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Topic: Fuel Pump Cam Lob is Toast

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Fuel Pump Cam Lob is Toast (1/11)
7/4/11 6:28pm

Almond81Vette
Former Member
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Stanley, NC - USA

Vette(s):
1981, dark blue w/carmel interior. 350 stock, auto tranny, Q-jet carb, ECM box

Joined: 8/9/2010
Posts: 91

Hope you never have this issue but cam lob for fuel pump rod is toast. Solved this with new 350/195HP GM crate engine. She is running fine now. Possible cause or factor is these current motor oils are not the best for these flat tappet cams. Think AmsOil from now on for me.

______________
Tommy

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Fuel Pump Cam Lob is Toast (2/11)
7/4/11 7:51pm

Jaws79

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Sykesville, MD - USA

Vette(s):
1979 Corvette Coupe Corvette Light Blue Midnight Blue interior Mirrored Glass T-tops

Joined: 4/27/2008
Posts: 4238

That's one smooth lobe, Tommy! Glad you got it straightened out!

Barry

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Fuel Pump Cam Lob is Toast (3/11)
7/4/11 8:06pm

Almond81Vette
Former Member
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Stanley, NC - USA

Vette(s):
1981, dark blue w/carmel interior. 350 stock, auto tranny, Q-jet carb, ECM box

Joined: 8/9/2010
Posts: 91

Yes Barry the lob is smooth just don't believe the angle is factory spec now. You should see the end of the push rod, will only fit one way to marriage up with the slope of the lob. Also it was rather difficult to remove push rod from block, Dub had to weld a piece onto fuel pump end of rod and use a puller to get rod out.

But these classic cars are fun......just at times expenses too.

______________
Tommy

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Fuel Pump Cam Lob is Toast (4/11)
7/4/11 8:53pm

Adams' Apple

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Duncanville, TX - USA

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#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
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Looks like the pump rod was stuck, as in not spinning properly....dang the luck...

How do all of the other valve lobes look, tho?

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Joel Adams
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Fuel Pump Cam Lob is Toast (5/11)
7/4/11 9:47pm

Almond81Vette
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Stanley, NC - USA

Vette(s):
1981, dark blue w/carmel interior. 350 stock, auto tranny, Q-jet carb, ECM box

Joined: 8/9/2010
Posts: 91

Most other lobes looked fair, #5's were wore down some, most all have some degree of wear on points. All in all was a rather expensive project but we went back with almost all new items while engine was out so at least now we know what we got and no bubba work done on it now.

Really concern about this oil one can get today. From research most lack ZDPP and Amsoil is looking to be my choice so not to have future issues. Need that Zinc to coat and protect better.

______________
Tommy

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Fuel Pump Cam Lob is Toast (6/11)
7/4/11 10:43pm

rod7515

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Red Lion, PA - USA

Vette(s):
1974 White 350 Corvette, TH400 Automatic 1972 Tangerine /Go Mango Convertible 383 Stroker, 2004r Automatic

Joined: 10/27/2006
Posts: 1182

Just out of curiousity, what oil were you using? Have you ever added the ZDDP oil additive when you changed your oil? So many car owners dont realize that todays oils do not have Zinc in them to help lubricate flat tappet cams. Its not talked about when these companies advertise their oils. Zinc in oil is said to cause converter failure. However lack of zinc or ZDDP causes failure to our older flat tappet cams! Good luck with your new engine. I am sure you will be very happy with it. Keep us posted on your progress.
Rodney

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Fuel Pump Cam Lob is Toast (7/11)
7/5/11 8:00am

Adams' Apple

I wouldn't be too quick to blame this failure strictly on the oil. There were several years, starting in '78, that GM had a serious problem with the cam supplier(s), and I've seen tons of these cams go flat like that....it doesn't matter what kind/brand of oil is used. Not to say that oil with a higher zinc content wouldn't help, 'cause it would.....but it won't negate the fact that the cams were not hardened properly to start with, and they didn't have the proper "slope" ground in, to keep the lifters spinning in the bores.

______________

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Fuel Pump Cam Lob is Toast (8/11)
7/6/11 10:29am

Almond81Vette
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Stanley, NC - USA

Vette(s):
1981, dark blue w/carmel interior. 350 stock, auto tranny, Q-jet carb, ECM box

Joined: 8/9/2010
Posts: 91

[QUOTE=rod7515]Just out of curiousity, what oil were you using? Have you ever added the ZDDP oil additive when you changed your oil? So many car owners dont realize that todays oils do not have Zinc in them to help lubricate flat tappet cams. Its not talked about when these companies advertise their oils. Zinc in oil is said to cause converter failure. However lack of zinc or ZDDP causes failure to our older flat tappet cams! Good luck with your new engine. I am sure you will be very happy with it. Keep us posted on your progress.
Rodney
[/QUOTE]

I was using Havoline 10w-40 and no did not add ZDDP........so maybe my bad mistake. We have RotellaT oil in now for breakin period on new engine and plan on changing that out in 400-500 miles and then going to use Amsoil...not sure of which one as of now but Dub is researching that and whatever he says to use I will use.

