Caddy 500 Rocker Arms

> G'day,
>
> http://www.ebay.com.au/itm/291809956418?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
>
> Comments?
>
> Regards,
> Rob M
>
> Rob,
>
> I'm with Ken because this lashup has not been "proven". Ken's setup has, so far. I may have such a thing with purple rockers in my 500 but
> there's a lot of valve noise at idle, and lack of compression not helped by squirting oil to seal piston rings. The original steel pivoted rockers
> are short lived, as Ken H. has demonstrated twice. It is very tempting to put this on as it might solve the new valve cover dilemma, or doubling up
> thick gaskets for clearance done by Ken H. I note the low friction rollers, the needle bearings, sounds so high tech. The previous pedestals broke
> where the stress was concentrated at the junction of the "T" where it makes a right angle. If the stainless pedestals are thicker and do not change
> cross section abruptly in that area, you "ought" to be good. The needles should slow down wear. Maybe they are bearing on the aluminum alone.
> Finding someone who uses this system should be your guide. Otherwise, you are the test pilot. The history of these fixes for the 500 goes back to
> the 1980's or even before when enterprising folks used steel Buick rockers with a shaft, if what I read was correct, and if my memory is also
> correct. I wonder why stainless steel? I can't answer as to the resistance to metal fatigue compared to mild steel, however, from what I gather,
> the design of the part, how beefy it is with no abrupt changes of cross section is far more important than just what sort of steel is used.
>
> Note that Ken H. hasn't proven his setup for over 100,000 miles, either. With the mileages these engines have racked up, we may be talking about
> valve train failures after more than 100,000 on the original pedestal system. JimK says he has had bad luck with original rocker pedestals, even
> new ones, IIRC.
>
> The problem with just running until it breaks is that if the lifter pops out of the valley, you lose oil pressure immediately.
>
> Carey
>
>
>
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--
Carey from Ennis, Texas
78 Royale, 500 Cadillac, Rance Baxter EFI.
 
I'm with both Ken and Carey on this. It does seem to solve the issue of using the stock valve covers. One of the stock valve covers has baffles
and goes on the side with the PCV valve. The baffles are designed to keep the oil mist from being sucked into the intake, thus increasing oil
consumption. This makes this rocker system somewhat desirable, but not enough to warrant trying it out. I spoke briefly with a machinist about making
a spacer for the valve covers, and he said that they could be machined out of a piece of 1" thick aluminum, but was convinced that laser cutting them
would be a much cheaper and better way to do it. There is a place here in Menomonie that can do that, but haven't had a chance to talk with them yet.
In the mean time, I'd stay away from these and stick with any of the systems that have been developed by MTS and The Cad Co. JMHO
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
Anyone know the reasoning behind the pedestals - as opposed to a shaft - in the original design?

--johnny
--
'76 23' transmode Norris upfit, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.

"Sometimes I wonder what tomorrow's gonna bring when I think about my dirty life and times" --Warren Zevon
 
> Anyone know the reasoning behind the pedestals - as opposed to a shaft - in the original design?
>
> --johnny

I don't know the rational, but can guess that those pedestals work just fine in a stock engine with stock valve springs. Problem is most of
us...wanting a little more performance...go for a RV cam or better, usually requiring a stronger spring to handle the steeper ramps and higher lifts.
This is.. IMO... just enough to become the straw that breaks this pedestal's back. Lots of stock Cad 500's out there with high milage and no issues.
But here we are with our testosterone laden decisions pushing the pedestal. Hummmm. JMHO
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
I was running stock springs when I broke the pedestals. But they were new
and the pedestals were not. The broken arms (4) all seem to show
pre-existing fatigue cracks where they broke.

The arms broke in my case; I've heard of others losing the rockers because
the spring clips, which are supposed to keep the rockers on the arms,
failed to do so.

Ken H.

> > Anyone know the reasoning behind the pedestals - as opposed to a shaft -
> in the original design?
> >
> > --johnny
>
> I don't know the rational, but can guess that those pedestals work just
> fine in a stock engine with stock valve springs. Problem is most of
> us...wanting a little more performance...go for a RV cam or better,
> usually requiring a stronger spring to handle the steeper ramps and higher
> lifts.
> This is.. IMO... just enough to become the straw that breaks this
> pedestal's back. Lots of stock Cad 500's out there with high milage and no
> issues.
> But here we are with our testosterone laden decisions pushing the
> pedestal. Hummmm. JMHO
> --
>
 
> I've heard of others losing the rockers because
> the spring clips, which are supposed to keep the rockers on the arms,
> failed to do so.
>
> Ken H.

