GSC Lifters too Tall? (Valves open)

[EG Hatch]

I recently bought a set of gsc lifters and when I installed them on the exhaust cam after bleeding them down I notice that even with dks regrind cams that the lifters are fully compressed and slightly opening valves. Cylinder 2 and 4 are slightly open with the dowel at the 12 o'clock position.

Is this normal or is the clearance in my 6 bolt head off? Is it possible that they need to be bled down more? I thought they seemed to be fully compressible when installed.

Thanks,
Eric

 

[Dxc545]

After the lifters are bled, they should be easily compressed with your fingers. Is the head on the block right now?

 

[EG Hatch]

Yeah head is on the block. The lifters are all easily pressed in by hand, and I was pretty sure that they were able to be depressed to the same height as when the bleeder valve was pressed.

 

[Dsmkauai]

Do you have the dks shims in the head that are normally used? Might be why there to tall. It's basically just a small washer that goes under the lifter.

 

[Dan90tsi]

I just finished my build and went through the same thing. The GSC lifters sat too high and the valves weren't closing...I just pulled them and replaced them with the 3g lifters. I just figured that the stiffer spring they use maybe causes them to sit a little higher which you need to machine the stem height of the valve to adjust for this. I just decided to replace them.

 

[EG Hatch]

Do you have the dks shims in the head that are normally used? Might be why there to tall. It's basically just a small washer that goes under the lifter.

Yes I have the shims but I installed the cams without them to check the working height of the lifters. SO even without the shims I am having the valves hanging open with the dowel at the 12 o'clock. I can rotate the cams and the valve can close when the base circle is on the rocker, but when the lobe is starting to cross the rocker it definitely opens them up.

So again with the cam installed and the dowel at 12 I should expect all valves to be closed with fully bled lifters?

I just finished my build and went through the same thing. The GSC lifters sat too high and the valves weren't closing...I just pulled them and replaced them with the 3g lifters. I just figured that the stiffer spring they use maybe causes them to sit a little higher which you need to machine the stem height of the valve to adjust for this. I just decided to replace them.

This is pretty concerning since these cost almost 200$... I really don't want to have to buy another set.

 

[Dan90tsi]

Yeah I totally understand man. I hated to do it myself but I had a little extra cash so I just did it. I hope you can maybe find the exact cause and let us know.

 

[Dsmkauai]

You relize at tdc there are a few valves slightly open its not until like 6-7 teeth past tdc that all the valves are completely closed. Or motors have valve overlap.
http://www.dsmtuners.com/threads/wh...-open-and-same-with-the-intake-valves.467087/

 

[EC17PSE]

Well im on stock cams but my gsc lisfters are perfectly fine, try bleeding them again and check the rocker is installed and sested correctly. I dont have any issues with mine so not sure why cams would make it any different! Cams are not that big to cause this and a stiff lifter would in its uncompressed state

 

[steve]

Have you measured the valve tip installed height on each valve?
Are the rockers loose when on the cam base circle?
Once you on the cam lobe ramp you want the rocker to start opening the valve.

The cylinder firing order for all 4G63's is 1-3-4-2 with cylinder 1 and 4 paired, 2 and 3 paired and 180* apart from 1/4 so that when 1/4 are at TDC, 2/3 are at BDC.

With the cam timing marks aligned and the dowels up the cams are set for cylinder 1 to be at the beginning of the power stroke, cylinder 3 at the beginning of the compression stroke, cylinder 4 at the beginning of the intake stroke, and cylinder 2 at the beginning of the exhaust stroke. (If I got the order right, it's early)

Gary posted a good explanation of the valve timing in http://www.dsmtuners.com/threads/degrees-to-close-valves.444971/#post-153071377 with http://www.dsmtuners.com/forums/attachment.php?attachmentid=128779&d=1318449301 to reference.

The net of this is that under these conditions (dowels up, marks aligned); Cylinder 1 has both set of valves closed, cylinder 3 has the intake valves open started to close, cylinder 4 has both intake and exhaust valves partly open (in overlap), and cylinder 2 has the exhaust valves partly opened.

So again with the cam installed and the dowel at 12 I should expect all valves to be closed with fully bled lifters?

I hope you see now that the answer is no.

This head looks to be close to TDC timing, note which are open.

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[EG Hatch]

Have you measured the valve tip installed height on each valve?
Are the rockers loose when on the cam base circle?
Once you on the cam lobe ramp you want the rocker to start opening the valve.

The cylinder firing order for all 4G63's is 1-3-4-2 with cylinder 1 and 4 paired, 2 and 3 paired and 180* apart from 1/4 so that when 1/4 are at TDC, 2/3 are at BDC.

With the cam timing marks aligned and the dowels up the cams are set for cylinder 1 to be at the beginning of the power stroke, cylinder 3 at the beginning of the compression stroke, cylinder 4 at the beginning of the intake stroke, and cylinder 2 at the beginning of the exhaust stroke. (If I got the order right, it's early)

Gary posted a good explanation of the valve timing in http://www.dsmtuners.com/threads/degrees-to-close-valves.444971/#post-153071377 with http://www.dsmtuners.com/forums/attachment.php?attachmentid=128779&d=1318449301 to reference.

The net of this is that under these conditions (dowels up, marks aligned); Cylinder 1 has both set of valves closed, cylinder 3 has the intake valves open started to close, cylinder 4 has both intake and exhaust valves partly open (in overlap), and cylinder 2 has the exhaust valves partly opened.

I hope you see now that the answer is no.

This head looks to be close to TDC timing, note which are open.

You must be logged in to view this image or video.

Thanks this is exactly what I needed to know. I haven't measured valve tip height as I dont have a tool to do so, but I haven't removed the valves/springs on this stock head with ~50k miles. I am just looking at the lifters to try to decide whether the shims are needed. They seem to be in the middle third of the operating range with the base circle on the rocker.

The rockers themselves are slightly loose when the base circle is on them but they can be wiggled without falling off. This is normal right?

This is my first time really getting into one of these heads so if I'm missing something I'd appreciate some more knowledge being dropped on me. My valve positions are identical to the image you posted as well, Steve.

Thanks,
Eric

 

[steve]

The rockers themselves are slightly loose when the base circle is on them but they can be wiggled without falling off. This is normal right?

Yes as I understand things, that wiggle is what the HLA is going to remove when it fills up with oil and pumps up.