engine improvements

[Klaus]

hello,
as l already announced here the first advice to get a more durable enginge for less wear.
It is fakt, that all moving parts (not turning) be lightend as can be.
Easy and keen are pushrods conversions.

You have fit original pushrods?
Ok this is second best. If you are cruising at max.4000 revs they are ok.

Someone recomment you SRM hight strength (strange) pushrods?
This will be the worst case......sorry to tell you

You ask why?
Now here the fakts.

I have scaled allways two pushrods long and short one.
Genuine ones are 83 gramms

The SRM ones are 133gramms
that means SRM pusrods are approx 62.5 % heavier

In conjunction with the low tension valvesprings it will be a disaster for cam and followers.
You all know the signs of exchange aggrement because they can't follow each other at higher revs.

Solution are alloy pushrods  from VW beatle, they can be used, often sale at ebay with a big deal for you.
Shortend to the righ length thy scale only 65gramms


Klaus

[edboy]

thanks for your information klaus. cam and follower wear is too great on my bsa and i would like to lighten the valve gear and believe the bsa standard valve springs are too heavy and non progressive. what are the low tension valve springs you are using ? who makes them?

[Klaus]

thanks for your information klaus. cam and follower wear is too great on my bsa and i would like to lighten the valve gear and believe the bsa standard valve springs are too heavy and non progressive. what are the low tension valve springs you are using ? who makes them?

hi edboy,
there will be a misunderstanding. standard valve springs are to low in tension.
A 357 cam at hight lift give a pressure about 65 kg to the standart springs at closed valves 35 kg.
I prefer 85 kg at highest lift, this is a good number for the valve pressure, otherwise the cam give the followers too much accelleration and they lift up. Pumping off the top of the cam and causes the usual signs of wear.
I shifting wrong gear and the result you seen at the pictures.

Tell you more about next week, when l left  the hospital with the pined collar bone.

cheers Klaus

[RichardL]

So, you're saying what happened to the engine is a bad thing? 

[worntorn]

This company supplied  made to order hollow alloy pushrods for my Vincent Special.
The cost was very low and their pushrods are used in race engines all over the US.
Glen

http://www.pushrods.net/

[muskrat]

I have been using solid duralium push rods for years. Polished ends are a must to reduce wear.
Reduced weight of pushrods, rockerarms and valve keepers reduce the risk of valve bounce and float. My A7SS regularly saw 7500rpm on the track.
Cheers

[edboy]

the problem with the dural ones i once used in a norton was that the alloy turned out to be like cheese and they wore out like mad until they jumped out of the socket. volkswagon pushrods sound interesting as such a manufacturer would hopefully use adequate alloys that stand a little abuse.

[Sasel]

Hi klaus,

All the best to your bones from Hamburg.

christian

[Klaus]

I gues it is time to make an update with the rockers.

Geting another engine with unmachined rockers, having a chance to take pictures befor and after.

Usefull item is a hexagon pin with a 5/16 BSC thead fixing the rocker in a milling maschine.

Best to explain is a look at the pictures.

The rockers don' t need to be polished. It is better the pairs have the same hight and being lightend.

cheers Klaus

[RichardL]

Klaus,

First, this is very interesting. Second, due to limited experience, I am in no position to second-guess your machining choices, so I ask for the fun of it: Why a hex pin in a 4-jaw chuck?

Richard L.

[Klaus]

hi Richard

   l was to lacy to fit a 3-jaw chuck for the quater of an hour work on the mill.


cheers Klaus

[Klaus]

hello,
as l already announced here the first advice to get a more durable enginge for less wear.
It is fakt, that all moving parts (not turning) be lightend as can be.
Easy and keen are pushrods conversions.

You have fit original pushrods?
Ok this is second best. If you are cruising at max.4000 revs they are ok.

Someone recomment you SRM hight strength (strange) pushrods?
This will be the worst case......sorry to tell you

You ask why?
Now here the fakts.

I have scaled allways two pushrods long and short one.
Genuine ones are 83 gramms

The SRM ones are 133gramms
that means SRM pusrods are approx 62.5 % heavier

In conjunction with the low tension valvesprings it will be a disaster for cam and followers.
You all know the signs of exchange aggrement because they can't follow each other at higher revs.

Solution are alloy pushrods  from VW beatle, they can be used, often sale at ebay with a big deal for you.
Shortend to the righ length thy scale only 65gramms


Klaus

Hi Klaus and All
I have fitted several sets of SRM pushrods and have not had any bad experiences

John

Hj John,

my first twin engine overhaul was made from SRM with a rollerbearing convertion. Its only last 10 tousand kilometres, (one year) one piston broke in line with the guedonpin, cam and folowers worn out, and I changed monthly the rockerbox seals, they are rubbed off.


cheers Klaus

[Sav]

I had ally pushrods collapse in my A10SR left hand pot on a VMCC demonstration parade on Manxland (was tootling along a bit  )

They bent slightly and the middle wore against the pushrod tube side until the inevitable happened. Shipped steel ones out there to get going, but have had the SRM ones in there for the last eight years without problem.

[Rex]

I always mount hex's in a four-jaw chuck too. I like the accuracy compared to a three-jaw.

[berger]

I like it Klaus, it has given me food for thought with the future engine build. MUSKY you little wheelie  high revving geezer what did you do with your rockers. as in the prisoner a 1960's epic TV series the new number 2 says - WE WANT IMFORMATION! well I do please