Cams & Rockers

I found a used set of 1.8s for a good deal. Trying to decided between a lower ratio rocker like 1.8 or 1.7 and a cam or just 1.9s. The power band a cam provides is more attractive to me than the 1.9s. This will be an early to mid spring purchase so I am starting to think about it now.

All depends on what you want, how much you are willing to pay, and what level install you can handle.

I like to think of it like this. 4 factors to consider: cost, power, installation, economy

1.8:1 (mod 1:9) Rockers = low/med cost, least power gain, simple installation + no tuning required, stock MPG

1.9:1 Rockers = higher cost, good power gain, medium level install + no tuning req'd, stock MPG

Cam = low/medium cost, good/better power, difficult installation + tuning required, noticeable drop in MPG

None are better or worse. Each offers something more/less than the others. Imo, a cam is the more extreme mod, because you are exchanging two comforts for two advantages, rather than losing only one comfort in the case of rockers.

charlieRobinson wrote:

I found a used set of 1.8s for a good deal. Trying to decided between a lower ratio rocker like 1.8 or 1.7 and a cam or just 1.9s. The power band a cam provides is more attractive to me than the 1.9s. This will be an early to mid spring purchase so I am starting to think about it now.

keep scanning clubgp.com for a set of 1.9RR's with springs and retainers I bought my last set for my regal for $230 shipped with springs and everything i needed minus valve cover gaskets.. which was a steal.. they were Yella Terra's too!

I cant register on clubgp. My account has never been activated there. I''ve reached out to moderators and the site admin but nothing. Ghost town forum, if you ask me.

I was planning on doing a cam for my 30th bday in august. But i figured maybe i should just get the trans rebuild and get it out of the way with some 3.29 gears. If i decide to do a cam. Can i run it with my fwi and hogan down pipe with stock pulley? Or would i have to drop pulley sizes right away etc. I have until august ti figure it out but i figured id start here and then email zzp and intense. I mean relistically i coukd just do the rockers springs etc. What am i looking to do with my car? If i can get 330hp and 3xx tq id be content and then make the ol girl look nice. Just want to surprise people who said the only reason these cars have superchargers is because they HAVE to because they are heavy ass cars lol. I want a broad powerband, dont really want to reach high rpms to make anypower. I guess i will have to ride in someones modded series 2 to figure this out, anyone near Virginia?

Heres my question after reading most of this post, which, cam or rockers, will cause less wear and tear on the trans?

highwaywarrior wrote:

Heres my question after reading most of this post, which, cam or rockers, will cause less wear and tear on the trans?

None or any - more depends on how you drive,tune,etc I think. Technically you could use any cam without changing the intake/exhaust/pulley, so fourth but it won't perform as advertised obviously. If you didn't go to a smaller supercharger pulley with it, all you're likely doing is picking up a little top end, loosing a tiny bit of low end, loosing some fuel economy, and arguably driveability. Doesn't sound like a great deal to me without the other stuff.
If you're able & willing to upgrade valve springs and stuff, I highly recommend the XP cam as it gives you lots of top end and maintains good low end also. VS is a good cam if you don't want to screw with other stuff but I'm of the opinion if you're gonna go through the trouble doing a cam in a riv, replacing the springs isn't the part I'd be worried about avoiding.

Probably neither is going to add transmission wear more or less than the other. Driving style, shift settings, and maintenance will make more of a difference, IMO. Potentially the cam is more apt to damage in theory, because the cam tends to build more midrange torque, and ultimately more power than rockers, which are reslly only active above 4k RPM. Swapping to a smaller SC pulley is ptobably more dangerous because you're creating more low end torque. Generally speaking, low-end torque is what creates the most amount of heat and strain on a transmission.

Low-end torque is the most fun in a city driving setting! GREEN LIGHT, GO!!!!!! SEE YA!

charlieRobinson wrote:

Low-end torque is the most fun in a city driving setting! GREEN LIGHT, GO!!!!!! SEE YA!

yeah true but only if you actually get the tires to hook and the race is short

True that. ^^^

Charlie makes a good point though about city driving. Having big torque on tap can get you out of a bind quickly, without making a scene. On the freeway and at the track, RPM/HP rules!

Can anyone with a ZZP VS Cam comment on fuel efficiency for daily driving?
I've read that its on par with the stock cam for DDing and only chugs fuel under WOT.
Can anyone confirm?

I cannot speak for a vs cam specifically - maybe Derek will come in, but with my experience with the xp & is3 cams, the greatest loss in fuel economy is on the lower end when you are getting a lot more valve duration than you need. The cam is letting a lot of air/fuel get tossed right through to the exhaust compared to the stock cam and that hurts at low rpm, low throttle hence the roughness in the idle. As you work up to more throttle, it starts to pay off a little and I find it nearly evens out on the highway as my fuel economy strictly on the highway cruise is basically like stock - in theory using the same amount of air/fuel but with a tiny bit less throttle perhaps (higher VE at that specific point).
A vs cam won't be as night/day about it but I would think it'd be the same kind of thing as the general method is the same - adding duration/overlap to the valves. You might honestly get better fuel economy at WOT with a cam if absolutely nothing else is changed because you usually end up with higher VE there.

