Valve train & Springs

[mdmax72]

Question regarding the above.

If l was to use a Webcam 86b camshaft in my build. People are recommending dual springs to help with the higher revs etc. Now if l was to re-bush the case and use some TP type 1 lifters with lightened rockers and Smith Brothers aluminium pushrods should l be aiming for single springs?

Can anyone in the know how clarify. What will be the long term affect to use light weight valve train with dual springs? Or is this ok? Or should l be using stock lifters with dual springs.

My way of thinking is the lighter valve train will help with throttle response and help with wear on cam but the dual springs will hinder what I'm trying to achieve. Or am l totally wrong??

Cheers

[Haveacamper]

I'd be very interested in the answer to this question also. I'm currently looking into a 2270cc (96x78) build and have been spec'd very similar to Stateside Tuning in the UK.

Web86b cam

For what its worth, they have suggested to use their own single rate spring and have also suggested using the supervee lifters (51g each) with the case machiened for bronze sleeves and honed to match the lifters.

My understanding is that reducing the weight will mean that you don't have to run such stiff springs and, as you pointed out, there is less force required to stop any loss of contact between cam and lifter - as well as reduced wear. Furthermore, have less mass to have to move in the valvetrain will mean less power required to push it = less parastic loss = more power to the wheels.

I would by no means take my thoughts as gospel as I am on this forum to learn from the many greats that frequent here

Nath

[mdmax72]

Hi Nath,
If I'm honest I've confused myself with to much reading in here, that's why I'm asking. Jim at Stateside has his springs specifically made to his requirements and his happy to use his single springs in single form with lightweight valve train for high revving engines without problems.
I am spoilt and have a new set of heads from stateside for a 2270 along with a new pair of Le200 heads with dual springs. Cant decide which to go with??? Will the alloy pushrods hold out with dual springs or start to bend?? Also will the cam suffer more wear???
I'm half tempted to use the same engine once built and dyno it, then swap out the heads and see what the results are on the dyno?

[Clatter]

You guys are totally on the right track.

Here's a big brain dump if you want it.
Maybe it might have something helpful..?

First thing to consider is that 'dual springs' or 'single springs or 'aluminum pushrods' are all general descriptions of parts.
There will be variation between manufacturers, and even between products of the same description from the same mfgr..

As in 'aluminum pushrods'; the factory pushrods were aluminum.
They are considered too weak for most performance cams.
Scat made some that were even weaker!
Aircooled.net is known for their performance aluminum pushrods (Smith Bros?) for bigger cams,
They make even stronger sets of al pushrods for very serious drag motors. (Dual tapered type)
These cost accordingly, and can make a significant difference in total reciprocating valve-train weight.

Single springs are just that, but, what people usually refer to as 'single springs' are the outers only from your typical dual spring set.
The Scat springs are palpably lighter than the Bugpacks, IME,
And super-heavy singles, like beehives for big V8s, are technically singles,
but are heavier than some duals, such as Scats.

What really matters is how many pounds of pressure they produce at rest, (installed height) and full lift.

Duals can cancel out harmonic vibrations (the springs ringing like a bell) as can the taper of beehives, to a certain extent. This makes duals have advantages beyond their pound rating, supposedly.
The friction between them that dampens harmonics can cause oil to run hotter, however.

Lighter lifters are better, all the way around, except for maybe the price.

Light aluminum (Pauter) rockers get to being $$ exotica, and aren't even made anymore IIRC.

Having bigger valves makes them heavier, hence people will go with a thinner stem to get some back.

Then there's titanium - valves and retainers.
Retainers for the street, yes. Valves not so much, they don't last very long.

There's a whole science to it, and when motors get more serious, so do the quality (and price) of the valve-train parts.
Lighter is better, but perhaps at a longevity cost, which at some point is considered worth it, or not, depending upon the intended use of the vehicle?

As the rev range of the motor goes up, so does the need for more spring.
Same with lift, and ramp speed, and duration,
Also needing more spring..

Back to real life..

The Web 494 is debatable as to needing 'dual springs'.
Any light valve-train parts, and you are likely safe with even cheap Scat singles.
That, or stay away from the drag strip..

The Web 163 is next - technically 'dual springs required' - with some light parts, maybe al pushrods and Bugpack springs would do the trick?

If you have a light flywheel, and a light car, the rapid rate of acceleration can make the need for spring relatively greater, as the rapid rate can 'fling' the lifters off the nose of the cam and cause float.

The 86b ain't a huge gnarly cam.. It's a big street cam, for sure, however the ramps are 'relatively' mild. The lift at advertised vs. at .050 will tell you a lot about how steep the ramps are..

If you had type 1 lifters, and al pushrods, and some heavier singles, beyond your normal blister-pack types I speak of earlier, you might be OK with the 86b.
Got some titanium retainers?
Valves only 42 x 36?

Lots of factors come into play.
Experienced builders (unlike me) will have tested different combinations of parts, in different environments, and kept good notes.
They will know what works and what doesn't.

Super-light valvetrains and lighter springs make more power with lower parasitic losses.
It's safer for parts vendors to just say "run dual springs"..

ANyhow,
Bla bla bla.
There's a TON of info out there on the subject,
And this is just a vague regurgitation of generalities,
Hope it helps...