AbeFM

iTrader: (3)

So, I'm looking at valve springs, to make a healthy revver. Ferrea is out of the business, Crower starts at insane seat pressures and goes higher, so the choices I'm liking (though open to suggestion) are SuperTech and Eibach.

The super tech kits are 9.4 lb/mm (single) and 12.1 (dual) with 56 and 75 lbs seat force respectively.

As best I can gather, stock is ~8 (7.5?) lb/mm.

The Eibach seems pretty ideal to me - 11.1 lb/in (single, 11.4 dual) with 66 lbs seat pressure. Which seems enough for the shorter duration VVT cams, and would allow stupid high revs (9,500 I'm sure), without putting too much load on the cams.

The trouble is, while the Eibach kit is a lot cheaper (like half price) it doesn't have the Ti retainers. But, what do they really save you?

Probably 15 grams (~2/3 the mass of the retainer)? The weight of the entire reciprocating mass includes:

Valve, retainer, clips (what are those even called?), tappet, shim, and figure half the spring. So, if 15 grams out of...???

Does anyone know what all that weighs? It sounds like it's going to be a 5% mass decrease, and the stiffer springs will handle the difference.

Any ideas?

Jeff_Ciesielski

iTrader: (10)

Some reading for you. No personal experience or input, just what other communities have discussed in the past.

http://www.dsmtuners.com/forums/cyli...ged-9-9-a.html

neogenesis2004

iTrader: (12)

I don't remember the individual weights, but when I used the complete supertech kit and mms shim under buckets on the 1.6 I built it weighed out to almost exactly 1 lb weight cut. I believe it rounded out to like a 50% drop in valvetrain weight. I can't even begin to tell you how much that motor loves to rev. Brgracer and scott can both speak to that.

As far as the retainers, they don't save a ton of weight alone. What you need to be more concerned about is if the stock retainers are compatible with the springs you pick.

y8s

iTrader: (8)

This is the part where I point out that I have the supertech singles with retainers for sale for less than retail.

neogenesis2004

iTrader: (12)

What a shill. :P

AbeFM

iTrader: (3)

That's not a lot of weight. I have a feeling, like you're saying, shim under bucket is the way to go, but I don't think I want to drop a grand or whatever it is. Plus I have all these shims, what would I do with them?

I guess I'll have to go home, weigh a full setup, but even if I went to MASSLESS retainers, it would still only buy me 10%. Probably less.

Weird how several of the comments there were about them failing.

Wow, I read like 4 threads on this, and I think it all comes down to the same thing - if the retainer isn't just the right shape, you're going to have issues. Your gains seem to be pretty close to mythical.

The only down side to stiffer cam springs is a couple HP loss and the possibility of wiping the cam. I'm thinking the slightly heavier spring will more than overcome the mass

(light assembly weight)/(stock assembly weight) = (Spring Force light) / (spring force heavy)

Assuming there's nothing weird with integrating of F=-kx? Which means a spring that's 11.1 lbs/mm verses one that's 9.4 lbs/mm (sure, this will work out) could drive an 18% heavier valve train at the exact same speed.

So, if I could save 50%, hands down, it's the way to go!! If I save 5 or even 10% weight by putting in Ti retainers and give up on 18% more force, I've got a lower reving motor.

Am I missing something?

Jeff_Ciesielski

iTrader: (10)

Nope, that was what I wanted to express. Ti retainers seem to be about the same as align-boring after main studs. 50/50. If the gains aren't good enough that they offset a *supposed* 50% likelihood of failure, then they aren't worth rolling the dice on. I had a set, and I got rid of them because they were going in a street car and I didn't know for sure.

neogenesis2004

iTrader: (12)

The SUB lifters cost like $200-250, then get a set of 6mm lash caps on ebay for like $10. Use a diamond coated knife sharpener and grind the tops in a figure 8. You won't find ANYTHING else that can grind them as quickly for as cheap. They are made of hardened tool steel. It takes ******* forever. You'll spend an entire weekend grinding, measuring, grinding some more. But its cheap as **** if you're not a moron, which I know you are not.

It helps a lot to have the head on your kitchen table with the cams out. Then you can put in 1 lifter at a time and go one by one.

You already have cams for solid lifters, so you don't NEED any upgrade there per say. Its 100% a worthwhile upgrade if you can diy and have a full helping of common sense and know how.

