Reinstalling pushrods on 3.0L

[mikeinsac2004]

I'm finally ready to reinstall the head, mani and riser on my 3.0L. I've read through my Clymer a couple of times and feel that I have most things covered.<br /><br />However, one thing I am not clear on is reinstallling the pushrods. When I took them off, I simply loosened the nut and slid them out.<br /><br />Can I simply put them back in and tighten the nut down? Does it need to be torqued to a certain setting? Any help would be great. Thanks.<br /><br />Also, book mentioned using Quicksilver sealant on head bolts. What other sealant can I use on these bolts instead?<br /><br />Any other tricks o' the trade I should keep in mind?

 

[Bizmark]

Re: Reinstalling pushrods on 3.0L

Mike,<br />The valve lash needs to be set for each rocker arm so that you don't run the risk of bending a pushrod by tightening the nut too much.<br /><br />Watch your rotor with the cap off and crank the engine until the rotor stops where cyl. #1 would be. This is TDC for cyl. #1. You can then tighten #1 intake and exhaust, #2 intake, #3 exhaust, and #4 intake. Tighten each nut slowly while you feel for side to side play on the pushrod. When you feel the play disappear, tighten the nut 1 more full turn.<br /><br />Now crank the engine until the rotor is on #4 and tighten the three remaining rocker nuts the same way.<br /><br />I use perfect seal to seal the threads on my head bolts, I think Permatex makes something simular.<br /><br />Good Luck!

 

[Boatist]

Re: Reinstalling pushrods on 3.0L

Mike<br />What Bizmark said may work but I like to adjust valves near top dead center of each cylinder on the compression stroke. Start with number one like Bizmark said then turn engine with a wrench until rotor points to wire for number 3 and adjust three. Next would be number 4 and then 2.<br /><br />adjusting valves the way Bizmark said and most books has a lot of risk. First you should do a static adjustment as above to zero clearance. At this point you can start engine and let warm up and also lifter fill with oil. Then with engine hot go back and adjust each valve as before to zero clearance and then one turn down. If everything is in new good condition it should be ok, but if you have a lifter that is stuck or that has reduced travel valve can be adjusted so tight it will not seat and it will burn the valve. So when you are done start the engine and a low idle listen for any miss. Also do a compression check to be sure all valves are seating. <br /><br />When I do it on my own engine I do it different. I start as above then start the engine and with it running I adjust slowly down until I get a miss then back up until smooth and then one turn up. This is messy but if have a bad lifter the valve will end up too loose instead of too tight. I still do a compression check when done.

 

[mikeinsac2003]

Re: Reinstalling pushrods on 3.0L

Okay, I put reinstalled everything today. Didn't have enough daylight to start it up, but thats okay because I was left with a question.<br /><br />I chose to tighten in the sequence that Bizmark and my Clymer manual suggested. Got rid of the lash and then went 1 additional turn. I turned the crankshaft one turn and tightened the rest. Then I let the starter crank the engine a few times just to make sure nothing obvious was going bad.<br /><br />I inspected the pushrods again and noticed that a couple of them were able to turn freely under the rocker arm. They weren't so loose that they could come out. Although I didn't measure it, I would guess there was about 1/32 up/down play.<br /><br />Is this normal?

 

[Fishermark]

Re: Reinstalling pushrods on 3.0L

It can be tricky getting all the slack or play out because everything is so oily and it is very subtle and easy to miss the exact place where the slack is gone. I always turn the nut till I feel that the slack is out, and then back it off... "twist and jiggle it".. make sure it is seated properly... tighten and loosen a couple more times... then do the final 3/4 turn. In answer to your quesiton - no, you shouldn't have any play when you are done. Now, it isn't unusual to be able to turn some, because there is not a lot of preload, but there shouldn't be any "slack."

 

[ron7000]

Re: Reinstalling pushrods on 3.0L

hey<br />I have a 2002 bayliner with the 3.0L and just did a valve adjustment, and also retorqued the head, this weekend per merc service manual #26.<br /><br />One correction, however insignificant, is it's 3/4 turn down from zero lash. Maybe if you have a much older motor it's a different spec. But #26 is from 1999 on.<br />According to the service manual, there's two ways to do the valve/lifter adjustment. With engine off, it was described correctly by bismark. The idea behind this method is you're only adjusting those valves whose lifters aren't riding on the cam lobe. You can basically adjust any valve regardless of the cylinder/timing position as long as you know the lifter isn't hitting the cam lobe causing the valve spring to compress. If that were the case, then when that lifter comes off that lobe (after you had ajusted it) it would be less than 3/4 turn down from zero lash, and at worse have a little play and clack a little. Then all you do is readjust it.<br /><br />The 2nd way to do it, and sometimes a better way, is with the engine running. Per the manual, you lossen a rocker nut until that rocker starts to clack (with engine at idle). Then tighten nut slowly till clacking stops. This is zero lash position. Now do 3/4 more, in 1/4 turn increments pausing 10 seconds or more each 1/4 turn as the motor rpms change. It is imperative that you pause, and not do a quick 3/4 turn in one shot, or you'll cause valve & lifter damage because the hydraulic lifter doesn't have time to adjust. Do this for every valve, one at a time. I did mine in 1/8 increments by the way. If you do the valve adjustment with the motor running, I recommend you get the little stamped steel pushrod covers that clip on the rocker over the pushrod which direct the squirting oil down onto the head. I didn't have them, and went through a dozen rags and needed a shower afterwards.<br /><br />The nice thing about hydraulic valves is they're very simple and pretty tough. Don't worry about getting exactly 3/4 turn from zero lash and trying to find zero lash exactly. As long as you know you're not going 2 or more turns down from zero, you're fine. And if you're not tight enough, all it'll do is make some noise. Get a vacuum guage. If you have fairly steady vacuum, 15 or more, then you're fine. Funny thing is, on my 351w in the other boat, all I do for those is torque to 22 lb-ft with the valve in a relaxed, uncompressed position. The same would be for the 3/4 or 1 turn down method, that's just a specific torque setting. If you find out what torque value that is, then you should be able to just use a torque wrench on all of them.<br /><br />Oh, I used a small dab of permatex 300 on the head bolts. I think the quicksilver perfect seal, going by what was on my head bolts from the factory, is just ptfe paste, the kind used for plumbing, available at home depot or sears hardware for $5/can. I swear it looked and felt like the same stuff.