Frank;

I see what you are saying with respect to the #1 cylinder minor thrust (middle). The #1 cylinder major thrust (middle) has alot heavier wall and I'm not sure how/if there can be some compensation there. I did make a few mods to this C2AE block to reduce crankcase pressure. One thing I did was drill out the road draft blank on the block so it could accept the stock road draft canister/tube. I also cut valve reliefs in the block and I'm planning on running 2 of the Moon valve cover breathers. I'm hoping these mods will reduce any excess pressure. I was more concerned with overheating if the cylinder walls were too thin.

Rono

  Ron Lane,  Meridian, ID

Ron

The area I'm talking about is the actual Cylinders. They'll actually bow out from the combustion pressure if the walls are too thin. Better to be a little smaller in displacement and have stiff strong cylinders that seal up. Especially with the blower. there when you want more power, add boost!

Frank/Rebop

Bristol, In ( by Elkhart) 

As Charlie mentions, timing cover and bellhousing measurements refers to the front and rear of the cylinders.  I’m going to assume at this point that the cylinder numbering is true to the Ford engines and not the scrubs.  You need to ask R&L this just to verify as it makes a big difference in interpolating the values.  But I’ve taken the values you have and based on them being real Ford Y Cylinder numbered values, I’ve put them on my own sheet to make it easier reading.  Looks like this:

 

 

If this had been a virgin block, then offset boring the cylinders would have helped to center the bores.  But another 0.030 overbore only requires 0.015” off each side so the current block is doable in that regard.  If you’re talking more than 10 lbs. of boost, then a small amount of block fill would be of some benefit but that needs to be done before the cylinders are final bored.  A plus to your particular block is that the major thrust side measurements are already better than the minor thrust sides.

 

Frank is right in that boost pressure deforms the cylinder walls.  Having additional crankcase breathers are not going to be much help in that regard.  Here’s the sonic test sheet for Randy’s block which was running 15 lbs. of boost and making gobs of horsepower with injected alcohol.  These cylinders were offset bored to minimize issues with casting core shifts.

 

Lorena, Texas (South of Waco)

Ted;

Ted;

According to John Erb, this supercharger will put out less than 10 psi boost with the high output impeller (he says 7-9 psi max). I appreciate you taking the time to transpose the numbers to your format. Much easier to interprete. I'll forward that to R&L Engines and see what they have to say. It's not too late to put the brakes on this block work if the motor may blow under moderate boost pressures.

Rono 

  Ron Lane,  Meridian, ID

Ron

Two more things about what Ted's telling you, and I learned from a couple years in a foundry. The cores are not terribly consistent and smooth. Hopefully you are seeing MINIMUM readings in the areas described. A 1/4 inch away from that reading it could deviate.

     As you can tell from comparing your block, core placement in a mold is not accurate in terms that machinists use. We think a +/- .030" core location is pretty good. Remember, your'e placing a 100# block of sand into another core. Likely these cores were made in two or more different core cavities, so they're not exactly identicle and fit differently. Get's to be pretty tricky to be consistent. Lastly as the tooling gets older, repairs and wear will cause the cylinder bores AND the water jacket to increase in size. Castings from older tooling will then have smaller walls as cast. You can't do anything about this but what you've done. I would definitely agree with Ted, if you can get by with .030, use that.

Frank/Rebop

Bristol, In ( by Elkhart) 

I'm kinda locked in with the overbore because I already have John M's 331 cu.in. stroker kit with the forged pistons and have milled off all of the 10cc domes. So, if I can't use this block for a supercharged application, I need to look for another C2AE block.

Rono

  Ron Lane,  Meridian, ID

You can sell them and get a set of smaller bore pistons. I think you could get pretty close to what you paid for them even with the domes machined - for some that would be a bonus.


Lawrenceville, GA

Charlie;

That's a good thought. I'll talk to the machine shop Monday and then give John M a call. So you guys naybe seeing a set of Probe Forged pistons and rings in the classified section soon.

Rono

  Ron Lane,  Meridian, ID

Ron, You could go .040 thats only another .005" (5 thou) off that wall. I would, and I'll bet Ted'll agree. I'd go some block fill at the bottoms of the cylinders and do it!

Frank/Rebop

Bristol, In ( by Elkhart) 

Frank;

I'm not familiar with block fill. How do they do that and can most shops do it?

Rono

  Ron Lane,  Meridian, ID