off the shelf rods/pistons for 470 B stroker for best rod ratio

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adam83

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I have a 400 block and want to make a 440 crank stroker,and I'm leaning towards the 470 with the offset ground rod journals vs a 451.

Because this is a street combo and I want it to last as long as possible before rebuilding, I've been advised to try and achieve a rod ratio of 1.8:1 or close to, and to use as tall of piston as possible.

What off the shelf rod and piston choices do I have?
 
Have you checked out 440source.com? Lots of info there.
Also do a search on amazon for mopar big block, @AndyF kinda wrote a book on it.
Do a Google search for 451 manifesto, that's his page.

You may be money ahead just buying a new stroker crank.
 
adam83 said:
I have a 400 block and want to make a 440 crank stroker,and I'm leaning towards the 470 with the offset ground rod journals vs a 451.

Because this is a street combo and I want it to last as long as possible before rebuilding, I've been advised to try and achieve a rod ratio of 1.8:1 or close to, and to use as tall of piston as possible.

What off the shelf rod and piston choices do I have?
Click to expand...

You have zero choices that will give you a 1.80 rod ratio in a low deck 470. The first thing you need to do is check the math with people on the internet give you advice. A lot of people on the internet who talk about engines don't know what they are talking about so you should stop listening to them.

If you do some research you'll quickly figure out that there are only a handful of ways to build a 470 using off the shelf parts. I built a chart a couple of years ago so some of it could be out of date but at the time it showed all of the possible ways to build a 470. This chart took me about an hour to build so if you want to spend an hour of your time doing the same thing you'll be the world expert on 470 combinations.
 

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Ottmundr said:
Have you checked out 440source.com? Lots of info there.
Also do a search on amazon for mopar big block, @AndyF kinda wrote a book on it.
Do a Google search for 451 manifesto, that's his page.

You may be money ahead just buying a new stroker crank.
Click to expand...

The manifesto gives parts for 451 to achieve 1.8, but not for 470.

I think if I already have a 440 crank, it'd be cheaper to just buy off the shelf rods and pistons vs buying a complete package from 440 source, muscle motors, etc
 
AndyF said:
You have zero choices that will give you a 1.80 rod ratio in a low deck 470. The first thing you need to do is check the math with people on the internet give you advice. A lot of people on the internet who talk about engines don't know what they are talking about so you should stop listening to them.

If you do some research you'll quickly figure out that there are only a handful of ways to build a 470 using off the shelf parts. I built a chart a couple of years ago so some of it could be out of date but at the time it showed all of the possible ways to build a 470. This chart took me about an hour to build so if you want to spend an hour of your time doing the same thing you'll be the world expert on 470 combinations.
Click to expand...


I'd never seen this before I'll check it out thank you Andy
 
adam83 said:
The manifesto gives parts for 451 to achieve 1.8, but not for 470.

I think if I already have a 440 crank, it'd be cheaper to just buy off the shelf rods and pistons vs buying a complete package from 440 source, muscle motors, etc
Click to expand...
There is a lot of work that has to be done to a 440 crank to get it to work in a 400 block, and then only get 451. IF it fits the budget , a matched balanced kit is the way to go , in my opinion, even if i did have a 440 crank.
 
33IMP said:
There is a lot of work that has to be done to a 440 crank to get it to work in a 400 block, and then only get 451. IF it fits the budget , a matched balanced kit is the way to go , in my opinion, even if i did have a 440 crank.
Click to expand...
That is true. I used to make 451 and 470 engines using factory steel cranks but those days are over for me. In fact, those days were over almost 20 years ago. Once SCAT was forced to open up the supply chain it makes more sense to just buy a new crank from Molnar or K1 or someone like that. The only way I'd start with a factory crank these days is if I knew a guy who owned a crank grinder and he was very bored and willing to work for almost nothing.
 
To get a large rod ratio, you need a long rod. You cant have both a long rod, and a tall piston in a short deck (383/400) block. If i were you, i would put together what works, and not worry for ten seconds about rod ratio. 400 small block chevys, and 454s, have horrible rod ratios, and have gone billions of miles.
 
