Tappet noise

[Changin Gears]

Sounds like not enough oil is reaching the rocker shaft, and since the engine is mounted slightly nose up whatever oil that is making it there is "draining" to the back of the rocker shaft.

A common problem when building an engine is not installing the cam bearings such that all oil holes line up, either not driven in to the correct depth and/or not clocked around correctly.

[72cudamaan]

I'm not a small block guy but can't the rocker shaft be installed improperly thus not allowing
oil to get into the shaft? ie backwards or upside down.

[mikeljAAR]

The oil is definitely coming up the ports to the shaft, seems to have been some casting burrs in the holes of the shaft.  I am replacing it all with the COMP Cams Pro-Magnum shaft, adjustable rockers, and push rods.  I couldn't find any OEM type T/A 340 shafts and rockers and push rods like were in it, guess no one makes them anymore?? But given the issues with the ones they used 5 years ago, maybe I am better off anyway with the COMP Cams stuff.

[jimynick]

By all means go with the Comp stuff, but every old 273 I ever saw apart had adjustable rockers and unless you're running the T/A offset head, they'd work. Smear a little moly lube on those shafts when you install the rockers and good luck.

[mikeljAAR]

By all means go with the Comp stuff, but every old 273 I ever saw apart had adjustable rockers and unless you're running the T/A offset head, they'd work. Smear a little moly lube on those shafts when you install the rockers and good luck.

I do have the original 340  T/A heads with the offsets on the original rockers, but the COMP Cams guy told me with the spacers in the kit, their roller tip rockers will work fine, I hope so.  I do wish I could have found some shafts and rockers like the originals, but no luck anywhere.

[mikeljAAR]

OH NO!    The COMP Cams shafts and rockers they sent will not fit the T/A heads like they said they would.  So now I have to get T&D Machine Products to make me some for me, 3 weeks!  These easter egg hunts for rare parts really suck, I had no idea the AAR was such a special car with such a low production engine that nobody makes parts for.  What a pain, guess I should have just got the Hemi 

[Chryco Psycho]

If you keep your eyes open T/A rockers do come up for sale , the other good option is to bush your originals . the T/A are very unique , I would pull  the  cam & check the brgs , either you have a weak oil pump or the cam brgs are not lined up , there is more to why this happened . T&D makes a good rocker as well .

[mikeljAAR]

When we pulled the rocker shaft and cranked the engine, lots of oil is coming up the holes to the shaft area, as I said, the shaft had some casting/machine burrs in it that was restricting the flow to the front 1/3 of the shaft.  A new shaft will solve this, and the original shaft is also worn pretty badly, so just re-sleeving the rockers won't solve the problem.  I need the whole thing replaced.

[Chryco Psycho]

weird , rebushing the arms should take care of the damage , you can use 273 exhaust rockers so it would just be the intakes

[mikeljAAR]

Thanks, I will have to check into that further, the mechanic said the shaft was shot, I better look for myself.  Seems odd that 250 miles of driving would destroy the 1/3 shaft and rockers that weren't getting oil.  I may need a second opinion. Maybe he is just looking for a big bill?

[Chryco Psycho]

the shafts are relatively cheap , save the rockers though even if they are scored why could they not be machined & bushed back to size ??