okay big jim....i think that you've convinced me. you're further explanation of the pressure leaking into the water jacket really sounds plausible. is there a sure-fire test for this. can i pressure check the cooling system, and if the pressure is off the chart.....well, there you go! i guess that i've been in denial. thanks again for all the help.

The Mexican 4.6 has a reworked head, that much I know. The spark plugs are the small diameter type, not your average 4.2 type, and if you don't use a thin walled socket, you can't get the wrench in there at all....a tight fit! as far as the crank and pistons, I'm a bit curious myself. The Mexican market has traditionally focused on straight sixes, as gasoline is pretty expensive here, especially if realize that the price of gas is so far out of proportion with the daily wage. Though the six is no penny pincher, it fares better than the 360 V8. This motor was designed to be put in the heavy early eighties Waggies which were and still are(you see them here as commonly as a Wrangler in the states) very, very popular. The motor is a real beast, and with it punched out a couple of thousandths, you've almost got a 5.0 liter on your hands that is a real torque monster. Added benefit....all of the outboard stuff from the 4.2 bolts on directly....no mods! Come on down and pick one up for about $50.00 USD! I found some stats to further answer the bore/stroke question. Enjoy, Rob

Here is some AMC 6 Cylinder engine data from Frank Swygert - FARNA@worldnet.att.net and Andrew Hay - adh@an.bradford.ma.us

AMC six cylinder dimensions in order of size:

SIZE YEARS BORExSTROKE
INCHES (liters) INCHES



195.6 (3.2L) 1955-65 3.125x4.250
199 (3.3L) 1965-70 3.75x3.00
232 (3.8L) 1965-79 3.75x3.50
244 (4.0L) 1987-present 3.90x3.41
252 (4.1L) Mexican Only 3.92x3.41
258 (4.2L) 1971-1995(?) 3.75x3.90
282 (4.6l) Mexican Only 3.92x3.90
293 (4.8l) Jeep Racing 4.00x3.90