rocker adjustment

thethirdmurph · April 30th, 2008, 05:03 AM

ok here's the deal.. when putting together my motor I adjusted the rockers/valves just the way everyone stated but when I attempted to start the engine I had 0 compression on all cylinders. So I backed them off till I got about 160lbs compression. I ran the engine but it doesn't quite seem right so I was going to readjust the valve train. my question is the first time I adjusted the valve train everything was not pumped up....so could that be the reason nothing "settled"?

from what I understand when you preload the valve train sometimes it will actually open the valve but after a few minutes everything will settle and the valve will close.. is this true??

jrh_1980 · April 30th, 2008, 09:30 AM

actually in order for the lifter to pump up it has to be able to move. If you already have some preload set with the hydraulic lifter bottomed out then you have gone tooooo far. give this a try.
1. Back out all your rocker so they are loose.
2. Run your engine up on TDC for the #1 cylinder.
3. That will ensure both valves are closed.
4. It doesn't matter which valve you start with, but just roll the push rod in your fingers and tighten rocker down until it takes all the slack out. but be sure your not collapsing the lifter.
5. at that point the valve is set without any preload.
6. go anywhere from a 1/4 to 1/2 a turn farther and it should be ok.
7. do the other valve
8. rotate engine 1/4 turn and do the next cylinder in the firing order
9. repeat this until you have set all the rockers

It is always a good idea to soak your lifters if you pulled them out. This will help them pump up once installed.

thethirdmurph · April 30th, 2008, 12:52 PM

that is the exact procedure I used when putting the motor together in the first place that didn't work. could it react differently now that I have actually run the motor?

ryans88gt · April 30th, 2008, 05:10 PM

Then you did something wrong.

The lifter plunger is spring loaded and that spring is all you are preloading. As soon as you feel slight resistance to spining the pushrod that is zero lash. Then you only need 1/2 turn from there. In order to hang the valves open enough to get 0 compression, you went way way too far with the rockers.

thethirdmurph · April 30th, 2008, 05:16 PM

I tried it again and didn't get 0 compression but I still go really low compression.. I finally just got it to 0 lash and left it. seems to be running alright except I don't know how to tune a carb..

ryans88gt · April 30th, 2008, 05:19 PM

Do you have hydraulic lifters or solid lifters? Sounds like you have a solid lifter motor.

thethirdmurph · April 30th, 2008, 05:36 PM

hydraulic lifters

95opal · April 30th, 2008, 05:52 PM

What type of rocker setup are you adjusting? stud or pedistal, if pedistal you might need shims.

95opal · April 30th, 2008, 05:59 PM

Read through comps article its much better than me typing the adjustment procedure. If you follow it carefully you should be all set.

http://www.compcams.com/Technical/In.../Files/151.pdf

thethirdmurph · April 30th, 2008, 06:02 PM

they are pedestal mount 1.6 comp cam roller rockers

thethirdmurph · April 30th, 2008, 06:09 PM

could my lifters be shot?

teal89 · May 1st, 2008, 02:44 AM

If you practically tighted them down like hell, I wouldn't be asking if your lifters are ok, I will be worrying about that cam. If I were you, I would just call a friend who has does that before and get em to do it or you could do this ONLY AS A STARTER...

Loosen all the bolts on the rockers, hand tighten (Don't he-man finger tighten), after you did that, take your rachet and ONLY TIGHTEN BY TURNING 1/4 AND MOVE TO THE NEXT. After you have that, crank it over for a little bit until you see oil pumping out and stop, then you will have to either do it the old school way and that starting the car and tighten down until you don't hear the rattling from the rocker or make it easier and follow instructions from a friend or something. YOU DON'T WANT TO OVERTIGHTEN, you will have a lifter busted to nacho's and a cam you can pretty much pull out from the top of the motor figurablly speaking.

thethirdmurph · May 1st, 2008, 03:53 AM

I adjusted them as though they were solid lifters and all seems well. I guess they could be solid since I didn't really inspect before reinstalling..I guess I just assumed they were hydraulic. we all know what that does.

thethirdmurph · May 1st, 2008, 05:13 AM

theoretically if they were solid lifters and that is a hydraulic cam how bad would that be together?

JBIGBOOTSY · May 1st, 2008, 07:42 AM

It would have less slack, and be as if the ramp angles were more radical.

thethirdmurph · May 1st, 2008, 08:34 AM

but solid lifters wouldn't damage the cam?

ryans88gt · May 1st, 2008, 06:41 PM

Pedestal mount rockers are non-adjustable. You are supposed to torque them to 18 ft/lbs.

