302 or 351W

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justineverything@gmail.com - 28 Apr 2008 18:13 GMT

I have purchased a 70 mustang with a 351w out of a ford torino. The
car starts up and moves but was back firing out the carb as well as
falling on its face after a short distance. The car smells like its
running rich I was thinking that the car was loading up and that the
timing was off. After messing with the car some more I found that the
spark plug fire order was off. So I changed the order to what a 351W
was calling for and yes I went counter clockwise on the cap. Although
that didnt do a thing for me. after I changed it it would not start at
all... So I thought Maybe I have a 302. So I tryed the fire order for
the 302 and It fires over. although it hasnt back fired since out the
carb, it still smells like its running rich or possibly running to
much fuel. I investigated further and looked up the part number on the
Intake manifold and it came up as 351 exclusively.... so my next
question would be WTF! how does a 351 fire on a 302 fireing order, and
if it is a 302 why or how did someone put a 351 intake manifold on it?
I am about to loose my mind..

As of now with the 302 fireing order, I place the car in gear and it
basically loads up... looses power

Any suggestions?

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C. E. White - 28 Apr 2008 19:11 GMT

A 351 intake will not fit a 302. Assuming it is a 351W, the firing
order should be 1-3-7-2-6-5-4-8 - I assume you understand how Ford
numbers the cylinders (1 2 3 4 front to rear on passenger's side, 5 6
7 8 front to rear on driver's side).

Ed

>I have purchased a 70 mustang with a 351w out of a ford torino. The
> car starts up and moves but was back firing out the carb as well as
[quoted text clipped - 25 lines]
>
> Any suggestions?

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Gene Wagenbreth - 28 Apr 2008 22:08 GMT

Dont know about the 302/351 distinction, but a friend did a valve
job on a Bronco 351 . When he put it back together he did the
firing order as labeled on the intake. It backfired, etc. A mobile
mechanic came over and said the firing order on the intake was
incorrect. He redid the wires and it ran fine.

I always wondered about that.

G

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Kruse - 29 Apr 2008 00:27 GMT

> Dont know about the 302/351 distinction, but a friend did a valve
> job on a Bronco 351 . When he put it back together he did the
[quoted text clipped - 5 lines]
>
> G

Ford changed the firing order of the 302 to the 351W firing order.
Really all they did was change the camshaft and it only changed the
order between two cylinders. I've been told they did it because over
the years a lot of engines were ruined because of crossfiring between
the plug wiring that would cause preignition on the firing order of
the old 302s. Can't say for sure that it is true though.

The OP has me puzzled unless somebody actually put an older 302
camshaft into a 351.

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.boB - 29 Apr 2008 06:44 GMT

> I have purchased a 70 mustang with a 351w out of
> a ford torino. The
[quoted text clipped - 33 lines]
>
> Any suggestions?

There's no real differance between a 302 cam
and a 351 cam - except the firing order. Other
than that, they are interchangable. In some
years, it's the same. In other years, it's not.
Whoever swapped the motor may have installed a
differant cam for some reason. You have to try
and figure out the proper firing order. Here's
how to do it:

Remove the spark plugs, and the valve covers.
Place a marker (blue masking tape) on each intake
valve rocker arm.
Place the engine at TDC, with cylinder #1on the
compression stroke.
Use a socket and ratchet to turn the engine over
two full rotations.
As the engine turns over, watch the intake rocker
arms. As they start to open, write down the
number
That's your firing order.

Who ever had the car before you, may have
been using the incorrect firing order. You can
make the car run, but not well. They may have
compensated by putting in the wrong jets, or
placing the base timing at some wierd setting.
Once you set the correct timing order, then you
can check everything else.

--------
.boB
2006 FXDI hot rod
2008 Mustang Coupe
2001 Dodge Dakota QC 5.9/4x4/3.92
1966 Mustang Coupe - Daily Driver
1965 FFR Cobra - 427W EFI, Damn Fast.

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scott - 07 May 2008 02:19 GMT

Blown power valve?Timing slipped?Which carb?Elec ign or points?Duraspark
ignition?

>I have purchased a 70 mustang with a 351w out of a ford torino. The
> car starts up and moves but was back firing out the carb as well as
[quoted text clipped - 17 lines]
>
> Any suggestions?

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