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Tolerances

78cordoba

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Hi, I'm about to start rebuilding my first engine a Chrysler 400, so bare with me I'm new to this. I will be putting the crank in this weekend but wanted to double check bearing tolerances. Does anyone know them off the top of there head? They are Clevite77 MS-876P-20 bearings. Also I don't know much on the torque specs are these correct:



Main Caps
85 ft-lbs.


Connecting Rod Bolts (Plain)
45 ft-lbs.

Connecting Rod Bolts (Heavy Duty)
55 ft-lbs.

Crankshaft Rear Bearing Seal
30 ft-lbs.

Cylinder Heads
70 ft-lbs.

Rocker Shaft brackets
25 ft-lbs.

Oil Pump Cover
10 ft-lbs.

Oil Pump
35 ft-lbs.

Oil Pan
15 ft-lbs.

Camshaft Locking Bolt
35 ft-lbs.

Timing Cover
10 ft-lbs.

Intake Manifold
40 ft-lbs.

Valve Cover
6 ft-lbs.

Water Pump
30 ft-lbs.

Fuel Pump
30 ft-lbs.

Starter mounting Bolts
50 ft-lbs.

Exhaust Manifold
30 ft-lbs.

Spark Plugs
20 ft-lbs.

Flexplate/Flywheel Cap Screws
55 ft-lbs.

Flexplate to Torque Converter
270 in-lbs.

Centerbolt
135 ft-lbs.

Bellhousing
50 ft-lbs.
 
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Stop!!!! Never ever rebuild "any" engine without a manual that gives tolerances and torque specs. If you can afford to buy the parts for the rebuild, you can afford to buy a manual.
 
Here are some specs, and you can go to mymopar.com and download the manual for free.

Service Manuals – MyMopar

Intake Manifold, 40 FT/LBS
Exhaust Manifold, 40 FT/LBS
Flywheel, 55 FT/LBS
Flywheel Surfacing, FLAT IN 1972-74, OTHER YEARS ARE UNKNOWN
Damper, 135 FT/LBS
Main Bearing Cap, 85 FT/LBS
Connecting Rod, 45 FT/LBS
Cyl Head, 70 FT/LBS
Camshaft Gear Bolt, 35 FT/LBS
Oil pump bolts, 35 FT/LBS
Rocker shaft, 25 FT/LBS
Rear seal retainer, 30 FT/LBS

Rod Journal Diameter, 2.3740-2.3750"
Oil Clearance, .0009-.0034"
Main journal, 2.6245-2.6255"
Oil Clearance, .0011-.0036"
Thrust Width, 1.2300" @ #3
Rear Seal Diameter, 2.8120-2.8150"
 
Spending thousands to rebuild a motor and not spending 50 bucks on a service manual is not the best idea. Please by a service manual
 
Im sorry I thought this was the Engine, Trans and Driveline tech thread, seems more like the go buy a book and leave us alone thread. I just figured I could find the same info online that I could in a book. Thanks for your help.
 
Im sorry I thought this was the Engine, Trans and Driveline tech thread, seems more like the go buy a book and leave us alone thread. I just figured I could find the same info online that I could in a book. Thanks for your help.

Lots of people on here do know the specs as do I but quite frankly, your jumbled hard to read thread is deterring me from answering any of it. Perhaps if you need the torque spec on one item it would be a different reply.
The recommendation to by a service manual was from a ‘good place’ as there is nothing better than having one on hand when doing a project like this. I imagine hundreds here would agree.
You never know what you’ll run across and when you’ll need that little extra bit of information at 2AM one night when you’re wrenching late that you though you knew but didn’t.
Suit yourself. Good luck
 
Im sorry I thought this was the Engine, Trans and Driveline tech thread, seems more like the go buy a book and leave us alone thread. I just figured I could find the same info online that I could in a book. Thanks for your help.
Refer to my post#3, and go download a FREE manual!! That means zero $dollars$, and a **** ton of correct information and procedures, not to mention proper tools needed, from Mopar.
 
Refer to my post#3, and go download a FREE manual!! That means zero $dollars$, and a **** ton of correct information and procedures, not to mention proper tools needed, from Mopar.
That post wasn't directed towards you. I appreciate your help! Would the 70s chrysler manual cover the torque specs on a 400 from a 78 cordoba? I didn't see a specific one for the 78.
 
Lots of people on here do know the specs as do I but quite frankly, your jumbled hard to read thread is deterring me from answering any of it. Perhaps if you need the torque spec on one item it would be a different reply.
The recommendation to by a service manual was from a ‘good place’ as there is nothing better than having one on hand when doing a project like this. I imagine hundreds here would agree.
You never know what you’ll run across and when you’ll need that little extra bit of information at 2AM one night when you’re wrenching late that you though you knew but didn’t.
Suit yourself. Good luck
I get that but I was hoping to get started on the crank this weekend, and trying to find a 78 Chrysler service manual (which looks like it might be tough to get ahold of) may prolong the build a few weeks.
 