______________
Tommy

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Fuel Pump Cam Lob is Toast (9/11)
7/6/11 1:41pm

Adams' Apple

Brad Penn Oils...good stuff.

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Fuel Pump Cam Lob is Toast (10/11)
7/6/11 5:41pm

Gunslinger
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Frederick, MD - USA

Vette(s):
1969 convertible L71 427/435 4-speed black interior

Joined: 9/8/2003
Posts: 3398

[QUOTE=Almond81Vette][QUOTE=rod7515]Just out of curiousity, what oil were you using? Have you ever added the ZDDP oil additive when you changed your oil? So many car owners dont realize that todays oils do not have Zinc in them to help lubricate flat tappet cams. Its not talked about when these companies advertise their oils. Zinc in oil is said to cause converter failure. However lack of zinc or ZDDP causes failure to our older flat tappet cams! Good luck with your new engine. I am sure you will be very happy with it. Keep us posted on your progress.
Rodney
[/QUOTE]

[/QUOTE]

It seems to me that even if you used oil with ZDDP it would not have prevented the cam wiping...it would only have delayed it awhile. It could have happened at a time and place that could have been most inconvenient, as if any time is convenient.

Several months ago I had a mishap in one of my fun cars (not my Vette)...complete brake failure as I was in the garage. I put it in reverse and the brake pedal went to the floor as the car shot backwards. The bad part? I have...had...a bad habit of leaving the door open until it's about to move...the door hit the wall and was pulled all the way around to the front quarter panel. It happened so fast I was simply unable to get the door closed in time...my bad!

The result...new front quarter panel, new door and hinges and a repaint. It's still in the body shop and getting made better than before but it will still be several weeks before it's done.

My wife said to consider myself lucky...I could have been on the highway when it happened instead of in the garage. The same goes for you and a wiped cam...it could have happened far from home.

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Fuel Pump Cam Lob is Toast (11/11)
7/8/11 2:43pm

nosal1
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Dunedin, FL - USA

Vette(s):
1980 Corvette Torch Red with Gold metallic 370HP/350 CU.IN.Turbo 350 w/shift kit.Originally CA.Car with 305 CU.IN.

Joined: 3/21/2006
Posts: 262

Hello All,

Adam you are right about the inferior cams installed by GM between 1978 until 1982 engines especially the Ca. 305 CI (GM did not get certification for the 350 in '80) as the lobes in #4and 5 went south in 65,000 - 70,000 mi. depending on the driver and their oil changing habits..My Vette was one that the lobes on 4&5 took a hike..The fuel pump problem was probably due to an inferior push rod or one that had a little bend in it that got worse..

Lube oil without ZDDP (zinc phosphate) is becoming a real serious problem to the point,when I finish a build,I give the customer a tutorial regarding the start up and running of the engine..It now has become a standard that when we order cams we get a notice or disclaimer from cam manufacture that an additive MUST be added to the start up procedure and the normal use of the engine..Some as in Comp Cams send a bottle of ZDDP with their cam along with the warning.. I also have the research done on the best of the best lube oil and have the results in file,however I will have to send to you by PM....It is a very good evaluation of the oils needed for the flat tappet cam/lifter engines
Below is the disclaimer and or advice I have giving to all the people that we build Auto and Marine engines we build...

To all have a great day..

Engine Start Up Procedure Regarding

Oil/Additive Usage in Flat Tappet Cam/Lifters

With the absence of lubricating chemical (ZDDP) in the present day

Oil from the oil companies available to consumer for typical oil changes,

It is highly recommended to add or use oil with the ZDDP available

In the oil you purchase. The Zinc Phosphate combination acts as a

Lubricating agent to reduce friction on the lobes and base of the lifters.

The EPA had mandated that these products (chemicals) be eliminated as it

Deteriorated the catalytic converter thereby increasing pollution.EPA

Sacrificed the metallic parts of the cam/lifters for the life of the converter.

The late model engines now have Roller Cams and Lifters and do not

Require the ZDDP,albeit I would recommend using the additive or buy

Oil with zinc phosphate available in the formulation.

To help identify the oil with ZDDP in the formulation, look for the

Round badge on the oil container that signifies API Service CI-4/SI

CI-4 Plus would also be indicated.

Be aware without the use of this type of additive or oil containing ZDDP during break in of cam/lifters along with normal operation of the engine would void the warranties you may have received from builder of the engine along with/cam/lifter manufactures.

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