emergency advice needed! Blown pushrod

[newmexTR3]

so... left this evening from brooklyn, made it half way to Buzzard's Bay doing 70-75 when suddenly the exhaust note changes and I lose a little power. I pull over to the next gas station thinking maybe one of my plug connectors had come loose. I change out the wire just to make sure, still no change in sound. Then I take off valve cover and lo and behold the #7 intake valve pushrod is sitting 3 inches below the rocker arm!

I jiggle it and it dissappears into the head. Luckily, in my emergency parts kit i have some chicken wire, and after removing rocker shaft I am miraculously able to remove both halves of the rod. Tonight I'm staying at a motel and hope to drive the remaining 90 miles early early, get a new rod overnighted and then install on Friday.

Is driving without the rod for that long extremely inadvisable? Since it's on the intake I don't think I will damage the head with it overheating as i could if it were the exhaust valve.

Also, what could have caused this? I changed my valve clearance to .014" a few weeks ago and had a great drive out to PA and back- a few hundred miles, no problems. Should I put the valves back to .010"? I have a nonstandard cam in it, but it was installed years ago and I'm not sure of the specs on it. Would having the valve clearance too loose cause this sort of stress at high speed?

Thirdly, do I just order one pushrod? or should i get new ones all around? Anything else I should do?

thanks! Another chapter in the love/hate relationship of me and my car. Could have been much much much worse i suppose.

Cheers,
Gavin

 

[TR3driver]

If it were my engine, I'd hope it was just metal fatigue and nothing more serious. I'd change the whole set (maybe with uprated ones from BFE) and hope for the best. Leave the lash at .014" if it runs better that way. Any damage running without the pushrod might do (like the lifter jumping out of the hole) is already done anyway.

A magnetic drain plug might also be a good idea, in case there's some swarf from the break.

 

[racingenglishcars]

I had blown about 10 pushrods many years ago on my TR3. Not quite sure of the cause, but the temporary solution was to limp home on 3 cyls. If an exhaust rod blew, I would take the intake rod and replace it to the exhaust.
I was running a non-standard cam and about 15:1 compression. (I still have the head) but I think mostly it must have been the cam. Too much shock on the pushrod, especially with larger valve clearances.

 

[newmexTR3]

If it were my engine, I'd hope it was just metal fatigue and nothing more serious. I'd change the whole set (maybe with uprated ones from BFE)

Sorry, brain not working. BFE is which distributor?

 

[martx-5]

British Frame & Engine. Ken Gillanders...forgot more about TRs then I'll ever know. I bought all my engine parts from him. He knows what works and what doesn't. Wonderful fellow to talk to.

 

[newmexTR3]

Thanks guys. Just rolled into final destination.

Car still ran well even on 3/4 power. It had a decidedly different feel that I couldn't place at first and then I realized what it was- it had the power characteristics of an MGB! :laugh:

Just kidding of course. Thanks again for the help.

 

[TR3driver]

I think it was Ken that once told me they tried looking at the stock 5/16" pushrods under a strobe light. He said they looked like "dancing spaghetti". I can vouch that the 3/8" chrome-moly ones he sells are a whole lot stiffer at about the same weight.

 

[Tinkerman]

Ken is a totally fine gentleman of the first order. Knows his stuff, but be prepared to hear about his pet Parrot. Small price to pay for his knowledge though.

Tinkerman

 

[2wrench]

Thanks guys. Just rolled into final destination.

Car still ran well even on 3/4 power. It had a decidedly different feel that I couldn't place at first and then I realized what it was- it had the power characteristics of an MGB! :laugh:

Just kidding of course. Thanks again for the help.

Just couldn't resist taking a swipe at the ole MGB's, huh? Got a smile outta me...again.

 

[NickMorgan]

You impress me with your ingenuity and persistence. I am sure most people would have called the breakdown services.
You are a true TR man!

 

[newmexTR3]

Thanks Nick! That means a lot.

So to give you guys an update: I ordered new push rods from TRF. The ones they supply are the more robust 3/8" ones. After talking to Ken at BFE, he said that those ones would be fine and that getting the race ones from him was unnecessary unless i was going to be racing the car. That guy is good people- I was fully prepared to spend some money with him and he was just honest about my needs and how I didn't really need to spend the extra $$ with him. Hopefully someday I can repay him in some way.

One small snafu when installing the new one- the tappet came out of its seat and was rolling around in the head! Luckily the friend I was staying with had one of those telescoping magnetic picker-uppers, which allowed me to reseat the tappet without having to remove the head. I immediately went and bought one to add to my toolkit- it's much easier to use than chickenwire! I would recommend that everyone have one of these on the road: magnet pickup tool

The car ran fantastic all the way back to NY. 250 miles at 70-75. Now I just need to replace all my old pushrods with the new thicker ones and I'll be happy.

here are the pics of the "malfunction":

and

 

[TR3driver]

I would recommend that everyone have one of these

Mine has an LED light built into the tip that comes in really handy ... Wish I could remember where I bought it ... :confuse:

 

[martx-5]

Thanks for the update, and that's just one nasty looking push rod. Glad it worked out for you, and yes, Ken is good people, but unlike you, I spent a ton of money with him.

 

[Tinster]

Wow!! How grim!

Are broken push rods a common Triumph problem?
I probably have the originals and I sometimes
drive at 70-75 mph.

Should I install new, heavy duty ones, just to be safe?

thanks,

d

 

[TR6BILL]

Should I install new, heavy duty ones, just to be safe?

thanks,

d

Dale, keep your hands out of that engine!!

 

[TR3driver]

Not a common problem on the 6 cylinder; nor on the 4s with factory 3/8" pushrods. It's only the 5/16" pushrods that sometimes get metal fatigue after a few hundred thousand miles (sooner if used with high lift camshafts, etc.)

 

[RonMacPherson]

NOPE! NYET!NADA! IXNAY!NEIN!


The only thing you should ever need to do is adjust the valves and make sure the philips screw is loctited in to the rocker assembly...

And after the phillips screw is loctited and secured. A valve adjustment no more than every 12000, that's twelve thousand miles......

 

[Andrew Mace]

Not a common problem on the 6 cylinder; nor on the 4s with factory 3/8" pushrods....

as well. I've never seen it, although I agree that any moving part might eventually suffer fatigue. Closest I ever came to this was BENDING a pushrod many years ago on a '51 Chevy six, and that was the delayed result of the cam gears disintegrating (fiber gears; talk about fatigue!). It was only one, and once I got the gears replaced, I went for a short period of time with that same pushrod straightened out in a vise...after having sourced what was supposed to be a correct pushrod from a "Chevy expert"! It turned out to be too long, and IT bent and then popped free before doing further damage. Those old stovebolt sixes were pretty tough...rather like most Triumph engines!