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-   -   roller rockers or roller tip rockers (http://www.hotrodders.com/forum/roller-rockers-roller-tip-rockers-7055.html)

Jared 03-10-2003 07:32 PM

roller rockers or roller tip rockers
 
Would I be better off running full roller 1.50 ratio rockers such as summit's SUM-G6910B or roller tiped steel rockers like comp cams 1.52 ratio magnum steel rocker. both are about the same price. The reason I ask is I have heard the full roller rockers become loose at the pivot point over time and fail or become sloppy. if you need my engine specs look to my dyno software question on page one.

statepen 03-11-2003 12:00 AM

this is true roller rockers must be adjusted. its not hard but time consuming and some times dangerous (anyone else had the header wrap mishap?) for a street car with hydralic lifters foller tips will be fine

willys36@aol.com 03-11-2003 07:09 AM

I really like the roller tip rockers. Perfect compromise of wear reduction and reliability for street/strip engines and a good bargain besides.

Busted Knuckles 03-11-2003 09:54 AM

I'm not near the expert Willys36 is, but I do know that aluminum fatigues/cracks/fails much more rapidly than steel. And that's why I went with the steel roller tipped ones.

BTW, has anyone here actually done a weight comparison between the two? I mean, besides the friction differences between the bearing pivot and ball pivot, Is there that much to be gained inertial mass wise? When you visually compare the two, the aluminum is massive in comparison to the steel rockers.

eliot 07-31-2007 03:07 PM

just wanted yo add
 
Comp. Pro-magnum are $$$ but they are steel,lighter than the alum.,and hold up well.

327NUT 07-31-2007 04:11 PM

For a good street engine the Comp Cams Magnum roller tip rockers will work just fine, $145 or so from Summit/Jegs. I've used them on three engines now and no problems.

Granted the gold, red, purple, blue anodized full roller extruded alum. rockers sure do look purdy and "race car" like but unless you have clear plexiglass valve covers you will never know the difference........until one breaks.

Holder350 07-31-2007 04:27 PM

Quote:

Originally Posted by 327NUT
For a good street engine the Comp Cams Magnum roller tip rockers will work just fine, $145 or so from Summit/Jegs. I've used them on three engines now and no problems. .

I'v used these before not sure on the reliability, but they are easy to set and they don't back off easily.

Kampr 07-31-2007 04:46 PM

Quote:

Originally Posted by eliot
Comp. Pro-magnum are $$$ but they are steel,lighter than the alum.,and hold up well.

That's what I'm getting ready to buy. A little more money but I haven't heard anything bad about them.

Danny

327NUT 07-31-2007 04:49 PM

Holder...why the coment on "reliability" have you ever had one fail...if installed properly and lubricated with good CLEAN oil?? Any part can fail ,no matter what it costs but most failures are caused by guys that think they're John Force and try to run a street engine at 9,000 rpm! I built a 355" chevy for a friend years ago with these same rocker arms, probably has 50,000 on it by now and no problems yet.

oldbogie 07-31-2007 05:47 PM

Quote:

Originally Posted by Jared
Would I be better off running full roller 1.50 ratio rockers such as summit's SUM-G6910B or roller tiped steel rockers like comp cams 1.52 ratio magnum steel rocker. both are about the same price. The reason I ask is I have heard the full roller rockers become loose at the pivot point over time and fail or become sloppy. if you need my engine specs look to my dyno software question on page one.

Some insight as what the engine is, cam, compression and how you're using it would be quite useful.

Generally putting roller rockers in the same ratio as the OEM factory used and running on the street doesn't buy much. With an OEM cam or up to about 225 degrees duration when measured from .050, going to a 1.6 where 1.5 was original is good for 10-15 hp at red line with a 2-5 pound loss of torque below 3500 revs.

On a competition engine roller rockers effectively reduce ball fulcrum friction which allows RPMs you otherwise can't get at with any reliability. This also reduces temperatures generated in the ball fulcrum which the oil has to take away thus eventually taking some load off the cooling system as well as adding life to the oil by not coking and otherwise frying the stuff. On the valve stem end of the world, the rolling moment reduces the side pull that a sliding rocker imposes on the stem. This again is a friction/heat reducer but also takes some side loading off the stem and guide which results in maintaining better dimensions between the two which improves heat transfer from the valve thru the guide into the cooling system making for happier (especially exhaust) valves. One has to realize that a competition engine being raced has some REALLY big friction and heat issues that are totally unlike anything seen on the street and these issues demand different engineering solutions.

The move from 1.5 to 1.52 is strictly an attempt by competitive racers to squeeze every bit of power out that the rules will allow, again all this is in the upper RPM ranges with long duration very high lift cams which work the valve train extremely hard. For a street engine the difference between 1.5 and 1.52 rockers would go un-noticed.

This is not to say you shouldn't run roller rockers on the street, but dyno and timing slip results vary widely between something and nothing being there.

It's a mighty good idea to run magnets in the heads oil returns and screens over all the valley to crankcase holes because if a roller fails, spilling its guts into the engine, it gets mighty messy when those chunks of roller bearing get into the oil pump and shot around the crankcase with the windage.

Bogie

7oNova 07-31-2007 11:12 PM

I agree with Bogie but if you're just going to run roller tip rockers(which I've seen dozens of times at swap meets with severe bluing and discoloration)you might as well just use some Summit long slot rockers( I've used with good luck)I've also used Crain Gold rockers with much success on my 350 SBC with Dart heads.It really depends on what you want from this engine & what you want to do with it. :thumbup:

Holder350 08-01-2007 12:16 AM

Quote:

Originally Posted by 327NUT
Holder...why the coment on "reliability" have you ever had one fail...if installed properly and lubricated with good CLEAN oil?? Any part can fail ,no matter what it costs but most failures are caused by guys that think they're John Force and try to run a street engine at 9,000 rpm! I built a 355" chevy for a friend years ago with these same rocker arms, probably has 50,000 on it by now and no problems yet.

I just mean that these ARE alum which stress and cracks easer than steel. I haven't run them for man miles and I don't know how they will hold up at say 120K miles.

Just sayin that I like em now.....but may prove problematic in the future.

I really cant say

327NUT 08-01-2007 12:45 AM

Comp Cams "MAGNUM" roller tip rockers are NOT aluminum, they are made out of investment cast 8650 chromemoly steel.

Lil Big Mec 08-01-2007 12:50 AM

I got a set of Crane Golds with over 70K miles on them. Been from Victoria to PEI and back about 10 times in a S10 and was a daily driver for 3 years as well. Went through many bronze distributor gears, but never broke one rocker arm. And they were clearanced about 10 years ago with a die grinder for larger springs. I forget the spring pressures, but they were on a 383 sbc with a very large solid roller cam with dual springs that look like they could support a small car. I do think the time is soon coming to retire them though. I think *quality* is more important than what the rockers are actually made out of. I don't think I would use any $100 ebay special "street beat" type of aluminum roller rockers on a daily driver. Come to think about it, if they are not good enough for a daily driver, I don't think I would use them on a weekend warrior or race engine, either.

hotrodf1 08-01-2007 09:51 AM

Not to get off track, but does anyone know if the Scorpion Performance roller rockers are any good?

They are made in the USA, the website claims that they are superior quality, and that they actually are the manufacturers for some of the other name brands out there.

Crane's Gold rockers look exactly like the Pro Series from Scorpion (or maybe the other way around, ???) but a different color.

They aren't cheapies at all, so that would be the reason to buy them.

I'v seen the Race Series rockers for $189 or so.


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