Yup, that would be me, spring clip fell off. However, as a side note, at the time I was also using an RV cam with Comp springs and new "T's". While I
don't think that the cam and springs had anything to do with the clip breaking and falling off, I personally think the stronger springs exacerbate
the T issue. JMHO
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
I have a stock jr. 500 cad engine on an engine stand in my shop. It has the
same everything as the 500 except it is a short stroke engine. ( did I
mention that I am a fan of short stroke/large bore engine configurations?).
It is bone stock and has broken rocker arm trunnion pins. This is
definitely a problem area for these Cadillac engines. Even if you are
running stock springs and cams, do yourself a favor and change out the
pedestals for a continous shaft rocker system.
Jim Hupy
Salem, Or
78 GMC ROYALE 403

> > I've heard of others losing the rockers because
> > the spring clips, which are supposed to keep the rockers on the arms,
> > failed to do so.
> >
> > Ken H.
>
> Yup, that would be me, spring clip fell off. However, as a side note, at
> the time I was also using an RV cam with Comp springs and new "T's". While I
> don't think that the cam and springs had anything to do with the clip
> breaking and falling off, I personally think the stronger springs
> exacerbate
> the T issue. JMHO
> --
> Larry
> 78 Royale w/500 Caddy
> Menomonie, WI.
>
> _______________________________________________
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>
 
Ken,
I do have a question here. When you had the problems with the pedestals, did the bolts into the head fail or just the pedestals? Were the bolts still tight?

In looking at this kit, it appears the pedestal is much more robust than the stock factory cast pedestal and the pedestals are tied together with the bar. It appears that it would make for a much stronger setup than the stock. I can see where it could be improved by added a pin or pins between the rocker support and the cross bar to fix the two together to prevent any rotational movement. JMHO

JR Wright

>
> I was running stock springs when I broke the pedestals. But they were new
> and the pedestals were not. The broken arms (4) all seem to show
> pre-existing fatigue cracks where they broke.
>
> The arms broke in my case; I've heard of others losing the rockers because
> the spring clips, which are supposed to keep the rockers on the arms,
> failed to do so.
>
> Ken H.
>
>

>

>>> Anyone know the reasoning behind the pedestals - as opposed to a shaft -
>> in the original design?
>>>
>>> --johnny
>>
>> I don't know the rational, but can guess that those pedestals work just
>> fine in a stock engine with stock valve springs. Problem is most of
>> us...wanting a little more performance...go for a RV cam or better,
>> usually requiring a stronger spring to handle the steeper ramps and higher
>> lifts.
>> This is.. IMO... just enough to become the straw that breaks this
>> pedestal's back. Lots of stock Cad 500's out there with high milage and no
>> issues.
>> But here we are with our testosterone laden decisions pushing the
>> pedestal. Hummmm. JMHO
>> --
>>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
John,

The pedestals broke right at where the arms meet the upright, on both sides
in both instances. I've still got one of them in the shop. I'll try to
find it and post a photo.

Ken H.

On Mon, Sep 12, 2016 at 12:21 PM, John Wright
wrote:

> Ken,
> I do have a question here. When you had the problems with the pedestals,
> did the bolts into the head fail or just the pedestals? Were the bolts
> still tight?
>
> In looking at this kit, it appears the pedestal is much more robust than
> the stock factory cast pedestal and the pedestals are tied together with
> the bar. It appears that it would make for a much stronger setup than the
> stock. I can see where it could be improved by added a pin or pins between
> the rocker support and the cross bar to fix the two together to prevent any
> rotational movement. JMHO
>
> JR Wright
> > On Sep 12, 2016, at 9:36 AM, Ken Henderson

> >
> > I was running stock springs when I broke the pedestals. But they were
> new
> > and the pedestals were not. The broken arms (4) all seem to show
> > pre-existing fatigue cracks where they broke.
> >
> > The arms broke in my case; I've heard of others losing the rockers
> because
> > the spring clips, which are supposed to keep the rockers on the arms,
> > failed to do so.
> >
> > Ken H.
> >
> >

