The Isky cam to which I refer has 0.420” lift at the valve after lash.  There’s typically no block or piston machine work required for any Y cam with up to 0.485” lift at the valve if that helps.  Exceptions to this would include where the heads have been heavily milled either by way of a straight cut or angle milling.

Lorena, Texas (South of Waco)

Ted, Paul,



Great info, the graphs are very helpful to figure out where I want to land between bottom and top. I want to keep the low down tq and just add some hp to the top end so figure the e4 or Mummert will be the way to go. I definitely do not need to get into machining or relief cuts, so staying below that lift threshold will be a must. If i ever have to get to that point of disassembly it will have to be accompanied by a full stroke kit. It is going to start off as a pretty mild build. Who knows where it will end.

I don't have any oil issues to date on the top end so hoping I can just swap in with old bearings and just replace lifters and cam-- just do a plug and play with the swap.

Mike Rizzo

1963 F100 "Rudy"

Daniel Island, SC

Riz: Mummert's cam ads say up to .450 lift is clear. His Y-265 might work well for you, it has .440 lift. He recommends it for Fordomatics so it has to idle decently. Ted's post on the Isky E-4 does not specify lift..so don't know how it compares.

Paul

Here’s a graph showing the dyno results for a +040 over 292 with an Isky E4 cam ground on 112° lobe centers and installed 5° advanced.  Other engine components include ECZ-G heads, MSD ignition, Blue Thunder intake and a List #1848 465cfm Holley sitting atop a ¼” phenolic spacer.  The bottom end is just a basic rebuild.  This particular camshaft has an advertised duration of 260° (4° more than stock ‘57) while the duration at 0.050” is 216°.

  

 

And here’s another graph showing the results of using another Isky E4 camshaft ground on the same 112° lobe centers in a +060 over 272 with ECZ-C heads, ECZ-B iron intake and 600cfm Carter 4V carburetor.  The cam in this instance is installed at 110° intake lobe centerline (2° advanced).

 

Lorena, Texas (South of Waco)

Paul,

I was looking into the 256 cam and was finding the same thing I was looking at the isky and could not find a part number. I wanted to keep the cam tame enough to avoid relief cutting and a bunch of machine work. Do you know anyone who has installed the mummert on a rig like mine and the hp/torque trade off. I would be interested to see low end vs top end when the peaks are.

Mike Rizzo

1963 F100 "Rudy"

Daniel Island, SC

Just for clarification, unfortunately true 1957 - 256* cams are basically unavailable. All the stock replacement cams revert back to 1956 & prior durations. In fact I believe most are truck spec cams. I've not heard of anyone recently supplying 57 cams. John Mummert advertises a 256* cam, but I believe it has less lift than the original.. Check with him if you want...

Paul

hi rudy, a stock 57 cam would work fine for your application.

 lincoln/merc. y-blocks &mel's                                                               bucyrus, ohio.

It is a weekend errand runner and occasional daily driver. I will take your advice and keep the 3:89. I like the oomph off the line. Just do not like kicking it at 3000 rpm for a highway jaunt at 75 mph. But I figure I can live with it. I tend to want to baby the engine rather than thinking of it as developed from a tractor motor.



Thanks again. Probably postpone the rear and cam and really just play with the timing and carburation and see where it needs to be. No sense rushing into rework.

Mike Rizzo

1963 F100 "Rudy"

Daniel Island, SC

Yeah. A rear gear change is the cheapest way to get the highway economy but it's really not the best way in my opinion. If this is a truck you will use regularly, as in a primary source of transportation, also install an overdrive transmission. This gets you the highway economy and 1st gear usually makes it like going up one or two ratios in the rear and you have an extra gear for around town - far better than any rear gear change will get you alone but it is more expensive.

If it won't be regular transportation, don't even worry about economy. The occasional blast up the freeway won't hurt a thing.


Lawrenceville, GA

Great stuff thanks for the heads up. I was only looking to drop the rear gear to lose some RPMs at highway speed with the 3 sp trans. Your post makes me want to change up the sequence of the next few projects and look into the cam and timing first see where I land in the RPM range and then play with the gear.



Many thanks you guys may have just saved me from a few rework projects.

Mike Rizzo

1963 F100 "Rudy"

Daniel Island, SC