351w with 302 '90 302 internals

[jete]

So I have a 302 and a 351w in my garage. The 351w is a 74' 351w which I heard was the strongest of the strongblocks. So if I took my 302 rolller cam and lifters to a machinest and had them work there magic on my 351w and drill the block into the cam valley what kind of preformance could I expect out of a .030 overbore 351w with a '90 302 roller cam and a nice edlebrock single plain intake? I would be expecting more then 250 hp. Would I be correct in this assumption

(BTW this is with stock 74 351w heads and with stock 90' headers and a stock duraspark ignition system)

 

[seijirou]

I wouldn't expect much more than 250 honestly. If you have a 302 and a 351 and you only care to have one of them running however. You are only a crankshaft away from a 393, which is a 3.85 crank, your stock 351 rods, and your stock 302 pistons.

Now you can expect some power

 

[vristang]

So I have a 302 and a 351w in my garage. The 351w is a 74' 351w which I heard was the strongest of the strongblocks. So if I took my 302 rolller cam and lifters to a machinest and had them work there magic on my 351w and drill the block into the cam valley what kind of preformance could I expect out of a .030 overbore 351w with a '90 302 roller cam and a nice edlebrock single plain intake? I would be expecting more then 250 hp. Would I be correct in this assumption

(BTW this is with stock 74 351w heads and with stock 90' headers and a stock duraspark ignition system)

Before you fully assemble the top end do some mock up on the lifters.

It is likely that the oil hole in the lifters will lift out of the lifter bore of that block, if you use a factory type cam.

In order to run a standard 302 cam in that block you will probably need to use 'link bar' conversion lifters (which are pricey).
The alternative, is to use a non-standard cam. A cam grinder can use a smaller base circle when cutting the lobes. this keeps the lifters lower in the bores.
The reduced base cirlce cams are frowned upon though, as they affect valvetrain geometry.

Using flat tappets will eliminate this problem.




jason

 

[joncash]

What makes a block a "roller block" is not the threaded hole in the lifter valley (although that's part of it), it's the depth of the lifter bores. Roller lifters are longer than flat tappets, and the block is cast with taller lifter bores to compensate.

To use the roller cam out of your 5.0 in a 351W you either have to use a '94 and later 351w block that is set up for a roller cam, or you have to use a special set of lifters.

The conversion lifters have a little metal bar that connects them in pairs to each other and prevents them from turning in the bore and wiping out the cam. They run in the $400 range and are available from Ford Racing, Comp Cams and a few others. (this is the option that I would choose, because it gives you the greatest number of options if you ever want to change the cam in the future)

The last option is to ditch the 5.0 cam and use a roller-conversion camshaft (available from Comp that I know of) made specifically to run hydraulic roller lifters in a block that was not originally designed for them. The difference there is the conversion cam's lobes are ground with a reduced base circle and let the roller lifters sink deeper into their bores. This cam will allow you to tap the holes in the lifter valley and utilize the "spider and dogbone" hardware from a roller 5.0.

 

[joncash]

Wow, simultaneous posting...crazy man.

 

[vristang]

How often does that happen???



cool