Tore U20 Down - STD Cyl Bore Size

[DCroadster]

All,

Tore down the separated U20 engine that was already in pieces. Will have heck of a time replacing all the missing bolts.

What is the STD cylinder bore size? The average was about 87 mm.

Main Crank surface - 63 mm.

Connecting Rod - 52 mm

The odometer shows 28,000 miles. Don't know last time engine in car. If dimensions are stock, then it may be 28,000 vice 128,000 miles. Engine looks to be original bluish color and freeze plug were not rusted at all.

If the engine was pulled at 28,000 what would be the reason for premature failure

20230415_153902.jpg

? Bottom half looks good but need to have it checked out, could it be with the overhead cam.

[Habitat.pat]

Standard bore is 87.2mm
Rod journal 51.961-51.974mm
I didn’t find main journal size but someone will post it.

Peace, Pat

[DCroadster]

Thanks Pat,

I was hoping someone would complete the picture with crank journal size.

I will tear down the head to see if failure was in the head as there would definitely be readily seen damage in the bottom end if something came loose while engine running.

I am searching for a reason why a 28,000 mile engine would be pulled from the car. Unless they wanted to supe it up and never finished.

Rob

[jhayden]

I was hoping someone would complete the picture with crank journal size.

Rob

Main journal: 62.922 - 62.935 mm

per Nissan "U20 Engine ... " manual, p. 37

Jon

[DCroadster]

Thxs Jon!

Looks like a 28,000 mile engine.

Too bad the rest of the car is not in the same pristine condition. A little rough, but solid.

Don't think it was in a time capsule the whole time, but will be easy to put back together.

Rob