Mark Dent wrote:
>
> All,
>
> After reading the current issue of ZCCD I see the Toyota conversion for
> 240's. Is it also a bolt on for the roadsters?
>
> Van suggested the Volvo 240 swap. Which 240 works? All of them? Bolt on?
> suggestions helpful
That is another caliper I have used (don't recall the year off hand). Anyway
there are issues with that caliper as well. It does use the same bolt
pattern as the roadster caliper, so it will bolt to the bracket.
Here's what you are in for:
1)It doesn't have the same disc offset, so you need a 4 of precision made
spacers. Any decent machinist can make these for you, but you don't
just use a stack of washers!
2)The caliper is drilled for a metric (12mm I believe) bolt, so you have to
drill the caliper (and if you ever replace one, that one too) to clear
the roadster bolt or weld new captive nuts to your brackets.
3)You have to turn the diameter of the roadster disc down (no big deal,
but you can't go back to stock without more rotors).
4) Since the offset was wrong, you need longer bolts, and they need to be
very good quality. Wouldn't use UFO's (Unidentified Fastener Objects)
from the hardware store on this application.
5) Worst, the caliper is a dual fluid design, yes, two separate fluid
paths in the caliper. Volvo ran two completely separate hydraulic
systems through the calipers. Since the roadster isn't designed
this way, you have to merge the two into one.
I machined an adapter block that used two low profile banjo
bolts and compression washers, then a SS brake line screwed
into the adapter. They would cost at least 50.00 ea. plus
the banjo bolts and lines.
You could run two flex lines to a T, but you wind up with a plumbing
puzzle and the obvious disadvantages of two flex lines per wheel.
That would be (and I'll be polite here) a &*(*ing rig. Obviously
Volvo ran two flex lines, but there is a very real advantage to
a totally dual system.
I don't think there is a single hydralic circuit Volvo caliper that
bolts up. If I am wrong, please let me know.
6) Also there isn't alot of braking force gained here. If you calculate
the surface area of the pistons in the Volvo caliper, it is very
close to the OE caliper. (the 4 pistons are small). This means that
the clamping force (and therefore braking force) is similar, so no
giant reduction in stopping distance over stock brakes, in good shape,
with good pads. The pads are bigger in the Volvo calipers, but that
really only significantly affects pad life, not fade or clamping force.
The Volvo's are a better match to the Master Cyl. than the Toyota's
would be.
The Volvo caliper is a much more reliable design than O.E and with
all the additional pad area, and the light weight of a Datsun, the
pad life will be very long. The calipers are cheaper than O.E's,
but you have to do all the other stuff, so I am sure by the time
you are done it will cost more that stock.
Considering all this, the Volvo's are still a much better fit than
most calipers. Just my opinion, to each his own.
Jim Tyler
Topless Datsun
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