Re: [Amc-list] Looking for parts

["Swygert, Francis G MSgt 436 CES/CECM" <Francis.Swygert3@xxxxxxxxxxxx>]

I'll throw my two cents worth in on the 4.0L -- and basically agree with
the others. For another 10-20 hp get a 4.0L head and bolt that on. The
triangular ports on the distributor side need to be filled (they were to
rinse sand out, no matching ports on block) because they sit very close
to the edge of the block (the 4.0L block is about 1/8" wider on top).
Easy to do -- fill with epoxy, or drill for 3/4" freeze plugs. Some
people have drilled and tapped for pipe plugs. Then just bolt it on! The
1980 intake and exhaust can be used, with some mods. Best to use a 4.0L
exhaust manifold though. The 4.0L heads are pretty common -- if your
head needs rebuilding I'd switch, otherwise it may not be worth it. Do
you need 10-20 more hp?

A 4.9L stroker is costly to build. A 4.5-4.7L costs little more than a
stock rebuild. A budget stroker is just a 4.0L block/head/pistons with
258 crank and rods -- and a carefully selected camshaft to make it run
right with the stock computer. You need to limit "running compression"
to close to stock. That means using a high overlap cam (compared to
stock 4.0L or 258) to reduce cylinder pressure. The various stroker
sites will list the recommended cams. Otherwise you need to have custom
pistons or modify stock pistons (deeper dish) to lower static
compression to 9:1 or less (stock 4.0L is 8.7:1). The 4.0L rods can be
used, but require custom pistons. There's a little better rod/bore
ratio, and some slight improvement in piston speed/wear, but no
noticeable reason to use 4.0L over 258 rods. Custom pistons and correct
quench height can get you 10-20 more ponies, but cost is much more
(around $2000 more). Just worry about compression and get 250-260 hp in
stead of 270-280. I run a 250-260 hp 4.6L, have for about five years
now. 

4.5L=stock 4.0L bore, 4.6L=+0.030". 4.7L=+0.060". Have a block sonic
checked before going to 0.060"!! A 4.9L is +0.060" and an offset ground
crank for a bit more stroke. 
_______________________________________________
Amc-list mailing list
Amc-list@xxxxxxxxxxxx
http://www.amc-list.com/mailman/listinfo/amc-list