rocker arms

[Chuck 98 RT/10]

The higher ratio pushes the valve further open allowing more fuel flow. According to the majority on this board the higher ratio rocker arms only benefit when done with other mods.

I read where a person said his Viper idled more rough with the higher ratio rockers. It would probably make it a bit louder too. That's good enough for me, I never whined about NGR or brake squeal or gear whine. I love the rawness of the Viper.

 

[treynor]

I was of the belief that the roller rocker design made some of its HP through lower friction against the camshaft? As Chuck says, it also opens the valve a bit wider, allowing slightly greater flow (although if you look at head flow #s, there's marginal benefit from this) and it corrects the uneven ratios found in many of the stock rocker arms (see the advanced tech section of the board).

 

[Jack B]

If you view the Crower site, they claim about 30 hp increase for about $700. Their site is listed in the "performance parts" section of the VCA home page.

 

[treynor]

I've heard estimates of 10HP; 30HP sounds wildly optimistic. I won't have the oppportunity to test upgrading just the rockers, but perhaps someone else on the list has done so and has results?

 

[Chuck 97 GTS]

By running a 1.7 ratio rocker you are increasing the effective lift of the cam. This accounts for the lumpier idle as well as increased air flow and resultant power. The reduced friction is probably worth a couple hp, but not as much as the added lift gives you. I've heard gains of 10-15 rwhp are typical, especially when coupled with other mods such as headers and exhaust. A shaft-style roller rocker setup like the T&D will also give you a valvetrain that is a bit more robust. But I'm just a benchbuilder so what do I know?

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[opnwide]

my favorite book is Chevrolet Camshafts and Valvetrains by Vizard. This guy is real smart. I've read the book about 10 times. For gear heads only! Weaker minds may explode.

 

[Bill/APEX Motorsports]

Chuck, you're right on the money! The stock setup is just cheap stamped-steel rockers that simply drag back and forth on the valve tip. This causes a lot of friction.
Roller rocker arms reduce friction between the rocker arms and the valve tips by way of a cylindrically-shaped roller on the end of the rocker arm.
The increased lift provided by aftermarket rocker arms (usually 1.7 ratio) keeps the valves open longer to ingest more air and expel more exhaust than stock. I like the T rockers because of their total beefiness and ability to handle quite a lot of hp. The Crowers, which are not shaft-mounted like the T, have been linked to multiple valvetrain failures on Vipers that spend a lot of time in the higher rpms. The stock lifters bleed off pressure pretty quickly, and if they can't keep the pressure up at higher rpms, the rocker tip can jump off the valve tip, causing valve float. What's even more problematic is that they can jump sideways and actually fall off the valve tip. Ouch! Big problems. The T don't suffer from that potential problem.
Also, don't believe 30hp. That's about 20hp overstated, no matter who the manufacturer is.

 

[HogWhisperer]

Interesting thread guys. By the way Ben, your HP #'s with the new HMS heads are very impressive, congrats!

Back to the rockers..... I've heard that installation of the T&D rockers void the warranty. Any truth to this?

Thanks!

 

[HouseofSpeed]

Man....the hits just keep on comin'...a new definition of valve float, and to top it off... the fact that anyone would suggest using lash caps. You guys making these suggestions are starting to look more and more like dealership mechanics and machinists that got their certification through a Sally Struthers infomercial.

Again, being the beacon of hope in this sea of misinformation...trust a reputable engine builder/machinist with your heads and engine work.

 

[Doug Supercharged Vipers]

The last time we used lash caps was on a big inch motor with *titanium valves*. I prefer not to use lash caps. Before we bolt on a set of heads, we do what we call a "mock up" by placing the head gasket, heads and roller rockers in place to check valve geometry. The supplied shims can be used but they work better for other projects. We can also compensate by milling the rocker pads but this has to be done prior to valve assembly. In most cases the stock push rods can still be used. Hardened pushrods are not necessary unless you're using guide plates (not needed for T&D's), high spring pressure, or wish to keep the valve harmonics to a minimum.

As far as valve float - The stock spring pressure will float like a boat

.

Regards,
Doug

 

[HouseofSpeed]

Good points Doug....however, I wouldn't reuse a factory pushrod because of its construction. I understand that one piece moly units and carbon matrix pieces aren't necessary for an engine such as the Viper is blessed with..but in the end I feel better with a good pushrod in place.

Lash caps have their place....and its definitely not on a V-10 with a hydraulic roller and shaft mounted rockers.

 

[Marc Lublin]

Not to beat a dead horse Kyle, but less than a year ago, when I believe you were working at HMS, you guys sent me pushrods and lash caps to use with the T&D shaft mount setup that you were supposed to send. Check the invoice if you would like to confirm. I knew not to use them on this motor at the time, but somebody there did not.

 

[HouseofSpeed]

Marc....your heads were done by a machine shop that had convinced John to go the lash cap route. I didn't agree with that then...and I still don't. After that relationship was severed and we brought the cylinder head work in house, the lash caps went away. You know what...there were several other Viper "tuners" that were (and still are) using lash caps. So that burden befalls many that have yet to be targeted by your vitrolic.

I see a pattern developing here with you....you got ****ed and now you are going to take it out on anyone that will give you the time of day. I am through educating you, from now on..unless you have something constructive to say from a technical perspective, don't say anything at all. Save the martyr act for personal posts between you and John.

