Whats better,grinding a crank or line boring?

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needsaresto

needsaresto

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EG; 400 block fitted with a 440 crank. I see that there are two ways to do this .First is to turn the 440 crank down to 400 main size. Now this would weaken the crank some and also usually means handfitting main bearings.

Other method would be to line bore the main caps and saddles to 440 size and simply drop the crank in using stock 440 bearings. Of course this is going to remove some material from the saddles,but is it enough to worry about? Im thinking probably not as the 400 has awefully thick main saddles.

From a strength point what is better?

Which method would have the edge in cost?

We are talking a fair amount of material off the crank to fit it to a 400.
 
First the counter weights need to be turned down .180-.200 to clear the block.
Second the mains are turned down to 440 specs and there crank is not any weaker at all.
Line honing the block is to ensure the main cap bore is true and straight to make sure there is no movement of the block to cause premature bearing wear.
Do not bore the 400 main cap bores,as you will have to redo the bearing tab to fit the 440 bearings.
Turning downn the 440 crank mains to a 400 allows you to use stock 400 main bearing and stock rod bearings.
Mrmopartech
 
Like 'Tech said... You have to machine more than just the journals or just the mains. So the best way out IMO is to get the 3.75 stroke B wedge crank from 440Source and make sure it's good. Then drop it in. If you started with a forged factory crank there is a chance that it will drop in with minor clearancing and large counterweights. I had one do that. But it's not too common.
 
Thanks guys.I do have a factory forged crank out of a 66 440.Was gonna have it offset ground with chevy journals to get a 3.92 stroke and yes,also have the counterweights turned down. Cranks ends up losing 5lb's? Could be that going this route gains me the lightest crank.Some of those aftermarket cranks weigh a ton.
My reason for asking is Im not sure the factory cranks can handle what the stage VI's will make.Im looking at at least 650 and more like 700,which I think may be just beyond it's limitations,even with rolled journals. Sure back in the day they used stock cranks all the time but power levels have kinda crept up since then.

Im sure the 440 source crank will be good enough for this power level. But what does it weight? Is it a big heavy pig Im going to have to lighten anyways?

I know that the mains/rod journals on these cranks usually have a radius fillet,and the procedure for fitting the bearings right is a pita.Either crank Id be doing that so it's a moot point I guess.
 
If you are to the level of worrying about the weight of the crank, you're beyond factory or 440Source IMO and you should be getting a better crank of not worrying about it. What has been done to the Stage heads? It would take a very seriously done set of Stage VIs to make those numbers. I would say a solid 600 is doable on the facvtory crank... But with all the work, just use Brandons. You will spend more, and have a factory crank with all it's miles and the factory crank will not have a decent radius unless your grinder puts them there (more cash...) You talking about $500 in work on the crank alone. You can get a rotating kit with decent pistons and rods for $1600 plus shipping, checking out, and balancing right from Source that will drop into the block with no muss or fuss.
 
I'll be the opposite side of the coin, cutting the block will open up many choices for main bearings, low deck main bearing choice pretty much sucks.

As far as having to fit bearings if you have the mains of the crank cut down, not if the person grinding your crank knows what he is doing. I have a cut down and offset ground Eagle crank in my low deck stroker project and it drops in, no hacking of either the mains or the rods is required, because the person who cut the crank cut it correctly. The reason you have to HACK bearings on the source and some other low dollar cranks is because the money you save over a decent piece like a K1 is saved by pisspoor machining.

Spend a few bucks more and buy a K1 crank , it'll fit out of the box , if it doesn't K1 will stand behind it unlike the other cheap charley, chinese junk, seller .
 
Sounds like a plan. At least that way if I decide I want to go even faster the bottom end will hold up. I've been having second thoughts about using the stock steelie crank ever since I picked up these stage vi heads. One look at the max wedge ports had me thinking real hard,lol....

Brandons moper? K1 John? Where to get.....
 
Grind the crank. I'd rather take material off the rotating assembly than the structure supporting it.

K1 cranks are about $900, 440source are $600... pick your poison
 
crackedback said:
Grind the crank. I'd rather take material off the rotating assembly than the structure supporting it.

K1 cranks are about $900, 440source are $600... pick your poison
Click to expand...

