Roller Rockers??

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Turns out that most all of my rocker arms on my '65 HIPO 289 are worn out.

I was wondering if instead of stock replacements if I could use a roller rocker arm on otherwise stock 289 HIPO heads??

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yes. That is exactly what I have done. I am using Crane Gold Race Extruded Roller Rocker Arms # 36750-16, Summit Racing ( http://store.summitracing.com ) has them for $335.00 per set.

No machining of the head is necessary Even though Hi-Po heads have built in push rod guides, I ( and the Crane folks) would recommend using the Crane #36650-1 push rod guide plates as well. I first installed the roller rockers w/o the Crane guide plates, only to have a mishap with one push rod soon after installation. With the guide plates I gone about 20,000 miles w/o problems.

Another bonus is with the roller rockers, the valves don't seem to need much adjustment.

If I doing this over again I would get the 7/16" stud size roller rockers & a new stud set ( 7/16"). The rocker cost the same for either size, and the strength of the stud is substantially increased with the 7/16" size.. A 7/16" stud set isn't that expensive. Again, there is no machining of the head involved. as the part of the stud that screws into the head is the same with both the 3/8" & 7/16" studs.

hope this helps,

Z. Ray

I second the Crane Gold 1.6 ratio roller rockers. I am using a set on my

5.0 and they are quieter then the cheaper Crane (Cobra) Energizer rockers. I have used Ford Racing as well (looks like Crane). I am also using Scorpion 1.6 roller rockers on my solid lifter 289. Also 7/16" studs. Now is also the time to change out the springs. If you do not want to do this, have a race shop recommend the proper springs and spring heights to match your cam and have them install them. Too high a spring rate can damage the cam and rob horsepower. And not enough... Also, quality light weight (titanium) retainers and machined (not stamped) locks are safe insurance. Or, you can just install the roller rockers. Before you install them, soak them in Varsol or mineral spirits and work the trunion back and forth to work out the assembly grease. The grease was used to keep the needle bearings in place during assembly and not to lubricate them. Dry of the rocker and now soak them in oil. This will greatly extent the life of your rocker assembly.<img src=images/icon_smile.gif border=0 align=middle>

What valve covers are you guys using with the roller rockers? Will stock chrome covers , or Cast Cobra covers work??

If you wish to use original valve covers, I believe you must remove the baffles inside. there are two other solutions, spacers, were my solutions. There are Cobra covers available that are deeper, so the look pretty stock, but give the necessary clearance. Let us know what you decide<img src=images/icon_smile_big.gif border=0 align=middle><img src=images/icon_smile_big.gif border=0 align=middle>

I am running cast aluminum Offenhauser covers. I am also using the extra thick Felpro valve cover gaskets.

I'm using polished Cobra covers that are slightly taller. Don't know the source.

Z. Ray

I just re-read your post. Chances are if your rocker arms are worn out then the chances are good that the top of the valves stems are worn as well. Check it out. Your engine will wear as a unit. The chances are, your heads could use a fresh valvejob and freshening up. <img src=images/icon_smile_big.gif border=0 align=middle>

You might want to get a set of good factory rockers and put them aside, so that an original set up is still in your possession. fresh push rods and lifters too. And while we are on the subject of wear, remember that the ZDDP has been removed from nearly all motor oils, and those that do not take steps to suppliment their valuable collector cars risk catastrophic engine failure. and if you have untreated Marine engines, failure there would bring new meaning to " nightmare ".<img src=images/icon_smile_big.gif border=0 align=middle>

As has already been mentioned, running roller rockers is no problem. What can be a problem is the extra clearance issues roller rockers create inside the valve cover. Plus if you use poly-locks, which I recommend, there will be even less clearance.

You can get around this by using spacers or taller repop covers as has also been mentioned, there are also some stock height repop covers that have differently designed baffles specifically for rollers that might work. If you want to use OE valve covers you will need to remove the baffles and build a custom baffle to shroud the PCV valve or you will suck oil like crazy.

