[DeTomaso] New Pantera owner on Long Island

[wkooiman at earthlink.net]

He said 4779.  That's a 750 dbl pumper - no vac secondaries.

I agree it sounds like a lean condition, but it could also be a bad timing chain - right?

Robert,

The cam gear in the stock 351C timing chain set is made of plastic coated aluminum.  The plastic falls apart after 30 years (probably more like 20 years).  As the plastic falls apart, it gets sucked into the oil pump, which causes the pin in the distributor gear to shear.  Even if the pin doesn't shear, the extra slop causes the cam timing and ignition timing to jump all over the place.  I could see the engine popping/backfiring when the timing jumps around.

I know it sounds like a lot of work, but you really should pull the engine and do a quick rebuild.  My stock timing chain jumped and all the intake valves kissed the pistons.

The rebuild should include a new oil pump, new timing chain, a new damper, and a Pantera specific pan.

By the way, your Holley should be fine if it's only 3 years old and only has 2,000 miles.  An Edelbrock/Carter is okay too, but it's probably just going to make your wallet lighter.


-----Original Message-----
>From: Sean Korb <spkorb at gmail.com>
>Sent: Mar 30, 2009 9:30 PM
>To: LEVITT1946 at aol.com, Pantera Forum <detomaso at realbig.com>
>Subject: Re: [DeTomaso] New Pantera owner on Long Island
>
>On Mon, Mar 30, 2009 at 4:55 PM, <LEVITT1946 at aol.com> wrote:
>
>>   When I try to  put my foot back on the gas she starts to stumble.she does
>> not stall. Under this condition I start from a standing start and she chuggs
>> and then all of a sudden she takes off like nothing happened.Does it sound
>> like power valve or bad plugs or something totally different? carb? Lost!
>> Should I just get rid of this 3 year old holley with about 2000 miles on it
>> and get an edelbrock? Open for any and all suggestions .I just want my baby
>> to purr.
>>
>
>It does sound like a power valve, but it could be an accelerator pump or
>premature secondary butterflies opening.  If you pump the throttle, does
>that help at all?  Pumping the throttle makes the accelerator pump squirt
>more fuel into the carb.  It sounds like you may have a lean condition.  If
>you disable the secondaries (keep them closed) that can rule out a premature
>secondary opening problem.  A kit is available from Holley with different
>spring rates to get the secondaries to open later.   And you might just want
>to pick up a new 6.5hg power valve and pop it in.  It works for most
>applications including my stock '71, but I had a moody 351C in my '68
>fastback that worked best with a 4.5hg valve.
>
>There's a lot to carburators Edelbrock, Holley, Rochester or Carter.  Entire
>books are devoted to tuning.  It's a mechanical computer, and it's
>programmed with nozzles, springs, cams and levers.  You can get a teacup to
>work; but tuning one is a science with a mystical lore surrounding it.
>
>Remember to keep a fire extinguisher handy!
>
>sean
>
>-- 
>Sean Korb spkorb at spkorb.org http://www.spkorb.org
>'65, '68 Mustangs, '68 Cougar, '78 R100/7, '60 Metro, '59 A35, '71 Pantera
>#1382
>"The more you drive, the less intelligent you get" --Miller
>"Computers are useless.  They can only give you answers." -P. Picasso
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