So, today while doing some research, I learned that Eagle is now making new h-beam rods for scrubs, in a 6.3 length with 2.1 big ends...That set wheels to turning, and I looked further, finding that 231 Buick Turbo V6 pistons have a 1.825 compression height.  This, coupled with the aforementioned rod, decking the block to 9.75, should come pretty close to getting where I want to be with a 292 crank.  With forced induction, I don't think .025 deck clearance is going to hurt too much.  Correct me if I'm off base here Ted, John or Pegleg.  I believe that Wiseco or Ross makes the Buick piston with the smaller scrub pin size for custom rods...still checking.  The JE pistons come with only the .940 pins, not what I want.  They do have a 22 cc dish though..Wheels are still churning....

I dd check out some stuff on 5.4 rods, which are 6.635 long, but they have a 2.245 big end, again, not what I want.  Now if I could find some eagle h-beams for 5.4, in the 6.5-6.6 range, with a 2.1 big end, I would be in business...have to look into a different piston though...

Any thoughts on other off the shelf combos like this?  I am near certain, that some kind of monkey motion would have to be performed on the big ends of the rods, such as narrowing or whatever, just sort of brainstorming as I hurry up and wait on the weather....

James Potter
`57 Fords International



`57 Custom Tudor

`57 Fords International National Director

Pass Christian, MS (near Gulfport/Biloxi)

Jim,

    Get hold of John Mummert, he has Eagles in various lengths, Yes you want to run them. You do want to Zero deck the block to avoid detonation. More squish equals less detonation and more power. John's also got Forged pistons, i believe he gets them from Probe and machines them to whatever you want. Go easy on the cam, you won't need a lot of duration and wide lobe centers with the turbos.   

Frank/Rebop

Bristol, In ( by Elkhart) 

James:

I am presently building a new engine with the 6.3 Eagles.  I had to narrow the big end to .871 from .943 and also put additional chamfer in one side of the chev bearing because I had a radius maintained on the rod journals when they were taken down to 2.0995, which with standard bearings, gave me .00175 clearance.  I had heard that the crank man I used, if you didn't specify a radius, would not dress one on his wheel and leave a square shoulder.  The cranks that I have found cracked were all undersize, and had no radius.  Must be SOP for non-performance crank shops.  Next time I may take the crank to 2.0990, I'll see how this works.  I used Mummert's domed pistons and had the pin holes honed to .927 and used .927 x 2.5" pins from Wiseco.  I decked it just enough to make it flat and square and equal on each side, and ended up taking the domes off plus an additional .034 to come out with 0 deck.  I had the crank ground to stock 3.44 stroke.  I think the Buick pistons are dished, so that may allow you to use G heads instead of 471 and still keep the compression ratio at a reasonable figure.

John

John - "The Hoosier Hurricane"

What is the actual deck height on the Y?  I have looked all over, and I cant find it even on Mummert's site.  I saw an approximate figure of 9.75-9.80 on the Ford Trucks Y discussion, but not an actual blueprint figure, which is what I want to base my figures on.  My block wont be left at that blueprint number, but I want to base my machining operations on it.  How much difference in chamber volume is there between the G and the 471, about 10-12 cc's?  Is Mummert available by phone on Saturdays?  If so, I will call him tomorrow.  I dont think I want to go the stroker route, as I feel a 292 will get the job done.  But the longer rods and shorter piston idea looks good to me.  I think it could make some wicked power, given the right conditions, and the right "other" combination of parts, ie cam, heads, intake, etc..

James Potter
`57 Fords International



`57 Custom Tudor

`57 Fords International National Director

Pass Christian, MS (near Gulfport/Biloxi)

James,

The 318 kit from mummert is a reasonable option.  All of the major machine work is done (rods narrowed, bearings chamfered, crank turned he will balance it for you but that's best to have done locally - if you cut the pistons it'll have to be balanced again.) and no clearancing should be required on the block.  It's a good value when you consider all of the work that has to be done.  It'll get a good strong bottom end.  I put one in my block.  3.82 bore, 3.47 stroke.  It's as easy an installation as a stock bottom end.  I was going to do the 312 crank in a 292 block but the cost of the 318 kit wasn't much more and it's probably a fair bit stronger.  I also didn't have a 312 crank.  If I had I probably would have gone that route.

I'm not sure about the figure for the deck height but you may want to assemble everything before decking to find out where it is and cut the deck based on that figure.  That way you won't take too much and have to cut the pistons.  G heads are 69cc and 471 are 82cc.  It'll be great when you get this done - a twin turbo Y in the states, the 2nd in the world, probably ever.

John,

Are you using the probe pistons in the Hurricane?  I asked JM about using boost with them and he didn't seem to think it was a good idea, particularly because I had to cut about .015 off of them to get good quench.  I see that you're taking .034.

Lawrenceville, GA

Charlie:

Yes, I have the Probes.  Looking at them, they appear much stronger and are lighter than the TRWs I have been running.  Of course I can't see the metallurgy, but physically they look better.  I guess I'll find out.  Can't get the TRWs any more anyway.

When I cut the tops, I still have two small valve reliefs left, so at least that part of the piston head isn't any thinner than original.  I haven't measured the top thickness, maybe I should do that.

John in Selma, IN

John - "The Hoosier Hurricane"

The number I use for the stock Y deck height is 9.775”.  By using a piston with a pin height of 1.770”, I can either use a 6.250” rod with a 3.48” stroke or a 6.300” rod with a 6.38” stroke.  These are offset ground 292 cranks with the 3.48” stroke having a 2.000” journal and the 3.38” stroke having a 2.100” journal.  This allows the pistons to be at zero with the deck with a 9.760” deck height.  This is just enough for a nice cleanup but not so much that I have to be concerned with intake manifold fit even if the heads are milled more heavily than usual.

For normally aspirated, I like a minimum of 0.200" for piston crown thickness.  For blown, I like to add at least another 0.050" to this and have no qualms with up to 0.350" thick.

Lorena, Texas (South of Waco)

Charlie/John,

              Mummert was able to get Ross's at one time as well as the Probes. The probe thing is recent, took him a while to convince Probe to consider Y Block parts.

Frank/Rebop

Bristol, In ( by Elkhart) 

The Probes are good looking pistons. JM said about the same thing as Ted. He told me that the pistons are around .200" to begin with and that's the main reason he wasn't confident about supercharging with them. I'm sure you'll put them to the test, John. I hope they hold up for you because that will mean I just need to bolt on some low compression heads and I'll be ready to go. I have the clearances in the bottom end so that it's a good compromise between an NA and boosted engine. I was at Don's shop last night, as I am most Fridays, and he had some pistons for a 6-71 supercharged engine. I felt them and they seemed to be real thin too but it looked like the pin bosses - is that the correct term - were extended closer to the center of the piston, so that could offer more support.


Lawrenceville, GA

Well, I checked my pistons yesterday, maybe I shouldn't have.  There is a strut in the forging that spans the area between the pin bosses that is .288 thick.  But, on each side of the strut are D shaped areas that are in the .170 area.  The remnants of the valve notches are pretty much over the pin bosses.  Now I'm concerned, but at this point I will try them.  I ran the old TRWs at about .256, no strut, and never had a problem, even with lean conditions and leaky head gaskets.  Had tops eaten by detonation and water intrusion, but never a sunken top.

John in Selma, IN

John - "The Hoosier Hurricane"