How hard would it be for me to replace the lifters? Anyone have any tips etc?

Oh and anyone know how much they are each?

do you mean the tappets? if so they are easy as... just need to take off the rocker gear. you'll need a torque wrench to do the rockers gear back up.

as for cost... i dunno. maybe around $6 each x 8 valves

put sigma rockers on!

There is a car at the local car yard (duno if it would go) that has "Astron 80" on the front of it, is that a sigma? Because I would like to do up the Factory rims on it and if it was I could get the rockers off that and put it on the magna...

But this leads to my next question, what are rockers?

as for cost... i dunno. maybe around $6 each x 8 valves


Are they that cheap..??

I am guessing they are what control when the lifters lift, which I assume is what they do, and I assume they lift the valves, how far off a I?

But this leads to my next question, what are rockers?

rockers run on the cam lobes and push the tappet that inturn pushed the valve open for the duration of the cam lobe.

tappets in our motors are hydralic, relying on oil flow to shut them up. they can be replaced if they get noisy. sigma uses manually adjusted ones that need adjustment when the start to come noisy. Putting a cam with different lift durations can lead to hydralic tappets dying sooner than expected. that is why sigma lifters/rockers are usually put on our magna heads.

TR/TS astron uses roller rockers. each rocker arm has a roller that runs on their respective cam lobe. they still function the same way. (ie open the valves for the duration of lift)


Are they that cheap..??

for an astron they are...

Sigma rockers huh?

Is it as simple as take to top of a sigma and then swap it with the magna one?

nope the heads are allittle different, i think they bolt up but wont actully work i think the cam is a few cms longer but in sure somone will be able to say for sure.
so in short the head wont work but the adjustible lifters will.

Screw it, I will just get them replaced...

sigma rockers should fit magna head... of not, take apart the rockers and recontruct the magnas using the sigma arms.

What BCX7 said is definatly the best bet. Its a PITA job but just takes time and patients. It also allows for a higher lift cam to be fitted, which is the main reason its done.

You cant run your hydraulic cam with Sigma machanical rockers.
The cam timing is will be out. And you cant run the sigma cam because of the Magna water pump location.
I have the early rockers and cam on my hydraulic head. No advantage ,but they are not as noisy as I imagined they would be.

im runing magna efi cam, sigma astron 2 rockers & manual adjust tapets, how to do? remove rocker cover unbolt the rocker/tappet assembly bolt bolt onto the magna head and adjust, do not use the sigma spec for the tappets as the rattle like hell, if you use the search function i posted the gap a while back.

If you wanna change the lifters yerself gimme a yell and i'll scan ya the relevant pages outta the manual.:D

Apart from needing a tension wrench its a simple job with basic tools. Easy.:cool: :)

Do you mean you use the Adjustable rocker arms on the astron II rocker shafts.
That the setup I have. When I enquired about using the hydraulic cam I was told the timing would be too tame.

Just wondering, how much better than the solids are the roller rockers?

Not much, they jsut free up a tiny tiny bit of valve train loss.

Give Stagma or Magna Buff a PM, they've done a TR/TR Roller Rocker and cam swap to Stagma's TP and boy what a huge difference they've made, it's quick now and it done over 300000ks

Just wondering, how much better than the solids are the roller rockers?

soilds will allow for greater lift and duration if the cam is changed over. having a cam that is ground for the roller rockers can be expensive. anyways, at the other end of the rocker is a hydralic tappet, which will deteriorate very quickly with a non standard grind.

as turbo charade said, while the roller rockers will free up a little bit of valve train loss, the solids will definately make up for it with a more agressive grind (ie valve timing advance and longer durations + increased valve lift).


Do you mean you use the Adjustable rocker arms on the astron II rocker shafts.
That the setup I have. When I enquired about using the hydraulic cam I was told the timing would be too tame.

reason being is because the hydralic cam provides clearance for the tappets to work correctly. the sigma cam has more lift at the cam lobe (different to valve lift). both cams with their respective cam will produce the approx the same valve lift.