• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

Dimensional Differences [brake Calipers]

Share this page

RAC68

RAC68

Darth Vader
Offline
I was told and would like verification that the front brake calipers on a BJ8 P2 are larger in overall size then those on a P1. Additionally, is it true that the wire wheel offset for a P2 is greater then that which is necessary for wires on a BT7?

I appreciate that the piston diameter of a P1 is greater then the piston diameter of a P2 but always though the overall caliper size were identical and the calipers could be interchanged. Also, I was under the opinion that the wire wheel offset needed for a BT7 was the same as a P1 and assumed a P1 was identical to a P2.

So, are my understandings and assumptions in error and if so, where?

Thanks,
Ray (64BJ8P1)
 
Last edited:
I believe you are correct that the two callipers have different external dimensions.

When I first had my phase 2 I was informed it was a phase 1 ( due to the single flashers) so ordered new callipers for a phase 1. They didn't fit so had to send them back and work out why they didn't fit.
 
Later BJ8 calipers are #16 and the bolt holes are 3.5" center to center. Earlier cars with disc brakes use #14 calipers and the spacing is 3.25". The rotor on the later cars is thicker as well.
As far as wheels, the 60 spoke, 4.5" wheels will clear both calipers ( as will the 48 spoke, 4" wheel ). The problem with rubbing comes up with certain optional wheels. For example, a 72 spoke, 5.5" wheel, # 480, will clear the #14s, but rub on the #16s.
Bob
 
Welch sells what I believe is an early '70s Triumph caliper which has the larger piston and pad of the BJ8 P2, but on the 3.25" bolt centers.

Just to muddy the waters - I'm using 5.5" 72-spoke Daytons having about 1/2" clearance on Toyota calipers on BJ8 P2 spindles. My wheels originally fit my drum-braked BN6. It's hard to believe the BJ8 calipers wouldn't fit. I'd call Hendrix to get the scoop. Their website specs are a little hard to understand.
 
My 67 BJ8 P2 has original calipers and 72 spoke 5.5 Chrome stainless spoke Daytons on it . I can get my pinkie finger in between the top outside edge of the caliper and the inner circumference of the rim . The gap between the spokes and caliper as the spoke pass the caliper is about 3/4 to 7/8 ".
 
My 66 BJ8 P2 has original calipers and 72 spoke 5.5 Chrome stainless spoke Daytons on it . I
do not have any clearance problems with the calipers either.
 
Back
Top