Author Topic: RGS pushrods  (Read 2476 times)

Offline Sunbeam

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RGS pushrods
« on: 01.07. 2011 10:06 »
Hi. I need help with my 1962 Rocket Gold Star. The rocker box was leaking and the head had to re- torqued due to the new copper gasket blowing sightly. After removing the pushrods so that I could clean the rocker box mating surface, I checked each rod for flatness on a sheet of glass. I then found that one was bent slightly (approx 3/4" from the end and another was starting to mushroom around the hardened end cap......both on the exhaust pushrods).

I have tried everywhere to get a set of steel pushrods, whether new or old stock, from usual suppliers (C&D, Autocycle, G. Prew) but they can now only get dural alloy. SRM sell Chrome / Moly rods, but looking at their website pics, end caps now drilled. Have even tried getting a decent secondhand set. Looking back at old posts, BSA fiitted hollow steel pushrods and someone mentioned that Dural pushrods can flex. Note: Have since found that Lyford Classic Services now sell HE30 solid billet pushrods with hardened EN36 ball ends.....Made in England. Any advice of which way to go would be grateful.
Howard

Offline alanp

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Re: RGS pushrods
« Reply #1 on: 01.07. 2011 15:46 »
I also gave up on the alum. push rods on the RGS engine. I don't understand what you think is wrong with the SRM rods, I use them and they are fine. I no longer expect them to bend.
Alan
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Offline Sunbeam

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Re: RGS pushrods
« Reply #2 on: 01.07. 2011 20:10 »
Thanks for the info Alan. I would not have a problem in using the SRM. When I went on their website, noticed their design mod with oil hole in the pushrod ends, similar to what AMC used on their heavyweight singles.

Howard.
Howard

Offline A10Boy

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Re: RGS pushrods
« Reply #3 on: 01.07. 2011 20:41 »
Hello Mr Sunbeam, welcome to the forum!  *smile*

I think it would be wise to establish why your pushrods are bent. I would make sure your valve springs aren't coil bound. That can happen if the caps under the springs are wrong way up, depending on the type.

HTH

Cheers
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Andy

1958 Super Rocket
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1974 Kawasaki Z1a
Yam XJR 1300

Offline muskrat

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Re: RGS pushrods
« Reply #4 on: 01.07. 2011 21:33 »
G'day Sunbeam,
                     ditto Andy, another cause is loose valve guides. Alloy or iron head? With alloy head they might seem tight when cold but when hot can ride up limiting the lift and bend a push rod.
I have alloy push rods in both my A's, the cafe has tapered (thick in middle, much like me) ones. I am looking at the Lyford ones for my next motor.
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Offline wilko

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Re: RGS pushrods
« Reply #5 on: 01.07. 2011 22:27 »
Also are the valve springs of the right poundage?

Offline Sunbeam

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Re: RGS pushrods
« Reply #6 on: 01.07. 2011 23:01 »
Thanks A10boy & muskrat. Will take your advice and check valve springs / caps / guides. Suspect a duff pushrod was fitted in the past. Three of the pushrods are nice and shiney....bent one looks as if its been around a bit with a nick at the point of the bend. Suppose the damage could be historic from incorrect pushrod / rocker cup location.

p.s. still finding my way around the bike as I have been a humble AMC devotee for longer than I would like to say.  *smile*
Howard

Offline Sunbeam

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Re: RGS pushrods
« Reply #7 on: 01.07. 2011 23:21 »
Hi wilko. Double valve springs have been fitted, HHC RGS engine. Will check poundage if head has to come off.

Howard.
Howard

Offline A10Boy

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Re: RGS pushrods
« Reply #8 on: 01.07. 2011 23:44 »
There's nowt wrong with having an AMC in the collection, got one myself, so has Groily and MG. variety and all that. *smile*
Regards

Andy

1958 Super Rocket
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1974 Kawasaki Z1a
Yam XJR 1300

Online groily

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Re: RGS pushrods
« Reply #9 on: 02.07. 2011 07:31 »
In fact, it speaks to your impeccable good taste Sunbeam.
Funnily enough, one meets not dissimilar problems with the tubular alloy pushrods on the AMC Twins, which can chafe themselves dangerously weak unless head gaskets are carefully pared exactly to match the drillings in the castings  . . . a variation on the theme you're facing!
Bill

Offline Sunbeam

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Re: RGS pushrods
« Reply #10 on: 02.07. 2011 09:50 »
Thanks A10Boy & groily. Looking at A10 pushrod arrangement where they come through head into rocker box, seems they could be easily scuffed which explains the condition of the secondhand pushrods I have come across.

Got two AMC bikes, one very long project which literaly broke the piggy bank and had to be shelved for a bit. Recent flurry of activity on the other one, would be nice to see it finished this summer. As for the 1962 RGS, well it was a moment of weakness bought from a dealer 2 years ago.

Howard.

Howard

Offline Nigel Johnson

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Re: RGS pushrods
« Reply #11 on: 02.07. 2011 15:50 »
Hi, my first post. Just to add a little variation to the theme. I've just been reading the Australian Rolls Royce Forum. It seems Silver Shadows have cast iron inlet valve guides. These can rust to the valve if the engine is not started for a while. So when the engine is started, eight inlet pushrods like a figure S. *eek*
Regards, Nigel.

Offline alanp

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Re: RGS pushrods
« Reply #12 on: 02.07. 2011 19:06 »
Hi, my first post. Just to add a little variation to the theme. I've just been reading the Australian Rolls Royce Forum. It seems Silver Shadows have cast iron inlet valve guides. These can rust to the valve if the engine is not started for a while. So when the engine is started, eight inlet pushrods like a figure S. *eek*
Regards, Nigel.
Good point. Thankfully my SRM guides are some bronze alloy or other.
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Offline rocket man

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Re: RGS pushrods
« Reply #13 on: 02.07. 2011 19:23 »
hi alanp you mean the Colsibro material valve guides composed of Copper, Nickel, Silicone alloy which resists wear, corrosion, spark erosion, has a high tensile strength and can cope with rapid temperature changes, the closer tolerance enabled by using this material allows for a cleaner running engine. ive had them done on mine i also have dural pushrods in mine no probs with them i also have the tufnel valves as well



dave

Offline Sunbeam

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Re: RGS pushrods
« Reply #14 on: 22.07. 2011 23:11 »
Just got a new set of SRM chrome moly pushrods. Good American site to have a look at for pushrod info.....smithbrothers@pushrods@net

Howard.
Howard