I've ordered my 1.6 roller tip rockers and will be installing them this weekend. I've looked at threads about rocker arms and adjustment and haven't seen any specific to the 1.6 rockers.

My question is after I get to 0 lash, the stock adjustment is 1.5 turns, but with the higher ratio rockers would it still be that or would it be less??

Any help would be greatly appreciated.

Thanks,
Scott

They should come with an instruction sheet. As for me I go 1 turn in. Is everything else stock?

its the same as 1.5 rockers - 1-1/2 turns.

there is much debate that 1-1/2 turns is to far, but the real key is how far the plunger gets pushed into the lifter, when the cam lobe is at its base.

This is a duel reply:

gunnie,
Ya, everything else is stock except for the EGR delete.

I deleted the EGR when it started leaking. I didn't want to pay the price for replacement parts and all I've read is it will work just as good without it (except maybe a small reduction MPG). And it seems to be fine.

Pythian,
I think I read a post from you in another thread about how far the plunger gets pushed down into the lifter for pre-load. If I recall correctly (which I probably don't), 1 turn is 1.5mm down the stud which gives you 2.??mm down in the lifter so 1.5 turns would get you about half the distance of the lifter plunger travel. But this ratio of plunger travel was calculated with 1.5 ratio rockers. Would 1.5 turns then be too much pre-load for 1.6 rockers? (Would it push the lifter plunger farther on 1.6 rockers as opposed to 1.5's?)

Thanks to both of you for your replies!

Scott

NOPE. the pre-load stays the same.
I myself use 1-1/4 turn, but it all depends on how accurately you can hit zero lash - and it aint easy - especially if you still have the intake manifold in the way. and, since your just doing the rockers, you probably do - so you cant see the lifters at all. but - dont sweat it - thats what hydraulic lifters are all about - absorbing the slack. anything from 1/2 turn to 1-1/2 turn will work just fine. being that you cant see the lifter, and are just going by feel, I'd expect your gonna overshoot zero lash everytime, so I would say go with 1 turn.

Pyrthian,
That's what I wanted to here!!! Thanks.

alt question:
Can you pull the valve covers on a 2.8L without pulling the upper and lower TB plenums? I haven't looked in the manual for that yet.

Thanks,
Scott

If you got the conversion studs, and are not using the stock Fiero studs, you need to adjust them by the SBC method.

You get 0 lash, and then 1/4 turn. No more than 1/2.

If you are using the Fiero studs you have a different thread and may be able stay with the Fiero 1&1/2 turns, if you have new lifters, (you have to adjust to anticipate wear-in whereas if you use the original lifters you don't.) Personally, I'd do 1 turn on the original lifters. Also, I changed my hydraulic lifters to new ones. Not too much money for the investment.

Arn

quote Originally posted by Pyrthian: NOPE. the pre-load stays the same. I myself use 1-1/4 turn, but it all depends on how accurately you can hit zero lash - and it aint easy - especially if you still have the intake manifold in the way. and, since your just doing the rockers, you probably do - so you cant see the lifters at all. but - dont sweat it - thats what hydraulic lifters are all about - absorbing the slack. anything from 1/2 turn to 1-1/2 turn will work just fine. being that you cant see the lifter, and are just going by feel, I'd expect your gonna overshoot zero lash everytime, so I would say go with 1 turn.

I'm gonna have my engine apart when I do mine, so I will be able to see the lifters. What should I look for to know when I'm at zero lash?

Thanks Arns85GT.

What I ordered are SBC 1.6 roller tip rockers. I'm going to re-use the 10mm balls, nuts, and studs. So I think I should go with the 1 turn.

Thanks,
Scott

quote Originally posted by Fastback 86: I'm gonna have my engine apart when I do mine, so I will be able to see the lifters. What should I look for to know when I'm at zero lash?

The Chilton book talks about turning or twisting the pushrod until you feel pressure. This is wrong. It is almost impossible to feel with roller tipped rockers. You need to gently move the pushrod up and down until you just have no movement. No tighter. You then turn your nut an additional amount.

