New Valve spring, sneak peak of new parts coming

[Neil Harvey]

As I stated in another post, we are developing all new parts for the air cooled engines.

Here is one of the new springs we will be offering for the 911 2V engine. This one is a stock replacement where the stock base and retainer can be used.

Valve springs and their ability to control the valves under motion is a commonly underrated part.They are an extremely important part of the valve train and probably the least understood.

Typically, they are over-used. Poor cam designs that induce high harmonic frequencies require the valves to be over sprung. Higher RPM’s also require additional loads to be used to help control the valves during their motions. Crankshaft harmonics also add to the valve train vibrations as this ‘noise” travels up through the chains and into the valve train. Now all of your time spent making sure the cam timing was perfect, just went out the window.

Commonly misunderstood, is the need for an installed height instead of seat pressures. Valve diameters and seat margins dictate the seat forces required not valve train weights or RPM. Spring rate and the set open pressures control the valve in motion.

There are many spring options available, some more commonly used than others. However, we needed to have our own wound that gives us the control we required. The biggest issue we found with options currently available is, the distance between coils from installed height to open height and the amount left to coil bind. Simply put, this causes the spring to wobble under load and lose control of the valve train.

Our new spring has its limits too. It will allow valve lifts of up to 0.525” with seat pressure as high as 100 lbs, with an open pressure of 290 lbs. Lowering the valve lift and engine RPM decreases the seat pressures and increases coil bind distances if ever required.

This new spring fits the stock base and retainers which makes it an easy conversion. The ends are finished ground and have an internal chamfer and the complete spring is tumbled and polished. We have Titanium and Tool steel Retainers in the works to go along with these springs when desired.

These are not inexpensive springs and we are not trying to compete with the other choices currently available. Along with our other engine components soon to be made available, these are for engines where a quality engineered solution is required.

[rwest]

Hi Neil,

Always great when we get more choices for our cars and engines.

If these were installed in a stock engine without any other changes, what if any benefit would one see?

Thanks,
Rutager

[racing97]

Is it just the photo or is there some surface disruption on the top coil in the top picture?

[Neil Harvey]

Originally Posted by rwest

Hi Neil,

Always great when we get more choices for our cars and engines.

If these were installed in a stock engine without any other changes, what if any benefit would one see?

Thanks,
Rutager

This spring has a lot higher resonance frequency over stock springs and another common after market spring.

This lowers the springs surge at high RPM helping to control the valve train. You loose performance rapidly when the spring goes into surge. If you can rise the RPM where this happens and lower the amount the spring surges, you gain torque.

[Neil Harvey]

Originally Posted by racing97

Is it just the photo or is there some surface disruption on the top coil in the top picture?

No its not the photo. I picked this spring out of some that have gone through a lot of testing. Just some surface dirt I did not see.

[Neil Harvey]

I'm sure if you look on the interweb you can find some slow motion video of springs tested on a Sprintron, going into surge.

Dyno results often show a dramatic drop off in performance and the reason often thought is the cylinder heads inability to flow. This can always be the case, but from our testing of stock springs and some aftermarket springs, I think its more about the springs going into surge.