Ok I believe I have this figured out. As near as I can tell, The gentleman sleeved the 312 down to a 292. I measured the new pistons, and they are 3.75. And my reasearch tells me that what I have on my hands is a stroked 292. I took some pics that I will post here. The rods are ECZ. The crank has what I believe is the "correct bung" at the front of it. Now I was lead to believe that the pistons are 10-1/10.5-1. Honestly that is part of the missing paper work. And while I'm on that, I see no "Mummert" marking. But I'm not sure if he marks his parts. Ill send a e-mail and ask. So until I do more reasearch (and with your help, I will learn this engine. I am determined to make this a fun, local daily driver!! Oh, and smell burnin rubber every day till I die!:0)
So here are the pics and I look forward to your feed back. Thanks7ab.jpg[/img]

Rowen
55CV
Woodland, Ca

I'm to long winded.....more pics.....

Rowen
55CV
Woodland, Ca

Sorry just one more..

Rowen
55CV
Woodland, Ca

Mummert's pistons are made by a regular piston company, so his name probably wouldn't be on them.  The piston in your picture looks a lot like I remember of the Probe pistons I got from him for my engine.



Lawrenceville, GA

Yes sir, it says probe on the box!

Rowen
55CV
Woodland, Ca

A couple of things caught my attention;  Sleeving a 312"  down to 292" is an unusual procedure, I wonder why?  However, it's likely fortunate it wasn't sleeved out from a 312" piston , as that apparently can result in a much weakend block. And you may know this already, but just in case you don't, the Cam you have is likely the one that Mummert sells as the Y-292-S. It's a street & strip race cam. It has a nasty idle..    


Paul

You should check with Mummert if it has not been done already but the valve guides may need to be shortened a bit with that lift to be on the safe side. Cam will be nasty, I have the 272 cam from him and love it in my driver.

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?

Thanks Paul, Billy,
Yes, I think you both are correct. I was looking at Mummerts site just last night and I couldn't agree more! The 272 cam seems to be a much better fit for me. First, I intend to keep my Ford-O. At least foe now. I may change it out, but that is is in the future. Second, as I said, I have 3 yrs till I retire and this will be my daily driver. I don't this cam will be practical for that.
So charlie, you saw my pistons and I believe you are correct. What cam are you using? What application, daily driver, drag car? What is your opinion of me going to the 272S cam? It seems a good fit for me.
Billy, if I go down to the 272, do you still think I might have to shorten the valves?
I really want this engine to be reliable and perform well. It will NOT ever be a race motor. But that is not to say I won't take it to the track every once in a while! :0)
I have to get back to work so ill look forward to hearing back from you fellas!! You guys are the best!!! Thanks, Rowen

Rowen
55CV
Woodland, Ca

My cam is a repro of the blower cam.  The Y-270-S is probably the most similar that John currently offers.  The biggest difference is probably that mine is on 112 degree centers, rather than 108.  According to his chart, the 270 is about the biggest you can go and still use the auto without hassle.  Mine is probably 99% daily driver street use and 1% strip use.
I also removed the dome from my pistons because the ultimate plan with the engine is to apply some boost.  If you plan to stay naturally aspirated, you will want to leave some of the dome.  You'll probably have to remove some of it to make it friendly with pump gas, but that will depend on the heads you end up going with, too.
If the heads were properly setup for the 292-S, then the 270-S will work just fine with those heads.  If you use another set of heads, you will want to check the clearance but it will probably be fine.  And it never hurts to future proof the heads and go ahead and ensure that you have enough clearance if you choose to go with a bigger cam later.  If you check the valve to piston clearance, you will know the max lift possible and you can go ahead and set it up for .500-.550", if possible.



Lawrenceville, GA

Thanks for your input Charlie, yep, I think I'm gonna put this up for sale and go with the 270S. Like I said, I'm keeping the Ford-O till I either blow it up or get a bunch more money to swap. As near as I could tell from the conversations I had with the builder, the heads are set up for this cam. So I gather from your post, that the 270S cam will work without modifying the pistons?

Rowen
55CV
Woodland, Ca