Valve lash and rocker arms torque specs?

[granatl]

I have 1.65 ratio roller rockers and will soon be re-installing them on my stock heads, along with a set of thicker-wall push rods. Can someone tell me the torque specs for the 3 bolts that hold the rocker shafts to the heads? I sorta think it's 15 ft/lbs. And also, I should reset the valve lash, since they're new push rods. What is the unloaded gap supposed to be?

 

[BlackBandit]

I thought the stockers went up around 30 ft-lb. As far as lash you shouldn't have any. If my memory is working today you should have between 30 and 60 thousanths of preload.

 

[QUIP'6']

25 ft pounds


TDC on #1 adjust the following valves,

Exhaust 1 - 5- 6
Intake 1- 2 - 3

Next turn crank over 1 revolution, and adjust the following valves,

Exhaust 2 - 3 - 4
Intake 4 - 5- 6

1/4 turn equals .0125
1/2 turn eqauls .025
3/4 turn equals .037
1 turn equals .050

 

[granatl]

Thanks for the info! That'll come in handy tomorrow when the push rods get delivered.

 

[pacecarta]

your heads if they are truly stock they'll require clearancing (cutting or grinding down) the sides of the pedestals to run roller rockers

and depending on the cam lift the 1.65 lift may bee too much for the exhaust and require that the exhaust valve guides be cut down and prepped for seals (which will also require new aftermarket exhaust valves without the stepped stem

and to run roller rockers youll need tall valve covers or billet valve cover extensions to use stock valvecovers , if stock covers with extensions the covers may requires some internal work depending on the rockers , if they hit the raised areas by the bolts youll need to grind



easier way to adjust is when the intake or exhaust valve for one cylinder is down the other rocker will be up and can be adjusted
preload should be about 30 thou which on roller rockers is 1/2-3/4 turn from zero lash


also pay attention to the rocker adjuster cup position as it needs to fall within a certain window to maintain the oil flow to the rocker (check the directions for your lrockers)

you really shouldldnt order pushrods until you have measured for them
set the rocker adjuster cup per manufacturers spec (usually cup flush to one thread sticking out of the bottom )
then with cam at base drop an adjustable push rod in (fullly shortened ) and bolt the rocker shaft down to the head.
extend pushrod until you have zero lash then go an additional 1/2 - 3/4 turn out (1 turn =.050) and thats the lentgh for your new pushrods

some rod makers you can send the measuring pushrod to them and they will make the correct pushrods for your application

 

[granatl]

This is a re-install. I've run this setup for roughly 3-4 years. I've had lots of problems bending push rods. I've been told that it's because I'm using stock push rods with heavy duty valve springs. So, I'm trying a set of .080 thickness push rods this time.

 

[TurboBuRick]

Sounds like you have other problems. Refer to pacecarta's post.

RL