Comp 910 Valve Spring Install How-To

This thread will discuss the how to of installing Comp910-16 valve springs. This does not discuss the very important part of ensuring correct installed height. I will let TARM either add to this thread with that, or start a new thread on it. He has done it so many times, I couldn't be near as eloquent. Lol! I am using .030 shims in this just to show the mechanics of it.

This is under the understanding you already have everything removed including the injectors.

First ensure the cylinder you are working on is at top dead center. You can do this by using either a bendy straw, or other plastic probe long enough to slide into the injector cup, to gauge the position of the piston. I say plastic because a coat hanger or other metal probe may score the brass injector cup. Put the straw into the cylinder (provided its long enough. You may need a second person to hold it while you turn the motor over) Now put a socket on the crank and turn the motor over slowly by hand until the piston reaches the top of the cylinder. Move the straw up and down slightly while doing this so the straw does not get bound up.

Now remove the rocker arms using a 5/16" socket. Then pull the push rods if you are replacing them with aftermarket rods.


You will need a valve spring compressor to go on. I have this type shown below. It will need the bolt cut in half and a nut welded to the end as shown. I regularly loan mine out if you need one.


Put the compressor on the spring and tighten it down.


Once it is compressed the two keepers will come out. The best thing to do is use a telescopic magnet to get them out as you push the spring down.




Then just slide the compressor and spring off.

Then pull the valve seal off. Under the seal you will put the CORRECT shim.


Ensure the shim is completely seated. There are ridges around it where the factory machined the seat. It must fully seat onto the machined surface. Then replace the valve seal. You may have to pull up on the valve while pushing on the seal to move on to the next step.



Next compress the new comp910-16 valve spring with the spring head on.



Now insert the spring onto the valve.


Now reinstall the keepers. They're kinda fiddly little things so it is a good idea to put a rag behind the spring in case you drop one. Install them as they came out and release the tension on the spring.




Now install your new pushrods if you are upgrading them as well. Ensure they slip down into the bowl if the lifter. You will feel it go in.

Now reinstall the rocker arms and torque to 15#.

Reinstall the injector and the rest of the parts you removed.

All done!

P.s. don't forget to repeat the process for finding top dead center of each cylinder before removing that cylinder's valve springs. We don't want any valves falling into the cylinder.

Also, to get the rear valvesprings out, you may need to jack the engine up. Just as in the head stud how to, remove the motor mounts and jack up one side using a 2x4 to reach the exhaust manifold from the jack.

Nice write up with pictures to go with it. The picture really help with the explanation of steps.

Nice write ups!
When I did mine I removed the heater box on the passenger side to help give more room.

Oh Geez I totally forgot about that! You have to remove the airbox. For studs too. I'll go add that to the stud writeup. Thanks!

You should copy and paste that clip about the shim sizes and seat pressure.

As well as can this be done without pulling the injectors ?

Here is the link to the Comp Cams Valve Spring Specs Sheet. The 910 is on page 3 of 6 on the right #910

Here is the specs and needed info:

Here are the specs for the 910 striaght from Comp cams:

Base install height: 1.850" Maximum Coil Bind Height: 1.280" Inside / Outside diameter: 1.354" / 0.940 Spring Rate: 415 lbs

Install height : lbs 1.900" : 72 lbs 1.850" : 92 lbs 1.800" : 113 lbs 1.750" : 134 lbs 1.700" : 155 lbs 1.650" : 175 lbs 1.600" : 196 lbs


Factory install specs:

Install height: 1.810 Factory seal integral shim .045" Spring install height with seal: 1.76" Cam .410" Max Coil Bind height: 1.28"

I would recommend simply following the above install heights for the Comp Cams 910s as well that will give you a 130lb seat pressure. IMO between 1.750"-1.760" including seal and 1.800"-1.810" with out seal (measurement goal for use with micrometer) This will get you seat pressure between 130lb-134lb.

For reference here is the stock OEM spring specs new:

Closed Seat Pressure @ 1.76" = 110 lbs Open Pressure @ 1.35" = 250 lbs 350lbs per inch rate

A few stock springs had been tested that had 100K miles on them by individuals that posted the findings and seat pressure was found to be reduced down to barely 70lb at that point. Thus you can see the issue and why these springs were considered soft.




The shims I recommend are from Jegs. They come in a multi shim thickness kit

JEGS Valve Spring Shim Kit #555-20591

Valve Spring Shim Kit
1.437" O.D.
0.645" I.D.
Includes:
(16) 0.015" (blue tempered spring steel)
(16) 0.030" (case hardened steel)
(16) 0.060" (case hardened steel)

If you want to do the most accurate job of shimming back to a specific height such as factory spec then I recommend purchasing 2 packs that way you can combine two or more as needed to get the proper height for each valve. This way you could combine a 0.015 and a 0.030 if you needed 0.045 to reach proper seat height spec. Or most any combo you might need to get you close enough.

From what I have seen and given even minor amounts of cam and valve train wear and the max coil bind height of 1.28" and that is the max it can be and mine all measured lower. You could set your seat range without binding issues and a safety margin between 1.74 - 1.76 For every 0.01" of height compression pressure increases by roughly 4.1 lbs 1.74" = 138 lbs 1.75" = 134 lbs 1.76" (stock height spec) = 130 lbs



I also recommend getting the Proform micrometer from Jegs as well as its not to costly and has a decent range that covers both above and below 1.800" which IMO is needed.

Proform Valve Spring Height Mic 66902 JEGs#778-66902


This should give you all the reference info you need to do the springs accurately and to the correct seat heights.

Thanks TARM!

Wow great info, wonder if we can sticky this or have this bookmarked in a How to thread?

This needs a sticky !

In the pics you don't have the injectors in. However I was just mocking up the valve spring tool and it seems this could be done with injectors in place.

Correct me if I'm wrong, but for someone just wanting to help out a tired motor and not swapping injectors would save a lot of time.

Great job, that info was more tools in the bag for me.

Great job. I will leave this for a bit to see about any good additions. After that, it will not be a sticky. It will go into the West Point.

As far as if you have to remove injectors, I think you can do it with injectors in. You will want to pull the glow plugs for the test rod to look for TDC. Also, I did mine without pulling the air box.

My valve spring compressor looks exactly like that also. On the passenger side I used a ratcheting box end wrench (no room for a socket and ratchet, air box was in the way).

Not sure how you use the micrometer to measure the height.

The depth gauge rod in the bottom?

Read the description but does it measure at a set tension?

Where can i find a Tool like that? I'll be doing some springs down the road.

After installing the keepers and you have let the valve spring compressor loose AND rotated the crank so that cylinder is no longer at TDC, I like to tap the valves with a rubber mallet. Just to ensure that the keepers are seated properly. Just my .02

Homesteader said:

Where can i find a Tool like that? I'll be doing some springs down the road.

Click to expand...

The valve spring tool? Any parts store will have one. It has a star shaped handle on the top to tighten it with. It needs to come off and weld a nut on the top of it.

I need sell my valve spring compressor. Took the head apart now don't need it.

I made this thread a sticky as it needs to go to the library. It appears there is confusion on using the micrometer. Can someone address that esp with some photos?

Tom

Good write up. I will be following these directions in the next couple weeks.