One question I get asked often is, what is the maximum bore size you can go with a crossflow.
So to demonstrate I have taken a damaged 84DA block, popped it in the mill and started cutting.
As you can see I have hit a corrosion at approximately 3.90. This block was in fairly good shape for its age(except for some un related damage).
Depending on what your desired bore thickness is you could have potential ran a 3.740 bore on this engine. Clearly corrosion is a killer and 9 times out of 10 the limiting factor on these engines these days. Please also note this is just one bore and only about 1.500 deep. If I was going to bore the whole block the results may vary. I've don't this purely for a visual exercise to demonstrate why those old blocks are not always a +.060 etc.
Now this brings me to the second part of the exercise, which is what is the absolute maximum bore size for a Crossflow (and any other ford small block 6)
As you can see here the bore has been taken out to 4.070 (which was the limit of this boring setup on my small milling machine). Keeping in mind the bore spacing of a Ford small 6 is 4.080 you can run a 3.840 bore in a dry block with .120 thick liners for a drag only application.
Not one to sit around and do what everyone else does, I am in the process of having some wet liners made. The goal bore size is 4.000, is it possible? Time will tell. In attempting a 4.000 bore there will be some major considerations and engineering challenges which is the exciting part.
Wish me luck.
Andrew Cox
Cox Custom Mechanical
So to demonstrate I have taken a damaged 84DA block, popped it in the mill and started cutting.
As you can see I have hit a corrosion at approximately 3.90. This block was in fairly good shape for its age(except for some un related damage).
Depending on what your desired bore thickness is you could have potential ran a 3.740 bore on this engine. Clearly corrosion is a killer and 9 times out of 10 the limiting factor on these engines these days. Please also note this is just one bore and only about 1.500 deep. If I was going to bore the whole block the results may vary. I've don't this purely for a visual exercise to demonstrate why those old blocks are not always a +.060 etc.
Now this brings me to the second part of the exercise, which is what is the absolute maximum bore size for a Crossflow (and any other ford small block 6)
As you can see here the bore has been taken out to 4.070 (which was the limit of this boring setup on my small milling machine). Keeping in mind the bore spacing of a Ford small 6 is 4.080 you can run a 3.840 bore in a dry block with .120 thick liners for a drag only application.
Not one to sit around and do what everyone else does, I am in the process of having some wet liners made. The goal bore size is 4.000, is it possible? Time will tell. In attempting a 4.000 bore there will be some major considerations and engineering challenges which is the exciting part.
Wish me luck.
Andrew Cox
Cox Custom Mechanical