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351w cam in302 engine

24K views 8 replies 9 participants last post by  PSIG 
#1 ·
is there any real advantage to putting a 351w cam in a 302 block
 
#2 ·
Well, even the experts will argue about that.

Here's my opinion anyway. ;) I say yes, there is an advantage. It will be a very small one, though. I'd guess something like a 1% increase in power. That can be hard to see on a dyno as you could have 1% variation run to run with no changes. The 351W firing order is supposed to better for crankshaft and bearing life, but if you have a fairly mild motor those parts aren't going to be stressed anyway.

All that being said. I would do it. JMO.

paulie
 
#4 ·
In General; besides the firing order change...

A "mild" cam in a 351 will become a step or two more radical when installed in a 289/302.

If you take the time to browse through the "off the shelf" cam catalog listings of your favorite cam ginder. Most of them will show that difference. It has to do with cubic inches, A smaller motor will tend to have a "lumpy", "choppier" idle when using what is listed as a mild cam in a larger motor.
 
#8 ·
In General; besides the firing order change...

A "mild" cam in a 351 will become a step or two more radical when installed in a 289/302.

If you take the time to browse through the "off the shelf" cam catalog listings of your favorite cam ginder. Most of them will show that difference. It has to do with cubic inches, A smaller motor will tend to have a "lumpy", "choppier" idle when using what is listed as a mild cam in a larger motor.
piston throw arms length makes differences to as to say short arm as to 3.1/2 inch throw takes more time to travel from bottom to top where as to piston throw arm of 5.1/2 inch throw long throw arm is faster to top for quicker top end response as well fow bottom end that gives you the best of both worlds to say. Then any upper top end improvements would be just even more to add as you build up . Old school high performance mechanic thought me that. Lol 😅 now reason on cam of 351 into a 302 is the smaller ports so your engine not loose it's thrust power for delays in seconds are lessor big ports loses the thrust delays in more of a seconds . Calculate the differences is why Ford decided to change to the 351w cam style with the heads of a 351 Cleveland even there new heads and cam modified make over is same as to the 351W cam with 351C heads. But they never done the throw arm change from short throw arm to long throw arm. Unless you buy the high performance kit.just saying you can build a budget build of junkyard find and build old School high performance. And get more performance or do buy the new crap and not get as much. Also if you have a manual engine cooling fan obsolete it put a twin electric cooling fans in instead gives engine another 25hp, egr valve obselete that too cut corners to have better engine life and performance. Manual belt driven water pump obselete that too install a electric water pump. Adds another 25hp with less stress on the engine crank and cam.all that being said let your mind do the understanding of what's works best for engine and how you want to build it.
 
#5 ·
This is from another board. But is what i have always been told.

"I have tested almost every firing order that you can dream up and you know what? If this is where you are looking for 2 or 3 HP, GREAT & more power to you. If this where you are looking for significant increases, then you are wasting your time just like the rod ratio bull$h!t.

The GM LS-x is what is known in the GM world as the 4/7 & 2/3 swap. If you number a Chev on papaer next to a SBF, then number the Chev like a SBF, the 4/7 & 2/3 is the same as the 351W/302 HO firing order. This is done not for power, but to reduce load on the crank. "

The GM 4/7 swap is the same as the BB Ford Pro Stock firing order that Bob Glidden/Billy Glidden developed. This was done with sheet metal intakes and split dominators. GM thought hey, why not! It does idle better, changes the tome of the engine, and makes not 1 HP on a cast intake engine.

The Ford *Old School* firing order vs the 351W/302 HO firing order was done for the same reasons as GM copied. Crank load.
 
#6 ·
Besides the firing order difference, many 351W-specific cams have different valve timing events to take advantage of the 351s longer stroke. Lift and duration numbers may be the same as a 302 cam but when the valves open and close can be different.
 
#7 ·
Ran a Blue Racer/Wolverine cam for a 351W in a 289 once.

204*, 0.448 @ 0.050 Intake
214*, 0.472 @ 0.050 Exhaust

It had great midrange torque, but probably no different than the old firing order. Instead of 2 cylinders firing on the same bank in succession, they fire opposite each other, albeit right accross from each other, 4-8, instead of 7-8. Therefore as others have mentioned, reducing the load on the crank.

Never had any problems with it.

Don't know that it really matters much. I've seen balanced 289-302's turn 7800-8000 rpms, in road racers.
 
#9 ·
I would say that it is far more important to pick the right cam for your engine build, trans, vehicle weight, gearing, fuel and driving style, than just picking a "different" cam. If you're going to do anything, make it worthwhile.
 
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