Well, I got my dent back after my mechanic fitted a new cam.....what to say? Where to start? Well, I guess it starts with F, ends in K, and it ain't firetruck!! It goes real good now!! He fitted a competition cams torque/mileage improver cam.....I am happier than ever now!! I was happy with the 'ol 400, but the new cam.....well, it really woke her up!!
If ya got a 400, re-cam it NOW!!
Shane

 

yep, that is all it takes to improve the performance of a 351m or a 400. From the factory the cams are set with 4 degrees retard timing so by adding a cam and setting it at 0 degrees the engine will run much better.

I am glad you like it.

 

This is old but do you mean Ford used a retard grind on the cam? Or can you get the in crease from just replacing the time set with a straight up time set like other smog truck engines?

 

Straight up timing set will make a big difference by itself.

 

I had just not heard of a retard cam grind from Ford. A++ to the time set change. If you have low compression that alone will be better than a lift cam.

 

Would it be the same end result on a 460?

 

Yes all 460's after 1972, I believe had the retarded timing. You could get an aftermarket set like Cloyes, or use a 1972 or earlier stock set-up.

 

So, if I wanted to replace my timing gears along with a new cam... What exactly should I be looking for in terms of the gears? Is there a specific part I need to make sure to have?

 

Like this:
Cloyes Gear 9-1122 - Cloyes Street True Roller Timing Sets - Overview - SummitRacing.com

 

Nice gain for 50 bucks!

 

so you are getting better gas mileage and more power?

 

Well with a smog motor like mine. Yes and yes! These engines have low compression and need advance at low load to fully burn the air fuel charge and expand right as the piston is starting on its down stroke.
These cheap factory tuning tricks of the 70's purposely miss the sweet spot to keep combustion temps down to avoid nox but sacrifice power and fuel mileage to do it. The unburned fuel is burned as it leaves the exhaust manifold. A total waste of fuel and power not to mention a heat issue at the exhaust ports and heads.
Early EGR works best with the retard. If you install a straight up Time set you might as well disengage the EGR also. I has very little control compared to modern computer controlled systems.
So tuning will be important also. Total time and carb tuning. Good choke and fast idle adjustment and some relief at the exhaust for street. Don't go to big of pipes on a stock engine.
So I get 13 to 15mpg consistantly and although the smog engine is low compression it is much peppier than it was.
Keep the stock cam. Just change the time set to maintain dynamic compression. I use manifold vac on my smoger to get full vac advance at idle and very low load. Thats when I need it. It will pull off when you increase throttle and as you pick up RPM's your mechanical will pick up the advance duties. At hyway cruise both work together to trim your fuel burn and give best gas mileage. Don't run lean! Listen for decell rumble and look at your plugs. Get rid of points. I use Pertronix 3 on my 73.

Just add: "Stock" 70's 360, 390, 351, 400, 460 will all see good performance/mileage gain from straight up time set and adjust total time and carb to it.

 

What's the problem with decel rumble?

 

Did you also replace the springs & retainers & add screw in studs & guide plates?

Did you use the 252H or 260H?

 

I am talking if you are sitting static....rev high and dump the throttle. If it back fires very lean, pops too lean, rumbles, in my oppinion still too lean, smooth transition from high gas flow down to idle is what I look for. Right in that area the adjustment is very sensitive. Idle is best, engine is smooth, runs cooler at idle and in hot weather. Set idle right to spec. My 2 cents. I get tired of my truck getting hot.