202 Roller Rockers

[jakbob]

Hi all, I have just about finished building a blue 202 for my vc and I put a second hand head on it thats had a fair bit of work done to it. A fair bit of metal has been taken out. But I only just noticed as I was going to bolt the rocker gear on that it has been modified for I think, roller rockers. The rocker pads have been shaved 5 mm or so and the holes have been drilled and re tapped. I found these yella terra rockers that require the head to be modified the way mine has been but they're very expensive: Yella Terra Holden All Red, Blue, Black, Motors Roller Rockers - Street Terra 1.6:1 7/16 screw in studs mount ST2012 - Kustom Bitz

These ones are more in my price range: HOLDEN 6 202 TORANA ROLLER ROCKER KIT 1.6 7/16 - eBay V8, Performance Parts, Car Parts, Accessories, Cars, Bikes, Boats. (end time 22-Dec-09 17:07:59 AEDST)
But does anyone know if they'll fit my head? I think I'd need to change the studs. Or am I just better to fork out for the yella terra ones? Or are there any other options(other than changing the head)?

[ari666]

you need to grab a 7/16 spanner and a 3/8th spanner and figure out which thread the head studs are before you look any getting anything. just pop the spanner (the ring side, not the open side) over the thread and which ever spanner slides on with no room is the size you need.

the size refers to the posi locks that you get with the roller rocker. if you get the wrong size, good luck finding posi locks by themselves, its easier to just change the studs. bear in mind you may also need guide plates for your pushrods, but im not sure with 202.

i dove in a bought a set of those procomp roller rockers for my impala cos' 175 bucks for a V8 is half the price. i really think im gonna regret it. they are made really cheaply, the roller bearings are unsealed, unlike the yella terras i have on my commodore, the roller tips wobble around and they are noisy as f..k. mind you, i have not adjusted them fully yet.

mate, advice is if you want to keep the enigne running for a long time at high rpm, your gonna have to spend the dollars on a good set.

385 bucks isnt that bad for street terras VPW Performance Mailorder

edit* that link is for 1.5's and your were 1.6... give VPW a call

[jakbob]

Ok so I checked the bolt holes in the head, they've been drilled out and tapped to 7/16, the original size was 5/16. The pad has been shaved 8mm or so, so in theory these should fit: Yella Terra Holden All Red, Blue, Black, Motors Roller Rockers - Street Terra 1.6:1 7/16 screw in studs mount ST2012 - Kustom Bitz
And then I would have to also buy the correct studs and guide plates?
I'm a bit confused about this whole roller rocker thing. The factory rockers are much simpler.
I'm running this cam: WER 2 Crow Megatork Hydraulic 6CYL Cams HOLDEN 149 - 202 - eBay Engine Parts, Engines, Components, Car Parts, Accessories, Cars, Bikes, Boats. (end time 27-Dec-09 14:50:03 AEDST)
with hydraulic lifters, standard push rods and standard valve springs. I know the standard springs aren't ideal, but I plan to change them later if they give any trouble. The engine is for a daily driver so I'm not going to be wringing its neck all the time.
Have I got any hope of setting up roller rockers in this configuration?

[ari666]

Have I got any hope of setting up roller rockers in this configuration?

let me start by saying that every engine should have roller rockers. and if they dont, they should be one of the first things to go on.

lol, i just had a look at the cam specs and realised that i had no idea what is acceptable with stock springs on a 6... anyway, you will be surprised. stock springs on a 308 can handle anywhere around 499 lift. any more than that and you are pushing the friendship. regardless, you will prolly get valve bounce with 499. the thing you gotta find out is what ratio your standard rockers are. stock SBC are 1.5, it looks like stock 6 cylinder holden are also 1.5 (but you will need to confirm that) stock 308 are 1.6. yella's for 308 are 1.65.

