PDA

View Full Version : Bent pushrods



ThorH
06-29-2011, 11:20 AM
Opened the valve cover to adjust the valves today......this is what I found! The intake pushrods on #1 and #2 are bent. What would cause this? There does not seem to be any damage to the rocker or the valve end. Is there anything else I should inspect before I put 2 new pushrods in and proceed?

Thanks!

Thor

SafeAirOne
06-29-2011, 11:43 AM
Cause? Possibly a slack or broken timing chain which caused the valve timing to get all out of whack which in turn had your pistons hitting top dead center with the valves still open, bending the push rods and breaking apart the tappets.

Of course, that's a worst-case scenario. You probably ought to thoroughly dismantle the thing for inspection, unless you happen to know that those pushrods weren't properly seated in the tappets for whatever reason.

SafeAirOne
06-29-2011, 11:52 AM
Oh..A more appealing scenario might be...


The adjusters were backed off too far to keep the pushrods captivated and they came loose and got bent up and destroyed the soft metal tappets.

Is there any reason the adjusters would be slacked off prior to you going in and adjusting them this time?

ThorH
06-29-2011, 12:16 PM
The adjusters do seem to be backed off quite a bit...but they all look approximately the same. There doesn't seem to be any damage at all to the adjuster or the tappet, just the pushrod.

I will turn the motor by hand and watch the vales do their thing.

This is the first time I'm in this motor, so everything is just as it was left by the PO. So, I really don't have much history on it.

Momo
06-29-2011, 01:56 PM
Correct me if I'm wrong but I don't think it's possible to have a valve in the 2.25 strike the piston as it is not a zero clearance engine. I had a valve stick open once due to an overheat and the only damage was a bent pushrod because the tappet crashed the pushrod. (The head was overhauled anyway due to seat recession but the piston was undamaged.)

SafeAirOne
06-29-2011, 03:19 PM
Correct me if I'm wrong but I don't think it's possible to have a valve in the 2.25 strike the piston as it is not a zero clearance engine.


Hmm. I'm not sure, to be honest. I'll have to retract my worst case scenario if the 2.25 is a non-interference engine.

The presumption was that it similar to its son, the 2.5, which is DEFINITELY an interference engine. Looking at the specs for both engines tells a story though--the stroke is longer on the 2.5 by a full third of an inch.

Terrys
06-29-2011, 04:03 PM
Sticking valves will do this

Apis Mellifera
06-29-2011, 04:36 PM
Possible hydro-lock damage?

PS: Is that antifreeze on the spark plug boot?

Firemanshort
06-29-2011, 09:20 PM
It might be worth a check on the other push rods to see if they are slightly off, as well. Pull them out and roll them on a flat surface. If they are not straight, the wobble will be apparent.

As much of a pain as it is, I would really hard pressed to put this back together without pulling the head and taking a look-see.

ThorH
07-01-2011, 05:20 PM
It is a drop of antifreeze. I had just taken the heater hose off to change it out....spilled a little!

I'm definitely going to turn the motor over a few times by hand to make sure everything is moving as it should. And i will check the other push rods.

Thanks!

Sputnicker
07-02-2011, 10:47 AM
It's possible that there was insufficient oil getting to the head/rocker assembly/valve stems. Bending two pushrods means there's something very wrong. I'd start by and disassembling the rocker assembly and looking for evidence of blockage or scoring on the shaft (it will be on the bottom side. Then take out the spark plugs and use the starter to see if you are getting oil flow through the little hole under the rear rocker pedestal.

4flattires
07-16-2011, 06:23 PM
+1 for the sticking valves. Seen this tooooo many times. Here's the typical scenario:

1. Vehicle has old gas.
2. Gas gums up between the valve and guide.
3. Delayed valve return gets met with downward rocker arm.
4. Bent push rod from off-center contact.

Been there....

:(

ThorH
07-18-2011, 05:49 PM
Haven't been able to work on the Rover for a little bit.

The gas was definitely bad. Drained it all out of the tank. Is there a way to clean the gummed up fuel around the valves without disassembling the head completely?

4flattires
07-20-2011, 09:56 AM
Is there a way to clean the gummed up fuel around the valves without disassembling the head completely?

Short answer, no.

That being said, are there things that one could try to minimize the tear apart factor? Sure. On solution would be to remove the plugs and valve cover, spray the valve stems with quality carb cleaner while rotating the engine with a hand crank. Repeat until Arnold envies your biceps and you figure you are safe.

Fire that bad boy up again with yet another can of spray carb cleaner ready on the wing and run that can dry....down the carb throat while running (preferably on a warm day to minimize the holding power of gas varnish).

At any time, should you hear intermittent rocker arm clicking going on, you can assuredly be headed down the road of a future bent valve.

Open a frosty beverage and repeat, otherwise if no noise, open up a frosty beverage.

Jeff

JimCT
07-20-2011, 02:16 PM
use that in the gas, freed up sticking valves in our old flathead 6 marine engine

ThorH
07-20-2011, 04:37 PM
Well...I'm just going to try the carb cleaner method for now. I need to order a hand crank so I can turn the motor over easily. I cleaned up the rocker assembly and put in 3 new pushrods. Worst case.....I'll take the head to the machine shop. For today anyway, I'm going to skip to the frosty beverage step!!

Thanks for the input guys! Having fun getting the Rover back up to par! Can't wait to drive it! Rovers North now holds a speed dial slot in the phone!

4flattires
07-20-2011, 05:39 PM
Have fun!

I googled gummed up valves (in order to attach a pic), and low and behold, look at the picture attached. Do those parts look familiar? :) They sure look like what came out of my 2.25l.

http://www.williammaloney.com/Misc/EthanolProsConsDrawbacks.htm

ThorH
07-20-2011, 08:51 PM
Okay.....the picture of the valves with the varnish on them is enough for me!!!! The head is coming off!! No point risking more damage when I have it more than half way apart already!

ThorH
08-01-2011, 06:24 PM
OK...got the head off today. There is a fair amount of varnish on the valves from the old gas. Two of the lifters have a little damage. I am going to take the head down and have it cleaned up.

There was also a fair amount of surface rust on the #2 & #3 cylinders. No pitting, but you can feel it with your finger. Can I just hone the cylinders to clean them up? How durable are the rings compared to surface rust?

I have no idea how many miles this engine has on it. Should I just consider a rebuild? I did not do a compression test before I took the head off (hindsight!).

Thanks for the input.