How many foot pounds needed to turn mag 5.9?

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78kitcar

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Long story short i dropped off my short block engine to a local butcher 7 months ago for final assembly. I gave him everything needed down to the engine paint! After 3 months of checking in with him he says " Somethings wrong.... it takes a lot of force to turn this engine" I asked how much? Responce " I dunno" He reccomends pulling it apart to check the rings. 4 months later all he's done was removed 1 piston!! I got pissed!! Went the next day and pulled everything from him. Figured i'm better off starting from square 1 then let this idiot touch it!! My question is ....... How many foot pounds needed to turn the pistons??

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Not much. I generally say "around" 25LBFT for a long block. A short block of course will be a lot less. How much is it?
 
From my harbor freight torque wrench and my inexperience i very between 25-31 pounds
 
From my harbor freight torque wrench and my inexperience i very between 25-31 pounds

Is that with a missing piston? Either way, that does seem high. Try breaking each main cap loose and try it. Retighten if it doesn't make a difference then go to the next one. If you do all the mains with no difference, do the same with the rods one at a time.
 
I guess it would be a good idea to reinstall the piston first. At least it would be more accurate reading
 
I guess it would be a good idea to reinstall the piston first. At least it would be more accurate reading

That would make for a better base line. If nothing is strange or wrong, the rings are the biggest source of friction. I would also look very closely at the connecting rod side clearance.
 
The guy tells me... your pistons are wrong! You have LA pistons in a Magnum block. At that point i knew i made the right decision.:wtf:
 
Since you've got a piston out, pull the rings off it and check the ring gap. See what feeler size gauge you can put in the cylinder and push the piston through with WD40 or other light oil and a moderate push. I'm with Rusty, it's probably rotational. Another question, have high strength rod bolts been installed without resizing the big ends of the rods? Or have the main cap bolts been upgraded without align honing the block?
 
The guy tells me... your pistons are wrong! You have LA pistons in a Magnum block. At that point i knew i made the right decision.:wtf:

Well he's right about one thing. They aren't the same. Interchangeable, yes, but not the same.
 
If it was me I'd just pull it apart and start over. You'll spend more time dinking around with it than it it's worth. It could be a bent crank or it needs a line-hone. You can't find that until the rods are out of the way.
But my guess is the rings are dry.I have watched mechanics grease the skirts with white grease, which after the oil runs out of it, leaves the soap behind, which then cakes up.....
 
If it was me I'd just pull it apart and start over. You'll spend more time dinking around with it than it it's worth. It could be a bent crank or it needs a line-hone. You can't find that until the rods are out of the way.
But my guess is the rings are dry.I have watched mechanics grease the skirts with white grease, which after the oil runs out of it, leaves the soap behind, which then cakes up.....

One of your shortest, most useful posts ever. I agree.
 
Connecting rod caps installed on the wrong rods will do that also.
Copied from another post.
“The chamfer for the crank filet clearance is cut on one side of the rod only. So the rods need to be oriented so the two rods touch each other on the side with no chamfer. The bearings are offset in the rod to clear the crank's filet so getting that backwards usually means it will be hard to turn over and will have no side clearance on the rods”
 
Connecting rod caps installed on the wrong rods will do that also.
Copied from another post.
“The chamfer for the crank filet clearance is cut on one side of the rod only. So the rods need to be oriented so the two rods touch each other on the side with no chamfer. The bearings are offset in the rod to clear the crank's filet so getting that backwards usually means it will be hard to turn over and will have no side clearance on the rods”
Warning!
off base and a diff. engine . I have my car up in the air , waiting on my new tti headers . Its been torn apart for about 5 weeks. Anyway yesterday , I went out to clean up from the garage flooding rain we had , (water went around the sides of the garage and out the back door) , no tools wet that I left under the car .
I decided to roll the engine by hand , just to move the valve springs to a diff position , I cant believe how much effort it took to roll it , even w/ the plugs out !!--kinda got me worried .
440/505 , w/ .002-.0022 main and rod clearance , ample side clearance on the rods / 1 16'' rings , w/ about 2000-2400 miles on the engine .
How much do u guys think it should tale to roll it over/move the crank ??-----all opinions appreciated .
Wonder if this is why this engine hasn`t lived up to my expectations so far !
 
@famous bob its hard to stick a number on what it takes to roll over an assembled engine without measuring it. But I can tell you that if you had the rod caps mixed up or something as serious as that, the engine would not last very long when running. A friend of mine in high school built a small block Chevy and all the caps were mixed up. He couldn’t turn it with a wrench. Decided to put it together and crank it on the starter. It started and ran, but not well and only lived about 15 minutes. For a comparison to your 505 the 468 BBC in my boat assembled without plugs in it takes at least a two foot pipe on the wrench to roll it over. It’s got lots of valve spring pressure and big bores so lots of surface area on the rings.
 
