INTAKE VALVE SPRING INSTALLATION

[tricky lugnuts]

Hey Everyone,

       Have a '71 Charge SE with a freshly rebuilt 340 in it. Problem is I broke an intake valve spring -- the one for the front cylinder of the driver's side engine bank -- and am curious to learn of a way to fix it myself in the driveway. Local rip-off shop wants $150 to fix it. New spring, for stock application, is only $4.60 through local parts house -- so I'd like to save some money, if possible.
       Last time I saw someone replace a valve spring, with the head on the motor, they used a neat little valve spring compressor ($20 at parts shop) and compressed air to fill the cylinder and keep the valve from dropping down, as well as a little magnet to pick the retainer locks out. Problem is, I don't have an air compressor.
       Will the umbrella-style seal on the valve keep it from falling down into the cylinder? Another Local Yokel rip-off mechanic refused to work on my car, but recommended feeding rope in through the spark plug hole until the cylinder is full, to keep the valve up so I can swap out the springs. Sounds kind of... well, strange... but I suppose it might work if you can stuff enough rope in there --- and hopefully get it all back out. Would a finger, or a coat hanger, reach into the cylinder and maybe be able to hold the valve up to swap the springs out?
     If anyone has any ideas/suggestions/warnings please let me know!!!

                                                                 tricky lugnuts

[Steve P.]

I have done it both ways you described. I like the compressed air in the cylinder the best. It doesn't take a huge compressor to keep the valves shut. You can barrow a small compressor from a buddy, do it at his house or rent one for a few hours pretty cheap.

To do it with an air compressor you will also need a special hose with an air chuck fitting on one end and a fitting on the other end that replocates a spark plug. These are easy to find. Just go to your favorite parts/tool store and buy or barrow a compression tester kit.

It may sound like allot of extras going on here, but these are tools you should have in your tool box if you want to make the car hobby part of your life..

Just make sure you have everything in hand before you go rent a compressor. If you do it right you should be able to get away with doing this job yourself for under 70. bucks.  If you have a buddy with a compressor, spring compressor and comp. tester, you should be able to do this for $5.00 worth of spring and enough beer to make your buddy happy...

[Chryco Psycho]

the rope trick works , use a soft rope , it is the second best way to hold the vlave up , air is better btu if you don`t have air rope works great

[tricky lugnuts]

Thanks for the advice Chryco Psycho and Steve P. I'll let you know how everything works out. New spring comes in this Thursday so I'm getting set to bust a few knuckles this weekend and get the old Charger back out on the road.   

                                                                     tricky lugnuts

[tricky lugnuts]

Thanks again for the input. No air compressor was needed. Valve spring installed in less than one hour, at a cost of $25 -- and now I have the compressor tool to do it again next time, too, without any worries. Charger runs great again. So great I splurged and bought some Mobil One fully synthetic oil to treat her too. Here's to more burnouts in the future!!

[Steve P.]

Glad to hear you GOT-ER DONE without much trouble..  Did you change them all or just the one??

[gremlinsteve]

kewl deal. but did you figure out why the valve spring broke and if the valve was bent in the process>?

steve-o

[tricky lugnuts]

I only changed one of the valve springs. This past summer I had the cylinder heads redone -- heads milled slightly for a flat surface, valves reground -- one exhaust valve replaced -- new guides, seals, and harden valve seats installed to run on unleaded gasoline. All of the valve springs were tested, and, reused -- so those I have not replaced are 35 years old, to the best of my knowledge. Also, the engine has a slightly higher lift cam -- so maybe that is why one broke. When the spring broke, I was doing one hell of a burnout and I don't have a tach installed, so....
As far as the valve being bent, I don't think it was... Runs like a champ again. But if you know of any way to tell if the valve was bent, short of removing it and checking, or any symptoms of a bent valve, I would be happy to know.... I never heard any kind of noise, such as valve hitting piston, so I'm thinking the valve should be fine -- but I am no expert. Thanks...

                                                                         Tricky lugnuts

[gremlinsteve]

it might have ridden without hitting the piston. my advise would be to replace all of the 35 year old springs. that way you dont have a terrible mess one day. its easy as you now know and its insurance against destroying that 340.

pull a compression check on the cycl. that ate the spring. if the valve is bent, you will be down on compression. you can also pull a leak down on it.

enjoy.

steve-o

[69fourspd]

Out of curiosity, how much pressure do you need in a cylinder to retain the valves?  I assume it would be a good idea if you put the piston all the way to the top just in case? Then you could retrieve the valve without pulling the head.  Right?