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1972 F250 4x4, 78 d44, 3.55, np205, 200hp 4bt nv4500 in progress
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Discussion Starter · #41 · (Edited)
I suppose it’s time for update. Visited the machine shop 50 miles away. Block magnafluxed, .020 over not honed yet but was told cylinders would be 4.036 honed off the top of his head. Middle range of the specification so that it would not run tight. Knowing that spec and doing the chamfer strokes my confidence level!

He took the valves out noted good continuous lap on each, was impressed with Promaxx head quality. On closer inspection the head came with white stripe larger springs exhaust. Any need to change the intakes to the white stripe springs?

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He jokingly told me to ‘read less’ as I humbly am particular with sticking to specs on this going through. Seems like consensus Of non-forums /reading folks is to ‘run it!’ and not worry about it! Anyone else have a similar experience?

New pin bushings/pistons/bearings/rod bolts all from McBee. Subcontracted balancer said 4 cyl cranks don’t benefit but I read others here have benefitted from rotating assy balancing. So, I’m persisting and if it doesn’t need much or any at least it would be peace of mind.

Sorry no painted engine porn pix just a boring flywheel:

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Dodge flywheel #3920378 with the nipple and crappy roller bearing. I know there’s sold a stouter sealed roller bearing that needs flywheel nipple to be machined to accept bearing, which would cause bearing to have to recess further into the engine side of the flywheel/affect input shaft. I’ve read machine an adapter then bearing into the adapter. Anyone have links to this or a tip or should I just buy the new flywheel with bearing. Even new FW not sure if the bearing is at the right distance.

My apologize if this has been answered, I’m not finding it.

I figure I went through the trans well for maybe 150,000mi and I’ll put a decent clutch in for the same, the first to go out would be the chinsy FW roller bearing getting dry.

Cleaning/painting up other parts and doing my mandatory forum/factory manual reading/cross referencing. I realize you all are giving of your own time/expertise with no return. I will try to figure out a way to buy everyone a virtual beer. Thank you!
 

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1972 F250 4x4, 78 d44, 3.55, np205, 200hp 4bt nv4500 in progress
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50 Posts
Discussion Starter · #42 ·
Gentlemen, Engine back in the garage, slowly reassembling.

First first major overhaul after doing a top end fe390. Plasti-gauged main bearings and they were smaller side of spec. Crank turned smoothly, checked min and max ring gaps all fine. New rod bolts, followed torque+angle spec then double checked torque from shop manual.

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Replaced oil cooler valves, reusing oil cooler core. Rotating assy balanced. KDP. Mcbee HV oil pump. Assembly Rotates ‘freely’ but pistons drag a bit when going up and down. is this ok.

Timed tdc / loctite the timing pin using shop manual method. Loctite blue on all internal engine bolts, high tack sealant on all gaskets. New core plugs with loctite 277.

Put an indicator on and measured bellhousing for runout. Is this dodge bell housing and adapter plate shot or is there something that can be done to fix the runout? Offset pins?

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Looks like you're making progress. You had a question on the valve springs. Don't know what that company uses there. If you're planning an engine that may hit numbers over 3000 RPM or will have an exhaust brake, then you want the 60 lb over valve springs. You only have to do them on exhaust to prevent floating a valve but most install them on both valves. Not a major expense item. As far as engine assembly balancing, few go to that expense but every little bit helps. The 4bt is a vibrating little monster mainly due to its firing order. It does not have harmonics like the 6bt so a harmonic balancer like found on those engines does little good to tame it. There is a balancer for the 4bt that was mostly on marine engines. It does help by adding mass to the crank. We have a few members using those but most don't due to cost. Fluidampr company makes one identical to the original Cummins and it's not cheap either. Below is a photo of the stock Cummins unit. That thing weighs about 26 lbs. A bit of piston drag in the cylinders would be expected with new rings and honed cylinders. The clutch pilot bearing in the flywheel should always be a sealed type. Open type would be guaranteed to fail. As for runout in a bellhousing, not sure how accurate those creatures are.
 

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When you machine a flywheel for a sealed 16352RS ball bearing you remove the boss and make the pocket so the bearing sits flush with the crank bolt surface. This supports the end of the input shaft perfectly and puts the bearing surface in an area on a used input shaft that is usually still good.

Blue loctite is not normally used on rotating assembly parts. You would use engine oil or assembly lube on the threads and under the heads so the torque specs work out right.

6BT balancer smooths them out some. All 4 cylinders shake some, but the 4BT can get pretty bad. The added mass on the front of the crankshaft helps to smooth out the rotational accelerations of the front of the crankshaft at lower RPM's. When the crank turns smoother the gears clatter less, the pump timing bounces less, everything just kinda smooths out more.
 

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1972 F250 4x4, 78 d44, 3.55, np205, 200hp 4bt nv4500 in progress
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50 Posts
Discussion Starter · #45 ·
ST, Got it appreciate the tips. Bought the torque king bearing you're mentioning because they have instructions for the machine shop. I'll snap a pic if anyone's interested.

Used engine oil on main and rod bolts for torquing but blue loctite on stuff like timing case, oil pump, pickup tube, etc. Cleaning stuff off, i usually wirebrush the bolts/holes, brake clean, blow dry to give the loctite good adherance. New mcbee rod bolts appeard and felt to be the same as cummins taken off. Taking a chance on mcbee using alot of stuff from them. Bought the cummins head gasket to not take a chance. 'impressed' with the mcbee stuff, doesn't seem chinsy but then I don't have the background. I used reliableindustries.com as they had lots of stock options between pai, dcec, mcbee, cummins for good prices. Don't like paying shipping twice needing two items.

Going to run the 6bt balancer even though i hear it's not designed for 4bt. Hoping the balancing on all the rot assembly helps with vibration.

When you machine a flywheel for a sealed 16352RS ball bearing you remove the boss and make the pocket so the bearing sits flush with the crank bolt surface. This supports the end of the input shaft perfectly and puts the bearing surface in an area on a used input shaft that is usually still good.

Blue loctite is not normally used on rotating assembly parts. You would use engine oil or assembly lube on the threads and under the heads so the torque specs work out right.

6BT balancer smooths them out some. All 4 cylinders shake some, but the 4BT can get pretty bad. The added mass on the front of the crankshaft helps to smooth out the rotational accelerations of the front of the crankshaft at lower RPM's. When the crank turns smoother the gears clatter less, the pump timing bounces less, everything just kinda smooths out more.
 

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1972 F250 4x4, 78 d44, 3.55, np205, 200hp 4bt nv4500 in progress
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50 Posts
Discussion Starter · #46 ·
What VE pump should I run?

3200 gov spring, calibrated for 120-120cc/1000 shots
 
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