I have another post dealing with valve lash cap issues. Long story short I need to replace them all. They are all stuck on and there is not enough "Bite" to get enough pull using vise grips. They do sell valve lash cap pullers but I thought if I could compress the spring down a bit and remove the keepers, I could get get more access on the cap to pop it off.
Problem:
I have the piston at TDC and the car in gear. I have about 80psi in the cylinder. As I compress the valve with my very nice LSM shaft rocker mounted spring compressor, the valve moves with the retainer and keeper causing the pressure to bleed to zero within the cylinder. The LSM tool instructions state to tap the top of the threaded rod with a brass hammer to free up the keepers. If I do that with no pressure in the cylinder, the valve will likely drop. Perhaps I am putting to much load on the spring and should just snug it up without opening the valve and then wrap it the hammer. There is enough play in the LSM tool possibly for that approach to work. The next question is how far can the valve drop? With the piston at TDC, flat top pistons with reliefs and zero decked and a 0.73" valve lift, it looks like if it does drop, it won't go far enough in to where I cannot still grab it. The heads are AFR 245's.
Any idea's? Tricks?

Thanks!

Keith

 

Place a socket over it about size of retainer (a little smaller) and give it a whack with a hammer. It should jar the retainer loose from keepers. Then you can compress springs.

JIM

 

 

I never had much luck with compressed air in the cyl for two reasons. First, if that piston is not perfectly at TDC, the engine would start to roll over.
Second, those rubber hoses that fit the sparkplug hole make it tough to clear header tubes and to snug it down with a wrench.

The trick with the rope method is to use nice soft, flexible line about 1/4" thick. Feed a couple feet in then hand crank to TDC. You should have about 0.080 - 0.100 clearance on the piston to valve near TDC. Those valves won't drop far if t all.

 

I did mine with compressed air. If the pistons up and the valve drops its going where. It wont fall into the cylinder.

 

I usually tap the retainer all the way around a few times to loosen the keepers. In desperation once I stuck a small zip tie through the spring coils and around the valve stem. Cinched it up as tight as I could and pulled the spring. Zip tie held the valve from dropping. Took it off with a penknife when reassembled.

 

Thanks guys for all of the great ideas. I thought about the zip tie but with double springs it looked like a real pain to get it in there. I like the rope idea!!

Thanks!!

 

I have tried both methods. I'm not fond of the rope but it works.

I use 150# compressed air. A good threaded sparkplug fitting with an O ring will not leak.
Tap the spring retainer with a socket held over the retainer just larger than the V retainer / keeper. Then compress the spring and remove the V retainer and the spring will come off easy. I have also tapped the top of the spring with a 5# rubber hammer with a rag on the spring to catch the V retainer / keeper if it comes out. Then use the spring compressor.
Both methods work well.

 

The zip tie suggested by stumpshot will work if you can get past your double springs. I had the same problem you are having with several keepers being stuck. Before tapping with a hammer to loosen them, I pulled a length of wire thru my double springs and made two wraps around the valve and then cinched it up tight to keep the valve from dropping. Then a good whack with the hammer loosened the keepers and allowed me to use compressed air to hold the valve shut and use my valve spring compression tool. The wire can be pulled out after you are done.

 

I just reinstalled my AFR heads. To put nuts on the head studs I have to remove 4 springs per side

I've done the air because I do leak down testing.

I was in a hurry so I just removed the springs with out caring about if they dropped down. Just compress the spring enough to use a magnet to grab the keepers. My guides and Teflon seals have enough friction that the valves don't really drop. I was able to grab the tips and place the spring and retainer over the valve stem, compress, and reinstall the keepers

in the past doing the same thing, I had a valve stem drop below the seal. I just put a breaker bar on the damper nut and hand rotated the motor and use the piston to push it back up .

the worst case scenario is that you have to remove the head. To me time is money so just skip the rope and air or if you are really worried just rotate the motor to TDC in each cylinder and it won't fall that far. At max lift in solid roller motors you have a valve to piston clearance. Even with the valves touching the pistons with no retainers the stem is still above the seal.

 

But OP is dealing with old stuck keepers with possibly no seal tension. It is possible to bend a valve using the piston to support it while freeing stuck keepers. And if air spins piston to bdc, it is possible to drop valve to where head has to come off. PITA that rope is, it spreads against a lot of the valve face and is soft, protecting both valve and piston.

 

I use a tool like in post 8. Once the springs compressed lightly wack the top of tool with hammer to drop the spring down n away from keepers. At this point remove keepers by hand, After hitting top of tool if valve drops its simply a matter of grabbing the tip by hand and pulling it back up. At 150 psi I had no issues with valve drop.

 

Works for me.

That valve spring compressor shown in this thread works ok, better for single spring applications but a a pain for dual spring apps.
I would recommend one like this.

https://www.summitracing.com/parts/p...4aAhM5EALw_wcB

 

cylinder with both valves closed, compressed air into plug hole. use lever tool, so easy.

 

I have shaft mounted rockers. This is the one I have:
https://www.summitracing.com/parts/lsm-sc-150

 

the problem with this unit is the short 9 inch handle. Not enough leverage, the 16 to 20 inch are good enough for racing roller springs

 

Yes I have used the rope idea posted. Preferably a nylon rope because it seems to have more give in it (compresses more) than other rope.

 

If the engine wants to spin with the air, I just leave the breaker bar and socket on the balancer nut wedged so it can't spin.

 

I was suggesting one of that design not that one specifically. Mine is essentially a pipe with a rubber handle slipped over the actuating arm, so you could use any length pipe you needed for the leverage desired.

 

So I gave the top of the LSM tool a couple hits with my brass hammer with tool just in contact with the retainer as directed. That did the the trick! with 100 psi. I was able to get the lash cap off with my handy Harbor Freight vicegrip slid hammer. Still not sure why they wore so badly with only a few dyno pulls on them. I will post a pic. My guess the builder may have heated them up to make them easier to install taking some of the hardness out of them. Also with the piston at TDC, the valves are in no danger of falling in far enough to be a problem.