When to change Valve Springs
 

Guys,

I'm running a 509 blower motor in my Fountain 29 and was curious how often I should change the valve springs. Thanks.

Re: When to change Valve Springs
 

The advice I have been given on HP500efi's is 200-300 hours. Also read that standard (n/a) HP500's were worse on valvesprings.
I assume you are running similar seat pressure to a HP500, so I would say between 150 and 250 hours.
How hard do you run? What conditions? What does your motor builder say?

Re: When to change Valve Springs
 

I am pretty easy on the motor. Mostly run in the 3500 -4500 range. Occasionally will make a short full throttle run. Close 90 in a 29 footer can be a handful at times.

I haven't talked to my engine builder yet. Just curious what you guys thought.

Re: When to change Valve Springs
 

A lot depends on the cam along with what springs are installed. If you trust your engine builder go with his reccomendation. Really need much more info or we are just guessing in my opinion.

Re: When to change Valve Springs
 

The advice I was given by my engine builder was 200-250 hrs for springs. My cam profiles are mildly aggressive with reasonable lift. I also rotate the engines intermittently during lay-up to keep the same springs from being under pressure all winter and taking a set. I have no absolute proof that it helps but to me it seems worth the effort.

Re: When to change Valve Springs
 

Moroso makes an spring checker that goes on the head and checks the spring. All you have to remove is valve cover. If the seat pressure (closed pressure) is 120# or below you need to change them. If you find broke valve springs and the wire break is jagged, that is a sign of harmonics. This means the spring has been bouncing after it closes the valve due to loss in pressure. Harmonics kills valve springs. If any springs are broke I would pull intake and check the lifters for cracks around the axle supports at the bottom of the lifter.

Spring checker runs around $80 mail order.

Chris

Re: When to change Valve Springs
 

Every 200 to 250 hours or sooner if you have stabbed the limiter or floated the valves on a few occasions. Once you float the valves then valve float will come on at a lower RPM the next time.

If you are one of those guys that over springs an engine then the valve springs will last a lot longer but you will be replacing your cam every 200 hours. I used to know a guy that put tri-spring K-Motions on his 6500 RPM street car. Well it took 200 extra HP just to turn the cam over and the thing was a dog. He got a blessing in disguise when the crank key sheared and grenaded the engine. Sometimes it is best just to start all over. hey he saved the cam though. :crazy: :crazy:

Roby

Re: When to change Valve Springs
 

Springs are cheap compared to the damage that can be done in my opinion. I know guys that have run a lot longer on a mild set up but I think your engine builder knows best. You can stretch the time longer but do you want to run the risk? By the way did you get any estimate from your builder on lifter life? Just curious. I struggle over these same questions and I do my own work as much as possible. :drink:

Spring checker will help but I would have to remove exhaust to use them. Why not just loosen evrything up during winter lay up and then check spring pressure at the start of the year during spring tune up and service if yor worried about it?

Depending on how long it has been it is almost as easy to throw a set of springs on. But I do my own work.

Re: When to change Valve Springs
 

Holy Crap !!! when I first read this I was thinking "this guys rotates his engines? " ....... :drink: