ptuomov

What kind of stiffer valve springs are people using on the '87 s4 4v heads? I've heard of people using Ford Pinto racing (dual) springs. Any other solutions?

Anybody knows of stiff beehive / conical springs that would fit? Do all racing valve springs that fit 944s2 and 948 also fit 928 s4? If they do, then perhaps the Lindsey racing beehives?

Any help would be greatly appreciated.

BC

944S2 springs. 12 bucks or so a piece, and you can get them from 928intl.

ptuomov

Are you talking about the part number 944.105.467.03?

How much stiffer are they? The 928 s4 redline is 6800 rpm and the 944 s2 redline is 6500 rpm.

ptuomov

Would these also fit in the 928 s4 heads?

http://www.lindseyracing.com/LR/Parts/LR-944-RVS.html

---copy and paste---

944S2 / 968 16v RACING VALVE SPRINGS:
We have 4 different valve spring set-up's for the 16v head.
1) "Standard" spring kit. This drop in replacement spring set (inner and outer) utilizes the stock spring cup and retainer. These have a seat pressure of 80# at installed height.

2) "Beehive Racing" spring kit. This is a Beehive shaped spring. This is a single spring arrangement with replacement spring cups and chrome moly retainers.

The Beehive style spring has several benefits. Because of the changing spring diamater, the harmonics associated with a straight spring are not there and they don't need a innner spring to cancel out the harmonics of the outer spring. The wire is actually oval shaped versus round. This allows for more lift before coil bind and the spring is thicker where it is usually prone to cracking making it more resialant. The smaller retainer end of the spring allows for a smaller and lighter weight retainer. The moving mass of the spring is lighter since that's the smaller end. Without a inner spring, they run cooler because there is no friction between the two. This can aid in cooler oil temps.

This "Beehive Racing" spring has the following specs:

80# Seat Pressure at Installed Height of 1.490".
202# Nose Pressure at .400" Lift.
235# Nose Pressure at .500" Lift.
245# Nose Pressure at .550" Lift.
Coil Binds at .600" Lift so max .550 lift cam recommended.

This spring works well on NA application or Turbo'd up to 15 psi of boost. If going higher in the boost, we go to the next set.

3) "Beehive Racing Plus" spring kit. This is the same Beehive shaped spring as the Beehive Racing spring kit. This kit simply uses a thicker spring base to increase the spring rate. Better suited for higher boosted applications of the 16v heads.

This "Beehive Racing Plus" spring has the following specs:

90# Seat Pressure at Installed Height of 1.490".
TBA# Nose Pressure at .400" Lift.
TBA# Nose Pressure at .500" Lift.
TBA# Nose Pressure at .550" Lift.
Coil Binds at .560" Lift so max .510 lift cam recommended.

4) "IRL Racing" spring kit. The Spring Kit includes 16 Inner and Outer valve springs, 16 spring cups and 16 Moly Retainers. You can also choose the Titanium Retainer option for additional valve train weight savings.

These are the same spring used on IRL (Indy Racing Leauge) engine and our top of the line.

BC

If you want to spend 600 dollars on springs thats up to you.

What I suggested works just fine in 928 race cars across the country.

ptuomov

For me, big part of the fun is just figuring out what would work and what would not. To make informed choices.

I agree with you that those Lindsey springs are unlikely to be cost effective.

Regarding the S2 springs. Do you know what's the rpm limit of these springs with the lighter 48 gram lifters, otherwise stock valvetrain, and GT cams (intake .393” / 214 deg, exhaust .353” / 200 deg)?

BC

With the lighter tappets it probably is above 7200rpm.

At least I hope it is.

hacker-pschorr

Trip down memory lane.......

Way back when, didn't someone have issues snapping timing belts using a very stiff spring, trying to run high 7k+ rpm's?

BC

944S2 spring need to be unsprung a bit for our 4V heads. If you were to use the current spring seats and the 944S2 springs you could break something.

RyanPerrella

im interested in lighter retainers

Is anyone making one for our cars that will work with the stock lifters, or ideally the lighter INA ones?

Whats the retainer market like?

slate blue

If you run too high a spring pressure your lifters may not be able to take it. Most well thought out designs choose to use lighter components and slightly higher spring pressures, 145# is pretty high and by Lindsay Racing's admission they have had lifter troubles.

Greg

ptuomov

It is my understanding that this is comment applies to the 2-valve heads. Two valve heads have big valves and thus have to use stiff springs. For two valve heads, the Lindsay website reads "We do not recomment going higher then 140# on a hydraulic lifter. We typically use the 150# kit on solid lifter cam set-ups and 160# if a very high boost and/or RPM solid lifter application. "

For 4-valve heads, I don't think one ever has to go to that kind of spring forces. Lindsey offers 80# and 90# rated springs for the 4-valve head. The 90# is for the "racing plus" springs that according to them will suit high-rpm, ober 15psi boost engines.

The hydraulic lifters are the same strength for both 2 and 4 valve heads, right? Is this assumption correct? If so, then I don't think the strength of the lifter is an issue for the 4-valve head. 90# rated racing plus for the 4-valve head is still short of the garden variety 2-valve spring rating.

The hydraulic lifters can still be a problem for the springs, but not because of their inherent durability but because of their weight. My guess is that the stock 928 lifters are 74g dry + 25g of oil = 100g. The light VW lifters are probably 48g dry + 25g of oil = 73g. Both are heavy. Using moly retainers probably cuts the weight of the retainers from stock about 24g to about 12g. In the same way, in my opinion the main benefit from the above-mentioned beehive springs is that the effective reciprocating mass is lower since the spring is much smaller in the top end which withstands the greatest accelerations.

I am not getting paid by Lindsey to advertise their products, by the way. $1k for beehive springs and moly retainers for the 928 is kind of mind numbing...

Vilhuer

When using 944 S2 springs correct 944 WSM measurements need to be used in setting them up into heads. IIRR spring installation lenght is 2.5mm longer than 928 S4 etc '87+ 32V engines. 928 S3 use same thinner lower spring plate as 944 S2.