I'm getting a 4000gsk kit soon. How do you replace the valve springs? Generally on gas powered motors I remove the sparkplugs and stick something in there to get the piston to the top so the valves can't drop but so much and change the springs. Can I do something similar with this 12v or is there another methiod?

 

honestly never done it on a 12 valve but have on many gas engine and the way you stated is the way i always did it also and that is the way i would do it if i were you

 

Bring each cylinder to TDC then if the fall you can just pull the valve stem back up , the valves will not fall as far as a gasser because of the smaller combustion chamber .

 

the fastest way i have found it to use a star type compressor, compress the spring all the way. this will let the valve down into the cylinder. then turn the motor over till the piston pushes the valve all the way up. then place a small magnet on the top of the retainer right by the keeper. then hit the star type compressor on the very top. the keepers jump out, the magnet catches them. the valve is resting on the piston. and the spring and compressor come right off. when putting in the new springs i find it works way better if you screw them in as far as you can before you start compressing the spring.

 

Thats kinda what I was wondering about. How to find tdc. I know that there is a pin that gets pushed in to verify tdc on #1 cylinder (I think #6 will be up also) but how about the rest? You say that the valves won't fall into the cylinder enough so that I can't get them out even if the piston is not up. And if they do I can rotate the motor buy hand to get them up?

 

I have been wondering about this too. Is there an adapter that screws into the injector hole allowing you to fill the cylinder with compressed air? Like thishttp://store.summitracing.com/partde...5&autoview=sku

 

No, you have to be sure you are working on cylinders at TDC, if you are off and the piston is down, the valve will drop right out!!!! This engine has a long stroke, the valve is no where near that long. There is a descriprion of which cylinders are up and down in the service manual.

You could also pull all the injectors and use a dial gauge with an extension and measure every piston to be sure it is at TDC. This would take forever.

 

re read my post, i told you how to do it easy, no tdc method needed.

 

What is this star type compressor that you are talking about?

 

it has the 5 or 6 sided screw wheel on top to compress the spring. i will see if i can find a pic.

 

http://cgi.ebay.com/ebaymotors/NEW-U...QQcmdZViewItem

 

I know what you mean!!

 

Cummins makes a spring compressor for 12v or 24v's. Compresses all springs at once on each cylinder. Very slick!

If you rotate TDC marking 120* each time you can do 2 cylinders at each setting.

RJ

 

gunracer1,
Thanks thats a bad a-- tool. I went ahead and purchased one. No more screwdriver in a sparkplug hole for me.

 

Mike, Will it fit on #5&6 with head on the block?
That's a lot better price than Cummins. After thinking about it, also like your way of finding TDC on each cylinder!
Learn a better way of doing things every day...on DTR.

RJ