DOD/AFM Delete Valve questions

[Geotrash]

Ok so I'm ordering the L9H cam tonight. Specifically #12711967 from LSXeceleration. I'm wondering if I should go ahead and change my valve springs since they have 90k police miles on them and the slight bump in valve lift might be too much for the already worn in valve springs. If so I might as well lap the valves while I have the springs off.

I'm planning on plugging my oil towers, and replacing my valley cover with one from a 4.8. I'm also planning on leaving the oil relief valve in the plan since I'm keeping the high volume oil pump. I'm replacing the push rods while I'm in there. Lastly I'm planning on replacing the seals to the exhaust manifold, air intake, oil pan, timing cover, heads, and valve covers. Anything else I'm missing?

Definitely replace the valve springs and stem seals. I assume you’re planning to replace the lifters but you didn’t mention it so figured I should. On the relief valve, plug it anyway. The oil pump has a pressure relief valve built into it so the only purpose the pop-off valve in the oil pan serves is to provide an instant release of pressure when the VLOM commands the DoD system off. Replace the cam thrust plate for sure as well. The gasket on the back side gets hard over time and can bleed off oil pressure. Chances are that engine spent a lot of time idling so get a good look at the timing chain and sprockets. They’re probably alright but they’re also easy to change and inexpensive.

I ended up doing my cam swap twice - partly because I didn’t replace the oil pump with a new one and had low oil pressure after the first swap. You’ll probably be alright, but just thought I’d mention it.

 

[iamdub]

Ok so I'm ordering the L9H cam tonight. Specifically #12711967 from LSXeceleration. I'm wondering if I should go ahead and change my valve springs since they have 90k police miles on them and the slight bump in valve lift might be too much for the already worn in valve springs. If so I might as well lap the valves while I have the springs off.

I'm planning on plugging my oil towers, and replacing my valley cover with one from a 4.8. I'm also planning on leaving the oil relief valve in the plan since I'm keeping the high volume oil pump. I'm replacing the push rods while I'm in there. Lastly I'm planning on replacing the seals to the exhaust manifold, air intake, oil pan, timing cover, heads, and valve covers. Anything else I'm missing?

Valve springs are cheap insurance and OEM "LS6" are the standard replacement. Chances are that the valve springs you have are the same ones. But, they're aged and now being subjected to more activity. You might look up stock valve springs for an L9H and go off of that. IMO, lapping the valves is a must-do since you'll have the springs off, anyway.

You can buy some fabricated plugs for the towers or, for ~$10, get a cheap wheel bearing from O'Reilly (THIS ONE), cut the cage apart and have a bunch of plugs.

Plugging the port in the oil pan can go wither way. As long as the valve is operational, it won't hurt to leave it. I replaced mine with a plug to ensure it would never be a leak point. Definitely replace the pick-up tube O-ring and be sure you install and seat it properly in the oil pump.

 

[Darren2014]

Valve springs are cheap insurance and OEM "LS6" are the standard replacement. Chances are that the valve springs you have are the same ones. But, they're aged and now being subjected to more activity. You might look up stock valve springs for an L9H and go off of that. IMO, lapping the valves is a must-do since you'll have the springs off, anyway.

You can buy some fabricated plugs for the towers or, for ~$10, get a cheap wheel bearing from O'Reilly (THIS ONE), cut the cage apart and have a bunch of plugs.

Plugging the port in the oil pan can go wither way. As long as the valve is operational, it won't hurt to leave it. I replaced mine with a plug to ensure it would never be a leak point. Definitely replace the pick-up tube O-ring and be sure you install and seat it properly in the oil pump.

I bought the little kit of 8 plugs from TSP. I ended up buying all my parts individually because I could never find all the manufactures of parts in the dod delete kits that are offered. I picked up Morel 7717 lifters, and Acdelco trays, all Felpro gaskets and head bolts, GM valve strings specifically #19420455, a new tensioner from Acdelco to throw in as preventative maintenance, a new GM crank bolt and cam bolt, and a new valve cover #12598832.

Started the tear down yesterday, got the intake manifold off, coil packs off, water pump off, harmonic balancer off, most of the exhaust manifold bolts out (left the two behind the dip stick cause I haven’t pulled it yet), and the fans and radiator. I’m gonna try and pull the the heads tomorrow if the weather permits. But here’s the progress so far

Oh and I was able to diagnose the problem as being the cylinder #1 exhaust valve lifter. It’s either collapsed or could possibly be turned in the tray. I think it might be turned because as crazy as it sounds, I could hear a cracking plasticy sound when I had it running yesterday.