If you need to adjust the valve train, then you need shorter pushrods or shims under the rockers.

trueblue01 · May 1st, 2008, 07:56 PM

Time to determine just what you have and what you have done. What heads? Pedestal mount rockers... What push rods? What or who's cam (brand, hyd. or mech., roller or flat tappet, all very important). As Ryan stated, pedestal rockers are not adjustable, bolts MUST be torqued to 18-24 ft. lbs. period. You CAN NOT mix hyd. roller, mech. roller, hyd. flat tappet or solid tappet in any way, shape or form. What you do from this point depends on what you have.

trueblue01 · May 1st, 2008, 07:57 PM

Originally Posted by thethirdmurph

but solid lifters wouldn't damage the cam?

Most likely.............yes it would

thethirdmurph · May 2nd, 2008, 01:57 AM

I'm sorry I was mistaken..my rockers are def adjustable.. what differences are there betw a solid cam and a hydraulic cam? is there any way to tell without pulling the cam itself out?

April 30th, 2008, 05:10 PM	#4
ryans88gt MM Fanatic Join Date: May 2007 Location: Bloomington, IL Posts: 3,768	Then you did something wrong. The lifter plunger is spring loaded and that spring is all you are preloading. As soon as you feel slight resistance to spining the pushrod that is zero lash. Then you only need 1/2 turn from there. In order to hang the valves open enough to get 0 compression, you went way way too far with the rockers. __________________ 89 LX 515 hp 497 ftlbs 11.3 @ 125 mph 88 GT 11.4 @ 118

April 30th, 2008, 05:19 PM	#6
ryans88gt MM Fanatic Join Date: May 2007 Location: Bloomington, IL Posts: 3,768	Do you have hydraulic lifters or solid lifters? Sounds like you have a solid lifter motor. __________________ 89 LX 515 hp 497 ftlbs 11.3 @ 125 mph 88 GT 11.4 @ 118

April 30th, 2008, 05:52 PM	#8
95opal Hardcore Enthusiast 95 opalfrost gt Join Date: Nov 2006 Location: Connecticut Posts: 1,076	What type of rocker setup are you adjusting? stud or pedistal, if pedistal you might need shims. __________________

April 30th, 2008, 05:59 PM	#9
95opal Hardcore Enthusiast 95 opalfrost gt Join Date: Nov 2006 Location: Connecticut Posts: 1,076	Read through comps article its much better than me typing the adjustment procedure. If you follow it carefully you should be all set. http://www.compcams.com/Technical/In.../Files/151.pdf __________________

May 1st, 2008, 02:44 AM	#12
teal89 Enthusiast 89 Mustang Lx Join Date: Feb 2008 Location: Rockwall, Texas Posts: 516	If you practically tighted them down like hell, I wouldn't be asking if your lifters are ok, I will be worrying about that cam. If I were you, I would just call a friend who has does that before and get em to do it or you could do this ONLY AS A STARTER... Loosen all the bolts on the rockers, hand tighten (Don't he-man finger tighten), after you did that, take your rachet and ONLY TIGHTEN BY TURNING 1/4 AND MOVE TO THE NEXT. After you have that, crank it over for a little bit until you see oil pumping out and stop, then you will have to either do it the old school way and that starting the car and tighten down until you don't hear the rattling from the rocker or make it easier and follow instructions from a friend or something. YOU DON'T WANT TO OVERTIGHTEN, you will have a lifter busted to nacho's and a cam you can pretty much pull out from the top of the motor figurablly speaking. __________________ 351w .40 over, K.B. Forged Pistons, Hardened I Rods and Pushrods, 60cc D0OE Heads with 600" valve springs, Comp 565" Cam, Barry Grant D.P. Carb, BBK Long Tubes, FRPP 9mm Plugs, E3 Spark Plugs(THE SHIT!)

April 30th, 2008, 05:03 AM	#1
thethirdmurph Newbie Join Date: May 2007 Posts: 37	rocker adjustment ok here's the deal.. when putting together my motor I adjusted the rockers/valves just the way everyone stated but when I attempted to start the engine I had 0 compression on all cylinders. So I backed them off till I got about 160lbs compression. I ran the engine but it doesn't quite seem right so I was going to readjust the valve train. my question is the first time I adjusted the valve train everything was not pumped up....so could that be the reason nothing "settled"? from what I understand when you preload the valve train sometimes it will actually open the valve but after a few minutes everything will settle and the valve will close.. is this true??

