I mispoke in the above post, I also raised the compression ratio to 10.2 and used Thunderbird specfic headers with the 214/220 .500 lift cam. This yielded outputs in the 280 HP range. (edit 380 HP)

Remember I was able to very nearly duplicate the results of Ted's engine with this soft ware (hp peak was within 2, peak rpm off by 500 rpm).

If building an engine from the ground up, then I agree, a bigger cam, and different pistons, and such is a good decision. I interpreted the original post as implying that these are necessities, rather than options.







If the airflow stalls, then you still have more to gain, new heads or old. It is when it drops off that you have no more to gain. Lets just say hypothetically that the heads peak at .400" lift but the flow does not drop off significantly until after .500". A cam with .500 lift should produce more power, even though it peaks at .400" because the valve will be open at or beyond the point of maximum flow for a longer time.



I think you will be able to get away with a bigger cam. Mine's 226 @ .050 and I get 15.5inhg at idle - and it's a copy of an old cam. If it were me, and I was spending all this money, I'd shoot for well over 300hp. We've seen that 280 can be achieved with iron heads with ease.


Lawrenceville, GA

Blew it, fat finger, didnt proof read, 380 horsepower.

Don,

You do understand the The Y has mushroom lifters, the ramp cannot be as newer roller lifter ramps can be due to the fact you would break the head of the lifter or it would dig in to the ramp severely accelerating the wear of these components, not to mention wear the lifter guides.

The program you are using to do your calculations may not be adding into the equasion that the Y is a solid mushroom lifter only, so ramp angle is limited on these.

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

Yes, I overhauled my first Y in 1959.

The mushroom on the Y is larger than diameter of lifters of even the Chrysler Corp. engines. This aids in its ability to handle more agressive ramps.

The concern with the Y is the small stem verses the dia of the head and the possibility of flexing/fracture at that juncture.

I do know of one Y built with the agressive ramps I want. It worked OK.

Yes, one "Y" with very aggressive ramps was documented in YBM a while back. And the builder has been on this site on occasion. However, I don't know if that was a street engine & if it has been run enough to prove reliable. J. Mummert has indicated that he feels the Y lifters are somewhat fragile. I don't know what he bases that on, but unless someone proves him wrong, I'd be inclined to go with his observations..

Paul

While it is true that the Y-Block's 1.00" lifter face allows the possibility of more aggressive cams with higher lifter velocities at some point the attachment of the stem to lifter face becomes a concern. If a person is considering a high velocity cam lobe a few things will help the lifters live:

Light weight valves and retainers. Titanium will greatly reduce the component weights and valve spring tension required to keep everything under control.

Well designed cam lobe. Some designs are harder on parts than others with the same basic specs.

Sufficient valve spring pressure. Nothing will break lifters quicker than weak valve springs.

Higher lift is harder on parts. Longer duration is easier on parts.

Keep in mind that better cylinderheads will make the same power at lower compression ratios and with smaller cams.

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

John,

On your site you have a range of cams. These are referenced to a spring. Firstly what cam are the springs, that are sold with the heads, designed for and Secondly do you offer other springs for specific builds? 

Grizzly (Aussie Mainline)

Grizzly, the springs on the site are listed by seat pressure but we sell them based on valve lift. The VS65 is for stock cams, VS95 for .450" lift, VS105 for .480" lift and VS115 for cams up to .520" valve lift. These springs can be used with any appropriate cam and fit common retainers with 1.060" inside step (except VS65).

The springs in the new heads will handle up to .520" lift but are not the same as the VS115.

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

I could have worded my question better I knew that springs were designed for different cams. So the heads can handle up to .520 delivered.

Thanks

Grizzly (Aussie Mainline)