[Amc-list] 4.0 head swap

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

Wayne E LaMothe wrote:
> Couple of questions for those in the know.  I know the 4.0 head will
bolt
> onto the 258. (Will it also bolt on the 232?)  I might have to close
off
> some water ports but it is a pretty common swap.  Is there a 4.0 head
> casting that does not need the water ports sealed (maybe a RENIX head)
or
> is it more to do with the 258 block?
>
> My current project is to put the 4.0 head and EFI from a 93 Cherokee
on
> the 258 in my Eagle wagon.  That engine has a 3000 mile rebuild with a
> performance cam.  I will have the bellhousing drilled to accept the
stock
> CPS and run the 4.0 flexplate.  Anyone see any glaring issues with
this
> plan?  The long term plan is to get the EFI setup running and then add
a
> turbo and 36lb injectors with a variable input voltage control on the
MAP
> sensor to fine tune the A?F ratio.
---------------------

The 4.0L head will bolt on any 199/232/258. Pre 71 engines will need
custom pushrods the correct length, and make sure the pushrods are
hollow for oiling. 

The 4.0L has a 0.125" larger bore and the block is about that much wider
on the right side (87-90 258 blocks use the same outer casting and are
also wider). There are 12 small triangular casting ports along the right
side of the 4.0L head that are very close to the edge of a pre 87 six
block. Pressure in the water jacket can cause seeping leaks along the
edge if the ports aren't blocked. Several ways to do it -- drill for
3/4" freeze plugs or tap for pipe plugs, use epoxy (stuff w/toilet paper
or water soluble packing peanuts, put in a layer of epoxy about 1/8"
thick, wash TP/peanuts out after curing -- make sure areas are CLEAN
before epoxying), or welding. The epoxy is supported by the head gasket,
and the ports aren't exposed -- just right at the edge of the block, so
it won't "blow out". I put them in the order I prefer, but I'd never tap
for pipe plugs. There are no heads that don't need this that I know of.
If you have a good drill press drilling is easy enough, if not use the
epoxy. To much risk IMHO to weld, though it's often done. Some builders
have got away with not blocking the ports due to core shift in the head
(I'm guessing), or just got lucky with the block. Like I said, the ports
are CLOSE to the edge, not over. The guys who've got away without
plugging may be running a lower pressure radiator cap for all I know!

As Keleigh said, you can't use a 4.0L flexplate with a TF
converter/transmission without modification. One person told me they
modified the converter to fit closer to the engine. I forget the
specifics -- it's been to long since I laid eyes on a converter from
either an AW4 or TF. I think they had to remove nuts from the TF
converter and had studs welded on? If you have a Renix engine that's
what it will take, or use the CPS relocator kit. Since you have a 93 you
can use a flexplate for a 93 Wrangler w/4.0L and TF999. 
_______________________________________________
Amc-list mailing list
Amc-list@xxxxxxxxxxxx
http://www.amc-list.com/mailman/listinfo/amc-list