In most cases, you can build a 470 stroker from 44 Source cheaper than you can accumulate the parts & have the machine work done. Not to mention you are getting new components versus 30 to 40 year old pieces that you have no idea how they were used previously, or how much they were stressed by the PO. I've gotten away from paying ridiculous machine shop prices when I can & by of the shelf aftermarket pieces to build my stuff. A fiend was wanting to build a stroker 440 to a big inch street engine. He did his leg work on pricing machine work & buying the pieces. I suggested 44 Source & he went with one of their complete kits & was bucks ahead. He's making gobs of HP & torque with a lot lees out of his pocket. I know this isn't for everyone, but it's a place to start looking.
 
Rod ratio...... way waaaaay down the list of things I look at when considering which parts to use in a rotating assy.
 
Molnar crank and rods and Ross pistons

0828201826.jpg
 
adam83 said:
I have a 400 block and want to make a 440 crank stroker,and I'm leaning towards the 470 with the offset ground rod journals vs a 451.

Because this is a street combo and I want it to last as long as possible before rebuilding, I've been advised to try and achieve a rod ratio of 1.8:1 or close to, and to use as tall of piston as possible.

What off the shelf rod and piston choices do I have?
Click to expand...

If you want to build a "budget" 470 then you need to start the process by figuring out which heads you are going to use and what compression ratio you want. Once you know those two things you can then search for a combination of off the shelf parts that will give you the result that you want. The rod ratio is irrelevant on a budget engine. If you want to design around a specific rod ratio then you'll probably need custom pistons since the odds are very low that you'll be able to find a long rod piston that provides the exact compression ratio that you want.

Getting the compression ratio correct is much more important than the rod ratio. Using the correct rings and bearing clearance is way more important than rod ratio. In fact, almost everything is more important than rod ratio for a street engine. The only people who care about rod ratio are a few F1 engine designers and few guys on the internet who argue about theory but don't actually build engines.
 
33IMP said:
To get a large rod ratio, you need a long rod. You cant have both a long rod, and a tall piston in a short deck (383/400) block. If i were you, i would put together what works, and not worry for ten seconds about rod ratio. 400 small block chevys, and 454s, have horrible rod ratios, and have gone billions of miles.
Click to expand...

and some run great at the same time !!
 
Thank you for all the input, I have more to consider now. I have had 2 engines built before and I've assembled quite a bit. The more i do it, the more I read up on these things. It is hard to tell whos right and what's true when you have to read up most of your information.

My goal is longevity and decent power in a street engine for my ramcharger. I gathered from what I read that side loading from too small rod wears out cylinders. Then I also have been reading about how compression height can do the same if it's to short, now that I'm planning this build I was trying to take everything into consideration.

If rod ratio doesn't matter much on a street engine, is there an 'ideal compression height' or range that I want to stay in?

I guess I also assumed the machining on the crank wouldn't cost too much, like $300, maybe I was just reading articles that were way too old though. I'll have to talk to the machine shop.

I plan setting up my engine to run with some cleaned up 516 heads with hardened exhaust seats, possibly milled, to get cc's in the low to mid 80's.
I want to get to the best quench depth I can through part matching rather than milling the block, because I want to avoid having to mill the intake of possible. I'd like to land near 10:1 compression
 
516 heads on a 470? If you are going to use 516 heads then just do a stock rebuild on the 400. Use the factory cast crank and cast pistons and it will last 100,000 miles.
 
AndyF said:
516 heads on a 470? If you are going to use 516 heads then just do a stock rebuild on the 400. Use the factory cast crank and cast pistons and it will last 100,000 miles.
Click to expand...
In the future when it comes out of the ramcharger, I'd like to be able to put new cam and top end on it with aluminum heads and put it in a duster.

Currently the 400 has lots of blowby, and needs to be rebuilt. So, knowing what I want to do with it in a year or 2 with the duster, I don't want to have it rebuilt to stock stroke now then have it rebuilt again with a stroker kit, I'd like to take care of the bottom end once.
 
if you plan an upgrade to the cam and top end in a year or two why not just hone and re-ring it as is for now and build the performance motor once. you'll have longer to collect and properly match your parts over the next year or so. meanwhile the fresh rings (and bearings too while you're in there) will serve you just fine.
neil
ps in case you missed it on here Bare Bones Budget 400 Build
 
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