Lee7

The only Roller rockers i can find for 2.8L Chevy's are 1.5, 1.52 and 1.6.

The 1.6 rollers cost $376.99, the 1.52 are $112.99.

the 1.52's are stamped steel, the 1.6's are Extruded Aluminum.

How much of a benefit would the 1.6's be over the 1.52's?

Lee7

Also, make the replies snappy please, im ordering in about an hour.

TomP

Can't help too much since I've still got stock rocker arms, but- V8 rocker arms are also supposed to fit. They use a 3/8" stud, we use a 10mm stud. A guy on here tried them (got them cheap at a swap meet), and said he just had to grind the arms a bit for some interference, but otherwise, they worked perfectly.

If emissions are a problem in your area, you might want to go with the 1.52's. The Comp Cams ones claim to be 50 state legal.

**EDIT: Fan-frickin-tastic!! I found the message. Not bad prices on those v8 sets! Message is here: https://www.thirdgen.org/techbb2/sho...threadid=62795

Lee7

w00t, thank you tom. Much love <3

Now i dont have to get those silly rice rockers (extruded aluminum) and i can get the Stamped roller ones.

unvc92camarors

ok, im a real "newbie' to the whole rockers thing
and a few newbie questions for ya...
1) planning on a cam sometime end of this year maybe and should i get these with it?
2) what kinda gains?
3) would they work for a 3.1?

thanks for listening to my stupid "newbie" questions

TomP

Hey, no problem. Make sure you come back and let us know how they work out!! (What brand/part # you get, etc!)

You could do them with a cam; might make sense, since you'd have to remove the rocker arms (or at least loosen them) to remove the pushrods so you could remove the old lifters, so you could install the new lifters.

AGood2.8

A word of caution- If you are thinking on 1.6's, you'll need taller fiero valvecovers to clear the increased rocker height. Also I strongly suggest you upgrade your valve springs, the stock springs are about maxxed with the 1.6 valve lift as opposed to 1.5 valve lift- you can easily float a valve at higher revs and goodbye motor.

unvc92camarors

are these emissions legal?
i looked at the 1.52 for the 2.8 and theyre 50 state (like tom said) but it doesnt say anything about the 1.6's.
also, what would you guys recommend: sbc rockers or the ones made for the 2.8?
http://store.summitracing.com/defaul...n+cams+rockers
those are the ones i found on summit

edit: just reread the thread...i guess the benefit for sbc rockers is cheaper price and better material....im not sure, i'm still too newbie

BitchinRS

What is the stock roker ratio? I thought it was some ware around 1.5 . Correct me if I am wrong but if stock is around 1.5 the 1.52 wont make difference, correct?

AGood2.8

The stamped steel rockers that come stock on the 2.8's & 3.1's do vary in ratio as low as 1.46- they are not accurate at all.

The Comp Cams 1.52's are a true 1.52 exactly and consistently plus the fact that they are roller tip and rev easier/quicker.

Here's some comparison figures I have calculated to show differences-

All figures taken with the stock 2.8/3.1 MPFI cam profile: .262"I/.273"E
--------------------------------------------
Stock stamped rockers as low as 1.46 = .382"i/.398"e total lift.

Comp Cams' 1.52 roller tip rockers = .398"i/.414"e total lift.

A good bit of difference.

1.6 roller rockers will yeld on that same cam profile= .419"i/.437"e {req valve spring upgrade}
--------------------------------------------
Note: stock 2.8 & 3.1 valve springs can only handle a max. lift of .420".
Crane springs (part#99848) can be used without any machine work for lifts upto but not exceeding .480" and 5000rpm's-
If you have up to .480" lift but exceed 5000rpm's then the springs will have to be changed to duals (GM part # 330585) that will handle .560" lift- Machine work is required so heads will have to be removed for this modification!

Doward

Yep, if you go 1.6s, get new springs, as well as Fiero valve covers.

TomP

Do they have to be Fiero covers? What about those Edelbrock covers?

V6camaroman

hey guys i would be safe getting the full aluminum comp cams 1.6 roller rockers for my car right. i just rebuilt the motor about 30,000 mi ago and it had new valve springs put in. i know i need the fiero valve covers already. will my motor be ok?

Lee7

Im rebuilding the whole valvetrain.

I figure that after 167,000 miles, every single part of the valve train is on its last legs.

Heres what im gonna order.



if the Eldebrock Valve covers are not tall enough, i will get some Fiero ones. (the guy in the other thread said he used these Eldebrock covers with the 2030 cam and 1.6 rockers)

BTW: What would happen if i put a "PowerMax Hydraulic Lifter Camshafts for Emissions Controlled Vehicles without Computer" .454/480 in my 89 2.8?

Would it not run at all? run crappy? or?

AGood2.8

Your sig doesn't say what springs you put in?

I am assuming from your sig however that you have 3.4 heads because of the 1.72i/1.42e valves. If so, then I do know that the stock 3.4 cam produces .427"i/.454"e lift with stock 1.5 rockers.

With your cam profile you will be at with 1.6 rockers-
.448"i/.471"e
Problem is that I can't find max. lift specs on stock 3.4 springs and can not confirm if you will be o.k.
I can tell you that the Crane single springs # CRN-99848-12 will hold max of .480" lift and they will insert without any machine work.
I would recomend the dual springs though- with .560 max lift- thats what I will be using when I switch to the HT3.4 and 1.6 gold rockers. I'll have total lift of .455"i/.484"e (very close to what you'll have). Thats as high as I care to go for a daily driver.

AGood2.8

More than likely it will run dirty- meaning that your intake and exhaust durations will have an amount of overlap that will produce excessive unburned fuel at lower rpm's and cause it to fail an emissions test.

I will have this problem but less dramatic with the new engine I am designing/building- I will have that same lift but with 1.6 rockers instead of 1.5's- thus not producing as much lobe overlap because of the ratio of lift steepness. It will have less lobe duration at that same lift. I am using a cam designed for 1,5 rockers with a lower lift and will bump up the lift by using the 1.6's- duration will also increase, but not as much as a cam with 1.5 rockers designed for that same lift.

You will have to have chip work done regardless to optimize the motors potential ( I am no expert on computer ecm's- But this info I am told from two different experts that I know are experienced in that field)
-----------------------------------
Edit: You want a cheaper route? stop your order (besides I don't know if those rockers will work for you. The stud nuts certainly wont- they are 3/8" and you need 10mm.

You would be better off getting the Crane cam lit # 253902 (cam and lifters- same setup in the stock 3.4 motors with emissions) It only says "non-emissions or computer cars" because legaly they cant sell it for those cars- even though it will work. It has the same lift specs with stock rockers as with what you are trying to do with 1.6 rockers. If you want roller tips, then go with the 1.52's- keep the stock pushrods if you want to save money, and change the springs to the crn-99848-12's like you were ordering. Then you have no clearence issues with the stock valve covers.You be at $387 subtotal- you don't need locks and retainers unless yours are bad for some reason.

AGood2.8

Here's a quick scketch of what going from 1.5 to 1.6 ratio rockers do. Note that drawing is not to exact scale and lobe arches are roughly drawn to just present an example.

Note that the lower scketch shows the intake and exhaust arches riasing form 0" to max lift at a steeper and faster rate than the arches of the 1.5 scketch.

The drawing shows how not only does lift increase but duration increases as well- meaning that the valve not only open higher, but also for a longer period of time- meaning more fuel intake.

What higher ratio rockers benfit is- less lower vavletrain movement to oproduce a higher lift- the cam, lifters and pushrods move the same distance as before

Downside?- the rocker and spring are under a greater strain and the valve has to open and close at a faster rate of inclination and declination.- This is why I strongly recommend dual springs with ratio rockers.

Lee7

The 1.6 v8 rockers from summit work on 2.8L's, you just need to re-use your old nuts and washer thing. No biggie.

Im using the Powermax 2030 cam with .423 (i/e), the cam you told me to get is for non-computer controlled vehicles, and you said earlier that it would not run right on computer controlled vehicles.

1.6 Rockers are better than 1.5's when you are going for power, which these 2.8's desperatly need. I have no worries about emmisions, i got a hookup

I ordered Eldebrock valve covers, not only do they look better, but they are taller than stock, so i should not have any clearance issues.

Also, Using worn pushrods = bad idea.

Im not that worried about money, i will be beefing up my suspension next month when i pay my credit card bill.

AGood2.8

I'll take your word for it on the V8 1.6's- I have never matched them up

The cam you posted above that you are ordering is .401"i/.423"e.
If you want the .423"i/.423"e then you need part # 254122

I agree on using new parts (pushrods) just offering a tip if money was tight 9via other cam and stock rockers & pushrods)


The .423/.423 cam with 1.6's will put you at .460"i/.460"e, The 99848 springs will work fine.

Lee7

****!

i ordered the wrong camshaft

looks like im gonna have to order a different one and send the wrong one back.

So what cam should i order this time?

I want the max lift i can get and not have the computer start throwing hissy fits.

And like i said, emmisions isnt a problem.

AGood2.8

Like I stated above- I will be using the stock cam in the HT3.4 with 1.6 rockers (not 1.5's)on a MPFI computer setup.
Thats going to give me a total lift of .455"i/.484"e. But you'll need the dual springs.

That cam kit # is crn-253902 at summit- same exact cam as the HT3.4 cam.

Lee7

alright, i just ordered the same cam as you.

Im using the single valve springs, because my transmision should shift right before valve float accurs. (besides, .004 is barely over the limit of the springs, and the springs are probably underrated anyways)

If it doesnt, i will just go ahead and order double springs.

82-T/A [Work]

In my HONEST opinion, I suggest against the 1.6:1 rocker arms.

In my opinion, the 1.52:1 roller rocker arms are the BEST buy for our V6 engine. The V6/60 was often used back in the day as a circle track motor for racing... a lot of the smaller mid-sized vehicles used it. This was one of the more common upgrades. It's true, the old factory rocker arms certainly are not a true 1.5:1. They are rated at that, but that would be in a perfect world assuming the motor came from the factory blue-printed with 100% perfection. But it certainly does not. Anyone that's ever taken a look at how the intake manifold and the runners under the plenum match up together will get a good idea of the build quality of the motor. Sure.. the motor IS a great motor.. but like all car companies, they cut corners where they can.


I can use my Pontiac Fiero as a comparisson. A few years ago, my water pump failed and the car overheated. I ended up taking of the cyl heads... I had a new valve job, and installed new springs and a set of 1.52:1 roller rockers. The only other thing I did was a complete port-match and polish of the entire intake and cyl head. On a scale from 1 to 10, with 10 being the best port-match job. I did about a 5. It was a real quick down and dirty job.

When I got my car back on the road, I noticed an unbelievable difference. I'd easily say I gained about 10 horsepower. I truely think this was mostly because of the rocker arms. The cyl heads before the car overheated.. were perfectly fine. I had perfect compression (I had just checked them a couple weeks before actually).

I don't think people should go with the 1.6:1 rocker arms on this motor. For one, it's a cheap way of trying to get performance without having to install a new camshaft. 1.6:1 rocker arms slightly changes the geometry that pressure is applied to the valve stem. This can wear out the valve shaft. It's just not worth it.... especially if you want this motor to last a long time (like I do with mine). In the Fiero, this IS the big motor (like the V8 would be for the f-body).

In my opinion, and in a perfect world.. everyone would have upgraded camshafts with 1.52:1 roller rocker arms.

1.52:1 roller rockers are a great upgrade for both modified motors, and a stock motor. You are guaranteed to see an improvement in power with these rocker arms. And they compliment a performance camshaft nicely. I'd almost say it should be a requirement to buy roller rockers when you upgrade your camshaft.


Anyway, I just blew close to $1,500 bucks on a pretty sweet V6/60 engine rebuild (this is for my Fiero remember, not my f-body). I went with a very radical camshaft, and 1.52:1 roller rockers. I went to the highest lift / duration cam I could possibly get while still being compatible with the stock computer.

a Phase 2 camshaft by ARI Racing Engines
www.engine-parts.com

IMHO, anyone considering upgrading their rocker arms, but that doesn't want to upgrade their cam right now... then get a set of 1.52:1 rocker arms, and do a real REAL good job of porting, polishing and port-matching your intake pieces, cyl head, and exhuast manifolds. You'll pick up about 10 horsepower just from that. I guarantee it.

There are a lot of fairly inexpensive things you can do...

You can upgrade to free-flowing catalytic converters. Seriously, those old 2.8s came with some crappy cats.. at least the earlier f-bodies... they had those charcoal brick cats.. which are horrible. Replace those with some free-flowing Ocelot cats. They're like $50 dollars each. I guarantee you will see more of a horsepower improvement by replacing your cat with a free-flow aftermarket one than you would if you replaced your cat-back exhaust system with a high performance one.

The other thing you can do is replace the factory fuel injectors. The 2.8 f-bodies came with 13lb fuel injectors. 3.1 f-bodies came with 15lb fuel injectors. The 2.8 motor is REALLY.. I mean REALLY pushing the limits of the 13lb fuel injectors.. with even minor modifications.. a 2.8 at WOT with 13lb fuel injectors is likely to run slightly lean.... therefore decreasing power. Either snag a set of 15lb fuel injectors from a 3.1 Camaro / Firebird, or get a set of 15lb injectors from the Pontiac Fiero. If you can though, get the ones from the Fiero. The Fiero's 15lb injectors and the injectors from the 2.8 f-body are actually a better design than the injectors found in the 3.1 f-body. They are the pintle style.. which is more or less the only style you'll find in a performance application. The ones in the 3.1 were made more or less for reliability sake. They are the rotary "disc" style.. which are self cleaning. The pintle style helps spray the fuel directly on top of the valves much easier than the disc ones.

AGood2.8

In my honset opinion- for such an expert? You've certainly trashed and sold off alot of cars in your short lifetime? Make me wonder why so many changes if you really knew your stuff?

1.6 rockers are a much better but more expensive way to go- lightweight aluminum Full rollers have less vavle stem shaft thrust than do stock stamped steel rockers.

You don't understand rocer geometry do you? 1.5 roller tip rockers with a higher lift cam giving a total of lets say .480" will have the same exact valve stem shaft thrust (bind) as do 1.6 roller tip rocers combined with a cam that give it the same max lift of .480"

With the 1.5 assembly- the lifters and pushrods are traveling a greater distance up and down to pivot the rocker so you have more parts of the valvetrain exerting themselves to get the same final valve lift as you would get with 1.6's

Dean

Lee7

I was about to say the same thing lol.

82-T/A [Work]

Ok, want me to go through all my cars??? I guess you guys can't take advice from someone without it affecting your egos.

1976 Chevrolet Camaro LT-350 (JUNKED)
- Got the car for free, it was completely rusted out. I took the
motor out, and that's what's in my 81 TransAm.

1985 Pontiac Fiero GT 4-speed WS6 (Sold)
- Bought it with 143k miles on it for $1,300 bucks. Put another
20k miles on it, sold it 2 years later for $1,600 bucks.

1982 Pontiac TransAm (LU5) (Junked)
- Bought it for $700 bucks. The motor spun a bearing during a
burn-out and threw a rod through the oil pan. I junked it.
It had a ton of rust, and wasn't worth fixing.

1986 Pontiac Fiero SE / V6 (Sold)
- Bought it for $1,500 bucks. Sold it a week later for $3,000.

1985 Pontiac Fiero 2m4 (Sold)
- Bought it for $250 bucks.. drove it around for 3 months, sold
it for $250 bucks to Archie V8.

1976 Pontiac Grand Prix SJ 400 (Sold)
- Bought it in a junkyard for $200 dollars. Saved it for someone
on the internet for a month, he paid me $500 for it.

1983 Datsun 280Z 5-Speed (Junked)
- Bought it for $900 dollars. Put $200 dollars into it, and drove
it for about ~3,000 miles. Spun a bearing, it had major rust,
so I junked it.

1988 Mazda RX-7 Turbo-II (Sold)
- Bought it in 1996, sold it in 1997 to buy my 87 Pontiac Fiero.

1984 Volvo 240 Turbo Coupe (Junked)
- Bought it from my parents in 1995, drove it around town.
Gave it to my brother, he wrecked it.

1984 Toyota Corolla LE Sedan (Junked)
- Bought it in early 1995. Brother stole it and junked it.

CC_HotRod

On the topic of heads...has anyone installed a set of push rod guide plates while doing the lifters etc. If so what set did you use?

TomP

You mean a new set of guide plates? Our motors already have them...

82-T/A [Work]

Yeah, that's not something you normally replace unless they were damaged in a mishap!

V6camaroman

agood2.8 i have 2.8 heads on my motor not 3.4's i just had the bigger valves put in at the machine shop when they were rebuilt. as for my cam it is a blue racer 204,214 duration and .420, .443 lift with 1.5 rockers. what will my lift be with the 1.6 full rollers? as for the valve springs they are just heavy duty valve springs.

AGood2.8

V6Cam,

You cam with 1.5's- .420"i/.443"e. Divide each by 1.5 the mutiply by 1.6- Its that simple

With 1.6 rockers you'll be at .448"i/.473"e

If you don't know the max. lift of the springs you have- my suggestion is not to guess- that can cost you big time. Play it safe and pick up some 99848-12springs at least.

I plan to definately use dual .560"max rate springs, with stainless steel valves, and titanium retainers & locks. I want this motor to be capable of 7000+ rpm's without damage. not saying it will necessarially pull those rpm's, just if its capable of 7000+ then it will pull 5500 all day reliably. I like a safety margin.

CC_HotRod

I don't have any guide plates on mine. Maybe someone took them out for some reason, I have owned my Camaro since 1988 and haven't had any problems in that area but I think when I do the roller rocker upgrade I will add a set of guide plates though.

Doward

Hmm... not sure if mine have the Guideplates... I'll check when I replace my heads/manifolds tho

Blah blah... dang it, you guys beat me to it! 1.6 ratio rockers + Melling MTC-5 (The cam ARI Cloned with the Phase 2) are what I'll be running.

On a personal note.....

YOU PUT A CHEVY IN AN '81 T/A?!?! GET THAT OUT OF THERE!! GET A 400 PONCHO FOR IT..

man... if you're gonna have a REAL t/a... get the right motor :P

(just ribbin'!)

82-T/A [Work]

Doward,

Very true... it's a Chevy motor! The thing is, I used to have a 1976 Chevy Camaro a couple of years ago. Actually, I got it for free from a friend of a friend. I had to have it towed back from Tampa which ended up costing me close to $500 bucks to Fort Lauderdale.

When I got the Camaro back to my place, I discovered that the motor in there was a CMJ block.. which this one in particular came from a 1974 Impala Police Car. It's a 350 4-bolt. The heads on the other hand were a set of High Output heads. They were the "double pyramid" heads. Not to be confused with the double camel heads.. the HO heads have the same valve sizes as the camel heads, but with more CC. It's a 76cc head with 2.02:1 intake and 1.6:1 exhaust. So, with that in mind, I wanted to find a fairly rare TransAm but one that wouldn't cost me an arm and a leg. So.. I found this one.. up in Lake Worth.

It's a 1981 TransAm with the rare factory medium metallic blue paint with the Saddle DELUXE interior. It originally came with the Pontiac 301 (which was better than the alternative Chevy 305 which WAS available in the TransAm.

Ultimately, I realized the Camaro was just too far gone. I worked on the motor a little to get it running and to see what the condition was. When I took the Camaro for a spin, I got stress fractures in the body. I went around back to check the underside of the car and put my hand on the rear right quarter panel. My thumb punctured the quarter panel and about 1 gallon of rust water poured all over me. It was at that point I realized I needed to get rid of it. So I pulled the motor that Sunday morning, and a week later, I junked it for $125 bucks.

I've got the motor in now, you can check it out on that link. I haven't taken any new pictures in half a year. I already have 80% of the work done in the front. All I need now is a replacement passenger side fender.. I just can't find one.

I'd like a Pontiac motor in it eventually, but for right now, this will have to do. When I buy another 82 TransAm, I'll drop this motor into it... I found at the junkyard a couple months ago, TWO complete Cowl-Induction hood scoop assemblies. One was from an 84 HO TransAm.. so the Cowl-Induction assembly is for a 4-bbl carbureted motor, and then I found another one from the Cross-Fire injected LU5 motor.. so I have the air cleaner assembly for that as well. I also purchased a complete Cross-Fire injection set-up from an 83 Corvette.. so it's JUST like what the LU5 came with stock, but set-up for a 350, not a 305! I'm going to have quite a sleeper stock looking 82 TransAm when I'm done. It'll look like a completely stock LU5 82 TA, but it'll have twice the power.

unvc92camarors

alright, im thinking this cam CRN-253902
and then i wanted to get some 1.55 roller rockers
i heard talk about them but i havent fonud them. anybody else have any luck?
and if i was to go with that cam and 1.6 rockers id be at 455/484 and would this be emissions legal? (i also know id have to use dual valve springs if i ran this setup)

Lee7

thats the same combo i have (1.6 rockers and cam)

dont buy the Crane Cams Gold Aluminum 1.6 rocker arms, get Summit part number: SUM-141507 They are made for V8's, but work on our V6's, just use your old washer thing and bolts.

An no you probably wouldnt pass emissions unless you ran some of that fuel additive, advanced your ignition timing and got an MSD box with multispark, (Helps burn up all of the fuel in the cylinders.) and get an uprgraded chip. Running it a little lean might help too. But luckily you only have to do emmisions once a year, and can go back to the good settings once you did it.

unvc92camarors

well, has anybody found any 1:55's? id prob go this route or 1:52's just to keep with emissions and everything.