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April 30th, 2008, 09:30 AM	#2
jrh_1980 Regular 89 Mustang LX Join Date: Feb 2008 Location: Macomb, Illinois Posts: 151	actually in order for the lifter to pump up it has to be able to move. If you already have some preload set with the hydraulic lifter bottomed out then you have gone tooooo far. give this a try. 1. Back out all your rocker so they are loose. 2. Run your engine up on TDC for the #1 cylinder. 3. That will ensure both valves are closed. 4. It doesn't matter which valve you start with, but just roll the push rod in your fingers and tighten rocker down until it takes all the slack out. but be sure your not collapsing the lifter. 5. at that point the valve is set without any preload. 6. go anywhere from a 1/4 to 1/2 a turn farther and it should be ok. 7. do the other valve 8. rotate engine 1/4 turn and do the next cylinder in the firing order 9. repeat this until you have set all the rockers It is always a good idea to soak your lifters if you pulled them out. This will help them pump up once installed.

April 30th, 2008, 12:52 PM	#3
thethirdmurph Newbie Join Date: May 2007 Posts: 37	that is the exact procedure I used when putting the motor together in the first place that didn't work. could it react differently now that I have actually run the motor?

April 30th, 2008, 05:16 PM	#5
thethirdmurph Newbie Join Date: May 2007 Posts: 37	I tried it again and didn't get 0 compression but I still go really low compression.. I finally just got it to 0 lash and left it. seems to be running alright except I don't know how to tune a carb..

April 30th, 2008, 05:36 PM	#7
thethirdmurph Newbie Join Date: May 2007 Posts: 37	hydraulic lifters

April 30th, 2008, 06:02 PM	#10
thethirdmurph Newbie Join Date: May 2007 Posts: 37	they are pedestal mount 1.6 comp cam roller rockers

April 30th, 2008, 06:09 PM	#11
thethirdmurph Newbie Join Date: May 2007 Posts: 37	could my lifters be shot?

May 1st, 2008, 03:53 AM	#13
thethirdmurph Newbie Join Date: May 2007 Posts: 37	I adjusted them as though they were solid lifters and all seems well. I guess they could be solid since I didn't really inspect before reinstalling..I guess I just assumed they were hydraulic. we all know what that does.

May 1st, 2008, 05:13 AM	#14
thethirdmurph Newbie Join Date: May 2007 Posts: 37	theoretically if they were solid lifters and that is a hydraulic cam how bad would that be together?

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May 1st, 2008, 07:42 AM	#15
JBIGBOOTSY Hardcore Enthusiast 1990 LX hatch Join Date: Aug 2006 Location: Hobart Indiana Posts: 2,064	It would have less slack, and be as if the ramp angles were more radical.

May 1st, 2008, 08:34 AM	#16
thethirdmurph Newbie Join Date: May 2007 Posts: 37	but solid lifters wouldn't damage the cam?

May 1st, 2008, 06:41 PM	#17
ryans88gt MM Fanatic Join Date: May 2007 Location: Bloomington, IL Posts: 3,768	Pedestal mount rockers are non-adjustable. You are supposed to torque them to 18 ft/lbs. If you need to adjust the valve train, then you need shorter pushrods or shims under the rockers. __________________ 89 LX 515 hp 497 ftlbs 11.3 @ 125 mph 88 GT 11.4 @ 118

May 1st, 2008, 07:56 PM	#18
trueblue01 Enthusiast 1989 Mustang LX 10.98@126.7 NA Join Date: Feb 2008 Location: N.E. Ohio Posts: 659	Time to determine just what you have and what you have done. What heads? Pedestal mount rockers... What push rods? What or who's cam (brand, hyd. or mech., roller or flat tappet, all very important). As Ryan stated, pedestal rockers are not adjustable, bolts MUST be torqued to 18-24 ft. lbs. period. You CAN NOT mix hyd. roller, mech. roller, hyd. flat tappet or solid tappet in any way, shape or form. What you do from this point depends on what you have. __________________ Never fast enough.

May 2nd, 2008, 01:57 AM	#20
thethirdmurph Newbie Join Date: May 2007 Posts: 37	I'm sorry I was mistaken..my rockers are def adjustable.. what differences are there betw a solid cam and a hydraulic cam? is there any way to tell without pulling the cam itself out?