rod through the rocker

[471_Magnum]

As you may have read elsewhere, I had some misfortune enroute to the Mopar Nationals with the GTX. Pulling off the highway for a fuel stop, it started clattering loudly and smoking bad on the left side.

A pushrod went through the #3 intake rocker, which in turn allowed the lifter to pop out.  It still had oil pressure when I got it off the road. I think I actually caught it before the lifter popped out and caused it to lose oil pressure.

I'm now contemplating my next move. Due to the loss of oil pressure, I think I'm going to pull the motor and inspect the bottom end.

I also think I'm going to pull the heads off to just to figure out what I'm working with. They are 346 castings, but I don't know if they have had bigger valves installed. Furthermore, the smoking has me wondering if a valve guide was damaged.

While at the Nats, I grabbed a set of 452s will 2.14/1.81 valves from Aerohead. My thinking being if I had guide damage, these heads were a relatively ecomical upgrade. If I don't need them, I can probably sell them locally.

Of course, while I've got it torn down, it would be a good time for a cam swap...

[mally69]

just had the EXACT thing happen to me about 3 weeks ago    didnt hurt anyting but i figured that the rest of them were not far from doing the same    so i bought a set of roller rockers from 440 source

[firefighter3931]

Sorry to see that Jim....looks like those rockers have some milage on them ! 

Why not do a compression and leakdown test before you tear into it....just to see what shape the rings are in. 



Ron

[471_Magnum]

As I suspected, those pushrods are incorrect. They are the older type with the smaller tip on the lifter end... AND THEY WERE INSTALLED UPSIDE DOWN!

I'd really like to get my hands on the hack that installed them.

The smoking was apparently the result of the intake valve being closed on the intake stroke, causing oil to get sucked past the rings.

New rods and rockers are definitely on the shopping list. The damage should be minimal.That said, the hack job on the top end makes me suspicious about the rest of the motor. I'm really tempted to open up the bottom end and check things out.

I think the 452 heads will stay in the box for now. I'll either return or sell them.

Now would be a good time to install a different cam though. Looking at the Summit SUM-K6401 

[firefighter3931]

As I suspected, those pushrods are incorrect. They are the older type with the smaller tip on the lifter end... AND THEY WERE INSTALLED UPSIDE DOWN!

Sounds like a bunch of re-cycled parts....those pushrods are from pre-68 engines right ?

New rods and rockers are definitely on the shopping list. The damage should be minimal.That said, the hack job on the top end makes me suspicious about the rest of the motor. I'm really tempted to open up the bottom end and check things out.

The MP XHD rockers are cheap and bullet proof....around $75.00 at Mancini    Probably wouldn't hurt to drop the pan and pull a few rod & main caps for a look-see 

Now would be a good time to install a different cam though. Looking at the Summit SUM-K6401

What cam is in there now ? I like the Engle k56 on a 112* lsa (with HP manifolds) for that combo. Comp #911 valvesprings. Easy swap and no valveguide mods needed. 



Ron

[471_Magnum]

Yep. Pre-'68 rods.

The stamped XHD rockers are about $85 these days. They fit the budget. Nothing fancy for this project.

I have no idea what cam is in there now, but it is VERY mild. I am assuming it a stock-type grind.

I ran a Hughes grind with similar specs as the K6401 in my 451 stroker back in the other car. It was a torque monster.

[firefighter3931]

I ran a Hughes grind with similar specs as the K6401 in my 451 stroker back in the other car. It was a torque monster.

Probably the old 2330 hydraulic grind from Hughes ? You might know this (or not) but the old Hughes cams were Engle split pattern grinds. The 2330 is basicly a k56/k58 profile on a 108* lsa. Manifold exhaust systems don't like lots of overlap so running a 112* lobe is the preferred arrangement to help reduce intake dilution. The fast rate Engle grinds make excellent torque as you've allready discovered. 



Ron

[471_Magnum]

After giving it some thought today, I decided I would just replace the rockers and push rods and move on.

Tonight, I took the intake off. The lifter that had popped out was trashed. The clip had come loose and it's pretty tore-up.

I looked into the intake ports and almost began to weep. What I found was possibly the ugliest attempt at porting I have ever seen.  Those heads have got to go. I'll be using those 452s after all.

That being the case, I will go ahead and do a cam swap as well.

Yes, it was the Hughes 2330, and yes I am aware Hughes used Engle grinds The Summit cam actually has a 114 LSA.

I'm open to suggestions on the cam.

[Ghoste]

Glad to hear the damage was minimal.

[rt green]

sometimes tragity can turn into a blessing

[471_Magnum]

I decided it would be best to pull the motor for the head swap. The reach across those pretty fenders is a bit too much for comfort.

Today I ordered the Comp Cams XE268H.

Tonight I continued tearing into it. I'll probably have it ready to come out tomorrow night, but I'm guessing it will be Thursday before it's out. Still have to detach the exhaust and clutch linkage.

I noticed the windage tray is missing. Add another item to the shopping list. One more reason to drop the pan and check the bearings.

There were some fine filings on the magnetic oil drain plug. I suspect these are left over from the fuel pump rod failure. Let's hope so.

[471_Magnum]

Quick update.

9:00 CDT. 92 degrees. 58% Humidity.

Motor and trans are out. I'm beat.

Tomorrow I'll tear it down.