Author Topic: PRW roller rockers under Lemans covers  (Read 1209 times)

mlplunkett

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PRW roller rockers under Lemans covers
« on: June 11, 2020, 06:14:54 PM »
I'm planning to use these PRW stainless roller rockers on BBM heads on my 428. Can anybody confirm that they will fit under the Lemans covers? Anybody got a decent set of Lemans covers for sale?

https://www.amazon.com/PRW-3239022-Stainless-Rocker-352-428/dp/B004C0AH0M
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Bob Gaines

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Re: PRW roller rockers under Lemans covers
« Reply #1 on: June 11, 2020, 06:39:20 PM »
I'm planning to use these PRW stainless roller rockers on BBM heads on my 428. Can anybody confirm that they will fit under the Lemans covers? Anybody got a decent set of Lemans covers for sale?

https://www.amazon.com/PRW-3239022-Stainless-Rocker-352-428/dp/B004C0AH0M
There is not much will NOT fit under the LeMans valve covers. With that said I am not familiar with fitment on those particular roller rockers.  Some times there is clearance needed to be done to compensate for the end stands. FYI the reproduction covers are very nice in comparison to originals and once installed with gaskets and grommets they look identical. Not sure if you knew they were available and given the nice tribute car you are trying to build the differance in savings may make sense.    Shelby Parts sells the repros and he may even have some originals. The nice repros would be much less expensive then originals in the same condition. I have nice originals but they will be more then the repros.
Bob Gaines,Shelby Enthusiast, Shelby Collector , Shelby Concours judge SAAC,MCA,Mid America Shelby

mlplunkett

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Re: PRW roller rockers under Lemans covers
« Reply #2 on: June 11, 2020, 07:31:24 PM »
Thanks Bob. I figured I'd be fine with the cast repops but they have gotten expensive lately. Jim still lists them for $350 on the web site but the actual price is $525 for the only set he has in stock. Tony Branda (where I got almost all my Shelby parts so far) has them for $485. It's crazy that you can find the 68 version for less than $300 but that's too obvious an error to make so I'm shopping for a bargain as usual. Surely somebody has a repop set that they replaced with originals and don't need anymore.
« Last Edit: June 11, 2020, 07:33:24 PM by mlplunkett »
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roddster

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Re: PRW roller rockers under Lemans covers
« Reply #3 on: June 12, 2020, 12:27:54 PM »
  Jim's set has polished fins and they look stellar.

Bob Gaines

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Re: PRW roller rockers under Lemans covers
« Reply #4 on: June 12, 2020, 01:31:07 PM »
  Jim's set has polished fins and they look stellar.
FYI the fins are suppose to be polished on 67 LeMans valve covers . Originally they were not mirror finish polish but more of a satin polished finish. Of course many people like things that are different then the way the factory did it. Slick paint comes to mind most.
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gt350hr

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Re: PRW roller rockers under Lemans covers
« Reply #5 on: June 12, 2020, 01:35:28 PM »
    They will fit , I've checked .
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2112

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Re: PRW roller rockers under Lemans covers
« Reply #6 on: June 12, 2020, 02:34:30 PM »
I'm planning to use these PRW stainless roller rockers on BBM heads on my 428. Can anybody confirm that they will fit under the Lemans covers? Anybody got a decent set of Lemans covers for sale?

https://www.amazon.com/PRW-3239022-Stainless-Rocker-352-428/dp/B004C0AH0M

Does this combo come with pushrods or are those length checkers in the picture?

gt350hr

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Re: PRW roller rockers under Lemans covers
« Reply #7 on: June 12, 2020, 05:48:45 PM »
    Length checkers. "I" recommend a "long" pushrod so the "cup" is close to the rocker which reduces the "leverage" strain , reducing the chance of the rocker failing right in that area. The rocker design could use some "beefing" in that area to eliminate breakage with heavier pressure springs.
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Wedgeman

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Re: PRW roller rockers under Lemans covers
« Reply #8 on: June 12, 2020, 06:12:59 PM »
My Harland Sharp Roller Rockers were making a slight scratch mark on the inside of my 67 Cobra Lemans  valve covers. My solution was double valve cover gaskets...fixed it.

67GT500#1594

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Re: PRW roller rockers under Lemans covers
« Reply #9 on: June 14, 2020, 10:01:04 AM »
I'm planning to use these PRW stainless roller rockers on BBM heads on my 428. Can anybody confirm that they will fit under the Lemans covers? Anybody got a decent set of Lemans covers for sale?

https://www.amazon.com/PRW-3239022-Stainless-Rocker-352-428/dp/B004C0AH0M

Iíve got two sets of original 67 LeMans valve covers Iíd let go. I also have a set of 68 Black LeMans covers and Cobra 427 covers. Iíll dig up some pics here in a few.

