'73 - 304 Pushrod surprise

HeyO all! Weather finally decent so it's time to get back to fixin' it up.
(I managed to get the front suspension done over the winter, need to update my post on that...)
The original radiator finally gave up the ghost so I started in on installing the aluminum one I bought several months ago.
Spent the last week when it was nice, tearing it down, cleaning up components and such. one of the bolts on the water
inlet was rusted solid and that was a bit of a challenge getting that off.
So last evening a buddy stopped by and we were discussing the valve train 'clacking' noise she was making when running
and we decided to pull off the valve cover on the passenger side bank and check things out.

The cover was very clean and there was not a sign of any sludge, however the rocker arm on #4 was extremely loose.
I decided to pull the rocker arm off and see if the pushrod ball ends were OK, and this is what I found:

Definitly not what I wanted to find with Spring upon us. Now to figure out what to do next...
Unbelievably, I figure that it's been running in that condition since last June. It's been noisy since I got her then.
My thoughts are that it was over rev'd. The history of the vehicle is that it was a recovered stolen vehicle that was found in some woods badly stuck between trees.
I'm hoping that all it is, is that the punks who stole her max'd her out trying to get it out of the mud.
And yes I am trying to ignore that it might just be a worn out cam or stuck valves.

_Dan

 

Good possibility.

 

Afternoon Autopsy:
Out of ( 8 ) bridges, (7) are the old style die cast. (1) is steel.
Every die cast bridge has at least (1) loose & sloppy. Every exhaust is loose. The steel one is nice and snug.
It would appear that the steel style is a bit better perhaps.
Another bent rod on #7 Exhaust. Haven't removed the other (6) yet.
I think I'll go grab (7) steel bridges and some push rods, install them and see what happens.

*****
*Update
All told she's got (5) bent rods... *SIGH*. All the die cast bridges were badly worn and the rockers were scored.
Since she was running, I'm going to replace all the rocker arms and rods and see what happens. If it doesn't work I may just consider
turning this into an engine swap project...

_Dan

 

Check valve up/down movement and for broken springs. Over rev's can break springs.

 

I had the same trouble with a 304 Jeep years ago but caught it before more damage was done. Replaced 2 bent push rods and drove it till I sold it 2-3 years later IIRC. This engine was high mileage and probably on its last gasp.
In retrospect I wish I had kept th old girl. Lotsa good memories in that Jeep.

 

hey gang, does anyone know the correct procedure to re-assemble the rocker arms?
I've spent an hour or so searching and the results are all over the place.
I ordered a complete replacement set of arms and rods from Summit. Finally got them, FedEX lost one order and mangled the box that
the pushrods were in on the second order.

I figure that I need to have the cylinder positioned at the bottom of the stroke with no load on the lifters.
The engine hasn't been cranked in a week so I'm not sure if the lifters are loaded or not.
I am unsure if I need to prime the lifters before re-assembly. From searching, I found recommendations stating primed and empty.

And then there is the weather. Either I'll have to clear out a slot in the garage or wait for the rain to cease and desist.

Thanks,
_Dan

 

Fsm says tourque to 19 ft pounds. Wouldn't happen to have part numbers for rods and arms?

 

Thx.
I went with Sealed Power for the replacements.
p/n R875 for the Rocker Arms (same type and style that was on #6 cyl.)
p/n RP3093 for the push rods.

I had to go a get a torque wrench @Sears that does 10-75 ft. lbs.. Luckily they are on sale for $40... Wish I could remember who borrowed my set

 

Thanks be shure to blow the pushrods out before installing them sometimes filings stay there

 

Thanks for that tip - I'll do be sure to do that.
If the last two ever get here. They packed this lastest shipment very poorly. The pushrods were all in one unsealed plastic bag
and they came loose and the box wasn't taped properly and two must have escaped in transit.
So on some FedEX truck or in some facility there's two pushrods floating around...
Hehe, maybe one of them jammed up a conveyor line...

 

Replaced all the arms and rods. Ordered Sealed Power parts from Summit. The 'gremlins' messed with the order (3) times.
First time FedEX lost one package in Nashville, second thing was that the pushrods were packed loose in the box and only (14) made it,
and then with (4) of the ( 8 ) boxes of the rocker arms I was "gothcha'd".

I was all sorts of confused installing these, didn't understand what was going on. First two sets went in fine, with the third one the arms were
very loose. Took me about 20 minutes to figure this out. (4) pairs of the pivots were .24" bigger/longer than what they should have been.
And the radius was about .060 smaller than radius needed. Had to then wait for Summit to ship out (4) sets of Bridges & Pivots. ((SP # MR1909))

Blew out the rods as suggested above and only one was 'dirty'.

Have a glance at the second picture - how in the devil was this ol' beast running on those?

Fired her up last night and she sounds great. Compression check beforehand returned 145-160 with the average being 152.
Onto the Radiator! Maybe, perhaps, hopefully, we'll be riding this weekend...
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Heh.

Congrats!

 

Running as a 6 cyl. :twisted: