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289 hipo roller rockers

Started by shelbyhertz66, August 03, 2020, 03:58:24 PM

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shelbyhertz66

Hi All,
I may rebuild my 67 Shelby's 289 hipo soon and may want to use
roller tip rockers , I want to use the original valve covers without modifying 
them,  the baffles will not clear on most brands of roller rockers and  valve cover
spacers are not acceptable. Has anyone found a quality brand that will clear everything?
Thanks much.
Dave

rmarble57

I purchased these roller tip rockers  SUM-141708PL   from Summit Racing and they should work without modification to your valve covers.............that is, unless you want to run poly locks which are taller.  The roller rockers will work with your standard adjustment nuts or you can purchase the same pitch thread with Ny-Loc.

Another way to make this work is to purchase a set of reproduction valve covers which are designed to clear the roller rockers with Poly-Locks.
I purchased these:  SDK-6A582-CP from Summit as well.

Either way, it is a significant upgrade in valvetrain.

gt350hr

    Dave,
       The rocker itself is not the usual problem. Normally it is the "poly lock" being taller and hitting the baffles. In the past , I have shortened the poly lock  ( yet still tall enough to clear the rocker) exposing the rocker stud so that a jam nut could be used instead of a set screw which raises the height.
   Randy
Celebrating 46 years of drag racing 6S477 and no end in sight.

Steve McDonald Formally known as Mcdonas

I run rollers and poly locks, use the thicker valve cover gaskets from a company called "Transdapt" available from Summit , no problems
Owned since 1971, NOW DRIVEN OVER 250,000 MILES, makes me smile every time I drive it and it makes me feel 21 again.😎

shelbydoug

Quote from: rmarble57 on August 03, 2020, 04:12:28 PM
I purchased these roller tip rockers  SUM-141708PL   from Summit Racing and they should work without modification to your valve covers.............that is, unless you want to run poly locks which are taller.  The roller rockers will work with your standard adjustment nuts or you can purchase the same pitch thread with Ny-Loc.

Another way to make this work is to purchase a set of reproduction valve covers which are designed to clear the roller rockers with Poly-Locks.
I purchased these:  SDK-6A582-CP from Summit as well.

Either way, it is a significant upgrade in valvetrain.

I used them with polylocks and the covers cleared, no problem.

It should be noted that there are at least two lengths of polylocks. Long and short. Also if you replaced the studs the Ford's are the shortest. The ARP studs are longer.
68 GT350 Lives Matter!

gt350hr

  All those are workable solutions. My "race" 331 has Edelbrock Vic Jr heads and Edelbrock had the presence of mind to raise the valve cover rail on their castings. I too run roller rockers without thick gaskets, spacers, or modified baffles on Buddy Barr covers which are the shortest.
Celebrating 46 years of drag racing 6S477 and no end in sight.

Bossbill

The subject and text of the OP miss a little here. Roller rockers are not roller tip rockers.
At least not in normal hot rod speak. The roller tip rockers are not much larger than standard rockers in that only the tip has a roller. These usually fit depending on lock nut style.
In hot rod speak roller rockers have roller fulcrums, roller tips and are usually made out of aluminum.
With Ford studs, Crane Gold aluminum roller rockers and short allen style locking nuts you can clear Cobra covers if you remove the baffles. That's how mine was when we took it apart.
Bill

67 GT350 Actual Build 3/2/67  01375
70 B302   6/6/70  0T02G160xxx

CSX2259

I used Comp Cams full roller rockers, the rockers fit under the standard steel covers. The poly locks were an issue until I machined part of the hex nut off of the poly lock body. They have worked perfectly ever since.

shelbydoug

Personally I think full roller rockers are overkill. 98% of the friction is in the rocker tips to valve stem.

I ran mine consistantly to 7,000 rpm with no issues and fit under the Cobra covers with no issues.

Now if you want to talk about uneccessary overkill and issues up the kazoo, ask me about my shaft roller rockers.
Oye vey! What a pain...but they're good to 9,000+!  I'm not though.
68 GT350 Lives Matter!

shelbyhertz66

When I posted this I should have been clearer .
Yes I would like to use the roller tip rockers not full roller rockers.  The last hipo I did
we used TRW roller tip but the poly lock was hitting the baffles so I removed the baffles
and fabricated new ones similar to the standard steel covers type baffle. Hoping I don't have to
do the fab mods this time. 
Thanks,
Dave

s2ms

#10
I'm using Scorpion rollers and had to user long polys to clear the rockers. Never could get them to fit stock valve covers, even with double thick gaskets, so ended up removing the baffles and hand fabricated a baffle for the PCV. Works fine but in retrospect I should have found a rocker/poly combo that fit better, lesson learned.

