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Push Rod looks a little short

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Russ Austin

Russ Austin

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In August I had my engine in my TR3A rebuilt, I then took the car to the body shop to repair some dent and complete paint. (That another story in it's self) Got the car back Friday from the body shop. Went out for the first drive (beautiful day 61 degrees) after about 20 miles I heard a strange sound and started to lose power. I pulled over, open the bonnet to see if any thing stood out. I tryed to start the car again and heard a clunking sound from the vavle cover. Got a tow truck and got the car back home, removed the valve cover and could see the push rod on the number 1 cylinder on the second valve (exhuast)? was not connected and was about 3/4 inch from the rocker. Looks like I've got more fun, where's the 6 pack at!
 

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OUCH!

My first thought was broken cam lobe, but it almost looks like the wrong pushrod - the cup doesn't appear to be the same as the others.

Whatever the case, hope this has a happy ending...

Mickey
 
Hey Mickey; I believe the cup has been chattered, when I felt around the cup it was chewed up!
 
Could be - but it also looks like there's a ring where the cup is joined to the rod. The other two don't have that.

How's the corresponding valve look - any apparent damage?

Mickey
 
I just got off the phone with my TR guru, he believes that intake valve has stuck in the open position. If I look at the valve springs on the number 1 cylinder the exhaust valve is up all the way and the intake is compressed all the way. He also said this may have damaged the piston as well. The trials and tribulations of the side screen TR.
 
[ QUOTE ]
I just got off the phone with my TR guru, he believes that intake valve has stuck in the open position. If I look at the valve springs on the number 1 cylinder the exhaust valve is up all the way and the intake is compressed all the way. He also said this may have damaged the piston as well. The trials and tribulations of the side screen TR.

[/ QUOTE ]

BUMMER /ubbthreads/images/graemlins/frown.gif But it's not just the sidescreens!

Gotta love 'em...

Any recourse with the rebuilder?

Mickey
 
Russ,
Those are chrome-moly pushrods, pretty tough stuff. Looks like the top of the offending rod had the cap driven down into the shaft a bit. Surprised you didn't hear anything going on before the meltdown. Of course when things go wrong, they can go wrong very quickly. Can you drop the pan and look up with a strong flashlight? Can tell what your cam is doing along with the bottom of your lifters. If your TR Guru does all the work for you, time to drag her in and pull the head. There may be a happy resolution to your dilemma. Don't be disheartened just yet.
Most reputable engine builders give a 12-12,000 warranty.

Bill
 
My TR Guru is a 79 year old great gentleman who is a former MG, Triumph Dealer in Southern Indiana. He did not do the rebuild. Until I hear from the rebuilder about what he may or may not do, I won't mention his name. My Guru may be right, the intake valve is compressed and the rocker arm is not touching it.
 
Russ, from the picture it looks as though your Guru is right.
But, for a freshly rebuilt engine, the rocker shaft and springs sure look grungy.
Jeff
 
Hi,

Ouch!

Stuck valves are definitely something to watch out for in rebuilds. The reason might be that the machine shop followed the manual closely and bored new "unleaded" valve guides to the specifications they found there.

Unfortunately, modern "unleaded" bronze valves guides need more clearance because heat expansion effects them differently than the original valve guides. The dimensions in the service manuals do not make allowance for this.

In his latest book, Kas Kastner notes that some very experienced TR engine builders are giving an extra .001 to .0015" clearance to the intake guides, and an extra .002 to .0025" to the exhaust guides, to prevent stuck valves. That means the guides need to be honed looser than specified in the manual, in fact pretty close to the "maximum allowable wear" dimension rather than the "new" dimension.

Sorry for the problem with your motor, hope it gets resolved quickly and at minimal cost.
 
Spoke with the rebuilder, he said no problem it's under warranty. By the way I refrained to give his name earlier, his name is Tucker Madiwick he owns AutoSport, Inc in Bloomington, IN. Interesting guy if you do a Google on his name you'll find some very interesting things about his father. (Good Things)
 
Whew! Good news - glad it's turning out this way, but sorry you'll have the inconvenience. At least it's not during the height of driving season.

Mickey
 
Looks like a competent place with a long history -- glad to hear he will stand behind it. Bloomington! Oh, to have one more Strom sandwich from Nick's on Kirkwood.
 
Sound and safe back home, Tucker at Autosport in Bloomington, IN put it under warranty. The tolarance on the valves were a bit close.
 
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