At 06:28 PM 7/17/2001 -0800, Gregg Baker wrote:
>.... MGA Roadster, 58, ....
>It seems that the wooden seat bases are not from the original vehicle ....
The raised portions of the bases are different heights, one being 1 1/4"
and the other being 2 1/2" at the highest point.
1-1/4" would be somewhat sub-standard for the stock MGA. Looking at mine I
think the 2-1/2" is about right, maybe including the thickness of the
bottom board. Years ago I made new parts for this using the original ones
for patterns.
>Also the lower base has three round holes in the ramp (for ventilation
maybe?)
Yup, big round holes. Not for cooling or evaporation, but to let the thing
breath for smoother compression of the foam rubber, so it doesn't act puffy
like a balloon when you sit on it. Pretty sure the vent holes were factory
issue.
>and the other has none.
I suspect someone fabricated a replacement part, took a few shortcuts, and
maybe the changed height of the ramp was a personal preference for seat
contour.
>Am I correct in thinking that the most straight side fits to the inside of
the car against the transmission tunnel and the door side is slightly
slanted outward towards the rear of the car? Is one the mirror image of
the other?
No, and almost. The straight side sits parallel to the outside frame rail.
The seat slide rails also go parallel to the outer frame rail. The
tapered side goes next to the tunnel. The seat frame and the cushion are
narrower at the front to clear the shape of the tunnel. The tunnel is a
little wider on the left near the front of the seat because of the shape of
the gearbox inside. The right side of the tunnel is nearly straight
forward in that area, but it also carries the hand brake lever, and the
right side seat is tapered at the front corner to clear the lever. The
result is that the seat bottoms are almost a mirror image. I couldn't
swear they were exact mirrors, but so close that an exact mirror part would
probably serve the purpose, and from the top the finished cushions look
like mirror parts.
> Has anyone else seen different seat bases or is it possible that one
side is suppose to be a different height, regarding the ramp, than the other?
>Are there any other differences anyone has noticed between Roadster seat
bases?
Pretty sure both sides should always be the same height. Coupe seats were
different than Roadster seats, with the bottom cushion being thicker in the
Coupe (at least from what I have seen). This might call for a higher ramp
in the base board (maybe), I suspect not, but I have never seen inside a
Coupe cushion. There were also optional Competition Seats which were
common in the Twin Cam models, sometimes found in the 1600 MK-II models
(especially the Mk-II DeLuxe), but only rarely found in the 1500 and 1600
models. I know what the competition seat looks like, with the backrest
being thicker around the edges and the bottom cusion appearing thinner in
the center. I have never seen inside the seat cushion of those either, but
pretty sure the ramp would have to be flatter to suit the lower center
section of the bottom cushion.
>....
>Can you purchase perforated material like that used in the metal box?
Something similar does exist on the rack. It's just perforated sheet
metal. Look for an industrial steel supply house. I have in my hand an
old Ryerson catalog (they never change) showing round hole staggered
pattern and round hole straight pattern. The correct one is the staggered
pattern with more open holes and less solid web (lighter weight naturally).
Measuring the thickness with a caliper I make it to be about 19 or 20
gauge (.042" including a little paint).
There is another interresting feature of the standard MGA bottom seat
cushion that I rather like. It is seldom seen these days after restoration
work, but I think it was original factory issue. This feature was on my
seats when I bought my MGA years ago (original seats I'm sure), and I have
repeated it in the restoration process. I have also seen this in other MGA
seats which I judged to be original. It has been common enough that I'm
pretty sure it is original factory issue. Please check the picture here:
http://www.ntsource.com/~barneymg
(Yup, that's my home page). If anyone should have need of a larger view I
could scan the original glossy for a larger image.
About four inches back from the front of the seat cushion the top fabric is
pulled down in a mild crease. This is done by threading heavy waxed string
(light cord) through the stitched seam of the pleats underneath where it is
not seen from the top. The string is tied off there and dropped down
through the foam cushion by poking a hole for the string to pass. This is
repeated for each pleat in the cushion, seven places. Directly below there
are seven holes about 1/4" diameter in a line through the bottom board.
The strings extend through these holes and hang out the bottom. After the
foam cushion and cover are installed these strings are pulled down about a
half inch to form the latteral depressed crease in the top of the cushion,
and the strings are stapled or tacked to the outside bottom of the base
board to hold them in place. Check the base board to see if you have these
seven small holes in either of your parts. These holes would be positioned
in a line just in front of the vertical ramp support board.
I think this feature has more function than just a cute appearance. It
seems to hold the top fabrc down and the foam slightly compressed, so it
doesn't puff up so much when it's free, and then it doesn't have to squash
so much when it's sat upon, so it feels firmer and settles in quicker when
you sit down. It may also extend the life of the cushion by reducing the
total amount of flexing of the materials.
The floor is open for comments.
Barney Gaylord
1958 MGA with an attitude
http://www.ntsource.com/~barneymg
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