Your SBC rockers are meant to go with the SBC studs, so the conversion studs are more correct. And, the adjustment is more true so far as I can tell. I PM'd another Forum member who successfully used the Fiero studs for the SBC roller tips, so I know it can be done.

BTW, there are umpteen different opinions on valve lash adjustment, and I've been through a whole whack of them. The twisting method though, is definitely not the way to do it on roller tips.

Edit - you do know how to establish when each valve is at the correct position to adjust it? It is in the Chiltons or Haynes.

------------------

[This message has been edited by Arns85GT (edited 11-15-2005).]

quote Originally posted by wsgarner: Thanks Arns85GT. What I ordered are SBC 1.6 roller tip rockers. I'm going to re-use the 10mm balls, nuts, and studs. So I think I should go with the 1 turn. Thanks, Scott

Why didn't you just order the Comp Cams 1.6 rockers for the 60* V-6's? Then you would have new balls and nuts.
You should also get the Comp Cams heavy duty pushrods as well. They have much better oil ports and are stronger.

[This message has been edited by Oreif (edited 11-15-2005).]

quote Originally posted by Oreif: Why didn't you just order the Comp Cams 1.6 rockers for the 60* V-6's? Then you would have new balls and nuts. You should also get the Comp Cams heavy duty pushrods as well. They have much better oil ports and are stronger.

Sorry to repeat myself Oreif, but I lost the thread where I asked you the part number for those pushrods. Could you post it one more time? Thanks in advance.

quote Originally posted by Fastback 86: Sorry to repeat myself Oreif, but I lost the thread where I asked you the part number for those pushrods. Could you post it one more time? Thanks in advance.

Comp Cams Heavy Duty Pushrods
Comp Cams P/N: 7816-12
Summit Racing P/N : CCA-7816-12
Cost: $30.39
www.summitracing.com

quote Originally posted by Fastback 86: I'm gonna have my engine apart when I do mine, so I will be able to see the lifters. What should I look for to know when I'm at zero lash?

when you have the intake out of the way, you can grab the pushrod alot lower, which makes it easier, and you can also move them side to side to find zero lash, instead of the twirling. and, if you do it by the service manual, you do them in groups of 6, and when you are done with one group, look at the lifters, they should all be pushed in the same amount.

oh yeah - be sure to have the intake manifold gasket in place before starting - the pushrods go thru it.

quote Originally posted by Pyrthian: when you have the intake out of the way, you can grab the pushrod alot lower, which makes it easier, and you can also move them side to side to find zero lash, instead of the twirling. and, if you do it by the service manual, you do them in groups of 6, and when you are done with one group, look at the lifters, they should all be pushed in the same amount. oh yeah - be sure to have the intake manifold gasket in place before starting - the pushrods go thru it.

You're right Pyrthian. I tried it on the roller tips and I found the rollers just rolled too easy for me to get as good a read as up-and-down. I expect the back and forth is preferable on a standard lifter, but I haven't tried it on a standard lifter to date.

Arn

quote Originally posted by Arns85GT: You're right Pyrthian. I tried it on the roller tips and I found the rollers just rolled too easy for me to get as good a read as up-and-down. I expect the back and forth is preferable on a standard lifter, but I haven't tried it on a standard lifter to date. Arn

I agree with Arn

If you re-use your stud and nut give it one turn after Zero lash. Simplest way to find zero is to spin the push rod in your finger as you inch the nut down.

Just BE DAMN SURE TO DO IT IN THE RIGHT ORDER. If you don't you will be doing it over and over again.

I have rebuilt and re-done 2.8's more times that I can count. Even after probably setting up lifters 20x I still use a chart to make sure I do it the correct order to make sure I don't make a mistake.

------------------
85GT 5spd MSD Everything,4.9 With Nitrous. www.captfiero.com

quote Originally posted by Pyrthian: when you have the intake out of the way, you can grab the pushrod alot lower, which makes it easier, and you can also move them side to side to find zero lash, instead of the twirling. and, if you do it by the service manual, you do them in groups of 6, and when you are done with one group, look at the lifters, they should all be pushed in the same amount...

I installed my 1.6 roller tips with the engine together. I gently shook the rocker arm back and forth. As soon as the slack was taken up, it wouldn't rattle any more.
I think I used 3/4 turn after that, but I don't remember.

------------------
Raydar
88 3.4 coupe...........

Praise the Lowered!
Read Nealz Nuze!

When I installed my 1.6 rockers, it was on an engine stand with the intake off. I use a dial indicator mounted to the valve cover bolt hole and an extension going into the plunger on the lifter. I tightened the adjusting nut on the rocker till the needle started moving. Did this several time to make sure it was at zero lash and tightened 1/4 turn, which came out to be .050. So I got the all within 1 to 2 thousands of each other. Haven't touched them since. This is probably the hardest way to do it but I think it's the most accurate

------------------
85 GT 3.4
Auto 3.08
14.9 @ 90 1.9 60"

I want to thank everyone for there replies. You've given me the info I needed.

OK, after there in what can I expect from performance? My goal is to be able to smoke the tires with my auto trans. Nothing like the smell of burning rubber and the sound of squealing tires to get peoples attention, especially from such a small package as a Fiero!

It will bark second now, and gets close to it going to 3rd. But, will not turn-em' over from a stand still. I don't think any thing has been done to the engine, but I've only had the car for about 2 months. I know the intake has not been ported (had it off to clean TB and delete EGR), so I am assuming that the exhaust hasn't been done either. I'm kinda’ scared that when I get the Valve covers off I'll find 1.6 rockers already on it!!

Thanks to all,
Scott

My Haynes manual says tighten until you feel resistance (stock pushrods and rockers), then 3/4 turn more. This is the way I did it. Am I going to have problems? I'd rather know now, so there's less stuff to remove to do it over, instead of finding out later.

quote Originally posted by brad460: My Haynes manual says tighten until you feel resistance (stock pushrods and rockers), then 3/4 turn more. This is the way I did it. Am I going to have problems? I'd rather know now, so there's less stuff to remove to do it over, instead of finding out later.

You can read the previous posts about adjusting. Are you going to have problems? Worst case would be a little clicking now and then, "maybe" the valves won't open quite as far. Better than being too tight!!!!!!!!!! Your call

OK everyone,
I thought I'd leave an update here. I got the rockers on this weekend and all is well. I did get some performance increase, but not as much as I was hoping. Can I brake the tires loss from a stand still, no! But, the improvement seemed to be between 3000 rpms and red-line. It pulled hard all the way until the ECM started cutting the fuel at ?6200? rpm's. It feels like the rmp's could go higher now because the torque was still there at 6200. It also seemed to "rape-up" the rmp's faster. I'm not running this on a track, so I don't have any times.

What did I set the rockers at (turns)? I took the middle of the road. I tightened the rockers until the rods would bind when turning them (this was with oily fingers so it should have been pretty close to 0 lash), then I turned them 7/8's turns. Not 1 turn and not 3/4, right in the middle! I think that the twisting of the rods worked for me due to the surface on the rockers where the rode rides was new and not polished yet.

I did notice something this morning on the way in to work though (if anyone has a clue, please let me know). As the engine wormed up (I'm guessing around 140* to 160*) I got some "sputtering" on acceleration. After the engine was completely wormed up, this stopped. HHHMMM???? Vacuum leak?

Any way, thanks to all for the help!
Scott

good job! always good to hear stuff that works out!

well, just about all cold running issues come from a bad CTS or MAT sensor. CTS, being the coolant temp sensor - located on the intake manifold, point out towards the pulleys/belts, MAT being the manifold air temp sensor - located in the air filter can. then, if your having fun with sensors - a new O2 is ALWAYS a good idea, and the TPS (throttle position sensor) is a good one to help with any low throttle/cruising bucking/sputters.

now that ya got the mod bug - taking of the exhaust manifold & porting them will give ya a nice HP boost for free - and it will make your 1.6 rocker mod even better to by freeing up the exhaust even more. free HP's just waiting for ya

Pyrthian,
Thanks for the info.

So far I've deleted the EGR, changed the TPS, changed the IAT, Changed plugs/Cap/Rotor, and changed Rockers and I've had the car about 2-1/2 months. I have to stop for a while! When I spend too much time under the hud of a car my wife get's.. Well you know! I have a 66 Chevelle 2 dr. sedan that I spent a lot of time on and am now trying to sell. That's proving to be a pain in the @@@! And I know she don't want me to "sup-up" another car. I've got to lay off a while and let the mod bug quit down. I plan to do some mods on my motorcycle after Christmas, so....

I know about the porting of the exhaust, but that looks like a tuff job. If some one local (upstate SC) would like to help me with it, I bet I can get her to let me have the time (sort of an "ohh, look. He's got a new friend." kind of thing).

Also thinking about a custom ECM chip, but have no way of burning a chip and wouldn't how to program it if I did!

Thanks,
Scott

quote Originally posted by Capt Fiero: I agree with Arn If you re-use your stud and nut give it one turn after Zero lash. Simplest way to find zero is to spin the push rod in your finger as you inch the nut down. Just BE DAMN SURE TO DO IT IN THE RIGHT ORDER. If you don't you will be doing it over and over again. I have rebuilt and re-done 2.8's more times that I can count. Even after probably setting up lifters 20x I still use a chart to make sure I do it the correct order to make sure I don't make a mistake.

Where might one find such a chart? I haven't looked in my Haynes or Factory manual yet, probably should. I remember reading something like set cylinder 1 to TDC, then do the intake valves on some cylinders and the exhaust valves on others. And how do you know which is the intake valve and which is the exhaust?

Hey guy,, sounds like your really itching for more & more power. Everybodys given you sound advise so all I can offer is some basic principles from the old school. From this you can get an idea of whats happening with the valve train.

Keep lifters in the same bore they came out of. Always use new pushrods, rockers & balls as a set if possible. If you use old with new they will have to wear themselves in again. It would be like putting a new bearing on an old worn race. Neither will last long.

Too bad the fiero intake is in the way but if it was'nt you could run the engine and back off the rocker nut til you hear a tapping sound, then turn it down til the tap goes away, then give it a half turn more.
The idea is to get the plunger in the lifter to the highest point. Oil pressure pushes on the plunger inside the lifter and takes up the slack giving zero clearance.
On the other hand if the adjustment is such that the plunger is deep in the lifter you could cause something called "valve float" when at high rpm. Your 1st experience with this phenonamon will be a look of bewilderment.
The end result of a good valve adjustment will be faster revving and a higher rpm without floating the valves. Also ask about adding a .001" shim under the valve springs to keep things pushed together tighter .

If I stated anything in error don't hesitate to correct. Like I said this is old school tech.

quote Originally posted by Fastback 86: Where might one find such a chart? I haven't looked in my Haynes or Factory manual yet, probably should. I remember reading something like set cylinder 1 to TDC, then do the intake valves on some cylinders and the exhaust valves on others. And how do you know which is the intake valve and which is the exhaust?

You answered your own question, Haynes manual. There is a section about putting #1 at TDC and then which ones to set.

------------------
85GT 5spd MSD Everything,4.9 With Nitrous. www.captfiero.com

quote Originally posted by Capt Fiero: You answered your own question, Haynes manual. There is a section about putting #1 at TDC and then which ones to set.

Guess I shoulda just done my reading like I said, too! Thanks Cap'n!

Hi all,

I'm going with the Comp Cams 1.6's with the 10mm studs...however I'm looking for 1.7's on the exhaust. I'll be using a roller cam block so I don't feel this is excessive. Can anyone reccomend me some 1.7's and what I need to tell the machinist to get them to fit?

Thanks,
Lou