aby vs aan rocker cover

[djh]

How much higher is a aan rocker cover at the front compared to a aan rocker cover?

[driftin jo]

It's the same

[UrS4boy]

rocker? Where in the 20VT did you find a "rocker"?

[driftin jo]

The only difference is the angle on the right hand side
on the ABY that allows the ABY throttle cam to work without getting stuck.
The later AAN is the same as the ABY in this respect and only differs
by the position/shape of the PCV tube at the front left.

[djh]

rocker? Where in the 20VT did you find a "rocker"?

rocker/valve cover

The only difference is the angle on the right hand side
on the ABY that allows the ABY throttle cam to work without getting stuck.
The later AAN is the same as the ABY in this respect and only differs
by the position/shape of the PCV tube at the front left.

thankyou

[UrS4boy]

rocker/valve cover

Personally, I think it is a cam cover since the valves can't be seen but the cams can be.

BTW, we both lose. Kate calls it the "cylinder head cover".

[djh]

Personally, I think it is a cam cover since the valves can't be seen but the cams can be.

BTW, we both lose. Kate calls it the "cylinder head cover".

Good point and there's probably quite a few different terms for it.

[UrS4boy]

How much higher is a aan rocker/valve/cam/ cover at the front compared to a aan rocker/valve/cam cover?

Here are some photos:

ABY





And this one (from someone here) showing the different PCV tube exit at the front of the cover:



AAN (similar but different)

[driftin jo]

Early and late AAN for ref.
Note late AAN is the same as the ABY with regards to the angle
on the oil cap side.

[UrS4boy]

Early and late AAN for ref. Note late AAN is the same as the ABY with regards to the angle on the oil cap side.

Whoa? I could be wrong (happended once ) BUT, I *think* your "late AAN" cam cover *IS* an ABY cover. Look at the front of the cover, nothing like an AAN cover.

[driftin jo]

no you are wrong , they changed the casting to the ABY one in later years, so the
only differance between the ABY and late AAN is the outlet for the PCV/breather tube.

[driftin jo]

look at the tube front left, tube to MAF outlet, AAN style straight and stubby, not cranked like the ABY.

[UrS4boy]

no you are wrong , they changed the casting to the ABY one in later years, so the only differance between the ABY and late AAN is the outlet for the PCV/breather tube.

Shockingly embarassing but I checked my photo files and you are right. I have photos off UrS6s with the UrS4 style cam cover AND UrS6 photos with the ABY style. Kate on shows one AAN cam cover PN now (92-97) so can't tell the break point. Probably the 1996 Model year (left over ABY covers, lower UrS6 production, etc).

Learn something new every day. Thanks.

UrS4 and early UrS6:


Thanks for the S-Fest 2010 Photo whoever took it

ABY cover:



Late (?) UrS6 cover


Thanks to whoever took this S-Fest 2010 photo

[driftin jo]

So that's twice you've been wrong now then

[UrS4boy]

So that's twice you've been wrong now then

Yep. Too soon old, too late smart.