Rob , the 400 has a fairly thick mainweb even on the non cold weather block , cutting it only takes out .062ish of material and it doesn't make it any thinner than a 440 mainweb .

440jim is running the 400 in his dart like this, he's going LOW 9's (hi 8's ??), and has been for some time.

If you really want cheap chinese junk that has to be fixed you can find a source like crank cheaper .
 
Thanks for that Cracked. Now the question is can I get the K1 crank in a drop in form? Fit right into the 400 block and has the 3.92 stroke?

I always thought the reason I would have to clearance bearings is because of the rolled radius added in for strength when grinding. Apparently there are no 400 main bearings that will fit this radius,thus the "hacking",lol.

no John,I dont want chinese crap.Not a fan,never have or will be thanks...
I have too many friends here and back east who have lost thier jobs due to the chinese flooding our canadian market with junk. BC isnt as affected as we are not as industry based but it still matters to me.
Im so antichinese I passed on the stealth heads on the chance the raw castings may be chinese. Seems to be the way 440 source rolls with thier stuff.

Soooo without turning this into a china bashing post (this will be started later,lol) what sort of crank/bottom end is 440jim running?

Low nines sounds cool but I doubt I can get there without extensive mods to the heads..

Cold weather block?
 
needsaresto said:
Thanks for that Cracked. Now the question is can I get the K1 crank in a drop in form? Fit right into the 400 block and has the 3.92 stroke?

I always thought the reason I would have to clearance bearings is because of the rolled radius added in for strength when grinding. Apparently there are no 400 main bearings that will fit this radius,thus the "hacking",lol.
Click to expand...

No, on the mains there is no radiused bearing, the reason for cutting it is because the chinese choose to FINISH grind their cranks the last .002 with flipping SANDPAPER . The reason to HACK bearings is because the crank journals are TAPERED and the RADIUS is TOO big. They have the exact same problem with the 440 sized mains . The only bearing that needs to be bought with a radius is the rod bearings and they are now making those bearings NARROWER and you may STILL have to HACK on them for a CCJ crank . :toothy10:

Like I said the Eagle is have is radiused and it fits in the run of the mill low deck bearing , just like a $3000 Callies does.

If you want to save money buy the cheapest 4340 material crank you can find and then send it to your local crank grinder and have it cut .010/.010.

Yes you can get a K1 that will be a drop in and have the counterweights sized so you don't have to make them look like SWISS CHEESE.

Where in canada are you ?
 
British Columbia John. About a 2.5 hour drive north of Spokane WA. A little town called Trail with a BIG smelter ,lol...there are no speed shops here.Closest I could come this side is Kelowna but Spokane is closer and likely less money.

Heck there isnt any real performance machinists around either. The guy I usually use mostly does street engines and I dont think I'd trust him with this engine.His equipment is pretty old for the most part. Decent guy but he flat out told me I was smoking crack if I think I can run 10's in a mopar...not the guy Im gonna deal with.


I think that wherevever I get the right crank it will likely have been cast in china...Seems offshoring has been waaay overabused.

Crap do we make ANYTHING here?..
 
I'd have to say that before deciding whether to go with a ground down 440 crank or open up the mains to 440 size you should have the mains alignment checked first. You may find that the mains are off enough that an align bore is required in which case go that extra amount and set them up for 440 bearings. JMO.
 
Eagle cranks come from China to...mine for my old 340 had to be cut .010/.010 right out of the box.....see if Mancini racing offers a Callie rotating assembly for your 400. Here's one they sell but they are using all Eagle parts, with clevite bearings and diamond forged pistons...

MANCINI - 400+.030" Stroker Kit - Internal Balance
Rod/Pin H-.990
$2,629.00
MRESTROKE-IKIT400

They have a 4.15 stroke Eagle forged crankshaft on sale for $399.00
 
Thanks for the link on the mancini stuff but Im still smarting from the last time they burned me on shipping. Wouldnt make it right so now they lose out.

Thats fine there are plenty of suppliers that dont charge exorbitant shipping.
 
