For some background I was experiencing high engine temps and low oil pressure on my freshly rebuilt 400. See this thread for the diagnosis. https://www.ford-trucks.com/forums/1...l-presure.html
This lead to puling the engine. Not a great start to my first engine build. I now have the bottom end apart (again) and the findings were not as I hoped.
What I've found so far.
Rod bearings: all wiped to copper in some fashion. some worse than others
#1 cylinder rod bearing: gouged. not sure why. I was meticulous about cleanliness during my build. My only speculation is debris from the other bearings wiping got in it and gouged it.
Mains bearings: wiped however in better condition then the rod bearings.
Crank: when installed was smooth, however now is very rough. needs to be machined without a doubt.

My suspicions are that my clearances were wrong during assembly and were too tight. I would like this confirmed though.

Question 1: What would cause this? and how can I prevent it from happening again?
Question 2: With the crank being machined will I need to have the rotating assembly balanced or just the crank?
Question 3: Any other assembly tips? This is the 3rd time in the last 18 months I've had the engine out. I really want it to go in and stay in this time.

Thanks in advance,

Mackenzie

 

My build was as follows

Machine shop work:
-Degrease head
-Resurface and magniflux heads
-Regrind valve seats
-Degrease and shot blast block
-Magniflux block
-Rebore .030" over
-Torque mains and check sizes
-Sweat new pistons on rods

New Parts:
-ARP Head, Main, and Rod bolts
-Clevite MS-981P main bearings
-Clevite SH-710S cam bearings
-Clevite CB 927P rod bearings
-Silvolite .030" over pistons
-Hastings .030"over rings
-Melling M-84A oil pump
-Qualcast valves
-Comp cams K32-206-3 cam kit (255DEH cam, Hydraulic lifters, dual valve springs, straight up timing set)
-Comp Cams 7837-16 push rods
-All new felpro gaskets and seals
-New frost plugs
-Edelbrock 4v intake manifiold
-180 deg Cleveland style thermostat (with hat)

Reused parts
-Block
-Crank
-Rods
-Rocker arms
-Holley Carb
-MSD ignition and distributor
-Harmonic balancer (new last year)
-Flexplate
-Waterpump

Attached are pictures of the crank and bearings:
https://photos.app.goo.gl/5wYRu7zMpQPtjtZi9

 

77F100stepside,

Bummer! Contamination somehow. How do all you cam lobes look? Perhaps some crud or metal shavings in an oil galley?

You will get the crank ground undersized, maybe 0.020" main and rod journals. You'll need the matching undersize bearings as well. I'm running 3/4 groove main bearings in my 400. If the clearances are right you really should be able to run a 5W30 oil and maintain pressure even when hot.

You will not to rebalance anything from getting the crankshaft ground undersize.

 

Cam lobes look good. Planning to pull camshaft early next week. That is possible. I'll have to flush block with a solvent of some sort.

That's what i was figuring. I doubted 0.010" would be enough.

Okay good to know. I didn't have the rotating assembly balanced the first time I assembled, however only pistons were changed from oem to 0.030" over silvolite oem style. From what I understood these engines were externally balanced. Therefore I shouldn't need to have had the rotating assembly balanced? But now I've done some more reading and I'm not so sure on that.

Would these engines ever need to have the rotating assembly balanced? or is balance controlled by the dampener only.
My flexplate has a counter weight on it but i cant find a key, dowel, or anything special to say orientation matters. Does it?

Thanks,

Mackenzie

 

Mackenzie,

The term "harmonic balancer" would really be better described as "harmonic dampener". Sometimes they have weight added in a certain spot to help balance an engine just as your flex plate does. These features make your engine "externally balanced" as most engines of the era.

At some point, when you change enough things in the rotating assembly, it's a good idea to have the engine rebalanced.

The flex plate should only go on one direction, the six bolt holes are not evenly spaced if I recall correctly.

 

Ok good to know. Adding balancing to the list of things to do now.

I don't believe my flexplate has an offset hole pattern. I will check for that though. If it doesn't I'll ask the machine shop to mark the orientation it was in when I have the engine balanced.

Have some work to do now. Going to pull heads so I can pull the pistons and rods and have it balanced. Once everything is back from the machine shop I'll post back here.

Thanks,

Mackenzie

 

just tossing this out but i did not see you mention where the shop washed the block? and I suggest you get it re washed to get all the newly created material out of it.

 

The block was cleaned at the machine shop. Down to bare metal. Then I cleaned it up myself as there was still grinding dust from the shop on the block when i got it back.

With having to get the rotating assembly balanced i plan on stripping the block down and doing a good cleaning .

Mackenzie

 

Get the main bearings align bore in the block checked. If they are out of spec, changing bearings and resurfacing the crank will just end up putting you right back to where you started.

 

Did you get a brush kit and swab and debris from the oil galleries in the crank and block when getting it back from machine shop? Must have been contamination debris from machining for the damage you describe.

 

Mark a. I was planning on doing that. Its alignment was checked when i had it bored however I don't want to pull the engine again so its getting checked.

79F2502wd I made my own out of a dryer vent cleaning kit but yes I did brush the oil galleries.

Started to pull the heads to I could bring the block to get checked. And I found more wrong. Bent pushrod. Timing chain was installed correctly. Valvetrain was fine when I put the second set of valve springs in after break in. Valve doesn't look bent. I'll see if it hit the cylinder when I pull the head.

Lifter looks stuck. They are new lifters. Maybe bore too tight?
Any ideas?

Mackenzie

 

77F100stepside,

The lifters should fit quite snug, especially in these 335 series engines. Too loose and they can bleed off much needed oil pressure.

Give the lifter and lifted bore a thorough inspection and check the valve and valve guide too.

 

Finished my tear down last night. Did not find anything good.

What I found:
-Oil in the cylinders
Not sure how it got there. Only thing i can think of is sitting turned upside down to long. However even then there shouldn't be this much.
-2 severely damaged lifters and 2 wiped cam lobes
Those two lifters moved freely in their bores until they got to the large bur from where it wore itself out on the camshaft.

none of the valves touched the pistons.
not sure whats going on here

Attached are some pictures of the cam and lifters and oil in the cylinder (click link).https://photos.app.goo.gl/Jcj6M946Ui5NimFL6

Mackenzie

 

I wouldn't worry about the oil in the cylinders, it wasn't running that way or you would have been fouling plugs.

I'd see if Comp Cams will send you a new cam and lifters! Did you use any kind of a break-in additive in your initial start-up and break-in? The camshaft and lifter failure is the cause of ALL your troubles.

 

I'm a little late in this conversation but based on my experience over the years all your bearing problems stem from the cam failure. My first experience with baking and shot blasting a block was 30 years ago. I thought it was great. It came out looking like a new casting until I discovered all the damage it had caused to the lifter bores. And if that shop truly did shot blast your block that always results in peening the edges of the lifter bores top and bottom. If a block is shot blasted the lifter bores need to be cleaned up with a ridged hone. If not it is almost inevitable that some of the lifters will bind up and fail to rotate. A lifter that don't rotate will kill your cam in 30 seconds. Good luck getting anything out of Comp.