Please help diagnose engine noise - S/C Roush 4.6L 3V

BlueDevil

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Thanks, nice writeup. I especially like the tip about keeping each cyl at TDC while pressurized. In the past, I've always just turned on the air flow and let the engine rotate to BDC. I guess I've just been lucky to never lose air pressure and drop a valve down into the cyl.

I may bug you with a PM if the need arises, if you don't mind.

Your car sounds good with those cams!!

Again, many thanks!
 

BlueDevil

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Thanks. Honestly, you can just rotate the engine so the piston in the cylinder you're working on is at TDC, and the valves can't physically drop into the cylinder. No air pressure required. You can also take some nylon braided rope and feed that through the spark plug hole if you want cheap insurance. Seriously, though...your back is going to be sore. When you're focused on back pain, the mistakes start happening. Go slow, be thorough, and eat Advil, haha.
P.S. I'm not using those cams or springs anymore if anyone wants to buy them. Comp 127500.
 

Mojo88

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Thanks. Honestly, you can just rotate the engine so the piston in the cylinder you're working on is at TDC, and the valves can't physically drop into the cylinder. No air pressure required. You can also take some nylon braided rope and feed that through the spark plug hole if you want cheap insurance. Seriously, though...your back is going to be sore. When you're focused on back pain, the mistakes start happening. Go slow, be thorough, and eat Advil, haha.

Damn man, you're a genius. That's the easiest way, for sure. I'll likely still use air pressure tho. And yeah, my back does get sore. I'll get the Advil ready, lol...............

I actually have the car on jack stands, and the extra height has been just wonderful for working on everything.
 

BlueDevil

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Damn man, you're a genius. That's the easiest way, for sure. And yeah, my back does get sore. I'll get the Advil ready, lol...............
Just be sure not to rotate the engine while the valves are free. Wouldn't take much pressure to mess up a valve.
 

msvela448

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The only thing I'll add about just using the TDC method without air is that during the re-assembly process the valve needs to be all the way up to get the keepers in place. If they are dropped down even a little bit (resting on the piston at TDC) you'll have a hell of a time getting those keepers on. Yes you could do some nylon rope in the cylinder to fill the void between the piston and valve in order to force the valve upward... That just makes me nervous about putting something in the combustion chamber that could get pinched, stuck, etc.

Also... Most of the dedicated 3v spring compressor tools are in fact designed to be used with the cams in place. The traditional clamp style tool would require you to remove the heads.

Sent from my SM-N986U using Tapatalk
 

JC SSP

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Not sure if this will work with 4.6 3V but in the past... I have stuffed long single strip of cloth rag (cut bed sheet that's 4' long and 2" wide) into the cylinder and then brought her up to TDC. The cloth compresses and holds the valves in place. Then just pull it out like a rip-cord. re-use as appropriate.
 

Mojo88

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The only thing I'll add about just using the TDC method without air is that during the re-assembly process the valve needs to be all the way up to get the keepers in place.....

Yeah, I'm gonna use the TDC method, then put the shifter into a gear position, and then load 'er up with compressed air.

I haven't had anything like this apart before, so I'm trying to wrap my head around removing a valve spring and rocker without removing the cam?? Is this what folks typically do? They leave the cam in place? It just seems like the cam would be seriously in the way.

Plus, I've removed the timing chains, which means I might have an issue with valve interference as I rotate the engine with stationary cams???? Or is this not an interference engine?
 

Mojo88

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You can remove the cam and replace it with a short length of 1” pipe for the spring compressor to work against.

Awesome! That's EXACTLY what I was thinking of doing, but wasn't sure if it was appropriate. Thanks!!
 

BlueDevil

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The only thing I'll add about just using the TDC method without air is that during the re-assembly process the valve needs to be all the way up to get the keepers in place. If they are dropped down even a little bit (resting on the piston at TDC) you'll have a hell of a time getting those keepers on. Yes you could do some nylon rope in the cylinder to fill the void between the piston and valve in order to force the valve upward... That just makes me nervous about putting something in the combustion chamber that could get pinched, stuck, etc.

Also... Most of the dedicated 3v spring compressor tools are in fact designed to be used with the cams in place. The traditional clamp style tool would require you to remove the heads.

Sent from my SM-N986U using Tapatalk
 

Mojo88

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If you use the old style iron bodied tensioners that ratchet you should remove the plungers and grind or file the teeth off the shank. They still have spring tension and will pump up hydraulically but will not lock and over tension the timing chains.
Hey Bud, I am gonna use the iron tensioners. I finally looked at the old plastic tensioners, and right away I saw a bad gasket leak.

I've got all the valve work done, new valve seals, checked valve springs, new followers, lifters, cams back in, new timing chains on and timed, MMR chain guides.... now just put on the Melling iron tensioners. As you mentioned in your post, I want to eliminate the ratcheting..... Do you have any pics or anything that shows exactly how to do this?

EDIT: never mind, I finally found a pic, and a little video. All done, the last 4 ratchets are ground off and the Melling iron tensioners are torqued in place.

Tensioner ratchet tab.jpg


Thanks
 
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