Topic: Rocker cover off, Surprise , Surprise ,Surprise ...!!!

[vik351]

My 1977 Hondamatic 750A looks to me as it has dual valve springs...

Is that the norm... All springs seem to still have the yellow paint on then I would have thought from factory...

 



All the head, cam etc nuts look untouched ...

vik... like opening a box a chockos ... 

[vik351]

Jeez look like a dickhead now, one bloke said that all 750's have em ...!!!

Yet in another post one bloke put his main ones in upside down and there was no mention of inner springs...

Was hard to see in the pic as well...

Ah well, ask first fcuk with it later...

vik... 

[MRieck]

 The paint just indicates which end of the spring goes up....makes for faster assembly at a factory.

[vik351]

The paint just indicates which end of the spring goes up....makes for faster assembly at a factory.

Thanks for that, so I presume the inner springs are the same, progressive ... or just helper ...

vik... 

[Jerry Rxman Griffin aka MuthaF'er]

The paint just indicates which end of the spring goes up....makes for faster assembly at a factory.

Up or down? Considering you do my heads I have not paid attention.... 

[web]

Some sources say inners and outers rub, acting as a damper. Others say the quicker (lighter) inner just irons out any harmonics / inertia in the bigger one. And duals help to not drop the valve into the motor if one breaks.

[maxheadflow]

Some sources say inners and outers rub, acting as a damper. Others say the quicker (lighter) inner just irons out any harmonics / inertia in the bigger one. And duals help to not drop the valve into the motor if one breaks.

Harmonics are bad for valve springs. They can effect valve close and bounce greatly.

Any spring that is straight wound will have a harmonic frequency.  Inners and outer are wound so the harmonics occur at different frequencies.  Allowed them to rub help dampen the harmonics but if simply close enough, when harmonics occur, the oscillations will cause them to bump into each other which also dampens harmonics. Progressive wound springs are better in that the harmonics don't exist. Honda springs really are not progressive springs but are dual rate springs. Again these reduce the magnitude of oscillation based on each natural (harmonic) frequency. Still the spring has 2 harmonic frequencies instead of one.  Beehives and taper wound single springs work very well.

[vik351]

Good info, thanks you blokes...!!!

Clever little buggers wernt they, did their homework on these magnificent beasts...!!!

Terry from OZ is supplying me with a 836 K7 carb and head set up, standard springs I presume, ya reckon stick with the standard springd with the 836, it is a slusher after all ,not hitting the red line every gear change...

Plus the fact I'm an old fart now, and just want the odd bit a squirt, when some harley pulls up next to me like back in the 70's... 

vik...