1957 420C seized - photo journey

[emmett]

I've had this beast since 2004 and it has served me well.
Had to rebuild one final drive, but otherwise no big projects required.
Unseen oil leak while running the winch for a few hours lead to a seized engine.
I'm in the process of rebuild.
Thought I'd add some photos.

ENGINE OUT!

[bscrawler]

Nice to see a few of your pictures during this rebuild journey .

[emmett]

Yeah, but I forgot how to post photos on this site!
I'm trying to link to my photos on imgur, but no luck.

[Stan Disbrow]

Hi,

Photo posting:

http://www.jdcrawlers.com/messageboard/ ... =5&t=13015

Stan

[Lavoy]

You have to use the direct link or embed code I believe, assuming it is like imgbb.
Lavoy

[emmett]

Next I have pressure washed the outside of the block (oil pan still attached).

[emmett]

OK, I've pulled the oil pan off and inverted the engine on the stand.
Next step is to unbolt the connecting rod caps and see which of the two cylinders is seized.
It's gonna be fun.....

[emmett]

Feeling very lucky.
Pistons came out easy.
Looks like the innards here have been visited before.
There are very nice machinist's markings on the crank and only one of the rod caps had the locking nuts installed.

Journal bearing (is that correct enough terminology?) for #2 is cooked.
See photo to see how the contact surface smeared. See the inside of the cap I placed below the crank shaft.
It transferred some of the alloy onto the crank surface.

I'm gonna get new pistons, rings, and crank bearings.
Gasket kit, oil seals.
Anything else while I'm here?

Next step is to punch the dowel-pin out of the crank pully and dig the crank out.

[Buckhorn]

Put the coffee on, and I'll come watch you. Not sure where you are in VT, but I live there too.
I can always learn something.
Pete

[Jim B]

I would suggest letting the machine shop you have recondition the crank, get the bearings and to keep any related issues in their court.

[Lavoy]

Sadly right now main bearings are out of stock nationwide. I can get rod bearings, but likely not mains.
Lavoy

[bscrawler]

I recently purchased a 420 . So I’m following closely what you are getting into. Thanks for posting

[emmett]

Hi Lavoy,

Full parts list coming by tomorrow.
With more photos.

This engine has been rebuilt before, as the crank journals are undersized.
It was really well done, surfaces are perfect and within 0.001 tolerance.

Fortunately, I don't have to send anything out for machining, I can reface the valves and hone the cylinders myself.
I got lucky 'cause there is no ridge built up on the cylinder tops.

I'll try to source the main bearings elsewhere, but I'm gonna need the rod bearings for 0.040 undersized crank rod journals.
It's the rod bearings that melted onto the journals when oil starved.
FYI, The main journals are 0.010 undersized.

Will also want two new pistons w/ pins and clips for 113 cc engine (4.250 diameter cylinder bores)
I'll also need one intake valve (one is slightly bent).
New clutch plate (why not?), throw-out bearing and pilot bearing (while its broke apart anyway).

Emmett

[emmett]

My very good and very smart friend has an engine shop.
I dropped the block w/ engine stand and head in my rig and drove it all over.
A good day's work and we had it disassembled, measured, cleaned up, valves resurfaced, and cylinders honed.
Some photos follow.

[emmett]

Block is inverted on the stand.
Cylinders honed nicely. I was lucky, no ridge built up on the cylinder tops.
Camshaft is in good shape. Turns freely. We decided to leave it be.