the 1.6/1.5/1.65 is a ratio, not a measurement. i means for every 1 measurement of travel, your rocker will lift your valve 1.6, 1.5 or 1.65 so for example, if you have a cam that lifts to .330 (at the lobe) then with stock 1.5 ratio's you will get .495 lift, however, if you went 1.65 terras you would have 544.5 lift, and waaaay exceed stocks springs capacity but what fun you would have breaking those springs

i didnt realise you only had the holes in your heads, thought you had screw in studs in there already. soz, should have read a bit better. if its just the holes then they should only be one thread size, cos' as far as im aware, all the threads are cut the same, bar race/speciality heads. so alls ya need to do is get a cheap set of procomp ones, i got a set from them and they are the only bit of kit i was happy with, exept the guide plates, they seemed fine too. you cant really go wrong with high tensile steel though.

i dont understand what you mean by "the pad has been shaved 8mm or so" do you mean the spring base? or where the screw in stud rests? if its the stud it doesnt matter cos you have over an inch of threaded adjustment. if you mean the spring base, then boy, INSTALL DOUBLES AND GET A MASSIVE CAM NOW BEFORE ITS TOO LATE lol. sorry.

hope that helps you a bit. did you ring VPW? they have a 1300 number and deliver to QLD and would kill the prices you been posting up.

[jakbob]

Haven't rang VPW yet. The post that has the hole in it that the studs/bolts screw into has been shaved/cut down. And the hole has been drilled out to 7/16 and retapped. The procomp ones on ebay come with studs that are 5/16 on one end and 7/16 on the other end. I'm assuming this is so the 5/16 end can screw into the original hole in the head and the rockers can bolt up to the 7/16 end. So if I were to run the procomp rockers would I just need studs that were 7/16 on both ends? I'm not real clear on how the posi lock setup works.
Cheers

[ari666]

posi locks are the nuts that hold your rockers on. they screw onto the studs (whatever thread that may be, 3/8ths or 7/16ths) then have an allen key grub screw which locks the nut in pace.

[jakbob]

I see now. Do you need a special allen key torque wrench to do them up? So do you reckon if I got studs that were 7/16 both ends the cheap procomp ones would fit? Don't want to fork out $300 only to find I can't make them work.

[ari666]

either-or would be fine 3/8th or 7/16th as long as you get the right posi locks with your rockers. TBH 7/16th is going a bit overboard. i would rather you go 3/8th just cos' they are smaller and tighter.

adjusting your rollers is a whooooole different kettle of fish to stocks. sadly that is where it gets really complicated really quickly... there are so many different idea on the subject but this is how i do it, based on crane cams instructions;

whip off the rocker cover. now what you need to make is make sure the lifter is completely on the heel of the cam, to do it properley the cam needs to be on its compression/power stroke. cos' im not huge on info for 6's i cant tell you exactly when that is, but what i do is watch the inlet valve while cranking the engine by hand, when it closes, you will be close to BTDC, a fraction of a turn from there will mean the piston is starting to rise in the bore up to its compression stroke and both valves should be on the heel of the cam.

now, the valves are shut so you need to find zero lash, which is a bit tricky and you need three hands. lol. the problem you will have here is that your lifters have no oil in them, which means that the zero lash you find will prolly not be zero lash at all and once you start the engine, all your rockers will be loose and rattle around like crazy and you will need to do this again, but dont fear. as long as you have guide plates, loose rockers are fine, tight ones are a worry.

so zero lash is when the pushrod 'bites' the lifter cup and rocker cup.a bit of moly bond is sometimes helpful here on the tips of the pushrods, but you dont want it inside the lifter. so only a teensie bit on the bottom. so with a hand on your ratchet at the top (with the allen key completely out of the posi-lock) and your other hand on the pushrod, you need to twist the pushrod back and forth while you turn the ratchet slowly to tighten up the posi-lock. once you feel the pushrod 'bite' it sorta means the psuhrod goes from wobbling around the place so suddenly becoming a bit more difficult to turn. there is zero lash.

now this is where people opinions vary. some say tighten 1/2 a turn, some say a full turn, i say 1/2 a turn only cos' there is no oil in the lifter, if there was oil and they were fully pumped then a bit less. i did a full turn on my terras in the VK and it was way too much, snapped a spring and might have burned a valve. loose is better IMO, and if it is too rattly for ya, then whip the rocker cover off later and do them up 1/8th of a turn. but remember to do up all of them exactly them same amount of turn from zero lash.