Backing the valves off

[outsider347]

I will soon be done with my 3.0 rebuild.
The engine will be in proper storage for probably more than a year before it will be back in the car for proper break in

Any problem with backing off all the valves to relieve pressure on the springs?

Tks Gents
& Happy Holidays to all

[Henry Schmidt]

Originally Posted by outsider347

I will soon be done with my 3.0 rebuild.
The engine will be in proper storage for probably more than a year before it will be back in the car for proper break in

Any problem with backing off all the valves to relieve pressure on the springs?

Tks Gents
& Happy Holidays to all

No problem, just a lot of work. You will find as you remove the valve covers that you won't have to back off all the valve adjusters and even fully loosened some valves will still have some tension.

[ahh911]

If you can get access, spin the fan/crank 30 degrees or so every few months, though I've never heard of springs going bad in cars that sit for a year, is this a known fact? I suppose dealers/manufacturers would have a best before date for new cars? Just kidding, why are you worried though, have you read or heard something?
Phil

[safe]

The valve springs are always under some tension even when the vales are closed.
Seems like a bunch of extra work for no benefit.

[outsider347]

Originally Posted by safe

The valve springs are always under some tension even when the vales are closed.
Seems like a bunch of extra work for no benefit.

We race stock cars, every engine builder, (V8 pushrod engines) recommends this during off season

[Walt Fricke]

Interesting that stock car racers would do this. I've never heard of it despite years of reading Circle Track (now defunct). My understanding of torsion bars is that a) they never change their rate, and b) they can develop a set or twist if overloaded.

Valve springs should be operated well within their elastic limit, so they ought not to take a set (reduced seat pressure, maybe lower "float" RPM). Just sitting there puts no unusual stress on the valve springs.

To be sure, a Chevy V8 with pushrod OHVs is a relative snap to deal with - pop valve covers, unscrew the nut holding the rocker on its post, and done. When it is time to start the engine, just tighten things back down to where they were. Not like messing with the exhausts on our 911s, where you are best off having drained the oil.

As Henry points out, the valves in the heads sitting on your work bench have pressure on them from the springs. In the engine with rockers installed some will be more or less open, others (roughly half) will be closed, but with seat pressure. If really worried, might be easier not to install the rockers.

Nobody does this with their street cars, Porsche or other. Lots of fine cars are not driven in the winter. All those driveable but seldom driven cars in museums and private collections. There are measures taken to keep batteries charged and gasoline from going stale. But worrying about valve springs?

[dannobee]

I was a crew chief in circle track racing for over two decades. We never backed off the rockers. Might be a regional thing though, who knows. Then again we had the ability to test practically year round on the west coast, so if it sat for a month or two it wasn't that big of a deal.

But if we're talking regional stuff, do you back off the rockers on snow plows or snow blowers? Of course not.