400 to 451 stroker questions

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Not arguing, just pointing out the facts of why rings have been getting thinner.
For someone who's been carrying on here like a ring expert, you don't seem to understand the simple physics behind it.
If anyone is interested, they can read this.
Why Do Piston Rings Keep Getting Thinner?


I read through most of it. It’s what I’ve been saying.
 
Yeah, I'm not crazy about cutting a factory forged crank. I just read that the main caps on the block can be bored and used with aftermarket caps to keep the 440 crank, yeah I know $$$
If I'm getting a kit it will be the 512 !!

BTW, what's the advantage of the larger mains on the 440, increased load bearing surface area and allow to block to hold more horsepower? I'm thinking that if I do it, I will have the advantage of the 440 crank, and the extreme beefiness of the 230 block


Estimates for the 72 , 400 , 230 block I have seen are 650, 750, 800, 900 hp
I'm planning 550 NA, up to 250 shot of n2o

I don't think anyone really knows
Is your block the early 71 230 casting that has the big main webbing? If it's not it's still a good block and 700 HP isn't hard on them if it's a super solid block and at that hp level you'd want to keep an eye on the main caps. Other than that we built a 451 at work a few months ago with the 440 source kit it has a 1.320 ch piston I think they have them listed at .025 under deck. We had to deck the block .028 passenger side and .032 driver side.
I wouldn't bore your mains out to 440 size.
Anyways it might end up being hundreds of dollars cheaper to just buy a kit from 440 source. I know that from experience lol. But I wanted a little higher quality rotating assembly (after seeing 440 source stuff 1st hand I'd buy it)
 
Who’s arguing? Only YOU. I don’t call it “significant” unless you are comparing a 5/64 ring to a .8 mm ring.

Most ring drag is when the piston is coming up the bore on compression and until cylinder pressure decays below some point I can’t think of right now.

Run a thin ring. And a 1/16 ring isn’t thin.
Hey don't dis my fat 1/16 rings lol
 
The gas pressure is only a factor on the firing stroke.
Talk to any of the ring piston/ ring manufactures, and they'll tell you that the radial tension is of significant value.
The firing stroke is where ring seal matters most.
 
Is your block the early 71 230 casting that has the big main webbing? If it's not it's still a good block and 700 HP isn't hard on them if it's a super solid block and at that hp level you'd want to keep an eye on the main caps. Other than that we built a 451 at work a few months ago with the 440 source kit it has a 1.320 ch piston I think they have them listed at .025 under deck. We had to deck the block .028 passenger side and .032 driver side.
I wouldn't bore your mains out to 440 size.
Anyways it might end up being hundreds of dollars cheaper to just buy a kit from 440 source. I know that from experience lol. But I wanted a little higher quality rotating assembly (after seeing 440 source stuff 1st hand I'd buy it)
That's the point I was trying to get across with my first comment. Not all 230 blocks are the thick main web blocks. Heck, a hard block fill to the bottom of the freeze plugs will add a lot of strength and still cool on the street.
 
That's the point I was trying to get across with my first comment. Not all 230 blocks are the thick main web blocks. Heck, a hard block fill to the bottom of the freeze plugs will add a lot of strength and still cool on the street.
Yep, I have a 73 630 casting I'm not worried about it. But the real beefcake 230 would be a nice piece
 
Yep, I have a 73 630 casting I'm not worried about it. But the real beefcake 230 would be a nice piece
Chit man, I think it's all splittin hairs, honestly. I'd build any of the blocks to mega power if that's what I was doin. They're all pretty dang stout.
 
Chit man, I think it's all splittin hairs, honestly. I'd build any of the blocks to mega power if that's what I was doin. They're all pretty dang stout.
Yeah exactly, friggin Andy put out close to 800 with the weak 530 casting.
 
Yeah, it’s a ***** to get much today that isn’t custom to get away from 1/16 ring packs.

When you do your tunnel ram engine you can get a piston with .8 mm rings and rotate the earth!!!
I'll have to get another raise 1st. My wife just spent 4k on 2 doors and shutters for the living room.
Atleast she likes nice stuff I guess. If I can get her in the dart when it's done (NOT IN THE DRIVER SEAT) She'll want me to have skinny rings.
 
I'll have to get another raise 1st. My wife just spent 4k on 2 doors and shutters for the living room.
Atleast she likes nice stuff I guess. If I can get her in the dart when it's done (NOT IN THE DRIVER SEAT) She'll want me to have skinny rings.

You can bring her over when your stuff is on the pump!! That make get you the skinny rings way quicker.
 
I built a stroker in the late 80s before the 'kits' were available. 440 crank in a 383 block, turned down the mains on the crank, no problems.
 
Is your block the early 71 230 casting that has the big main webbing? If it's not it's still a good block and 700 HP isn't hard on them if it's a super solid block and at that hp level you'd want to keep an eye on the main caps. Other than that we built a 451 at work a few months ago with the 440 source kit it has a 1.320 ch piston I think they have them listed at .025 under deck. We had to deck the block .028 passenger side and .032 driver side.
I wouldn't bore your mains out to 440 size.
Anyways it might end up being hundreds of dollars cheaper to just buy a kit from 440 source. I know that from experience lol. But I wanted a little higher quality rotating assembly (after seeing 440 source stuff 1st hand I'd buy it)
I saw where 440 Source has an all forged kit for $2300 for a 512 stroker !!
 
I saw where 440 Source has an all forged kit for $2300 for a 512 stroker !!
Yeah they're all the same price. It's a good deal for good stuff. They claim there stuff is balanced but we had to do minor corrections to balance it perfect. A 512 will be good, it won't have to work very hard to make the power you want. You'll want atleast main studs and mainline honed .
 
Turns out it a 76-78 , 400 block
I'm not disappointed tho, I read a couple of places that Ma Mopar continued to improve the 400 from it's inception in 71 to 78.
If it's true, and quality control increased, I think I might have a good block. Sonic testing is in order. Picking up the 400 next weekend
At this point it's going to be a 512
Can't pass up a balanced stroker kit from 440 source for $2250
 
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