 

[iamdub]

I bought the little kit of 8 plugs from TSP. I ended up buying all my parts individually because I could never find all the manufactures of parts in the dod delete kits that are offered. I picked up Morel 7717 lifters, and Acdelco trays, all Felpro gaskets and head bolts, GM valve strings specifically #19420455, a new tensioner from Acdelco to throw in as preventative maintenance, a new GM crank bolt and cam bolt, and a new valve cover #12598832.

Started the tear down yesterday, got the intake manifold off, coil packs off, water pump off, harmonic balancer off, most of the exhaust manifold bolts out (left the two behind the dip stick cause I haven’t pulled it yet), and the fans and radiator. I’m gonna try and pull the the heads tomorrow if the weather permits. But here’s the progress so far

Oh and I was able to diagnose the problem as being the cylinder #1 exhaust valve lifter. It’s either collapsed or could possibly be turned in the tray. I think it might be turned because as crazy as it sounds, I could hear a cracking plasticy sound when I had it running yesterday.

View attachment 345136

"Cracking plasticy sound"... This could get interesting. You pulling the engine out?

 

[Darren2014]

"Cracking plasticy sound"... This could get interesting. You pulling the engine out?

Trying my hardest not to. Unless I take the heads and timing cover off and everything’s just exploded in there, I don’t plan on it.

 

[iamdub]

Trying my hardest not to. Unless I take the heads and timing cover off and everything’s just exploded in there, I don’t plan on it.

With the heads off, removing the engine isn't much more work. It might seem like such a big jump, but if you're down to cam swap level with the heads off, you've already done all the hard work. The rest is just removing bolts and plucking it out. There's eight bolts in the bellhousing (which are super easy to get to with the heads off), three in the torque converter and six in the mounts. Chain it and away it goes.

My main reason for removing is because the cover (front, rear and oil pan) alignments are very critical. When swapping the cam and replacing the crank seals and gaskets, it's just so much easier to ensure all the alignments are spot-on with it out of the bay. The extra labor is minimal when compared to removing the trans later to replace a leaky rear main seal. It also gives you access to the barbell in the back of the block.

 

[Darren2014]

With the heads off, removing the engine isn't much more work. It might seem like such a big jump, but if you're down to cam swap level with the heads off, you've already done all the hard work. The rest is just removing bolts and plucking it out. There's eight bolts in the bellhousing (which are super easy to get to with the heads off), three in the torque converter and six in the mounts. Chain it and away it goes.

My main reason for removing is because the cover (front, rear and oil pan) alignments are very critical. When swapping the cam and replacing the crank seals and gaskets, it's just so much easier to ensure all the alignments are spot-on with it out of the bay. The extra labor is minimal when compared to removing the trans later to replace a leaky rear main seal. It also gives you access to the barbell in the back of the block.

Those are great points but unfortunately I don’t have an engine pulled or stand. And to be honest I’m not really planning on doing a job like this again any time in the near future or do I have the space to store those larger tools (I live in a small apartment but I’m doing the job at my grandparents house).

 

[Darren2014]

Ok got the driver side head off and found that the cylinder #1 exhaust lifter had been spinning in the tray and the roller is pretty torn up. I’m guessing the cam looks about the same. Only thing I’m curious about is what orientation the no dod rollers when I go to re assemble. I see the little oil ports on the side of them but is there a specific direction they need to be pointing?

 

[Geotrash]

Ok got the driver side head off and found that the cylinder #1 exhaust lifter had been spinning in the tray and the roller is pretty torn up. I’m guessing the cam looks about the same. Only thing I’m curious about is what orientation the no dod rollers when I go to re assemble. I see the little oil ports on the side of them but is there a specific direction they need to be pointing? View attachment 345180

It doesn’t matter. I installed all of mine with the oil port facing up but it truly doesn’t matter. Whatever you do though, use new OEM lifter trays only.

 

[Darren2014]

It doesn’t matter. I installed all of mine with the oil port facing up but it truly doesn’t matter. Whatever you do though, use new OEM lifter trays only.

Picked up Acdelco trays yesterday.