Originally Posted by Rick0636
RGR, I think where his reasoning might come from is this engine has been bored and stroked about to its limits by Ford, it started as like a 2.6L I believe, the OHC was added like around 10 years ago.
The 4.0 is a different block than the 2.6, 2.8, 2.9, 3.0 series, and is far from maxxed out
More later * ...
The reason Walker says they are junk is that he sees lots of them getting
repaired, and I guess he has seen many types of problems. I will ask him
what some of these are and how to avoid them. His "junk" comment was
relative to other less problematic Ford engines, like the 3.8, that was the
context of his comment.
* As for the 4.0 blocks, they have the widest bore spacing I've seen on
anything short of a big block, and bigger than some of those off brand
big blocks. It is 4.76" and theoretically you could get 4.5" bores if it were
sleeved to the max.
If you poured the block I'd guess you could get a 4.100" bore give or take,
the stock bore is 3.95" and you could probably go 60 over no problemo.
I could see some nice high RPM NA setups with a big bore, stock stroke
making some great HP. Get a 4.2-ish OHC motor revving to 7500 and you'll
see some serious power if the heads flow really well. 450 BHP with 300 CFM
and good combustion at least, if the crank holds up