Maybe there would be a difference past 7000 rpm.

 

Going strictly by the dyno chart, it doesn't appear to even be trending anything different above 7k.
But you never know......

 

The only thing I'll add is a broken single spring usually won't save an engine. I once had an outer spring break, and the inner saved me on my dual spring setup. This was somewhat lucky, because it happened on a brand new motor (300 miles on it) and I was taking it easy. As I left a stop sign with just enough pedal to shift into 2nd gear (A4), WAP WAP WAP!!! Probably only 2,000 rpm. I'm not so sure a dual spring would save anyone if one broke at 7,000 rpm!!

 

Yeah...that might be a bit iffy.... LOL!

 

That's not enough of a rate difference to really see anything. The cam was lazy crap too. Valve control is everything and a better cam/more aggressive love would see a greater difference with the lighter setup. Rare of accelerating of the engine itself is a thing and lighter valvetrain contributes to that. It's not so much the pressure, it's the control.

 

My friends car that runs my old reground comp 228 232 xer cam has broken 2 sets of dual springs and been saved by the secondary spring. It's sort of a nice safeguard although it might not help when in the upper rpm, both times he was just putzing around. This car has had a lot of street time and road race track days also, still running stock 70k lifters etc.

 

Based on some figures I've seen a beehive might have 10% less spring rate compared to a dual spring for an LS. I'd think weight gain and higher pressure would show up as a hp loss as it takes more force to move the spring. It might be a function of the dual spring rate not being enough to overtax the lifter.

 

This video uses miss guided terminology. I kept hearing rate, when it should have been load. A stock LS6 spring has a higher rate than a 26918, but lower seat load.

A beehive will beat a dual every day in dynamics, as long as you are comparing similar "rates" and close loads.

 

Holdner tests always seem to have thier heart in the right place but the data usually doesn’t apply to anything but his specific test. So I dont’ see how it helps real world racers much. Put real RPM to it with an actual radical cam and re-test. Results would be much different IMO.

Weight is everything for a high rpm perfomrance valvetrain. Esp if there is any sort of endurance event. Hands down the beehive beats out a dual spring in every way. Vizard goes into this quite a bit on his channel and lists all the extreme weight reduction methods they used for circle track valvetrain weight reduction. Some of them were pretty entertaining.

IMO, main reason for a dual spring is if you run 2 valve heads with big heavy valves. Then need high ramp rates and lift (.700+). Then you need the dual spring for control. Otherwise better off with a beehive.

 

​​​​​​The weight becomes really critical as the rpm goes up, which leads to more rate/strength to control it. It's funny to think, but 7000rpm in a LS valvetrain really isn't taxing it much, depending on the cam lobe. I know a lot of really serious drag/drive motors being built right now that are using conical springs and picking up noticeable power and running more aggressive lobes. The conical springs seem to have a shorter lifespan than a serious dual or beehive, but the control is way better than both from what I'm told I'm on other engine building sites and, sadly, the basic tech in here stalled out like 15yrs ago. I'm planning on at least trying some conicals on the new motor I've got going together. I want to see first hand how they last in a street car environment.

 

Well, part of that is that a large percentage of guys here are using a LS6, Fast 92 and Fast 102 intake which peaks at 6200-6400 rpm and only sees max rpm for a few seconds at a time. The drag guys who are using a Holley low ram or sheet metal intake are turning significantly higher rpms and the lighter spring makes sense. Same goes for a road course car that operates in the higher rpm range for long periods of time.

 

Ben Strader who runs 10k technologies just came out with a new spring that is sort of a hybrid conical/beehive design. Anybody that doesn't know who Ben is, he is one of the lead masterminds behind Project Spinal Tap 1.0 and 2.0. Very, Very knowledgeable guy.

Anyways, the new springs he is producing have some pretty good data behind them and seem to be a good option going forward.

 

https://10k-technology.com/products/...ve-spring-copy

 

545#-560# rate is pretty high, that must be a solid roller application. FWIW, I was told that the spring rate that they are using on a friends 426 Hemi supercharged funny car is in the 450# range.

 

 

WTFF???? @Che70velle

 

ecmtun must have done a poopoonasty......

 

https://www.nhra.com/news/2019/how-p...-your-race-car

Interesting article on the subject.

And after some reading, it seems my friends comment regarding valve rate on his Hemi engine was probably seat pressure, not open pressure.

 

Holdeners tests leaves a little to be desired.

I like beehives and conicals are even better. With that said we've ran the btr 660 springs to 8k + rpm. I think the biggest secret isn't even a secret......gm showed you. Use the lightweight valves.

 

I'm sure the lightweight valves would help.