,was told steel main caps for aluminum rods,or aluminum main caps for steel rods,so not sure on my choice of main caps yet,milidon steel caps,or pro gram caps,still in the planning stage and getting everything on paper,opel machine in Chicago will do my machine work if I go with pro gram caps,i will also be going with bushed lifter bores as I run roller cams,when the build starts going ill post,have one block only I will use as a mock up block,as to see where I will grind for rod clearness,as I have 2 other blocks that will get the build,i know truck pullers run the 400 block with big cubic inch
 
Just askin here as I've never built anything that damn big, but won't you be pushing the limits of a stock block power wise? It seems like unless you build a "mild" 540 that you would make more than the block can stand. Unless you are planning on an aftermarket block.
 
4.5 stroke w/2.20 rod mains, 6.535 chebby rods, 1.120 CH (ie 4.15 crank) pistons has fit before, if you turn down the counterweights. Will need external oiling and block clearance, and probably some Mallory for balance. I have a plan to do this with a set of Victor heads; have the heads, crank and rods sitting in the basement, have to order pistons. S/F.....Ken M
 
My friend built a 508ci stroker out of a 400....020" over block, 4.25" stroke that I think was an ex-Top Alky crank. (He got it at-where else?-Carlisle.) Note that almost all aftermarket forgings are from China. :( (Hence his use of the used billet.) A HUGE help for bore clearance was using rods (Carillo H-beams, IIRC) that use button-head capscrews instead of bolts. He also used main bearing studs and a stud girdle...note that the crank was NOT turned down, the block was align-bored to the RB bearing size. Oiling system is factory except for a big pan & Hemi pump/pickup; it balanced with no Mallory metal...you want to keep things light!

He did convert to a roller cam...top end is a set of Indy heads off Racingjunk, single-plane intake I think is an old M1, and a 1000cfm Thermoquad with stock air cleaner. Pulls like a diesel from 1200RPM in any gear even in a 4000lb car!
 
This is what I have been looking for. I know the 4.15 in a lot of kits has a very short cd and the rod pin almost/ does intersect the oil ring. I just wanted to know if it has been done.
My block is at the machine shop now. I will find out if I have a good downer Monday and my BCR aluminum caps and girdle will be here this coming week.
I want to build something different than the rest but don't want to loose my *** doing it or find out in need 1k of custom pistons after I buy the crank and rods. I just wasn't sure if the lower cylinder walls of the block would make issue with rod swing or other issues.
 
echo -- what kind of power did that low deck 540 make. I was looking to run a solid roller in the 650 lift range with a low duration. backed up with a pair of middle of the road heads and keep the RPM under the 6500 range

Would love to make a 700hp 700tq motor or a 650hp - 700+tq pump gas street engine
that way I can run a sub 4.10 gear with my 32x14.5 tires and my 727.
 
Sounds like a cool, big $$$$ build. I, personally wouldn't spend that much $$ and time stuffing that in a stock block.....you KNOW where the weak spot is. Just my 2 cents. Good luck and keep us posted with the progress!!
 
Certainly don't need a 4.5" crank to make 700hp these days. Heck it's not too hard to get a 3.75" stroke to run those numbers with factory oiling, etc. Also less stress on the block.
 
I know it doesn't take a big crank to make big HP and torque on pump gas. It wouldn't be hard to order a 4.25 kit (512) and run with it BUT minus having to buy custom pistons and maybe adding about another 175.00 to cut the counter weights on the crank and some added cost to balance the overall price will be the same. The big issue I see will be the block work to get it to fit.
I don't have the heads to support over 750HP and if I keep the revs low the weakest point should only be the webbing over the crank.
I am in no way an expert and I know this maybe considered wilder build because of the stock block and not the hp level but I have been running researching for weeks and the part prices are the same or not that much more.
If I am crazy please let me know.
 
MidTexCuda said:
echo -- what kind of power did that low deck 540 make. I was looking to run a solid roller in the 650 lift range with a low duration. backed up with a pair of middle of the road heads and keep the RPM under the 6500 range

Would love to make a 700hp 700tq motor or a 650hp - 700+tq pump gas street engine
that way I can run a sub 4.10 gear with my 32x14.5 tires and my 727.
Click to expand...

IDK, hasn't been put together yet. It may well not work worth a damn, but I know it's been done before. I don't have a bunch of $ into it and if it's bunk, I'm only out a crank, all the other stuff I have fallback plans. I have an evil scheme and big tires in mind for this one. Here's another guy's project.

http://board.moparts.org/ubbthreads...=+StrokerAspen&topic=&Search=true#Post8096230

I'd expect with decent heads, MW Victors or -1's(spit) it'd go 700HP without even serious porting, that's only 1.3hp/ci. If I didn't already have the Victor heads, I'd seriously look at B-1's, they're made for that sort of combo. Yeah, they're a little $, but the simple fact is that if you're buying everything from scratch, it's not much more than anything else, and you're 30-40cfm and a nice small (65cc) chamber ahead.

That said, this is a lot of engine. For choice, I'd go with a 4.25 or 4.3 crank combo, those fit better, with less massaging, and are proven off the shelf(OTS) combos. Still more torque than you can plant. I have a B1, EFI, mega block, dry sump, custom everything project that I've been working for four years now, and OTS looks really good at this point. This is really marginal with a stock block IMO, even with aluminum caps and a girdle. Read that as, don't be surprised when something cracks and you come out to the car sitting in a puddle of various fluids. I accept that, I have my reasons; it's racing, stuff breaks. If it doesn't break, you're not pushing hard enough. That said, the BCR girdle/mains setup is premium stuff and probably the best chance to avoid driving over your crank. The Pro-gram and Dvorak cross bolted stuff seems logical too, but the theory behind aluminum caps makes sense in this instance to me. I may be all screwed up. Wouldn't be the 1st time, lol. S/F.....Ken M
 
It's the safer, certainly cheaper, option. Your tire dealer had better be your best friend, either way, lol. S/F.....Ken M
 
I think the issue comes from the piston and counterweight hitting. At some point "big" gets too big. You can cut down the skirts, but the pin boss will still need to be there. Run the smallest pin diameter you can (custom rods), and the short skirt pistons (custom), and the crank with the counterweights as small as possible (custom machining, possible balance issues depending on the bobweights of the other custom stuff. Or - IMO the better approach - build a B wedge based KB block with available parts and get a stronger bottom end, and better cylinder walls, with shelf parts. ou can always tell them it's something else - as long as it makes enough steam to perform...lol.
 
Well, the one I saw seemed to need 7.140 crank C/W diameter with a 1.12 CH piston and a .180 skirt and .060 clearance for the C/W. That's a 4.5" stroke and a .990 pin. A couple of people seem to have done it, so it's possible. Just doing the math, it seems you can go to a 1.195 CH, if you have a true 9.980 deck height on the block, and go with a zero deck height piston. I figure get the block machined, see what the true deck height is, then order pistons accordingly. Diamond will move the pin height for a reasonable fee.

The KB (or Koleno/World/etc) is a better deal, completely agree, but I have a bunch of 400 blocks and a pile of parts sitting about. S/F.....Ken M
 
But a 400 block will not be that good - for long anyway. The lower end might take it after you spend on the girdle and fitting it - but the cylinder walls will still be moving. It's just IMO a waste for nothing more than saying you have a 540, but it's your $$.
 
Got a friend with a 4.380 bore,4.25 stroke, chevy 6.635 rods with a girdle and after market caps running 5.30's leaking water in 2700 lb car on motor
 
Everybody's got friends. My friends' decisions generally don't affect my wallet.
 
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