Forum

[NEV]

Hi everyone! I'm busy changing my iron barrelled Bullets exhaust valve to the larger one due to burning and wondered if changing the valve springs upper collar to alloy version 90126 might be a good idea to reduce weight & stress on the valve train, i'm using standard springs. Anyone used them?

[mauri]

a bullet engine is a low reving engine.



will it do bad, no.
will it do good, close to nothing.
in this type of engine in its standard state(small amount of lift and duration, the standard cams are closer to axels with a lump on them = little stress.) its more eye candy than actually useful.

[stinkwheel]

If I was looking at ways to reduce the moving mass in bullet valve gear, the first place I'd look is the rockers. The difference in mass and balance between a standard rocker and a balanced samrat one is marked.

[NEV]

Hi Stinkwheel, Yes i have a set of the Samrat rockers from our hosts ready to install, one of the originals was showing signs of distress in only 6500 miles

[ChrisD]

NEV. I've been down the same route and changed out the OEM steel top collars (valve spring retainer) for our hosts alloy ones. One of the alloy ones broke some 1000kms further along with no warning and dropped the inlet valve into the engine - which cost me a complete rebuild including new piston (the valve broke through the crown and into the crankcase), gouges out of the cylinder head, resleeve and new piston. Fortunately the engine was idling in a traffic queue. If I'd been at full chat going down a freeway and that happened, I'd have been under the nerest truck as everything locked solid instantly and the damage would have been much worse. Never again will I try to save a few grammes. I should say that I've heard of only one other such failure despite the reports of hundreds of sets sold. I'm not trying to knock our hosts - just to advise a fellow bulleteer.
Cheers, ChrisD

[Chris [Stockport]]

Was there something quite a long time ago that the Samrat ones Hitchcocks were selling were ok, but beware of ones from some other sources?

Really can't remember how many years ago this was. -C

[Chris [Stockport]]

Just found this in the Hitchcocks catalogue 2011:

Please note that the rockers we sell are not the standard Samrat items but have been specially supplied to higher tolerances exclusive for Hitchcock's. Additionally each set is checked and finished in the UK to meet our stringent quality control. If purchasing these from your local dealer, you need to find out whether they have been obtained through Hitchcock's to ensure that they have been subject to our quality checks and are not the standard Samrat items.

[NEV]

Thanks Chris