Gen II Valve Springs
- Thread starter GPW
- Start date
Valve springs are selected based on many factors. Depends on the cam specs/valves/engine spec/etc. Sorry there is no easy answer there are alot of variables. Switching from Ti valves to SS valves alone may be enough merit to swap in "stronger" springs.
Last edited:
With all of our race motors we have specific seat and over the nose pressures that need to be met depending on valve weight and cam profile, also spring wire material is selected to keep from "coil bind" None of this is good area to "learn" what does not work as I am sure you already know..
I would most certainly hit up the guys that built the valves/cams as they should already have benched the combos to find any bind/float or bounce issues...
I would bet that the heavier SS valves need higher over the nose pressures to stop float and higher seat pressures to stop any bounce..
I would most certainly hit up the guys that built the valves/cams as they should already have benched the combos to find any bind/float or bounce issues...
I would bet that the heavier SS valves need higher over the nose pressures to stop float and higher seat pressures to stop any bounce..
Draco1340
Registered
"If" you wanted to make the Ti valves work at 250HP+ levels at slightly increased spring pressures, it would also make sense to increase the valve land for increased heat transfer. The modulous of titanius drops dramatically at temperature, and the land is really the only area the heat gets out. There are some exotic materials that were looked at for F1 valve seat materials that haven't yet trickled down to bikes (tungsten coppers and such?). SS is the industry standard for valves, but unfortunatly SS is heavy and conducts heat very poorly.
hmmm Beryllium Copper alloys :drooling3: 
hmmm Beryllium Copper alloys :drooling3:
Beryllium can be a very hazardous material. Please be careful when handling this material and especially if you do anything like grinding, milling, or cutting. It can cause death. There's no cure for Chronic Beryllium Disease.
Hectic
Registered
I think I still have some beryllium ping wedges, should I get rid of them? ???
after you open up that seat width, what kind of issues have you seen with carbon or other build ups? or can the still keep the garbage beat off?
We worked very rarely with Ti valves (cost vs benefit) but plenty of SS on fuel and sodium on gas motors.. we kept faces as narrow as possible to avoid leakages..
yep, send them to me
Draco1340
Registered
Carbon buildup isn't the worst of it (and yes it happens). You lose flow with a wide seat land. A fancy 5 angle valve job flows great but has bad heat transfer. Just about everything you do for a nitrous motor comprimises a N/A motor. All the normal nitrous tricks (advancing the exhaust cam, dropping compression a tad, bumping spring pressure, retarding ignition, increasing exhaust valve diameter and land, and increasing octane) all tend to hurt power off the juice. I've lost motors twice due to melting the heads off the valves, so I typically open up the land and accept the comprimise. Its worth talking to your engine builder about it.
Regarding Berillium Cu, there are better things out there for seats. Just an interesting story, in the mid 80s, the cost of Berilium dropped after what was left of the Soviet Union started shipping tons of it to this country. It turns out they were using the material to regulate the fuel rails in reactors, and a lot of this material that ended up here in the states was radioactive as hell. The shop I managed at the time actually measured rads on any new lot of Berillium alloys that came in. It was a real problem. There was even some clever group that started building bicylce frames (BeYond I think was the name) that went belly up after they found peoples nuts started glowing at night.
202mphbusa
Registered
beryllium is hazardous when cutting it
not when just sitting there
I machine beryllium copper just about avery day at work
keep a oil line on the cutting and don't breath the smoke
VER IMPORTANT
not when just sitting there
I machine beryllium copper just about avery day at work
keep a oil line on the cutting and don't breath the smoke
VER IMPORTANT
Sounds like something I'll avoid.
Draco - I was just reading an article about Cliff Moberg of Moldstar. Seems they're got a great replacement to the beryllium aloy seats. Have you heard about Moldstar 90 (MS90)? MS90 comprises of a copper alloy with 7% nickel, 1.5% silicon and 1.5% chrome. I've heard/read about the MS22 being used for valve guides and pushrods with excellent results but the use of MS90 is new to me.
On the same Beryllium note, they've been using making piston pins with beryllium in a steel sleeve. Better than the Ti DLC coated pins (galling issues) and has a reduced mass compared to just steel pins.
On the same Beryllium note, they've been using making piston pins with beryllium in a steel sleeve. Better than the Ti DLC coated pins (galling issues) and has a reduced mass compared to just steel pins.
Regarding Berillium Cu, there are better things out there for seats. Just an interesting story, in the mid 80s, the cost of Berilium dropped after what was left of the Soviet Union started shipping tons of it to this country. It turns out they were using the material to regulate the fuel rails in reactors, and a lot of this material that ended up here in the states was radioactive as hell. The shop I managed at the time actually measured rads on any new lot of Berillium alloys that came in. It was a real problem. There was even some clever group that started building bicylce frames (BeYond I think was the name) that went belly up after they found peoples nuts started glowing at night.
Last edited:
Draco1340
Registered
Commuta,
Pretty much exactly what I was refering to. The MS90 is very similar to the 18200 / 18150 Chrome / Copper I've played with before. The ~1.5% Chrome gives the copper great strength and hardness without affecting the thermal conductivity of the copper. 18200 is probably cheaper than the Moldstar alloys.
The material I whant to try (but haven't yet) is Copper Tungsten (~55% W) used in high speed electro forges for stainless. The hardness and strength (around 150ksi) is pretty rediculous for a copper alloy.
Pretty much exactly what I was refering to. The MS90 is very similar to the 18200 / 18150 Chrome / Copper I've played with before. The ~1.5% Chrome gives the copper great strength and hardness without affecting the thermal conductivity of the copper. 18200 is probably cheaper than the Moldstar alloys.
The material I whant to try (but haven't yet) is Copper Tungsten (~55% W) used in high speed electro forges for stainless. The hardness and strength (around 150ksi) is pretty rediculous for a copper alloy.
I've strayed away from tungsten in the past but will have to look into this alloy after all. 
No one knows. You have people that milled this stuff for 30 years and are healthy and clerks that worked next door that are ill. Kinda like an allergy that takes the lungs out.
Similar threads