As far as the PRW roller rockers, most FE engine guys run away from those parts!! Too many failures and breakages!! If your not running too much spring pressure your probably on but IMHO, run away and pay the money for Harland Sharpís.

The Going Thing

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Re: PRW roller rockers under Lemans covers
« Reply #10 on: June 15, 2020, 12:14:01 AM »
I'm planning to use these PRW stainless roller rockers on BBM heads on my 428. Can anybody confirm that they will fit under the Lemans covers? Anybody got a decent set of Lemans covers for sale?

https://www.amazon.com/PRW-3239022-Stainless-Rocker-352-428/dp/B004C0AH0M

Iíve got two sets of original 67 LeMans valve covers Iíd let go. I also have a set of 68 Black LeMans covers and Cobra 427 covers. Iíll dig up some pics here in a few.
Go take a gander at the FE Power Forum. They break.  I would go to Doug at Precision oil pumps. 
As far as the PRW roller rockers, most FE engine guys run away from those parts!! Too many failures and breakages!! If your not running too much spring pressure your probably on but IMHO, run away and pay the money for Harland Sharpís.

shelbydoug

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Re: PRW roller rockers under Lemans covers
« Reply #11 on: June 15, 2020, 09:59:01 AM »
There has been some attention paid to the rocker arm failure recently by the aftermarket.

Even Harland Sharps have some history of failure.


There are so many variables possible in setting up the valve train that it is difficult to pin point specific issues but the ones I've seen are fatigue related.

It would seem that the data available shows that the aluminum arms themselves have an expected life span much shorter then expected.

Companies like Compcams and Crane are now recommending steel and stainless alloys as more reliable. Remember though that in most cases those companies have been sold over several times and are only in name what they used to be.


It's been pointed out that spring pressure and geometry are the two largest culprits but using aluminum for the bodies needs to be added to the mix.


Here's the thing with metal alloys. These things are not "aircraft" certified and maybe that's the level they should be at for the desired dependability?


The other thing that should be considered no matter who supplies them, is the push rods. The ball and or cup needs to machined as one piece to the shaft.

With FE's using ball/cup push rods, that complicates the offerings.


I've had two push rod failures. In one (Crane) the tips came off of the shafts of several of them. That wiped out in that case several rocker arms and necessitated disassembly to clean the fragments out of the engine.

Those ball ends were spot welded on the tubes. At the time these were the ULTIMATE duty push rods available.

The other, my new heads (AFR) spring pressure bent about four push rods and two of the balls (TRW) of the push rods fell off. Those were FRICTION welded on. VERY VERY BAD IDEA!


So far there are one piece Compcams (blackened) pushrods in and holding up.


The point is, don't take the push rods for granted. Make sure they are hardened and not just painted black (a new trick). Use a file on them to make sure they are hardened. The file will be ineffective if they are and do nothing.

Use ONLY one piece push rods regardless of who makes them.

While we are on the subject, if using guide plates, check for hardness as well with a file. Take none of that for granted.

The lack of quality control on parts today is terrible. Parts are largely spot checked, i.e., 1 out of 100. That's too high of a risk to take.
« Last Edit: June 15, 2020, 09:25:15 PM by shelbydoug »
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The Going Thing

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Re: PRW roller rockers under Lemans covers
« Reply #12 on: June 15, 2020, 12:22:17 PM »
Isky still offers a 3/8" Ball-cup off the shelf. Smith Bros is another good choice for custom length.  They are also finally making 1.76 ration non-adjustable roller rockers and those use a ball-ball rod.
The non-adjustable are available via Brent Lykins of Lykins Motorsports.

mlplunkett

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Re: PRW roller rockers under Lemans covers
« Reply #13 on: June 15, 2020, 08:58:01 PM »
Great input. A fellow forum member sold me an unused set of Blue Thunder valve covers today so I can check that item off the list. My builder had several of the same opinions about the longevity of steel rockers compared with aluminum. He said the measured spring pressure on the BBM heads was right at the limit of what he would put on a factory cast rocker so we moved up the strength scale to the stainless. I think we made the right call for a street motor that I want to be reliable and driveable. Getting ready to order the rest of the valvetrain. Good times ahead.
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2112

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Re: PRW roller rockers under Lemans covers
« Reply #14 on: June 15, 2020, 09:26:54 PM »
Which stainless rocker did you go with?