1970 Med Olive Project

[GR8-68]

I have a quick question, I am wanting to add the same master cylinder to my 68. Can you share where you purchased it, I looked on ebay but seen the 1 1/8" bore which I believe is correct but want to be sure as there is so many options. Also are you using the stock actuator rod with this ? Thanks

[MMcMasters]

Originally Posted by GR8-68

I have a quick question, I am wanting to add the same master cylinder to my 68. Can you share where you purchased it, I looked on ebay but seen the 1 1/8" bore which I believe is correct but want to be sure as there is so many options. Also are you using the stock actuator rod with this ? Thanks

Larry,

If you plan to run manual brakes like I am then you will want a 7/8' bore. Some guys go with a 15/16" with manual but I think the 7/8" gives the best feel. The 15/16" feels soft to me.

I got everything from Summit

7/8" Master cylinder- https://www.summitracing.com/parts/w...9-bk/overview/

Proportional valve- https://www.summitracing.com/parts/w...1179/overview/

If you are going power brakes (vacuum) I would use a 1" bore and if you go with hydroboost then that 1 1/8" would be a good choice. These are all my opinion from my personal experience and you may get differing opinions from other people.

[GR8-68]

Thanks so much for the info Mike, I will order mine from Summit also. Yes I had planned to run manual brakes, but there is just so many different things out there without ample knowledge sometimes it can be hard to see what you really need.

[69short]

Originally Posted by MMcMasters

Larry,

If you plan to run manual brakes like I am then you will want a 7/8' bore. Some guys go with a 15/16" with manual but I think the 7/8" gives the best feel. The 15/16" feels soft to me.

I got everything from Summit

7/8" Master cylinder- https://www.summitracing.com/parts/w...9-bk/overview/

Proportional valve- https://www.summitracing.com/parts/w...1179/overview/

If you are going power brakes (vacuum) I would use a 1" bore and if you go with hydroboost then that 1 1/8" would be a good choice. These are all my opinion from my personal experience and you may get differing opinions from other people.

Originally Posted by GR8-68

Thanks so much for the info Mike, I will order mine from Summit also. Yes I had planned to run manual brakes, but there is just so many different things out there without ample knowledge sometimes it can be hard to see what you really need.

I have never driven with manual brakes. Can i ask what the benefit is? I'll be doing my brakes soon and haven't decided between manual or power. I'm just running wilwood d52 calipers, nothing fancy.

[MMcMasters]

Justin,

I will give you what I like about them personally. A properly designed manual system will stop just as good as a vacuum or hydraulic assisted system, in some cases it just requires a little more leg effort. If you get the proper bore size on the master cylinder, have a good caliper/rotor and have the proper pedal ratio, manual is great. It is nothing like the crappy manual drum systems we all remember from back in our younger days.

I usually build and run engines in my street cars that are not friendly with vacuum assisted brakes. Camshafts with large .050 duration numbers and tight LSA's generally don't make enough vacuum for a vacuum assisted system to work very well. You end up with a very hard pedal and poor performance.

Lastly, while hydraboost systems work great in any application, I don't care for how they look and how much real estate they take up.

[GR8-68]

Mike's Q&A today I am also running D52's on the front and the 4 piston calipers on the rear. I am in the thought of why clean up the firewall and then add a big ugly booster I have manual steering and brakes, both of which I am fine with

So which cam am I needing to run with my sniper manifold and FI, pretty much a stock bottom end but may upgrade if need be

[MMcMasters]

Originally Posted by GR8-68

Mike's Q&A today So which cam am I needing to run with my sniper manifold and FI, pretty much a stock bottom end but may upgrade if need be

Man there are endless options. Try Tooley, Tick or Texas speed and give them what you have for gear ratio, trans and what you want out of it. They are all three reputable companies in the LS world. I went with One of Brian Tooleys stage 2 LS3 cams. It's 225/238 @.050 .612/.585 on a 113LSA . It's not too big and it should have a fairly healthy idle and will make great power. I also went with a 3400 Circle D converter.

[69short]

Originally Posted by MMcMasters

Justin,

I will give you what I like about them personally. A properly designed manual system will stop just as good as a vacuum or hydraulic assisted system, in some cases it just requires a little more leg effort. If you get the proper bore size on the master cylinder, have a good caliper/rotor and have the proper pedal ratio, manual is great. It is nothing like the crappy manual drum systems we all remember from back in our younger days.

I usually build and run engines in my street cars that are not friendly with vacuum assisted brakes. Camshafts with large .050 duration numbers and tight LSA's generally don't make enough vacuum for a vacuum assisted system to work very well. You end up with a very hard pedal and poor performance.

Lastly, while hydraboost systems work great in any application, I don't care for how they look and how much real estate they take up.

Thank you for the explanation. I think I will go with manual as well. Sounds like 7/8" bore is the ticket.

[GR8-68]

Originally Posted by 69short

Thank you for the explanation. I think I will go with manual as well. Sounds like 7/8" bore is the ticket.

Nice thing is they sell it as a kit also

https://www.summitracing.com/parts/wil-261-13271-bk

[Smittee]

Originally Posted by MMcMasters

Larry,

If you plan to run manual brakes like I am then you will want a 7/8' bore. Some guys go with a 15/16" with manual but I think the 7/8" gives the best feel. The 15/16" feels soft to me.

I got everything from Summit

7/8" Master cylinder- https://www.summitracing.com/parts/w...9-bk/overview/

Proportional valve- https://www.summitracing.com/parts/w...1179/overview/

If you are going power brakes (vacuum) I would use a 1" bore and if you go with hydroboost then that 1 1/8" would be a good choice. These are all my opinion from my personal experience and you may get differing opinions from other people.

Might I suggest you talk with the folks at Wilwood for the proper sizing? I know that is what the person that helped me size and order my parts did. I did end up with a .875 diameter bore as well though! I am going with D52 calipers up front with 12' rotors and D154s out back with 12' rotors for reference.
I also must say that I am really enjoying watching you two (Mike and Larry) with your builds. I am in the process of doing a little bit of what both of you are doing. Kind of a blend of some of your best. I just hope I can execute the plan as well as you two have! Although I am not lowering my truck quite as much as you are Mike.

Thanks for all of your posts; although my wife probably would not second that sentiment!
David

[MMcMasters]

Originally Posted by Smittee

Might I suggest you talk with the folks at Wilwood for the proper sizing? I know that is what the person that helped me size and order my parts did.

This is excellent advice! I would feel horrible if anyone followed what I did and ended up not happy with the results, especially with the components being as expensive as they are.

[Smittee]

Originally Posted by MMcMasters

This is excellent advice! I would feel horrible if anyone followed what I did and ended up not happy with the results, especially with the components being as expensive as they are.

Note though, from what they set up for me YOU WERE SPOT ON! So I am guessing you REALLY DO know your stuff! I really did not mean to imply you didn't. I hope you didn't take it that way.
Also, based on your whole thread anyone can tell you know waht you talk about.

[MMcMasters]

Originally Posted by Smittee

I hope you didn't take it that way.

Absolutely not sir! I agree 100%

[Smittee]

Originally Posted by MMcMasters

Absolutely not sir! I agree 100%

Sometimes people take my "directness" in a way that I did not intend! Good to know you didn't.