I have a VS camshaft. It's pretty mild. There is only a very slight mileage drop, which may be attributable to other factors such as the tune. I get approx 23.5 statute MPG combined out of every tank, higher if mostly highway.

The VS cam is pretty mild, but a nice step over the stock cam an extremely slight milage drop, if you are really tracking maybe a few tenths. I spent a lot of time idling in city traffic and so low end manners were important to me. Still a very nice improvement over the stock cam. Let me run the 3.4 pulley all day long with an aggressive tune or play around with the 3.2 pulley with no problems at all. If you do that and still aren't satisfied with a street driver, you will need a few additional go-fast parts anyway and increasing the cam to an S1X or XP would be justified.

When you guys say it's 'mild' what exactly do you mean? Not much different than stock? A great improvement but not crazy on fuel? Easy on the valve train?

Would you all recommend the VS? I think XP is more than I want until I get ported heads or otherwise go EXTREME.

Thanks

To me, "mild" means less lope at idle RPM, because the valve lift/duration more closely resembles stock. Some high-performance race cams will barely stay running at stock idle RPM, so you need to tune the idle a few hundred RPM higher. But these aggressive cams result in much more HP at WOT.

Compare to rockers, with basically stock duration, but much increased lift. Actually, the effective duration if a high-lift rocker is longer than stock, but it's a miniscule difference, and difficult to explain why this is.

Codith, what does VE mean?
What do you set the idle at for XP and similar cams?
If I average ~22mpgs now with my driving style. Should I expect to be ~19-20mpgs with an XP or similar cam?

charlieRobinson wrote:

Codith, what does VE mean?
What do you set the idle at for XP and similar cams?
If I average ~22mpgs now with my driving style. Should I expect to be ~19-20mpgs with an XP or similar cam?

If I had to throw out a wild ass guess, i'd say yeah, something like that for MPG. It's kinda all over the place with results because most people end up getting tunes and pulleys and stuff after a cam and you can do some favors to fuel economy there.
With my xp, I was ok with all stock idle speeds. On the IS3, I have the park/neutral idle stock at 800 and I think I raised in gear about 150rpm because it's pretty low stock (like less than 650 IIRC) and makes some situations a little uncertain feeling. Some people have had issues with big cams like that where the car will die out at stop lights and stuff due to the rough idling but I haven't had anything that bad.

There was a VE thread started here:

https://rivperformance.editboard.com/t9784-volumetric-efficiency-and-fuel-mileage

If anyone wants to supply further knowledge on this subject, it would be appreciated!

Oh oops sorry Charlie yeah ve is volumetric efficiency

Hello everyone,

I've been toying with doing new rockers in the Riv for a little while now. At this point I'm sure that I want to do them, and having done a set (twice...dont ask) in the Lesabre I've had good experience installing them. I do have a couple questions though for those that are more experienced than I am.

My real goal is not to achieve some mind-blowing powerhouse. I already have my terrifying Lesabre. I just want a little more power to make the Riv feel BETTER.

1) I'd like to do 1.8:1 rockers to avoid changing valve springs. Worth doing? I can't see there being more of a gain with 1.9's as there are going to 1.8 from 1.6.

2) Why change the pushrods with the Series II 1.8 rockers? I didn't have to with my Series I, but I DID end up changing the lifters...

3) On a hotter day (85+) degrees I'm seeing up to 4 degrees of KR between some shifts, and for extended periods of time. Rockers help a bit huh?

4) Anyone want to tune my car when I'm done?  



Thank you everyone!

-Andrew Z

I dont know half what most guys here know, but, from what I understand, the valve springs should be appreciated as a mod themselves and not just a part needed for another mod (rockers/cam).

Dont the upgraded springs let you safely rev to higher RPMs producing more power? too soft and you cant get as high and too stiff and you and put too much tension on the timing chain?


Correct me if I am wrong, please, but that's how I understand them to work?

go with the 1:84 RR if you can still get them. No need for springs unless you are upping the shift points or using 1:9 rockers. OR pushrods help keep the oil where it needs to be but are not a necessity when changing the rockers. They do just slide in in literally 2 seconds though so might as well do them while the rockers are off.

Yes rockers should help a little with KR buildup at higher rpm, but 85* really isnt all that hot unless you are heat soaked and WOT. And i dont see a pulley drop in your sig so i dont think you should be worried about blowing the motor with 4* at the top of a gear.

You could probably safely do a 3.5 pulley with the rockers if you also did some exhaust work to open up the out flow of air. At least a plog and DP would make a decent change in how the car feels light to light.

Just my 2 cents.  
Matthew

Thanks guys!

Yeah I won't be upping shift points or anything. So the pushrods that come with the rockers are the same length? Interesting.

Regarding the knock, I'm talking about uphill, heatsoaked, WOT. And actually I do have a Hogan DP on the car. I guess I should consider a plog too at some point. I've also smoothed out (not really ported) the LIM and blower outlet.

I just wasn't sure if it was worth doing the 1.8's. They made a HUGE HUGE HUGE difference in my Series I L67 in my Lesabre but I just wasn't sure with this engine, really, even though I've done a good bit of reading.

Yella Terras are still available for the Series II through Intense.