Steering, Suspension, & Brakes

Yesterday I had all of the parts and time all in one place. I made a new mock up and test fit the secondary bracket to be used with the more accurate Bob Harper drawing of the Sentra mount bracket. This 240SX bracket moves the caliper in slightly for better placement of the pads. The previous bracket placed the pads even with the OD of the rotor. This bracket places the pads at the outer edge of the contact surface of the rotor. Bob Harper has agreed to create the cad drawing of the bracket also. I will post when it is available. Attached is the more accurate drawings for those who want to go ahead and make their own bracket. One suggestion is to drill the 5th hole once the brackets are attached together on the axle. I was not able to establish a spot on accurate location for that hole. The attached drawing is a tracing from the mock up bracket. All other measurements are accurate.

Another consideration, my CBBGT is lowered by using 5 leaf rear springs and early roadster front springs and it does have a wire wheel rear axle. With 2 people and luggage it does bottom on the bump stop when hitting a harsh bump. Though measurements show adequate clearance it is very close. As a preventative measure I am adding an Energy Suspension 9.9117G to the bump stop on the axle. I'll get better measurements for the 2 CBB conversions I'll be doing in May. Those cars have not been lowered and have bolt on wheels which moves the caliper outboard in relation to the body. No issues are noted with the RBB roadster at normal ride height.





Edited 1 time(s). Last edit at 04/11/2018 08:33AM by geezer.

Bob Harper was kind enough to draw up both a PDF and a DXF CAD drawing of the secondary 240SX bracket. The DXF file is laser cutter ready. If anyone wants a copy just PM me your e-mail address and I'll send it right out. I have not commissioned any brackets based upon the drawings, however, the drawings do match my tracings of the prototype bracket.

The question has been asked about increased pedal travel. There is some additional pedal travel though I would not consider the additional travel as disconcerting.

My master cylinder shot craps on me, I was expecting it since it would lose the front circuit occasionally. While I had the system open I took the opportunity to install a pair of 2 psi residual check valves. The valves did make a difference and brought the pedal to almost the original position. I would say try without and see what you think. If you feel the travel is too long, installing the residual valves may be the answer.

I have posted my closing comments on this conversion here

[www.mgexp.com]

Unless there are further questions I am putting this to rest

Charles,
A question about the connections at the brake lines. How did you make the connection from the MGB brake line to the Datsun or Nissan caliper ? One is British threads and the others metric
Werner

Hello Charles I'm new on this site and have just found your post's about disc brakes on mgb and was wondering how thick the mounting plate you made was. Regards Robin

VernerVC, Nibor1,

I apologize, it's been awhile since I visited this forum.

Yes the Nissan caliper is metric. The flex hose I used has a compatible banjo end for the caliper and the other end is -3 inverted flare for a 3/8-24 thread inverted flare nut. The hard line has an inverted (double) flare on the 3/16" pipe.

The primary bracket is made of 3/8" flat steel and the secondary bracket is 1/4". I have positive feedback from one fellow who made the brackets from aluminum.

Hope that helps

'I have positive feedback from one fellow who made the brackets from aluminum. That is interesting. I can cut aluminum much easier. I am curious what thickness he used.

Carl,

I'm using 1/2" 6061 aluminum for my rear caliper brackets. Different set-up than the OP, with Wilwood calipers on a Mopar rear end but no issues with the brackets at all.
Bill

As a general rule I'd expect that anything over 5/16" should be adequate. Probably the biggest issue is having adequate depth of thread in the aluminum part.

Jim

I hadn't thought about threading the aluminum. I am sure y'all would say to use fine thread.

Or steel thread inserts. The one who used Charles design probably used the thicker dimension and milled down to the thinner. Anything under 3/8" I'd use steel if 3/8" or thicker aluminum would be fine.

For lightest weight nutserts would be another option.

Jim

Yeah, I forgot to mention that I also installed heli-coils for the caliper mounted bolts.
Bill

I used a version of Charlie's design on my rear axle. Works great! Just an FYI, the caliper brackets on the Honda Civic calipers I used are threaded so you don't need thread's in the fabricated brackets, just holes.

Thanks for that info, Scott!

I just saw the comments about threading the brackets. None are threaded and I used nuts and bolts. The caliper factory bracket is threaded so that bolt goes through a drilled hole into the factory caliper bracket..

FWIW I did weld the 2 brackets together, along with using the bolts and nuts, just for my satisfaction.

It has been awhile since I have posted here. Just thought I would update this thread. Tim Nagy is now making the brackets for the rear disc conversion. If interested, contact him directly.

Rear brackets available here

morspeedperformance@gmail.com

[morspeedperformance.tgnagy.com]

Good to know. Thanks, Charles! Tim, as well. :)