Build Off to a Good Start. My '74 40 Series

[TwelveGravity]

I was hunting around online to try to find a sort of diagram or block cutaway to show how the oil flows through the inside of the block, just to get a better understanding of what's going on inside there. I've not been able to find one yet.

 

[TwelveGravity]

So trying to think my way through it since I haven't broke on down myself and looking through other old threads (sorry for stealing the pictures).

This looks like it would be the oil pump outlet, oil would then flow through the block to the oil filter.

Then through the oil filter back into and through the block up to the head. I am suspecting that I am restricted in here. I could have this totally ass backwards.

 

[TwelveGravity]

Oil should come up through the block after the oil filter via the smaller port (GREEN), then through the teardrop void in the head gasket it should go up head bolt cavity (RED)

To then make it's way up to the rocker assy

 

[majdomo]

I can't remember if you have a 2F, but this was interesting reading and aligns with your experience (spoiler alert - it was a clogged oil passage on an engine that had sat a while): Tech thread here.

EDIT - post 17 in that thread shows the oil flow from what looks like the filter out, to main bearing 3, then to the cam (maybe?), and from there up to the top of the head.

 

[TwelveGravity]

I can't remember if you have a 2F, but this was interesting reading and aligns with your experience (spoiler alert - it was a clogged oil passage on an engine that had sat a while): Tech thread here.

EDIT - post 17 in that thread shows the oil flow from what looks like the filter out, to main bearing 3, then to the cam (maybe?), and from there up to the top of the head.

I believe I still have an F being that it's an early '74. January of 74 to be specific.
I'll check out the thread you included. Thank you.

 

[Pighead]

I believe I still have an F being that it's an early '74.

It is an F, but it's a "Late F" or 1.5F
Sorta almost a 2F in the oiling but still an F in displacement.

 

[65swb45]

/this\

 

[TwelveGravity]

EDIT - post 17 in that thread shows the oil flow from what looks like the filter out, to main bearing 3, then to the cam (maybe?), and from there up to the top of the head.

I am guessing that I'm plugged at the cam. If I'm able to push air from the oil filter out, through the main bearings.

 

[majdomo]

I am guessing that I'm plugged at the cam. If I'm able to push air from the oil filter out, through the main bearings.

View attachment 4148430

Hm. I wonder if it's the original cam and if there are differences from year to year... or if it's just some crud in that passage.

Seems kind of excessive to pull the cam just to check, if there's a different way to diagnose.

 

[65swb45]

I have never had the head off in the 1.5 years I have owned it. When I bought it from the PO, he stated the engine was rebuilt 10 +/- years ago. He had hardly driven it at all since.

It IS possible that if the cam were changed in the rebuilding process, that there could be a mismatch. The 73 and older cams were drilled at the 2nd journal; the 74 and newer at the 3rd. And some machinists/ assemblers are not quite attentive enough.

 

[majdomo]

It IS possible that if the cam were changed in the rebuilding process, that there could be a mismatch. The 73 and older cams were drilled at the 2nd journal; the 74 and newer at the 3rd. And some machinists/ assemblers are not quite attentive enough.

Tech to the rescue again.

 

[65swb45]

Tech to the rescue again.

Good sleuthing John.

 

[bhsdriller]

seems like a blockage or something is more likely

Not like it's a super fresh build, It's been driven. Even if only 100 miles it wouldn't last that long with zero oil up top?

 

[Pighead]

I am guessing that I'm plugged at the cam.

Don't you have to rotate the camshaft so that the drilled hole lines up with the holes in the cam bearing?

 

[TwelveGravity]

Don't you have to rotate the camshaft so that the drilled hole lines up with the holes in the cam bearing?

Good point. I was thinking that was done when I previously put Cyl 4 at TDC, but figured I'd go out this morning and roll it over and see. While rolling it over and simultaneously running the drill slowly, I found I do not get oil at TDC but when I come slightly off TDC I'm getting oil.

 

[TwelveGravity]

I'm thinking now, I'll clean everything up and reassemble it with the proper head gasket, reinstall the rocker assy and see if I can pump oil though it. I was reading this morning someone else having a similar issue with oil delivery across the rockers, found play in the shaft. I'll keep an eye out for that as well.

Thread 'Rocker Bushings and Oil Flow. (Long)'

May 19, 2023

I have poor oil flow out of my rocker holes. I get barely an ooze from valve side rocker hole and practically noting out of the smaller push rod side hole. Rocker shaft and bushings were replaced new in 2000 and still look in very good shape. There is no slop at all in the bushings, but the rockers slide and spin freely on the shaft. The rocker assembly was disassembled and thoroughly cleaned with every orifice checked. I get good flow out of oil hole in head that feeds up to the #4 pedestal although when spinning the oil pump with a drill, I can stop the flow with a fair amount of...

• Steamer
• Replies: 18
• Forum: 40- / 55-Series Tech

 

[Pighead]

when I come slightly off TDC I'm getting oil.

So, oil does move through the cam bearing to the top of the block. Rules out wrong cam. Your problem was probably just the wrong head gasket then?

 

[TwelveGravity]

So, oil does move through the cam bearing to the top of the block. Rules out wrong cam. Your problem was probably just the wrong head gasket then?

Agree, wrong head gasket was probably the main issue but I also think it was restricted by the gobs of silicone I removed from the oil filter housing.
Thinking If I get everything back together and find oil delivery across to all rockers, is there a way to check tolerances on the rocker assy since it has run who knows how long without lubrication? I have probably 10 hours run time on it since I bought it, there's no telling how much run time it had with the PO but he said he hardly drove it because he was unable to get in and out of it.

 

[Pighead]

is there a way to check tolerances on the rocker assy since it has run who knows how long without lubrication?

Probably, what you should do is disassemble the rocker arm and look at it, see what damage has been done.

 

[TwelveGravity]

My shop helper supervising me.