Im sorry I thought this was the Engine, Trans and Driveline tech thread, seems more like the go buy a book and leave us alone thread. I just figured I could find the same info online that I could in a book. Thanks for your help.
With all do respect …..you’ll find some great info on this forum….some guys know exactly what they are talking about, some offer good input, some offer suggestions, some offer options, some don’t have a clue…you would be most likely better off listening to a few of the comments and get a Manuel, or download the info…..Guessing is not the way to go with any rebuild…..get your facts from someone that knows….a few of these guys have offered knowledgeable info to you…reply to them…they will help you out…..
 
With all do respect …..you’ll find some great info on this forum….some guys know exactly what they are talking about, some offer good input, some offer suggestions, some offer options, some don’t have a clue…you would be most likely better off listening to a few of the comments and get a Manuel, or download the info…..Guessing is not the way to go with any rebuild…..get your facts from someone that knows….a few of these guys have offered knowledgeable info to you…reply to them…they will help you out…..
Never said I was planning on guessing.. Just looking for some correct information online thanks
 
78, BTW which torque spec are you asking about? Main caps? With a good stock bolt the main cap spec is 85 ft/lbs.
That has nothing to do with the bearing clearance though. The bearing clearance needs to be measured. Micrometers are best, plastigage, maybe. I never trusted plastigage.
 
I spent 23yrs in the Army working on helicopters, turbine engines and Never walked up to the helicopter without the appropriate manual. The reason is, we are human n forget. The manual will not forget. It will also give you the order in which to torque which is extremely important. It will also give you "notes" "cautions" and "warnings" along w telling you that something else may need to be done before you do "x". And in the end, when you look it up, you are more confident in your work and know where to find it next time.
As for a '78 400 or a '70 400. The specs will be the same for the engines. Not emissions or carbs etc, but for the actual engine.
And you are asking for help, the "best" help you will get is from a manual. Someone's "I think" or "typo" number could totally ruin what you're doing. Your original post asked tolerances and torque specs. Nothing about what order. "That" is a perfect example of why you need a manual.
 
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Do you have the proper tools for a rebuild ? Are you installing new/reconditioned parts or used ? Reground crankshaft or factory worn ? A non machined (worn) crankshaft will have oval shaped journals so it is difficult to get a consistent clearance measurement. Plasti-gauge or micrometer. Beam, digital or click torque wrench?
Even if your bottom end is all new parts, it takes many hours to check and assemble.
Not a bad idea to get a book on Mopar B/RB engines. Many available with tips on engine assembly.
CLOEAN, CLEAN, CLEAN is the name of the game with internal engine parts assembly.
Have a large, organized clean area for your parts and tools.
Good to have an extra set of hands and eyes, preferably with prior experience on hand to help.
 
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I spent 23yrs in the Army working on helicopters, turbine engines and Never walked up to the helicopter without the appropriate manual. The reason is, we are human n forget. The manual will not forget. It will also give you the order in which to torque which is extremely important. It will also give you "notes" "cautions" and "warnings" along w telling you that something else may need to be done before you do "x". And in the end, when you look it up, you are more confident in your work and know where to find it next time.
As for a '78 400 or a '70 400. The specs will be the same for the engines. Not emissions or carbs etc, but for the actual engine.
Thankyou, and Thankyou for your service! Ill will try and get ahold of a 78 manual looks like Ebay actually has quite a few. But for now with the crank install ill use the 70s service info thanks again.
 
Good rule of thumb for bearing clearance is .001" per 1" of journal diameter.
Doug
 
78, for many things the '78 FSM will be really valuable, but if you are adding other year parts, you may need other manuals. Only problem with the FSM's is figuring out what tool you really can use to do the job. Factory tools don't make much sense. Need to figure that out by yourself.
Consider getting a few of the Direct Connection or Mopar Performance "bibles". Later ones probably good for you. Lots of good info in those.
 
78, for many things the '78 FSM will be really valuable, but if you are adding other year parts, you may need other manuals. Only problem with the FSM's is figuring out what tool you really can use to do the job. Factory tools don't make much sense. Need to figure that out by yourself.
Consider getting a few of the Direct Connection or Mopar Performance "bibles". Later ones probably good for you. Lots of good info in those.
Its just a 78 400 bored 40 over with kiethblack 240 pistons, crank turned .020 on mains and rods, and a stock roadrunner cam not looking for a race motor just a cruiser for pokeruns
 
Never said I was planning on guessing.. Just looking for some correct information online thanks[/QUOTE
Good rule of thumb for bearing clearance is .001" per 1" of journal diameter.
Doug
I agree….I worked with a guy who told me .0005 for oil, .001 grease…..I’m not a rebuild specialist so I’m not about to argue…….
 
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