Yes, an excellent article, showing the type of test equipment that major valvetrain component suppliers use to do R&D.

Wouldn't it be great to have a valve motion graph for a modified L motor at 12 psi and 6000 rpm vs. 18 psi and 6000 rpm?

 

In dead it would!! Also note that Endura-Tech, the company the article was about, offers the strongest valve spring available for the Lightning at 112# seat pressure. Because valve spring design is a complex issue is why JDM has gone to one of the largest valve spring manufacturers for a stiffer spring design for the L.

 

The way I see it now is with good springs the KB's will be that much more ahead. Not so say that the Mag isn't good but the KB's should benefit from good springs as much as the mag's right?

I have to say thanks to Rob. If it weren't for you money and problems i don't think this would be as big a deal. You really showed what good springs and bad ones can do!

 

Your joking right?

 

Stiffer springs will bump the entire Lightning community up a notch including stock Eatons with a pulley as Jim pointed out a few posts back. The more boost pressure a supercharger is capable of the more it will benefit from stiffer springs.

 

I would like to re-ask my question...

Regards, Rich

 

FYI: As previously noted by "kdanner" - the valve refacing machine JDM refers to using, is probably is a "Serdi," although I suppose there could be a "Certy" machine out there. If you had one personally in your shop, I'm pretty sure you would call it a "Serdi" - as it has big bold lettering on it. Serdi, in Stone Mountain Georgia, makes a variety of sophisticated cylinder head rebuilding machines and are known worldwide. Many Formula 1 shops in Europe consider their valve refacing macines the best available, as do many serious engine shops here do. It's the machine to use if you're serious about accurate 3 - 5 angle valve face jobs.

 

You asked this of Jim but perhaps I can add something useful.

Boost pressure reduces “effective” spring pressure by way of the differential pressure created across the valve head because the engine’s volumetric efficiency is not 100%.

The function of the spring is to keep the valve following the cam and as RPM increases so does the inertia of the valve train. So it follows any reduction in the valve train mass would be helpful. However considering the enormity of the issue the mass difference of just the retainer I would think is too small to make a big difference. I have a Top Fuel valve spring in my office that is made of titanium that was given to me by a spring winder, they are so strong I can only compress them 1/16” or so with both hands and they are so light they weigh almost nothing considering their size. Of course titanium springs are not suitable for street use but it does indicate the extent to which the Top Fuel guys go through to close the valves running 65-psi boost.

Charles

 

tomato-tomato

 

Here is what a valve spring looks like in a running motor at high rpm.Stan

http://www.engr.colostate.edu/~dga/h...pm_1000fps.wmv

PS what is really strange is,is all of this info has been out for atleast 20years I have a book on forced inducetion dated in the late 70's and they tell you about the effects of PSI on the backside of the valve and give you the math to figure out how much stiffer the spring needs to be.Plus since the majority of us bleed ford blue does not anyone remember how sorry the valve springs were on the 5.0 mustangs.I must of replace 40 sets of them before they even had 40k on the motors.

 

 

Is there anything that would tell what RPM that would be at?

 

not without running them It has to due to harmonics of the spring in relation to the lift heat weight of the valve train itself.the reason 'beehive' spring are so popular is that due to the design[each coil is different in length] they have a TENDIENCE to dampen themselfs.unlike the normal springs that are found on the older V8s that is why they have a flat wound spring inside them that is TOUCHING the outer spring.Stan

 

Yes I did spell Serdi wrong; Dave, Alan, and Rick run this machine, I do not. It also came from the factory in Alan's equipment color.

In an earlier post at the begining of the thread someone said that they would rather leave their decission to an expert at comp cams. Their springs are really no different than factory springs, I knew this over 2 years ago, thats why we never use them. The main focus of the Serdi machine for me is to make every cylinder identical in the valve job and how deep the valve is set into the head so we can keep lifter preload the same. I have gone through 4 different cam grinds so I could keep the power up while dropping the lift in the cams, and in order to get more spring pressure. The same goes for our CNC port design. We recieved two sets of springs today from our manufacturer. One set will go through a destressing process of mikronite coating. The other set we are going to test raw as is.

Rich,

If Im not mistaken your talking about titanium retainers, the keepers are what hold the retainer in place. The lighter you make your valve train the more stable it becomes.

Charles,

That top fuel valve spring they only use for 1 run. Prostock cars change their springs every 3 runs. Im right in the middle of purchasing an ultrasonic cleaning machine right now there is only a few of them in the country, Warren Johnson has one of the first ones produced. The sales guy actually calld Warren from my shop and I got to speak to him. Not only about the machine but we got into the conversation about Mikronite coating. He told me that with their valve springs they get 3 times the life out of them with the mikronite. We have taken a set of our springs, Mikronited them, used them in Vinnies truck. There is 30 low to mid 10 sec passes and some street miles on them, Vinnies comming in next week to get his 4V. The first thing Ill be doing is testing his spring pressure on the Mikronite springs.



Jim@JDM

 

Thats what I was thinking.