> >

> >>> Anyone know the reasoning behind the pedestals - as opposed to a shaft
> -
> >> in the original design?
> >>>
> >>> --johnny
> >>
> >> I don't know the rational, but can guess that those pedestals work just
> >> fine in a stock engine with stock valve springs. Problem is most of
> >> us...wanting a little more performance...go for a RV cam or better,
> >> usually requiring a stronger spring to handle the steeper ramps and
> higher
> >> lifts.
> >> This is.. IMO... just enough to become the straw that breaks this
> >> pedestal's back. Lots of stock Cad 500's out there with high milage
> and no
> >> issues.
> >> But here we are with our testosterone laden decisions pushing the
> >> pedestal. Hummmm. JMHO
> >> --
> >>
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Rob,

I've been out of contact because of a little health problem. But I did
scroll down to check the other comments on
those rocker arms. Nobody is aware of the real problem. When that EBay ad
first appeared, several guys on the
Cadillac Forum said "Beware, that outfit has a reputation fore half-assed
engineering and letting the customers
sort out the fixes. They also changed their name recently to avoid the bad
press". For instance, do you see
anything that would preclude the pedestals from rotating?
If you purchase a shaft rocker system, make sure of the ratio. They didn't
have correct rockers for the Cad initially,
so they used something made for a Buick or "?". There are a lot of those
systems still floating around. Also, on a
lot of those shaft systems the end rocker, which is only supported on one
side, would break the shaft. I have to
think that this might be a result of too thin a wall on the shaft and too
stiff valve springs. Regardless, they then
developed girdles to go over the top which stopped that problem. This, of
course, required tall valve covers.
I realize this is a little tedious, but I know you like to know all the
parameters of a situation.

Gary Kosier
77PB w/500Cad
Newark, Ohio

--------------------------------------------------
From: "Rob Mueller"
Sent: Sunday, September 11, 2016 9:12 PM
To:
Subject: [GMCnet] Caddy 500 Rocker Arms

> G'day,
>
> http://www.ebay.com.au/itm/291809956418?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
>
> Comments?
>
> Regards,
> Rob M.
> USAussie - Downunder
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
I cannot remember as to which rocker I have been running in my 540 Cad for
over 600,000 miles on the Tube shaft since 1992, but I have never had any
problems since I went with it.

> Rob,
>
> I've been out of contact because of a little health problem. But I did
> scroll down to check the other comments on
> those rocker arms. Nobody is aware of the real problem. When that EBay
> ad first appeared, several guys on the
> Cadillac Forum said "Beware, that outfit has a reputation fore half-assed
> engineering and letting the customers
> sort out the fixes. They also changed their name recently to avoid the
> bad press". For instance, do you see
> anything that would preclude the pedestals from rotating?
> If you purchase a shaft rocker system, make sure of the ratio. They
> didn't have correct rockers for the Cad initially,
> so they used something made for a Buick or "?". There are a lot of those
> systems still floating around. Also, on a
> lot of those shaft systems the end rocker, which is only supported on one
> side, would break the shaft. I have to
> think that this might be a result of too thin a wall on the shaft and too
> stiff valve springs. Regardless, they then
> developed girdles to go over the top which stopped that problem. This, of
> course, required tall valve covers.
> I realize this is a little tedious, but I know you like to know all the
> parameters of a situation.
>
> Gary Kosier
> 77PB w/500Cad
> Newark, Ohio
>
> --------------------------------------------------
> From: "Rob Mueller"
> Sent: Sunday, September 11, 2016 9:12 PM
> To:
> Subject: [GMCnet] Caddy 500 Rocker Arms
>
> G'day,
>>
>> http://www.ebay.com.au/itm/291809956418?_trksid=p2060353.m14
>> 38.l2649&ssPageName=STRK%3AMEBIDX%3AIT
>>
>> Comments?
>>
>> Regards,
>> Rob M.
>> USAussie - Downunder
>> AUS '75 Avion - The Blue Streak TZE365V100428
>> USA '75 Avion - Double Trouble TZE365V100426
>>
>>
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk
http://www.appliedgmc.com
1-800-752-7502
 
G'day,

Your comments covered my thoughts on these rocker arms. I reckon this is one time I won't mind being shafted!

;-)

Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
 
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