Gotpsi?

iTrader: (5)

The retainers are not just about loosing reciprocating mass they are about valve weight, at higher revs your valves will have a better chance of closing because there is less weight for the spring to push closed. = less valve float. The LS7 has a 7k red line and the valves are huge. to accomplish this they use full titanium valves as well as retainers, I know its not the best example because its a push rod motor with roller lifters but I think you get the idea.

AbeFM

iTrader: (3)

The lash caps are for setting the valve lash? Take the place of the adjusters?

Do you then you use same factory springs? Is that where you gain your weight, then, the smaller shim?

neogenesis2004

iTrader: (12)

The SUB lifters are basically a "cup" with a pintle-like thing protruding from the inner center, downward toward the base. This part is what makes contact with the top of the valve to push it open. The lash caps sit on the pintle on a 1.6 because the valve stem above the keepers is not tall enough. On a 1.8 ther should be room to fit it on the vlave stem. Either way it doesn't matter much, its never coming out once assembled. You grind the top of the cap to give you your clearance. MMS sells lash caps in various sizes. These will work on a1.8, although they are expensive as all hell. On a 1.6 is is completely necessary to grind your own caps because the MMS ones will not give you a small enough clearance because the difference in stem length. I could draw you a picture in paint, but if you go on the miataroadster forum I swear I remember bill having a nice pic made up of how it all goes together.

They are compatible with any springs, they are just lifters like any other solid lifter. The difference is that its a ton lighter because its mostly hollow and uses a very small lash cap. The caps can't weigh but a few grams each. The weight came a lot from the smaller shim, but also the lifter itself has much less mass.

y8s

iTrader: (8)

neogenesis2004

iTrader: (12)

ty y8s.

as seen in that pic, its basically an empty bucket. The top ans dies are like 2mm thick. Top might be a little more, but not much.

AbeFM

iTrader: (3)

That's just what the NB tappets look like anyway, sans the spacer. But they have that same hollow bore with a protrusion to contact the valve.

I weighed everything, the whole chain (valves, shims, tappets, retainers, clip things - per side, so all the intakes, or all the exhausts) is ~1300 grams (~1290 ex, 1310 in). The retainers are ~180 grams, so saving 2/3 is 120 which is ~8-9% weight savings. I was shocked the valves were so light. I should add in 1/2 - 1/4 the spring mass, but I didn't, to keep it as favorable as possible. The +1 valves were heavier, on the order of 30 (ex) - 40 (in) grams more.

So, it would seem I'd need springs around 12% heavier than the same set up with the supertech - which the eibachs are, but not by the margin I was hoping for. Of course, 1/3 of that is the heavier valves.

Either way, I'm good, so while I have 18% heavier springs to drive (some of that energy HAS to come back, they are springs after all!!!), overall this should be higher RPM, without resorting to dual springs, and at $170 I can't bitch.

The

AbeFM

iTrader: (3)

Better numbers later, this is from memory. I do remember the 9% being solid, though.

neogenesis2004

iTrader: (12)

I wish matt could weigh that lifter for you. I think the difference is more significant than you think. The SOB lifter's shims are gigantic by comparison. In both thickness and diameter.

AbeFM

iTrader: (3)

Matt, or anyone who can handle such things:
Do you have the spring specs for the VVT heads? I'm used to the springs being identical ex vs in. Not so on this head. It looked like the intake got beefier springs.

I would assume in a VVT engine manual, there's an inspection procedure for the valves, which must have a seat pressure measurement and a spring rate measurement. See if you can find that page and post it - I want to know if I just bought springs worse than stock. :-)

Thanks!! Oh, if you have a VVT repair manual, I'd like to see it anyway, I don't know what the valve lash, etc, is anyway.

AbeFM

iTrader: (3)

Oh, interesting... My numbers are... Different. The valves I measured only 8, but everything else I measured 16. Which means the valves ARE much more important as I originally thought.

Data to follow.

y8s

iTrader: (8)

I know a bag of 16 shim under bucket lifters is about a pound. shipping weight. in other words, they're not here anymore.

i do have a spare 01 head but dont want to disassemble it.

send me your email and I'll email you the engine mechanical section.

aznDragonX

iTrader: (5)

yeah..they are being ship to my engine builder!