Dural Pushrods and Iron Heads

[bassgreg]

Hello people.

My A10 is finally on the road, sort of.
After 800 miles I have taken her on a 280 mile round trip and have unearthed a problem.

Tappets have been a fiddle from the outset, regular re adjustments had been needed. On the last ride, the tappet noise increased considerably over the lats 50 miles or so, and I assumed that just yet more adjustment was needed.

Opened her up to find the left hand exhaust tappet miles out , but still locked up correctly, so I lifted the rocker box to have a better look. The Push rod on that side is now almost 6mm shorter than it should be, straight as an arrow, but worn down considerably.

The guy who re built the engine fitted alloy ( I assume they are Dural ) push rods, and these seem totally ridiculous to me. I have sourced a set of steel ones and will be fitting them regardless.
Question is, are there any other things I should be looking at, I am also replacing the exhaust rockers, the LH one looks a bit worn, although that could be a result of the dodgy push rod just as easily as the cause.

Any experience of these alloy push rods, known problems and any other guidance is welcome.

Cheers.
Greg.

[Greybeard]

I bought a set of Ali, (Dural?) pushrods from Draganfly when I first got my A10 going. They were poor quality. I had to smooth the radii that sit in the cups, (by using my electric drill as a lathe). One of the pushrods broke quite soon. I have recently bought a set of steel pushrods from SRM. They are good quality and hopefully will last as long as needed.

[bassgreg]

Yup, that is my impression of the alloy pushrods.

[Greybeard]

I know Musky speaks well of Ali pushrods. Maybe it depends on who makes em!

[Klaus]

I use alloy pushrods in all my bikes. They are shortend  VW Beatle and with steel caps. Knocking on wood with no problems all the years.
The SRM pushrods are very heavy and in my opinion not recommented. Original old ones are the  better way.

cheers Klaus

[duTch]

 I forget where I bought mine but Kidderminster comes to mind(?)- had the same experience as GB, but haven't broken.

I had to smooth the radii that sit in the cups, (by using my electric drill as a lathe).

  After ~6500 miles on the clock (+10% wrong speedo), I've only had to adjust the valve-lash minimally on the few occasions I've checked, so I guess there must be bad ones and not-so-bad ones....

 

[bassgreg]

I think that is part of the problem, there are so many on the market, coming from so many manufacturers that quality is all over the place.
I am sticking to genuine BSA parts from now on, of faithful recreations of originals. None of this "improved" cheaper, lighter stuff.

[muskrat]

Yes I like the ones I've got in my cafe. Tapered (thick in middle) dural. Ends must be polished and the cups checked for any burrs or irregularity. Minimum adjustment over 5-6 years.
Cheers

[terryg]

I think I mentioned in another thread that I have a set of ally pushrods now demoted to paint stirrers. After a few hundred miles the ends were wearing uncomfortably fast so I switched to a tubular steel set with hardened end caps, from C and D.
The replacements are still on test, with only 100 miles run.

[bassgreg]

I have a set about to join the ranks of demoted. I was thinking perhaps wind chimes.

[Dean]

Done about 3k on both my bikes with alloys with no problem.

[BSA500]

Yes I like the ones I've got in my cafe. Tapered (thick in middle) dural. Ends must be polished and the cups checked for any burrs or irregularity. Minimum adjustment over 5-6 years.
Cheers

I have a set of these in my A7 for approx 20 years. Still going strong. The original steel ones were bent when i checked them?

[Greybeard]

The original steel ones were bent when i checked them?

That goes to show how tough they are!

[WozzA]

I have a set about to join the ranks of demoted. I was thinking perhaps wind chimes.

Keep the wife happy & give her flowers   

[duTch]

 I have to admit, this thread is giving me the jitters.....went out for a jaunt last night andrunning ok, but felt things a bit rough...same again today doing some errants (normally errands, but the way I do them they become errant)...and felt a bit extra racket coming from under the tank- even after I fueled up. I reckon soon as I have a chance, I'll have a look at the valve lash(aka 'tappets'); stay tuned, but in the meantime I'll be researching pushrod alternatives