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Brake Caliper Upgrade

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Following the link to the caliper brackets on the BCS site, no mention there is made of the bolt center dimension - it probably is the original 3.25" version.

DWR price converted is $158 vs $210 at BCS.
 
steveg said:
Following the link to the caliper brackets on the BCS site, no mention there is made of the bolt center dimension - it probably is the original 3.25" version.

DWR price converted is $158 vs $210 at BCS.
Click to expand...
The DWR bolt center dimension is 3.5”. BCS sells the DWR stuff. The calipers are the metric Girling 16 calipers. I rebuilt mine using the TR6 kits from Moss. One can use BJ8 or TR6 pads.
 
Well everything is bolting up so far:

BJ7 Stub axle
Denis Welch Racing BJ8 Caliper Brackets: https://www.bighealey.co.uk/bj8-caliper-bracket-kit-girling-cbrk152bl?search=caliper brackets
BJ7 Wire Wheel Hub
BJ8 Brake Disc
Toyota 4 pot calipers
TR6 Metric Shoulder Caliper Bolts

IMG_0491.jpg


Will report further when the conversion is finished.
 
Rick,
Did you get the techna-fit hoses?

If so, do you have a spec or PN I could pass along to a friend who's also installing the Toyota calipers?

Another thought: I never had to install a booster while retaining my original drum brake .75" master cyl. Will be curious how your pedal travel is with the Toyota calipers. Assuming you have non-boosted .625" MC.

I think you could install a .75" MC for superior performance. I also think the Toyota calipers must have a self-servo effect due to the smaller/larger piston design. Would be interested to have this confirmed.

My friend is installing the Toyota calipers on a BJ8 also with rear discs, so it'll be interesting to see how the .875" MC with booster feels.
 
Steve,

I already had Techna-Fit hoses going to my stock set up, so I'm making hard lines going to those hoses following your photos. I'll be interested whether I'll need to change the master cylinder as well. Time will tell. I still have the standard, non-boosted .625" MC. Couldn't your friend have Techna-Fit make up a set of hoses using a banjo fitting to the Toyo calipers?
 
A banjo-fitted hose would be a solution, but would require milling a sealing surface on the boss as well as a 10 mm x1.0 banjo bolt & sealing washers. Probably easier to source a hose from techna-fit like the one sold in the Moss kit.

screenshot.1750.jpg
 
HealeyRick said:
Steve,

How about a 10mm to 4AN adapter leaving the caliper: https://www.amazon.com/Fitting-Braided-Caliper-Bryke-Racing/dp/B004FS3EJW Then using a 4AN 90 degree elbow connecting to 4AN braided hose?
Click to expand...

That's unlikely to work as it'll probably stick out too far and hit the shock tower. You need the absolute tightest bend.

Am curious if your BJ7 has the angle-cutoff shock tower (like BJ8) or the square one like my BN6. Just got done reading the Moss Big Brake Kit instructions...
https://mossmotors.com/media/instructions/586-725_INST.pdf
...and IMO their brake hose has the potential to hit the shock tower at extreme lock and bump.

There are a lot of banjo hoses available for reasonable prices. If you were to remove the spring and take a vertical pic like below, you'd see if you have the clearance for a banjo hose.

I strongly advocate removing the spring and moving your suspension to full lock and bump to verify your hose or pipe doesn't hit the shock tower.

VertPipeClearance.jpg


My second design pipe and tube nut would also hit the un-notched shock tower flange at full bump:
LowerPipeInterfer.JPG


My first design - similar to Moss' kit - hit the tower backing out of my driveway onto the street:
DamagedPipe.jpg
 
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Rick, I really like the brake package you are putting together. I'll be very interested in seeing the final package (hopefully with part numbers :smile: ?) Right now I'm too involved in my EFI engine development and rebuilt to actively participate, but I'll sure watch with interest. A brake upgrade is definitely on my to-do list.
 
HealeyRick said:
Got everything assembled and plumbed, using hard lines from the calipers per Steve's pictures. Pedal travel is kind of long. I'll try bleeding again, if that doesn't work I'll switch to a 5/8" master to shorten the pedal travel. Luckily, I have one in my spares.
Click to expand...

Rick - I thought your BJ7 already had the 5/8" MC it came with. Going to a larger bore (I advocate 3/4") would shorten the travel, as you'd be moving more fluid per unit length of travel.

My setup with the Toyota front calipers and 3/4" MC, with no booster, has moderate pedal pressure no worse than the original drums. IMO if you go with the 3/4" MC you'll like it.
 
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I run early 3000 front discs with the DW 'upgrade' calipers and jag disc rears and I found the .700 to be preferable in mine. I felt a little like Goldilocks - the .625 had too much travel, the .750 was too hard, but the .700 was just right...:smile:
Dave
 
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red57 said:
I run early 3000 front discs with the DW 'upgrade' calipers and jag disc rears and I found the .070 to be preferable in mine. I felt a little like Goldilocks - the .625 had too much travel, the .750 was too hard, but the .070 was just right...:smile:
Dave
Click to expand...

One of the joys of modifying. It always costs more money every time you want to try out a different bed to see which one is more comfortable. :smile:
 
With respect, Dave and John - we're not apples-to-apples here with the Girlings vs the Toyotas.

The thing with the Toyota calipers vs the Girlings: they have a small and large piston on each side which seems to give a self-servo effect. So, based on my own experience, I believe the 3/4" won't be "too hard". Definitely think it takes more force for the Girlings.

FWIW, a friend is running the DW Girling setup with the Jag rears and has the same issue of too much travel with the 5/8" MC. I've driven this car and the pedal pressure is OK, but the pedal goes almost to the floor.
 
steveg said:
With respect, Dave and John - we're not apples-to-apples here with the Girlings vs the Toyotas.

The thing with the Toyota calipers vs the Girlings: they have a small and large piston on each side which seems to give a self-servo effect. So, based on my own experience, I believe the 3/4" won't be "too hard". Definitely think it takes more force for the Girlings.

FWIW, a friend is running the DW Girling setup with the Jag rears and has the same issue of too much travel with the 5/8" MC. I've driven this car and the pedal pressure is OK, but brake pedal goes almost to the floor.
Click to expand...
Understand that the comparison my not be applesauce. Do we know what the Toyota piston areas are? That may help in comparing.

I’m wondering if having the small and large pistons in the calipers is an anti-squeal mechanism, kind of kike the shims in Girling calipers?
 
Not a math wizard, but if I have it right (always doubtful). If the sq. in. area of the type 16 Girlings is 7.09/caliper and the Toyotas are 5.52/caliper - that mean the Girlings have approx. 28% more area which would explain why the .625 master has a longer stroke. This may explain why Steve is happy with the .75 master, and John likes the .6875 and I like the .70 master (roughly 15% more area in the .75 than the .70). But again, math is not a strong point with me.

Unfortunately I was only able to see part of the first page of the link Steve provided because you apparently need to be a facebook member, something I'm not. But at least I saw the illustration and reasoning behind the smaller leading piston - something I did not know - thanks!

Dave
 
I've probably said this before, I'm more of a cookbook modifier than a chef. I can follow a recipe well enough but it's more difficult if I'm left to my own devices. Steve has been my guiding light on this mod and I've ordered the 3/4" MC from Pegasus (the only place I know that still sells Girling stuff, although I don't know how "original" it is.) I'll continue to update once I get this finished. This all came about when I was doing a gymkhana run that ended in a downhill to the finish line. The small block Ford in my Nasty Boy was great for building speed to the finish line. The stock brakes with improved shoes and pads ... not so much in the stopping department.
 
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