Rod Bearing Wear pattern (1975 280z)

[Zed Head]

Anybody know what the spray bar is made of?

[corbenB]

On 10/14/2022 at 8:21 PM, kickstand80 said:

Looks like brass/copper and aluminum. Pull the thrust bearing main cap and check it. It should be the 4th main cap counting from the front. I can't think of anything else that has brass or copper inside the engine.

You  can see the thrust bearing circled in blue in this photo

 

 

I took the bolts out, however the cap wouldn't come off. I have the whole engine in the car still, just with the oil pan off. Is there a particular way I have to go about this? Thanks!

[Racer X]

2 hours ago, Zed Head said:

Anybody know what the spray bar is made of?

Mild steel. And a bit of brazing rod.

Edited October 28, 2022 by Racer X

[Racer X]

19 hours ago, corbenB said:

What do you think? looks fine to me personally. I was really hoping it was this to be honest, cause it seemed like an easy fix. 

The gear teeth look pretty good, nice wear pattern. Does look like a high mileage engine though, lots of varnish.

I had one on a race engine shear the teeth clean off. Happened at Portland, going down the back stretch.  Accelerating hard, just shifted into 4th gear at about 110, when it went. Flames shot out around the left and rear edges of the hood, and then nothing. I coasted into the paddock, almost to my pit location. When I pulled the hood off the air filters were blown apart and burned. I suspect the distributor spun a few more rotations and the gear train was turning the crankshaft, out of sync with the distributor, and the spark plugs ignited the incoming air/fuel mixture when the intake valves were opened, resulting in vigorous explosive fire coming out through the intake.

 

Edited October 28, 2022 by Racer X

[corbenB]

1 hour ago, Racer X said:

The gear teeth look pretty good, nice wear pattern. Does look like a high mileage engine though, lots of varnish.

I had one on a race engine shear the teeth clean off. Happened at Portland, going down the back stretch.  Accelerating hard, just shifted into 4th gear at about 110, when it went. Flames shot out around the left and rear edges of the hood, and then nothing. I coasted into the paddock, almost to my pit location. When I pulled the hood off the air filters were blown apart and burned. I suspect the distributor spun a few more rotations and the gear train was turning the crankshaft, out of sync with the distributor, and the spark plugs ignited the incoming air/fuel mixture when the intake valves were opened, resulting in vigorous explosive fire coming out through the intake.

 

That's wild haha. At this point, I might just throw it back together and see what happens. At least now I can say I got all of the pieces cleaned out. Worst comes to worst, I have a couple of friends who work with GM engines, so I can probably source a LS from there. Also have some friends who have lots of TDI Jetta engines/trannys, and I think that could be a cool swap as well lol. 

[kickstand80]

you need to make a puller to get that cap off. Thats why there are 2 small bolt holes in the cap

[Reptoid Overlords]

I made a cap puller out of a Harbor Freight slide puller and the end of a half shaft.  The bolt pattern matches up perfectly.

Edited October 29, 2022 by Reptoid Overlords

[Racer X]

There is only one hole in the center bearing cap.

I welded a bolt that fits the thread in the cap, to a nut that fits the thread on one of my slide hammers. Doesn’t take much to lift the cap out of the journal.

 

Edited October 29, 2022 by Racer X

[corbenB]

3 hours ago, Racer X said:

There is only one hole in the center bearing cap.

I welded a bolt that fits the thread in the cap, to a nut that fits the thread on one of my slide hammers. Doesn’t take much to lift the cap out of the journal.

 

I do not have a welder, is there any way i could rent a tool for it? I'm trying to look around for one but i cant find one. any help would be appreciated. 

[siteunseen]

@corbenB

I used the tom monroe's book when I rebuilt mine. He uses a 2x4 and a pry bar under the bolt off the front cover threaded into the center hole on the center and rear caps. It worked pretty easy for, dont recall any difficulties.

I've taken some pics of the text. Hopefully I will get them in order. Good luck.

Actual picture in the next post...

Edited October 29, 2022 by siteunseen

[siteunseen]

[Reptoid Overlords]

Jeez, I can't imagine what I used that puller for then.  Maybe the nursing home is closer than I think haha.