If you are using the roller tip rockers with stock style lock nuts you will not have a problem...
Dave - 6S1757

gt350hr

Quote from: shelbydoug on August 03, 2020, 07:25:23 PM
Personally I think full roller rockers are overkill. 98% of the friction is in the rocker tips to valve stem.

I ran mine consistantly to 7,000 rpm with no issues and fit under the Cobra covers with no issues.

Now if you want to talk about uneccessary overkill and issues up the kazoo, ask me about my shaft roller rockers.
Oye vey! What a pain...but they're good to 9,000+!  I'm not though.


      Doug , the "majority" of the friction is on the trunion. ( focal point) The ONLY benefit of a roller tip (only) rocker is less guide wear. I frequently see the "cup" portion of the roller tip rockers with blue discoloration from HEAT. Comp says this is because of the material ( a variety of stainless) and it "shows heat" more than conventional cast iron and is nothing to worry about. RIGHT
     Yes shaft rockers are WAY overkill on a non dedicated "race" engine.
Celebrating 46 years of drag racing 6S477 and no end in sight.

shelbydoug

Quote from: gt350hr on August 04, 2020, 11:10:56 AM
Quote from: shelbydoug on August 03, 2020, 07:25:23 PM
Personally I think full roller rockers are overkill. 98% of the friction is in the rocker tips to valve stem.

I ran mine consistantly to 7,000 rpm with no issues and fit under the Cobra covers with no issues.

Now if you want to talk about uneccessary overkill and issues up the kazoo, ask me about my shaft roller rockers.
Oye vey! What a pain...but they're good to 9,000+!  I'm not though.


      Doug , the "majority" of the friction is on the trunion. ( focal point) The ONLY benefit of a roller tip (only) rocker is less guide wear. I frequently see the "cup" portion of the roller tip rockers with blue discoloration from HEAT. Comp says this is because of the material ( a variety of stainless) and it "shows heat" more than conventional cast iron and is nothing to worry about. RIGHT
     Yes shaft rockers are WAY overkill on a non dedicated "race" engine.

The ball fulcrum IS a type of ball bearing. That is not where the wear patterns show up.

Run long enough the valve stems will wear into the cast rocker arm besides wearing the guides in an oblong pattern.


The shaft rockers are a regular PITA to set up right. Right off, they bent four push rods. They have to be zero on in three axis compared to only two for stud mounts.

Whats wrong  with overkill? What's wrong with two 725 carbs on 347?

That's why I'm know as DD. Dirty Doug. If you're gonna' hang, hang way up there, not just so your toes can't reach the ground? 8)
68 GT350 Lives Matter!

pbf777

Quote from: gt350hr on August 04, 2020, 11:10:56 AM


      ..... the "majority" of the friction is on the trunion. The ONLY benefit of a roller tip (only) rocker is less guide wear.


     Agreed, with perhaps a benefit to the valve stem tip to rocker relationship also.          :)


QuoteI frequently see the "cup" portion of the roller tip rockers with blue discoloration from HEAT. Comp says this is because of the material ( a variety of stainless) and it "shows heat" more than conventional cast iron and is nothing to worry about. RIGHT 


     "RI-I-I-I-IGHT!"           ::)

      That line belongs next to the one:  "never heard of that before"  or perhaps:  "we've sold thousands of those, and nobody else ever complained"!           :o


     
Quote from: shelbydoug on August 04, 2020, 11:31:04 AM
The ball fulcrum IS a type of ball bearing. That is not where the wear patterns show up.


     Perhaps, but it's not a rolling bearing, rather a sliding surface relationship.               ;)

      Scott.

gt350hr

  Nice try Doug. "Your opinion" on the fulcrum being some sort of ball bearing and not where you see a wear pattern is W R O N G. The highest load is the "cup" of the rocker and why the trunion is so large in surface area. There is NO "rolling action here. It is a back and forth action with very high friction. Same for the cup in the pushrod end.
     Dig out your 40+ year old physics book and do some homework.
   If you want to talk about carburetion , start a new thread and I'll tell you why 2,000 CFMs worth of carburetion is TOO SMALL for 351CI.
Celebrating 46 years of drag racing 6S477 and no end in sight.