COOL DOME with or without Head Stay?

[ERBE]

Whats the Pros and Cons of a Cool Dome with and without a head stay???

[matt250r21]

I have had both cool heads with and without the head stay mount. The only difference is one has the mount and the other dose not. Didn't matter to me, I never ran the head stay anyways. I would worry more about if it has an o ringed head gasket or not. The only other difference I can think of is one would wiegh a little less.

[C-LEIGH RACING]

A head with the stay bolted up is useing the head & cylinder as another member to support the engine & frame.
If you have a head with no head stay mount, when running the engine it frees up the top end to vib & rev out a little more.
With the head stay bolted onto the engine it locks everything in place & at times, binds the top end.
With no head stay, you stand more of a chance of breaking case studs from the top end being free.
In a sence, when you realy pump up an R engine with compression & hp, its trying to rip the top end off the cases everytime you run it & is easier to do that with no head stay in place.

Its just one of those little things people do trying to add hp, all those little thing soon add up.
Neil

[ChvyCruzen]

I was wondering what the affect of no headstay has on the R's. The R I just bought doesnt have a headstay or the mounts.

[matt250r21]

Been a long time since I had a stock frame, forgot how bad they crack without the extra support. Good points Neil! How much compression would it take to pull the studs out of the cases? I 've been running my R's without the head stay for 10 years with no problems and my compression is around 200.

[deathman53]

I use the head stay(with all the stuff), some guys use the head stay, but don't put a bolt in the head-head stay, they use the head stay for the extra frame support. I have one 250r without using the head stay, its a 86 atc250r, one of the holes is being used to mount the cr 250r ignition coil. If you use spacer plate motors, sometimes the head stay doesn't line up with the head, its off, many just use a smaller diameter bolt.

[Tom TRX250R]

I would not suggest running without a headstay. You are losing some of the frame's support, plus Honda designed the frame for support there so without it will cause other places to be prone to cracking.

[matt250r21]

On a stock frame all the support you can get is a good idea, but the Leager frames are pretty tough. I've never run a head stay on them.

[wilkin250r]

Originally posted by C-LEIGH RACING
If you have a head with no head stay mount, when running the engine it frees up the top end to vib & rev out a little more.

Neil

Do you really think the headstay binds up the top end?

No doubt you have more experience with these engines, but all my experience with electric motors and vibration is exactly opposite.

It started with legos when I was young. I had a motor running a propellor, and one side of the prop broke off. I found that holding the motor tightly to reduce it's movement dramatically increased the RPM.

Years later, I had an electric motor driving a belt at my place of work, and it was off-balance and vibrating, and only runnging about 600rpm. By welding extra braces and securing it to the table securely, the speed increased to 900RPM.

Another time, I had a motor attached to a small fixture about the size of an end-table, used to rotate a small drum. The motor itself was securely attached, but the balance issue would vibrate the entire fixture. By securing the fixture to the concrete floor, the speed of rotation increased. The motor was geared down, so I don't know the actual RPM of the motor, but it was used to rotate a small drum, and the rotation of the drum increased from 15rpm to 20rpm, which says the motor speed saw at least a 30% increase.

These experiences tell me that the more tightly and rigid something is held, the FASTER it can turn. Granted, these were external imbalances, and electric motors, but I figure the same principle would apply.

By that logic, I can't imagine that taking out the headstay would allow the engine to rev faster. If anything, I would imagine the opposite.