 

[Tom Sessions]

I am testing a new set of 1.7 rockers for a company .These rockers have a common shaft that connectes 2 rockers together so you get 10 sets of rockers no machine work is needed for installation.They use a allen bolt that bolts them to the heads and the adjustment for lash is done above the push rod.These should work well at hi rpms with reduced risk of walking and causing valve train damage due to the common shaft between two rockers.Dyno results show about 20 HP on a gen 2 engine.I'will be installing in a gen 1 and will post numbers in about a month.I dont have price info yet but they should be in line with others like crower.

 

[Marc Lublin]

Kyle,
I like the line that you are through educating me. You sound a little full of yourself thinking that you have educated me at all. Though I don't build motors for a living, so far you have not said anything that even the backyard builder shouldn't know. Maybe you know alot about motors, but to assume that others don't because you do is just plain dumb. If you didn't agree then about the lash caps maybe you should have said something. You are pretty vocal now. Maybe tell the customers that have them that it is not the best setup and offer a kit with pushrods to change them out. Wow, customer service and caring about the customer after the sale, what a great idea. If HMS had done that with me, I would have never needed the headwork in the first place. The reason for my valve stem damage was due to a comp cam rocker setup that HMS installed. Instead of riding over the center of the valve stems, the were all cocked to the sides. Some worse than others, causing the stems to get ground away. John was fully aware when I contacted him and he told me that is why they don't use them anymore. Although I purchased the car second hand after the mods were done, I was in contact with John a number of times about the car. Even if he didn't cover the costs it would have been nice if he let me know that I have components in the car which have been known to fail. I took digital pics of how off they were if anyone would like to see. I can email them to you if you would like. Kyle I think it is pretty "constructive" to talk about how HMS should take care of the customer after the sale, don't you?

 

[RED 97 GTS]

I AM GETTING READY TO INSTALL CROWER 1.7 ROLLER ROCKERS SHOULD I CHANGE MY PUSHRODS. IF SO WHICH ONES TO BUY. THANKS

 

[Chuck 97 GTS]

Could somebody please explain to the novices in the audience what a lash cap is?

 

[Doug Supercharged Vipers]

Hello Chuck,
In simple terms...... A lash cap is a small cap that can be placed on top of the valve stem so the tip of the rocker arm roller rides on the cap.

Regards,
Doug

 

[Bill/APEX Motorsports]

OK, you caught me. My fingers were faster than my brain. I didn't mean to say that the valve would float. I meant to say the the valve wouldn't open if the rocker arm tip came off the valve tip. This, in turn, would cause the unseated rocker arm to bounce back and forth against the rest of the valvetrain, most likely bending/breaking the valve, rocker arm, and rocker mount.
I made an honest mistake in my typing, although your attitude makes it seem like it was the end of the world. Sheesh, what's happening to this board?

 

[Mad Max]

I am testing a new set of 1.7 rockers for a company .These rockers have a common shaft that connectes 2 rockers together so you get 10 sets of rockers no machine work is needed for installation.They use a allen bolt that bolts them to the heads and the adjustment for lash is done above the push rod.These should work well at hi rpms with reduced risk of walking and causing valve train damage due to the common shaft between two rockers.Dyno results show about 20 HP on a gen 2 engine.I'will be installing in a gen 1 and will post numbers in about a month.I dont have price info yet but they should be in line with others like crower.

Tom,
Who's rocker arms are these? How did they perform during your testing?

Brent

 

[speedracervr4]

From his description it sounds like Jesel rockers . They're probably the best, but also the most expensive. I have them on my Viper and they're easy to install as well.

 

[Sybil TF]

Ok so which is best? Not cheapest. I don't care about cost. Stock 96 GTS ,no power adder's except M & M header's ,hi-flow cat's and 3 inch Borla exhaust.

[ ] T&D

[ ] Crower

[ ] Harland sharp

[ ] Jesel

I want to add these before I order my SCT tune.

 

[99 R/T 10]

Did you guys notice the date on this thread?! 12 years ago, might not be relavent now. Soooo many good choices in rockers from Jesel to Crowers.

 

[VIPER GTSR 91]

On my old GTS I did the 1.7 T&D rockers along with all internals etc. to get the 650 pkg. About a 15-20 hp gain with rockers alone but as you mentioned its the whole pkg. that compliments the rockers. Wow you are right, this is a very old thread.

 

[99 R/T 10]

Well since the thread is now on going.....................

http://classifieds.viperclub.org/showproduct.php?product=6456

 

[happy]

What's your guys take on the gen 3 rocker arms?? There 1.7 too if a fellow could get a set at a good price, would ya say go for it or Harland sharp??

 

[uvbnbit]

Ok so which is best? Not cheapest. I don't care about cost. Stock 96 GTS ,no power adder's except M & M header's ,hi-flow cat's and 3 inch Borla exhaust.

[ ] T&D

[ ] Crower

[ ] Harland sharp

[ ] Jesel

I want to add these before I order my SCT tune.

I think the more HP you're putting out, the more $$$ you'll need to spend. Seems like the "budget" H/S's (what I have) are good to the 700hp range from what I remember

 

[Viper Specialty]

Holy crap old thread alert! Lol

 

[troublemaker]

It's one of the few technical questions that this forum has seen in a while, and it seems like a cheap and easy upgrade for the money.

 

[CSXT802]

What's your guys take on the gen 3 rocker arms?? There 1.7 too if a fellow could get a set at a good price, would ya say go for it or Harland sharp??

You just can't bolt on gen 3 rockers on a gen 2. The rocker arm hits the valve spring retainer. The gen 3 uses a bee hive style spring with a smaller dia. Retainer