Yes I know Eagle cranks come from China and they used to have the same problems , journal taper and too big a radius .

needsa , check with Muscle Motors for a kit as well as Hughes , being on the other side of the border you are going to get reemed on shipping no matter what. Do you have a contact on this side of the border you could ship to and go pick it up yourself ?

As far as opening the mains , with what you said about that machine shop I wouldn't let that guy near your block to open the main holes , buy a low deck kit .

There are some fast Mopar guys that run at Mission , you should be able to find a Mopar friendly shop some where up there ?
 
bremereric said:
Eagle cranks come from China to...mine for my old 340 had to be cut .010/.010 right out of the box.....see if Mancini racing offers a Callie rotating assembly for your 400. Here's one they sell but they are using all Eagle parts, with clevite bearings and diamond forged pistons...

MANCINI - 400+.030" Stroker Kit - Internal Balance
Rod/Pin H-.990
$2,629.00
MRESTROKE-IKIT400

They have a 4.15 stroke Eagle forged crankshaft on sale for $399.00
Click to expand...
I temporarly am going to change my avator to crackhead for one day...my bad it is on sale for $499.95 still a good price I think...8)
 
John I agree. This machinist has decent head building equipment,a computerized balancing program but thats realy as far as Id trust him.I will have the stuff shipped to Waneta across the border.There is a gas/postal service right there,about a ten minute drive. I have had many parts shipped there before. It will save me huge amounts of money.

I ALWAYS declare my crap at the xing,have no desire to be fined,thrown in jail and my vehicle confiscated...the tax is a minor inconveinience compared to that.

As for assembly,port work,clearancing,smoothing the block etc I can do all that.

My brother lives close to mission dragstrip. He is a mopar guy so might know something good. I have heard there is a Dvorack? machine shop that is top notch and knows mopars on the coast. Maybe someone from the coast can speak up...


Wilde,the issue is not how much rpm it can handle but how much hp it can take. Most folks reccomend no more than 600 and 650 is pushing it. 700 and you better start to worry.

My hp level will be 650 easy. I dont like leaving expensive parts on the ground so I want to build it once and build it right.$300 more for a good crank is a small price to pay compared to how much it will cost if I blow up the motor.

I guess I will have to sell the stock crank now...
 
The nice deal with a K1, you can get a BB Chevy pin on any stroke crank they make IIRC. That opens up a slew of different rod lengths to choose from. One thing that torques me about most 4.15 crank suppliers is they use a BB mopar pin which limits rod length choices and forces you into that crazy short piston if using a B block.
 
Yup I've noticed that about stroker cranks for the bb mopar 440 source seems to have noticed too,thier cranks all use the chevy pin/journal. It's nice because it opens up a world of rod selection,not because it's chev stuff,lol! I can build exactly the combo I want and juggle the rod length to get what I need at the piston.
The 6.7 rod will work for me fine,no pin hole in the middle of the rings! And I can use off the shelf pistons to keep costs down.

This is what freedoms all about baby!
 
Staying with the 400 main size is more economical. Boring out to the 440 main size costs some bucks but opens up the opportunity to better bearings and better cranks. What you're building sounds pretty mild so if it was me I'd just stay with the smaller bearing size.
 
needsaresto said:
Yup I've noticed that about stroker cranks for the bb mopar 440 source seems to have noticed too,thier cranks all use the chevy pin/journal. It's nice because it opens up a world of rod selection,not because it's chev stuff,lol! I can build exactly the combo I want and juggle the rod length to get what I need at the piston.
The 6.7 rod will work for me fine,no pin hole in the middle of the rings! And I can use off the shelf pistons to keep costs down.

This is what freedoms all about baby!
Click to expand...
440 Source also mentions they do the chevy rod journal size for clearance issues...thus does not spin as close to the bottom of the cylinder...8)
 
AndyF said:
Staying with the 400 main size is more economical. Boring out to the 440 main size costs some bucks but opens up the opportunity to better bearings and better cranks. What you're building sounds pretty mild so if it was me I'd just stay with the smaller bearing size.
Click to expand...

I think the best path lays in getting a good crank with 400 mains and a 3.90 stroke. That way theres no fussing around with the block and the crank just drops in.

As far as bearing selection,theres enough for me.

Pretty mild? It's borderline for the street but mild for a race engine I guess.
 
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