View Full Version : 1.7 to 1 rockers or Mopar magnum cam and lifters

Indy Ram
09-21-2000, 12:49 AM
Anyone have dyno experience comparing 1.7 to 1 roller rockers vs the mopar performance R/T cam in the 2000 catalog? Rockers would sure be easier and are supposed to be worth 10 hp alone according to Kenne Bell.I already have the performance computer and Flow masters. Whats the best way to go?

09-21-2000, 12:57 AM
Indy Ram:
Welcome to the forum!!! You will learn so much information and help so many people here, it is a very rewarding experience. There is a neat search feature on the upper right side of the screen. There are many posts concerning the RT cam. I think it would really depend upon how much money you are willing to spend and how much hp you want. If you give some specifics about what you want, we could probably help you a lot more. Welcome and hang on for the ride, this forum is getting big!!

2000 Ram reg cab short bed 5.9
Edelbrock stainless steel headers
true duals
Dynomax high flow cats
Flowmaster 40 delta series mufflers
Megs rolled edge oval stainless tips
Trans-go shift kit
B&M 28,000 gvw tranny cooler, hard lined in
Hughes 2500 HD stall converter

dreaming of power
09-21-2000, 01:10 AM
I ordered the Crower 1.7. When I get them in Ill let you know how they work out. Crower actually claims more HP then KB.

99 5.9 QC, MP Computer, Gibson Cat Back / Airraid / GY GT II 295 65 16, AR wheels, Downey SST Cover.

09-21-2000, 03:24 AM
The Crower 1.7 roller rockers are a solid investment. They are a top quality product by a proven company. If you really do want to eventually run a performance cam, you will run into some problems finding one that will work with the 1.7s though. The lift will be much to high. Furthermore, anything over a .470 lift will require some head work in order to fully realize the increased airflow. Good luck with your decision. There certainly is a wealth of knowledge to be had here.

94 Dakota Sport 5.2L, 3.90 auburn LSD, K+N X-stream filtercharger, MSD 6A, Blaster Coil II, Taylor wires, MP Computer, Pacesettter headers, Dynomax supercat, Flowmaster 50, Crower 1.7 rockers, Lakewood traction bars, Hellwig sway bar, Transgo shift kit, MP valve covers, Firestone Firehawks SS20

09-21-2000, 08:24 AM
hi indy ram nice to have you here. i have the
mopar 1.6 rockers and cam they are good for 22hp to 25hp. the 1.7 rockers are good for 12hp to 15hp. the 1.6 and cam are better and work with the hole r/t package http://www.moparchat.com/ubb/icons/icon6.gif
thanks cmyindy

09-21-2000, 12:05 PM
Welcome to the forum !!!

I checked into 1.7 roller rockers - cost was around 380 bucks + installation for the ones from http://www.straightline-perf.com/

And from what I have found out - they do lift up higher and you will need to install the MOPAR PERFORMANCE valve covers.


Direct bolt on, can be installed in a few hours. Consists of extruded aluminum rocker arms with roller fulcrum and tips. Also includes .080 wall 4130 Moly pushrods.

If you have any other questions, contact:

SBROWN@RACEMUFFLERS.COM - Scott is a friend of mine and used to work for Dynomax, MUSCLE MOTORs and the Mopar tech line - so he knows what he talking about. Mention the "RAM MAN" sent you when you call.
"Good Luck on your project."

Mid Michigan MOPAR Enthusiasts

[This message has been edited by RAM MAN (edited September 21, 2000).]

09-21-2000, 12:34 PM
Welcome to the board. Let me throw out another option. I don't have them but the SALE sign caught my attention. I don't see a 1.7 advertised but you could give them a call. http://www.hughesengines.com/general/rockers/magnum_rockers.asp

09-22-2000, 03:22 AM
Does that $380 include the new valve covers also?

09-22-2000, 01:09 PM
nope, unfortunately the covers are about another 100 bucks on top of that.

"Good Luck on your project."

Mid Michigan MOPAR Enthusiasts

09-23-2000, 01:05 AM
Indy Ram
I have done some considerable research on this topic, and I have ordered the MP 1.6 roller rockers, along the R/T cam, springs, lifters, retainers, tensioner, and MP valve covers. Ater much consultation with some of the cam manufacturers and with Mopar Performance tech line, I have decided to stay away from the 1.7 rockers because they will give me over .500 lift (with the new cam) and nearly everyone I spoke with says that is more than enough for the computer to handle and still run decently. If you are able to have custom programming done on your pcm, you might be able to do it. I know some guys in here have 1.7's, but I don't know if they are running the stock cam or not. You will want to research this topic completely, because it is a lot of work to change the cam, springs, rockers, etc if it doesn't run right after the install. Good luck and keep us posted.


