• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

440 + 413 mix

Christian-440

Member
Local time
4:00 AM
Joined
Jan 6, 2024
Messages
18
Reaction score
14
Location
Michigan
Okay, weird idea, I have a 413 which I know came with 6 Pak Rods, a forged crank, and a windage tray, unfortunately it's an industrial motor so the heads are pretty much useless. What's yalls take on putting the Rods, crank and some factory 10:1 pistons in a 440? Windage tray too of course. I know 413 pistons are about 1/8" smaller, so I'm curious if there's any balance issue I'll have to address with the 440 pistons in it's rotating assembly? Assuming compression in reality is gonna be around 9-9.5:1 not 10:1, so I'll probably get the heads shaved .020". Port the heads, aluminum intake all that. Any input? Power estimates? Is that much off the heads too much? Not enough? I want around 10:1. Cam recommendations? It'll be a fairly mild build in the world of big blocks, hoping for 500-600hp, but I'm expecting less.
 
It's a 440. If you made 1hp/ ci you're doing good.
500hp, super good
600hp, of course, why not.
700hp, just as easy.
 
It's a 440. If you made 1hp/ ci you're doing good.
500hp, super good
600hp, of course, why not.
700hp, just as easy.
I like you thought process..... lol

In reality though, I'm not throwing $10k at it or anything. Stock heads, used forged bottom end, good compression, ported heads, probably a mild (ish) street / strip cam. I doubt it's gonna be any monster, but she'll smoke some tires I'll bet.
 
If your shortblock is good just do all that to the 413 and save yourself some time and money.
I have both motors, it's not so much a time and money thing as they're both RB motors so it's direct swap. I'm just not sure about the balance, but I think the extra displacement it worth it. And I'd have to shave a lot off some 906 heads to make the 413 usable because it's an industrial motor, different water pump, spark plug orientation and manifolds.
 
I've taken apart a few 413 industrial engines over the years and none had 6bbl rods in them. They do have a completely different balancer on them. In general, when I strip one, I save block ,crank,LY rods, and scrap the rest. Build the 440 and mabby use the crank from the 413. However I would definitely have a balance done no matter what combo of parts you use.
 
So what are the details on the 440.
440 is currently low compression. Around 80-90 psi wet, it doesn't run. It's sat outside for some years, I don't think the cylinders are beyond just a hone to fix. It's not locked. It's a 78 block, and has miss match heads, same chamber and valve sizes (rating wise), different casting numbers. Nothing special. It is a 4bbl motor though.
 
I've taken apart a few 413 industrial engines over the years and none had 6bbl rods in them. They do have a completely different balancer on them. In general, when I strip one, I save block ,crank,LY rods, and scrap the rest. Build the 440 and mabby use the crank from the 413. However I would definitely have a balance done no matter what combo of parts you use.
I've been told they had forged 6pak Rods, whether that's true, I haven't been in it. But, the crank and windage tray are worth taking. I suppose I'll have to make a call to a machine shop.
 
What does the flywheel end of the crank look like on the 413? They can be a lot different then a car, they can protrude out farther towards the transmission, have no registry to center the flywheel and usually have 8 bolt flanges, or maybe it's same...but compare it to the 440 before you proceed.
I would be surprised if it had HD six pack style rods. All 413's had forged cranks..as far as I know.
 
Last edited:
What does the flywheel end of the crank look like on the 413? They can be a lot different then a car, they can protrude out farther towards the transmission, have no registry to center the flywheel and usually have 8 bolt flanges, or maybe it's same..? Anything is possible? but compare it to the 440 before you proceed.
I'll have to check although it's bolted to a common 727 transmission right now, so I don't think it protrudes like the early Hemis and others did....
 
Long crank 413 ended in 1962 I believe...the 413 industrial cranks I've seen are basically 440 steel cranks with normal 6 bolt flywheel
 
Ih ave owned several dozen 413 Industrial engines.
None had six pack rods. I also just keep the short block
and throw the rest away including the Weird Water pump
and heads etc.
 
Ih ave owned several dozen 413 Industrial engines.
None had six pack rods. I also just keep the short block
and throw the rest away including the Weird Water pump
and heads etc.
Like I said, that's just what I was told. Either way, it still has some good parts I'll probably use. I'll probably still keep the block and everything I don't use anyway to be honest. (Besides the useless heads and water pump and whatnot)
 
if using 440 pistons on a 413 crank.......weigh the pistons on a decent digital scale. the 440 pistons will likely be heavier. grind the difference off the pin end of the rods, making them all the same as the lightest one. now you are at factory 413 balance and better because all 8 piston-rod assemblies are closer to the same than they were from the factory. good enough up to 6000 rpm.
 
[1] Industrial BB engines I have seen had beefier rods, but not 6 pack rod. More like max wedge.
[2] 1961 was the last year of the 'long' crank.
[3] Post #17 is a good idea. Contact someone like Ross pistons & get some light weight piston pins to get the weight correct.
 
I was considering doing the same with a motorhome 413 that I came across last year as the heads, waterpump, and exhaust manifolds are all useless so was going to have to source those anyway which starts adding $$ up. The 413's bottom end is sturdy as all get out and built for running at 3K for hours under load, but they are 7.0-7.5 compression so will need better pistons to get respectable compression (even with closed chamber heads) so now you have to take on not just pistons, but figure in block machining too so more $$ is necessary. If the 440's bore is serviceable then just run it as is with new rings and planed heads or closed chamber heads. Swapping/balancing the pistons requires a decent scale (alont with patience and effort). Cast crank 440's are generally accepted to be reliable to at least 500 horsepower so focusing on running it would be my recommendation and keep the 413 for rainy day or spare parts (or to sell the valuables to fund your 440 build). Good luck with the build and keep us posted for how it turns out.
 
Last edited:
so now you have to take on not just pistons, but figure in block machining too so $$ is going to add up. If the 440's bore is serviceable then just run it as is

Cast crank 440's are generally accepted to be reliable to at least 500 horsepower so focusing on running it would be my recommendation
Extremely wise words. Trying to make something out of two sows ears is a fools errand.
I just about got into the 11s with a nothing 77 440 smogger short block. In a stock fully trimmed 64 Dodge.
K.I.S.S.
 
Auto Transport Service
Back
Top