What Hemi Block part number for at least 572ci potential?

I am wanting to order a Hemi block this week for a engine that can be taken to 572 cubic inch at the least.

Would it be best to get something that has finished piston bores and finished lifter bores?

Would it be best to get a siamese block? I would still want to drive the car on the street and strip.

Anybody have an idea of what part number I will need?

Let us know what the expected delivery date is after you order it.

Your options are "The Block," Indy, and KB. Go through one of the builders that sponsors this board as all of the above options are going to require machining. Good Luck!

And more than likely, a fair amount of lead time.

Here are the old Mopar numbers.

Mind you these are made from a special material: Unobtainium

P5155072AB 4.25 finish

P5153862AB 4.500 finish

P5153942AB 4.24 rough


Although there have been reports of J-- machine in Michigan shipping a handful recently, I have reason to believe these were very old Dalton castings that have been sitting around...Dalton hasn't made any in years....

Recent posts indicate new part numbers, which is how it is supposed to be done when there are big changes (supply chain being one).
the P516-AC numbers are going to be the most recent.

It will have to be a siamese block. You need the 4.500 bore. Order one from Jegs P5160150AC and wait. Hopefully it will eventually get there.

Looking at Jeg's it looks like that block is no where to be found listed but lost in space. but you might be able to get P5160151AC but it's a 4.240 and max bore is .030 over. But you can stroke it to 4.5 and get your 572.


Sorry I screwed up the decimal point max bore is 4.56

Where did you see that .030 is max bore for that block?

My bad I had decimal in wrong place.

Click on Overview 4.560 max bore good for 4.5 stroke for 588ci.Can be machined for another .250 stroke for a total of 620ci.

Mike

Awesome I will call them about P5160151AC. I hope that is finish piston bores and lifter bores.

I'd be calling Todd at Marsh Performance to enquire about a KB block. If the timeline for getting a KB isn't to your liking, ask about an Indy block.

Yes, that is the corporate "safe" recommendation there as it's always been for this generation of casting.

4.600+ has been done in the field post sonic test, at least I've seen it done a few times.

Mine is at 4.503" currently and still has plenty of meat left.

I Agree 100%

I am not wanting to pay 6K for a block. I am wanting to keep my block purchase at most 3K to 4.5K.

I have also read that the Indy blocks are not very good and always need tons of work.

In the current marketplace, for $3-4.5k........ I think you’re going to be looking for a used block.

Yup! And maybe it will come with a window to look thru, So you can see all your moving parts. LOL

Look like you are going Chevy then , I guess



Tex

I thought the KB block was 7K with the dedicated head studs adding another 1000+ to the total. Not counting whatever else is required in additional machine work.

Do you know if the siamese blocks have problems with cooling when driven on the street or fairly long trips?

Looks like a megablock from the 40th week of 2006. Motor Castings foundry.


https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F113294814297

If you can even find a brand new cast iron block, you'll likely pay $4500+ for it. Then it'll need basic machine work plus work to fix issues if needed.

Your best bet is to find a used block that's already been run and go from there. Good luck.

I'd run an Indy aluminum block before any of the cast iron blocks out there...JMO. For the cost of any of them, I'd go aluminum for the ability to repair just about anything on it later down the road.

The Siamese bore blocks don't have cooling issues.

You won't have a cooling problem. The siamese blocks have been around for a long time.

I doubt you’re going to be able to accommodate 572”+ without a Siamese block.

There's 2 mega blocks on ebay 1 water block and 1 siamese MCF casting both have Mcf casting ground off on top right side. Beware might be rejected blocks my old block is not ground.

Yeah that is unusual to see half the foundry mark removed like that, have to wonder if that was deliberate or what happened. Unfortunately Motor Castings was taken over by Dalton awhile back so I don't think we're going to get a straight answer.

I think the partial removal of the Motor Castings foundry mark is the result of removing the wedge motor mounts.

Good thought Mike, could be that.
Rich

[quote=Superlead]I think the partial removal of the Motor Castings foundry mark is the result of removing the wedge motor mounts.

Could be but if that was the case I would guess the 2 to right of it on 1 block or the 3 to the right of the foundry on the other block would also have been ground down?

Also the one has no lifter bores.

Looks to me like the “2” has been kissed by the cutter.

For a few years, Mopar offered some Hemi blocks without lifter bores.

Yep. As noticed...the one I linked to on ebay above is without lifter bores + without pushrod holes. Really not for the @home builder LOL. Although there are plenty of shops that could handle it and get it ready.

I'm not sure if I am remembering right but, on another motor castings block that I have seen I don't recall the foundry mark being touched when the wedge mounting "ears" were chopped off. But I also think that one is different because it is a water block so, apples and oranges/maybe foundry mark in a different location(?). I know where it is located and will take a look if I get a chance.

Lots of history and details to learn about these.
Which can either be helpful, or just trivia lol.

there are plenty of shops that could handle it and get it ready.
and they will send their children to college from that one job.

Curious: why such a specific number?

Definitely helpful as I only seen one block on eBay

Trying to hold out for a wedge block before I go ahead and start the process of building a motor

My youngest recently asked "you run Premium (gas) in this car?"

I said "yep."

He said "isn't that kind of expensive?"

I said "well Sam, Sometimes, if you want to dance, you've got to pay the fiddler."



Big laughs from all ensued.

The same seller of the block also has some damaged super stock heads, I can only imagine the fiddler's bill for those! but, it looks like he chased the rainbow pretty darned hard. Maybe it was worth it, or not...it's all relative...

I agree a lot to learn. I have a hemi water block with wedge mounts. 2468330 M MCF block cast #6K29 top pad is stamped HW1194. Whats confusing is I don't believe you could get a siamese hemi block with wedge mounts so why would they have them? The siamese blocks are a total different casting than a water block. They have Mopar cast on the side where the water block doesn't.

Wedge and Hemi use a common casting. All of them came out of the mold with wedge and hemi mounts cast in, and then the wedge mounts were chopped off for dedicated hemi applications + the hemi motor mount pad was drilled for hemi mounts + the other differences are also machined in.

This is true of all 3...the old water block, the old siamese megablock, and the newer so-called World block. They were all cast with both types of mounts, then final machining took care of the rest.

Likewise, the wedge versions will have some of the unique hemi motor mount pad but it won't be finish drilled and tapped (unless somebody smoked their lunch that day). World Wedge had a portion of the hemi mount chopped off on one side (if I remember correctly the left side) in machining but hemi artifacts are clearly visible.

Oh, forgot... 6K29 is a Cummins Recon machining center code.
Wish I knew what it means, but I have no idea. During my time at mp the Cummins rep (although a nice fellow) would never directly decode those numbers for me, and the engineer I had to go through (although also a nice fellow) treated those codes as if they were proprietary information.

My stance: When a vendor is coding YOUR product, you have every right to it. So, where's the magic decoder ring?

His stance: that's their information, why should I care, all I really care about is the part number.

Try as I might to learn the logic behind the codes, it wasn't ever made available.

Zippy thanks for the info. I guess all that's important is it's been a good block for over 10 years without any problems no matter what the secret code means. Lol Mike

You bet, Mike. There are plenty out there who know more than I do, and when they speak up (however rarely) I'm all ears. It's an old product with history, that went through alot of changes, I just try to share what I know in hopes it makes a difference.

Here's one the foundry mark never quite made it, but I can tell it was probably motor castings from the general shape of the "blob". If it would have made it, it would have been damaged at the same time the wedge ears were chopped off.