98 SS/T, 2-4 drop, Gaylord's tonneau, RTT bumper cover, Reflexxion Steel cowl induction hood, painted handles and stripes, SS mirrors and grille inserts, clear tails, APC white face gauges, MP performance computer and cold air intake, QuickD tb, Gibson headers and dual Flowmasters with stainless tips, MSD wires, Transgo shift kit, all synthetic lubes, and more to come. Up next: R/T cam and roller rockers.


09-23-2000, 05:01 AM
I'm in the process of a Crane 2030 and 1.7 RR's... on paper I get .48x and .49x" total lift.. we'll see how it goes, I may have to shed the 1.7s for 1.6s

Jon Smith
Cary, NC
www.fast4x4.net (http://www.fast4x4.net)

09-23-2000, 05:20 PM
In the 'For What it is Worth' department, I have modelled the 1.7 versus 1.6 rockers on the EA 3.0 software using Magnum 5.9V8 specs.

The EA predicts the 1.7 ratio rockers gain about 7 hp in the 4500 to 5200 rpm range. That didn't seem like a good deal to me for the $400-600 investment.

One other thing that I found was that the EA 3.0 software predicted that the part-throttle fuel economy would be worse with the 1.7 ratio rockers.

This got me interested in rocker ratio and I modelled 1.5, 1.4, 1.3, 1.2 and 1.1 ratio rockers too.

In each case the fuel economy got better with the lower number ratio. I then found that I could leave the intake valve rocker at 1.6 and change just the exhaust valve rocker to the lower number ratio, and get almost the same part-throttle fuel economy improvement.

If the EA 3.0 software is predicting correctly, this indicates that one of the reasons the Magnum engines don't get better fuel economy is that the exhaust valve cam profile opens the exhaust valve too early for economically low rpm and part-throttle performance.

Of course, there is a performance penalty here too. Closing the exhaust valve later hurt high rpm power by 5-15 HP.

Seeing these predictions set me to thinking that maybe the Magnum engines would benefit from variable valve timing like the Mercedes ML430 and the Toyota Tundra V8 has.

09-23-2000, 09:14 PM
While I don't dispute the computer model's assessment - I know not enough about that particular version - I wonder how well it can predict what it says it can. Are there enough flow parameters inputted to correctly model the Magnum head and manifold flow? Was the software developed and calibrated on a Chebby engine, then 'forced' to work on a Mopar? These are pretty small differences - is it truely sophisticated enough to produce accurate values, and what is its error window? Just wanting information, not flaming anyone. http://www.moparchat.com/ubb/smile.gif

09-24-2000, 07:13 AM
for people who are concerned about the Cummins TurboDiesel not being able to rev to 4,600 RPM. (Sorry RobertC, your obsession with the V10 isn't as serious as my obsession with the turbodiesel not being able to equal the rpm limiter of your V10, which may explain why I got a 360 V8.)
"The world would be a better place if more people threw pies." - The Three Stooges


2000 Intense Blue Ram 1500 Quad Cab Sport SLT+, 5.9 L, Auto, 3.55 Sure Grip, Service Group (big battery, transmission oil cooler, & heavy-duty engine cooling), MOPAR tonneau, MOPAR bedliner, MOPAR Ram mudflaps, MOPAR side moldings, Flowmaster 50-series SUV muffler with heat shield, JBA silver ceramic coated headers, Quick D throttle body, K&N Gen II FIPK, MOPAR PCM, 180 degree thermostat, R/T Cam Package (cam & lifters), new valve springs & retainers, and new timing chain, and sometimes a full tank of premium gas.

Did I mention it was INTENSE BLUE?

09-25-2000, 01:27 PM
HankL - I would have to believe you are right - 400 to 600 hundred bucks could be better spent on other performance goodies installed with a lot less hassle.

I originally was thinking of going with 1.7 roller rockers, but don't think 7 hp is worth all the work and hassle.

"Good Luck on your project."