I freshened my 367, FIVE winters in a row, looking for surprises to take care of, before they became an issue. That's how much I didn't trust the "pro-shop's" assembly work...... even tho they handle almost all the local circle track work.. Plus it was my first trip into pushing 185 to 200psi (alloy heads), so I was looking for signs of detonation (which I never did find).
During those FIVE freshenings;
Twice I changed the rings,
Once, no twice, I changed the top ring gap, and once the second as well.
One time I changed the rod bearings,
Once I cut the decks,
Once I shaved the decks,
Once I had it line-honed,
Once I had the bores opened up a tad,
Once I replaced a migrating pin-bushing,
On time I resized a rod, and
another time I replaced a different rod.
I never kept track of anything...... because I never thought it would one day be important. I had not yet discovered FABO, at that time.
Having said that, turning torque in the short-block, was always important to me. And so my rule was;
As long as each additional piston/rod, going into the short block, increased the turning-torque* required, by a similar amount, I was happy.
In my engine, the drag was always on the rings. How do I know that?
Because one atta time, I fit every rod to the crank prior to installing the crank into the block, and gave each of them a lil spin after measuring the clearance.
And One atta time, I set the naked pistons into their specific holes, and watched them drop of their own weight.
And one atta time, I made sure the wristpins were correctly clearanced.
So by process of elimination, the turning torque revealed only the tight rings. After I installed Plasma Moly file-fits on my KB107s, with "towing" ring-factor clearance of .008, the turning torque became significantly less.
The very first assembly was done by the pro-shop. And that engine was prone to locking up every time I shut it off; and it hated traffic; it even ran hot on the hiway. To say I was frustrated would be an understatement. To it's credit, it ran gangbusters in third gear with 3.55s. I tried everything, with very little improvement. Finally, I added a half a thou (average) of bore clearance, and added .006 thou top-ring end-gap,and added .002 second gap; and got control of it. That allowed her to run a 195 stat, with no more issues. The Moly-Plasmas went in on a later freshening.
The point is this;
IMO, with KB107s, the .0065 plain cast-ring, ring-factor that results in .026gap, in a 4.04 hole, is too tight.
IDK if it needed to be as much as .008 factor, but since it solved my problems, and the engine was killer-strong; I never tried less. That was the end of the mods. The next freshening revealed nothing amiss, so was the last one. That was 2004 or 2005. Since then, actually in total, that engine has well over 100,000 miles on it now; I'll guess about 60,000 since the Plasma-Moly rings went in.
As to the turning torque;
If I had to guess, I'd guess about 4 or 5 ftlbs per piston assembly, so total of 32 to 40?, and with the "loose" Plasma-Moly file-fits, a lil less; say 3 to 4 per piston; but it's just a guess.
I was never sorry that I installed those Moly rings nor about the slight rattle at start-up due to the additional skirt clearance,(now, IIRC, pushing .004 or a tad more skirt clearance) which only manifests at the beginnings and ends of the season; and goes away in just a few seconds. Otherwise, it doesn't seem to be a problem.

To walk you thru reassembly; there are a bunch of smarter than me guys here on FABO, including several? current and past engine-builders. And A bunch of hobbiests like myself.
Best of luck finding your problem, and I hope it's a cheap fix.


*not the breakaway torque
 
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@famous bob its hard to stick a number on what it takes to roll over an assembled engine without measuring it. But I can tell you that if you had the rod caps mixed up or something as serious as that, the engine would not last very long when running. A friend of mine in high school built a small block Chevy and all the caps were mixed up. He couldn’t turn it with a wrench. Decided to put it together and crank it on the starter. It started and ran, but not well and only lived about 15 minutes. For a comparison to your 505 the 468 BBC in my boat assembled without plugs in it takes at least a two foot pipe on the wrench to roll it over. It’s got lots of valve spring pressure and big bores so lots of surface area on the rings.

No rod caps mixed up or anything like that . used a standard long craftsman ratchet/1 1/4'' socket to roll it . First time I `ve rolled it w/ the plugs out , its a ***** rolling it w/ them in setting the lash--------->??
 
No rod caps mixed up or anything like that . used a standard long craftsman ratchet/1 1/4'' socket to roll it . First time I `ve rolled it w/ the plugs out , its a ***** rolling it w/ them in setting the lash--------->??
Mine is also.
 
Thx for the help fella's! I've decided to take it to another shop and hope for the best. They come highly reccomended but so did the 1st guy.
 
Thx for the help fella's! I've decided to take it to another shop and hope for the best. They come highly reccomended but so did the 1st guy.

I'm not askin this to be a smartass.....so please don't take it that way, but why not do it yourself and learn something? You could be assured that you would find the problem yourself if there is one, fix it yourself and save yourself some money all while learning something. That learning thing is priceless.
 
I'm not askin this to be a smartass.....so please don't take it that way, but why not do it yourself and learn something? You could be assured that you would find the problem yourself if there is one, fix it yourself and save yourself some money all while learning something. That learning thing is priceless.

Rusty there's nothing more I'd love to do! The thought of me building my engine gets me pumped. I'm scared!! I've watched the youtube video's and i know i could handle it. I'm still scared. I'm sure I'll need some specialty tools. I don't mind buying tools!! Who does? Oh by the way ....................still scared :lol:
 
Rusty there's nothing more I'd love to do! The thought of me building my engine gets me pumped. I'm scared!! I've watched the youtube video's and i know i could handle it. I'm still scared. I'm sure I'll need some specialty tools. I don't mind buying tools!! Who does? Oh by the way ....................still scared :lol:
Don’t be scared. Look for one or all of the “how to build small block Mopar” books and jump in and get your hands dirty. Gotta start somewhere.
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