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You might want to get a set of good factory rockers and put them aside, so that an original set up is still in your possession. fresh push rods and lifters too. And while we are on the subject of wear, remember that the ZDDP has been removed from nearly all motor oils, and those that do not take steps to suppliment their valuable collector cars risk catastrophic engine failure. and if you have untreated Marine engines, failure there would bring new meaning to " nightmare ".<img src=images/icon_smile_big.gif border=0 align=middle>

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Do not replace the lifters unless you plan on replacing the camshaft at the same time. The lifters and cam lobes on initial startup and breakin lap together and are hardened and can be considered a matched set. Don't replace one without the other.

Has anyone used Comp Cams Magnum roller tip rockers? They look more like the original rockers and I'd suspect they fit well under the valve covers. I realize they are just roller tip and not true roller rockers...

http://www.compcams.com/information/Pr…agnumRoller.asp

I'm using the CompCams Magnum Roller Rocker arms and have had no issues with either fit or performance. As an added benefit, they sorta look original-ish <img src=images/icon_smile_wink.gif border=0 align=middle>

I have them under the Black Crinkle finish covers and did not have to remove the baffles - though I also am using ARP studs & thick gaskets for ease of use.

j

for those of you that have changed to roller or aftermarket stock style, have you noticed a performance gain? I see the comp link above boasts 15-30 horse increase over stock. are they saying factory rockers (ratio) are that far out of spec? I would have thought factory parts would be tighter spec than some china built replacement parts that are out there.

I see they also have a 1.7 ratio. Anybody cheating a little with those?

ACCURATE

You can’t get maximum horsepower from your engine if your rocker ratio is off. We checked other rockers and found rockers that were as much as .040” short on lift. The Magnum Rockers™ are super Accurate. They check dead on every time.

POWERFUL

The Magnum Roller Rockers™ can make between 15 and 30 horsepower over other rockers! Why? The secret is that not only does the roller tip reduce friction, the Magnum Rockers™ incredibly stiff design and super accurate ratios yield more effective valve lift.

Edited by - 289kford on 04/19/2008 14:07:05

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for those of you that have changed to roller or aftermarket stock style, have you noticed a performance gain? I see the comp link above boasts 15-30 horse increase over stock. are they saying factory rockers (ratio) are that far out of spec? I would have thought factory parts would be tighter spec than some china built replacement parts that are out there.

I see they also have a 1.7 ratio. Anybody cheating a little with those?

Edited by - 289kford on 04/19/2008 10:18:08

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it's the friction reduction that is the basis for the horse power claims.

Guys, I had purchased a set of Compcams Pro-Magnum full roller rockers before I saw this thread and finally got around to installing them on my engine over the last few weeks. There seems to be very little thread left on the studs above the rocker arms for the polylocks to screw down onto. It's about 6 threads or 1/4" on a standard 1 3/4" stud. Anybody else have this problem? I'm nervous that the polylocks will come loose. How much stud was there left for those who installed the Crane rockers? I also had to use longer pushrods for the rollers to sit properly on the valve heads. I think they were 6.95" vs standard 6.80". Anybody have the same situation?

Any help or guidance would be appreciated.

Thanks a bunch,

Mark

Assuming that the fulcrums are properly orientated, you may have to replace the screw in studs with longer aftermarket (ARP) studs. This is not a bad idea anyway. Measure your oem studs and check to see what the standard screw in stud is.

I went down the same path with the Pro Magnum rockers from Comp. I located a set of screw in studs that were for another application and were slightly longer than the ones ARP sells for SBF. I also had about 1/2 of the length parted off the locking nut, as there wasn't any stud thread engagement in that part of the nut anyway. With this combo and modified internal baffles, I was able to run the standard Cobra valve covers.

Rockhouse, by chance do you recall where you got the longer studs and what application they were supposed to be for so I can do the same? Thanks

Mark