Home » Public Forums » GMCnet » [GMCnet] Caddy 500 Rocker Arms
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Re: [GMCnet] Caddy 500 Rocker Arms [message #307002 is a reply to message #306987] |
Sun, 11 September 2016 22:37 |
cbryan
Messages: 451 Registered: May 2012 Location: Ennis, Texas
Karma: 3
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USAussie wrote on Sun, 11 September 2016 20:12G'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 Henderson 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 Henderson. 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. Editing now after looking more carefully at the ebay ad, it appears that the pedestals are aluminum. If so, the fatigue breaking possibilities are much greater and should be another reason to shy away. End editing.
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. The rockers do look adjustable, and that would make setup easier, but different length pushrods may still be required to begin with.
Note that Ken Henderson. 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.
[Updated on: Sun, 11 September 2016 22:48] Report message to a moderator
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Re: [GMCnet] Caddy 500 Rocker Arms [message #307019 is a reply to message #306987] |
Mon, 12 September 2016 08:16 |
jhbridges
Messages: 8412 Registered: May 2011 Location: Braselton ga
Karma: -74
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Anyone know the reasoning behind the pedestals - as opposed to a shaft - in the original design?
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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Re: [GMCnet] Caddy 500 Rocker Arms [message #307025 is a reply to message #307020] |
Mon, 12 September 2016 08:36 |
Ken Henderson
Messages: 8726 Registered: March 2004 Location: Americus, GA
Karma: 9
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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.
On Mon, Sep 12, 2016 at 9:28 AM, Larry wrote:
> Johnny Bridges wrote on Mon, 12 September 2016 08:16
>> 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
> --
>
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www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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Re: [GMCnet] Caddy 500 Rocker Arms [message #307029 is a reply to message #307025] |
Mon, 12 September 2016 08:56 |
Larry
Messages: 2875 Registered: January 2004 Location: Menomonie, WI
Karma: 10
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Ken Henderson wrote on Mon, 12 September 2016 08:36
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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Re: [GMCnet] Caddy 500 Rocker Arms [message #307036 is a reply to message #307029] |
Mon, 12 September 2016 10:48 |
James Hupy
Messages: 6806 Registered: May 2010
Karma: -62
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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
On Sep 12, 2016 6:57 AM, "Larry" wrote:
> Ken Henderson wrote on Mon, 12 September 2016 08:36
>> 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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Re: [GMCnet] Caddy 500 Rocker Arms [message #307040 is a reply to message #307025] |
Mon, 12 September 2016 11:21 |
powerjon
Messages: 2446 Registered: January 2004
Karma: 5
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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
> On Sep 12, 2016, at 9:36 AM, Ken Henderson wrote:
>
> 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.
>
>
> On Mon, Sep 12, 2016 at 9:28 AM, Larry wrote:
>
>> Johnny Bridges wrote on Mon, 12 September 2016 08:16
>>> 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
>> --
>>
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J.R. Wright
GMC GreatLaker
GMC Eastern States
GMCMI
78 30' Buskirk Stretch
75 Avion Under Reconstruction
Michigan
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Re: [GMCnet] Caddy 500 Rocker Arms [message #307050 is a reply to message #307040] |
Mon, 12 September 2016 13:28 |
Ken Henderson
Messages: 8726 Registered: March 2004 Location: Americus, GA
Karma: 9
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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
> wrote:
>>
>> 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.
>>
>>
>> On Mon, Sep 12, 2016 at 9:28 AM, Larry wrote:
>>
>>> Johnny Bridges wrote on Mon, 12 September 2016 08:16
>>>> 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
>
>
> _______________________________________________
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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Re: [GMCnet] Caddy 500 Rocker Arms [message #307064 is a reply to message #306987] |
Mon, 12 September 2016 17:23 |
Kosier
Messages: 834 Registered: February 2008
Karma: 1
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Senior Member |
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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
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Re: [GMCnet] Caddy 500 Rocker Arms [message #307079 is a reply to message #307064] |
Mon, 12 September 2016 23:18 |
jimk
Messages: 6734 Registered: July 2006 Location: Belmont, CA
Karma: 9
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Senior Member |
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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.
On Mon, Sep 12, 2016 at 3:23 PM, Gary Kosier wrote:
> 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
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>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
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>
>
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--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
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jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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Re: [GMCnet] Caddy 500 Rocker Arms [message #307081 is a reply to message #307079] |
Tue, 13 September 2016 01:36 |
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USAussie
Messages: 15912 Registered: July 2007 Location: Sydney, Australia
Karma: 6
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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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Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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