Mid Michigan MOPAR Enthusiasts

09-25-2000, 01:38 PM
Just a little sidebar on roller rockers:

There may be a reason Mopar Performance has chosen to market the Crane 1.6 roller rockers as their own. These are the ones I have. They are strong, reliable and do what Mopar Performance claims.

Cosmetically they suck. Crane's Gold Roller Rockers are mechanically the same as the Crane/Mopar R/T roller rockers, but look prettier for a price, . . . .

09-25-2000, 05:07 PM
Okay, now i'm thoroughly confused. while going to Crowers web sight it claims that 1.7 offers 20-25 hp on V8's while they give 25-30 hp on the mighty V10. they also claim that the 1.7 can be used with the stock valve cover. I too wanted to make this investment because there is so little available for the V10. What is more likely to the actual gains,,,7hp or 25-30hp?

09-25-2000, 05:33 PM
Just to muddy the waters even more -

Can the 1.7 roller rockers 'truthfully' give BOTH a 7 hp gain and a 25 hp gain at the same time ?

Well, yes they can.

How ?

Well the 7 hp gain that I talk about is what I think most people talk about - the hp gain at MAXIMUM horsepower near 4000 to 4400 rpm.

But what if you rev the engine to 5200 rpm. At 5200 rpm the stock Magnum 5.9V8 may only be making 170 hp due to lack of breathing - since it is past 'the peak'.

If you add the 1.7 ratio roller rockers the stock Magnum camshaft now lifts the valve higher with a bit more duration too. The engine now breathes better at high rpm { but worse at 1500 to 3500 rpm}

So now the Magnum engine with 1.7 roller rockers installed may make 195 hp at 5200 rpm.

That is a '25 Hp Gain' is it not ?

Can this "25 Hp Gain" be advertised that way truthfully ? Hmmmm ?

How many of you would see '25 Hp gain' advertised and immediately add that to 245 hp at the peak and think that now you have a 270 Hp engine ?

My grandmother used to have many mountain sayings she would restort to. One of them was:

"Figures never lie,
but liars always try to figure."

09-25-2000, 06:21 PM
in the topic Roller Rockers I posted a dyno chart from truckin magazine tht showed the gains from installing 1.7 in a 97 318 dakota. The gains were in the 4200+ range and the diference was not 20 hp it was more like 10-12 hp.

09-25-2000, 06:55 PM
While I do not have solid HP numbers to give you (I have not been on a dyno), I can honestly tell you that on the stock cam, you can really feel the power boost from 3000+RPM with the 1.7s. I am not disputing anything that anyone has said here because the only thing I have to back up my statements is the SOMP. The Mopar (Crane) rockers are 1.6 to work with the R/T cam which is designed to get the most benefit from stock magnum heads. IMHO, if you open up the heads a little, you can still run the 1.7s with the R/T cam and see better gains than 7 HP over the 1.6s. I fell that running anything larger that that will kill too much low end power at which point you need to upgrade to a stall converter. Bottom line, 1.7s will get more air into the engine and exhaust out without moving the powerband. This means more power. http://www.moparchat.com/ubb/smile.gif

BTW, lets also remember that the more pieces of the puzzle you have together, the better that the whole thing is going to work.
94 Dakota Sport 5.2L, 3.90 auburn LSD, K+N X-stream filtercharger, MSD 6A, Blaster Coil II, Taylor wires, MP Computer, Pacesettter headers, Dynomax supercat, Flowmaster 50, Crower 1.7 rockers, Lakewood traction bars, Hellwig sway bar, Transgo shift kit, MP valve covers, Firestone Firehawks SS20

[This message has been edited by Fastdak (edited September 25, 2000).]

09-25-2000, 07:42 PM
Thanks for posting that reminder 95redsport, the address for what you posted before is at:


Here's a repost of your numbers:
You guys made me dig through all my magazines but I found it. In a TRUCKIN article, they installed crower's 1.7 rockers in a 97 318 Dakota here are the numbers:

Horsepower/modified Hp Torque/modified Tq

1500 60.4 70.1 217.6 225.5
2000 85.4 84.1 230.7 229.7
2500 111.3 112 240.1 244.9
3000 136.3 138.8 245.4 251.4
3500 160.2 158.2 247.3 247.1
4000 181.5 187.1 245.1 255.7
4500 193.7 204.3 249.8 257.1
5000 184 192.7 235.2 252
These were measured on a chassis dyno.

09-27-2000, 07:12 PM
Robert we are all tired about your RPM crap. So just leave it at that. You've told your story now end it.