firewall information and pictures

Tue Jun  9 22:29:25 2009
From: Kevin 

Here you go:

Firewall seam of 89 XJ to radiator support: 30.5" (if you're putting in a v8),
35.5" if you're getting an inline. The recess for the inline six is roughly
11" wide. The side of the engine bay that doesn't have the AC stuff (and has
the steering column and brake booster) has an extra inch and a half of 
clearance. 

motor mount bolts appear to be 19.5" apart, and the frame rails where the
motor mounts meet appear to be 27-29" apart. center line of the motor mount
is 16" from the radiator support on the driver's side and 18 on the passenger
side. Center line of the motor mount to the firewall is 14.5" on the 
passenger side and 18.5 on the driver's side. Remember, 4.0 motor mounts are 
slightly staggered. (obviously)

At the radiator support, you have roughly 13" of clearance from the
frame rail to the hood. At the back right in front of the brake booster, 
you have 17.5. An AX-15 bellhousing is roughly 16" tall by 18" wide, and you
know it's a tight fit in the tunnel. There isn't a whole lot more room to 
go up on the trans into the tunnel if you're using the stock crossmember
and a stock-ish transmission. An AX-15 is roughly 24" long including 
bellhousing, and an NP-231 with slip yoke is roughly 16" long. An AX-15
bellhousing detached from the transmission is 7.5" from mounting surface
to mounting surface.

A bare 4.0 block appears to be 10" from oil pan surface to head surface. The
oil pan's sump is 9" deep, head is 3.5" from mounting surface to mounting
surface, and the rocker cover is 4.5" from mounting surface to the top
of the oil fill cap. This jeep has a dent in the oil pan from the axle 
coming up (don't ask) that spans from 13"-16" measured from the flywheel end
of the oil pan. The 13" mark is where the sump ends. The oil pan is 29" long,
and the non sump portion of the oil pan is 3.5" from the bottom to the mounting
surface. 

Remember an XJ starter is quite small compared to a lot of other things, 
and if it was any bigger, the passenger side upper control arm would make 
things interesting. Oil filter could be an issue as well, but there's kits 
to move those.

In case you're wondering, I have an 89 XJ apart in my garage. The 90
you are eyeballing should be the same. 

I'd say let me know if you need anything else, but you really don't need
this kind of encouragement, and you're wife's an excellent shot :)

On Tue, Jun 09, 2009 at 11:42:43AM -0700, john wrote:
> that sounds great...
> 
> you may be right on the weight... all I can remember right now
> is that the 4.2 in '83 was 50lbs less than earlier 4.2s and 4.0s are
> very close... 
> 
> 490lbs might be what they weigh, which is perfect, only adding 200lbs to
> the front of an xj won't be as serious... it's as though I would be standing
> on the front holding a heavy bowling ball, or lead weights or a large multitopping pizza... :)