Money is no object, 3.75L I6

In terms of engine geometry the 199, 232, 258, 4.0 family of engines has certain things in common with the Small Block Chevy in terms of bore spacing and such. And no a AMC I6 is not a SBC. But let's play around with a couple of ideas. First if the bore of the 4.0 can be punched out to 4.000" without getting the wall thickness on the cylinders too thin along with a 199 crankshaft we get the same bore and stroke combination of the 302 (the best of the '60's SBC's IMO) for a displacement of 226 CI. Now if we have a decent Crossflow Head (remember MONEY IS NO OBJECT) just what kind of power and torque curves would be possible along with just how fast could you spin such an animal. And how would they compare to the HO head from the 4.0. Now developing a crossflow head wouldn't be cheap but some of the technology today makes some things easier. Stereo Lithology would eliminate the need to make patterns for casting the head. In fact the  old style stereolith machines that used glued paper layers would allow one to make mock-ups that could be used for checking flow rates, clearances etc. Going the OHC route has some problems. First is the cam drive. Belts would be eaiest. Second the oiling system. The Oil Galley hole drilled from front to back would need to be blocked where it intensects the lifter bores. Then you need lube to the head. Plus the Cam Bores need to be left intact as you would probably need to use the cam to drive the oil pump.  Where I'm going with this is the possibity to turn a '65 American into a real screamer without having to resort to stuffing a V-8 in. Think something along the lines of an American BMW    Now I worked the KEP's Tool Room from '73 to '05 and we heard rumors about a 4 valve head in the 1999, 2000 time frame IIRC. It could of been earlier. Roller Lifter blocks were machined in the TR around 1990. Plus I have been told that there were OHC versions run in experimental in the '60s.

The 199, 232, 258, 4.0 family have a bore spacing of 4.380 same as the sb ford. Sb chevy is 4.440 .

The Hesco/Patriot aluminum head is just a copy of the iron head. Supposedly has a bit more "meat" for enlarging ports, but you don't really need to enlarge the ports on the 4.0L head. I'm not even sure if it's still available.

Hmmm... is the 4.6L Modular Ford the same bore spacings as the old SBF? Cut and weld a couple heads and make a new cam...  It seems that I recall someone cutting and welding a V-8 head of some kind to fit a six, but I don't recall any details. Might have been SBF heads on an AMC six...


Edited by farna - Apr/06/2012 at 4:46pm

Let's face it this is more of a "what if" than anything else. Does any one have a set of drawings for the 4.0 block and or head. I actually had a set when I worked at Kenosha Engine as we would have to build special fixtures from time to time but I left them behind.

  I think IKA later redesigned the head,  moved the valves a little and changed the cam to 12 lobes.