Brake master cylinder bore

[fletcherson]

My master is under the floor,,but does not hang under the frame, the only thing that does it the bottom tip of the pedals, but very little and if it a
Was an issue, could be

Leg room is one of the few areas I'm not likely to have issues. The body is stretched 8-9"... and I'm only 5' 7", with legs shorter than typical for my height. Yes, I am a freak of nature...lol. Seriously...on paper using a made to fit plywood and webbing based seat, I'm coming just a couple inches shy of the legroom dimensions of our Buick LeSabre, with the seat full back. Of course the thickness and density of the cushioning will vary that dimension.

if I were to build another one, it would definitely be a stretch. That's why I quit working on mine for a year, I decided it was too short, and was going to either stretch my tub or order one, but the way the frame and suspension was built made it impractical to do so. It made me get creative, I feel better about it now. Can you mount the master in the cowl and get it off of the floor?

 

[Zandoz]

My master is under the floor,,but does not hang under the frame, the only thing that does it the bottom tip of the pedals, but very little and if it a
Was an issue, could be

if I were to build another one, it would definitely be a stretch. That's why I quit working on mine for a year, I decided it was too short, and was going to either stretch my tub or order one, but the way the frame and suspension was built made it impractical to do so. It made me get creative, I feel better about it now. Can you mount the master in the cowl and get it off of the floor?

How tall is your frame rail? I've not encountered any reservoir on top masters shorter than 4-1/4" tall. I guess an access lid on top of the floor would gain 3/4" over the frame rail height, but there would still be the accessibility issues and the need for more bracketry and linkage.

I know a lot of folks go the cowl/firewall mount route, but I'm just not comfortable going that route without substantial structural reinforcement. As is, I'm planning on the body being little more than a fairing...something Ted Brown drilled into me. The extent of the cowl/firewall reinforcement will be a kind of shorty roll bar esque tubing hoop, that will be roughly bottom of the dash height, and will fasten through the floor to outrigger platforms on the frame. The steering column will hang from the hoop. There will also be connectors between the hoop and door hinge mounting points to reinforce them.

Since the 5/8" bore masters I have are insufficient, no matter what I do, I have the cost of replacing them. I'm thinking the path of least resistance, complexity, and cost is to keep the pedal assembly I have. and go with a pair of the Wilwood compact masters of the appropriate bore. If it turns out that my planned configuration will not work out, I'll have the smallest size masters I've seen, to try squeezing in other configurations.

 

[fletcherson]

How tall is your frame rail? I've not encountered any reservoir on top masters shorter than 4-1/4" tall. I guess an access lid on top of the floor would gain 3/4" over the frame rail height, but there would still be the accessibility issues and the need for more bracketry and linkage.

I know a lot of folks go the cowl/firewall mount route, but I'm just not comfortable going that route without substantial structural reinforcement. As is, I'm planning on the body being little more than a fairing...something Ted Brown drilled into me. The extent of the cowl/firewall reinforcement will be a kind of shorty roll bar esque tubing hoop, that will be roughly bottom of the dash height, and will fasten through the floor to outrigger platforms on the frame. The steering column will hang from the hoop. There will also be connectors between the hoop and door hinge mounting points to reinforce them.

Since the 5/8" bore masters I have are insufficient, no matter what I do, I have the cost of replacing them. I'm thinking the path of least resistance, complexity, and cost is to keep the pedal assembly I have. and go with a pair of the Wilwood compact masters of the appropriate bore. If it turns out that my planned configuration will not work out, I'll have the smallest size masters I've seen, to try squeezing in other configurations.

Frame height is 4". There isn't any trick linkage, the pedal is mounted on a post through the frame, sticks up through the floor, the mc rod mounts to the bottom of the pedal and goes directly back the the rearward facing mc. You can make the rod however long suits your particular instal. I will try to get some decent pics. I posted some a while back, but they were blurry, I think my garage camera got dust on the lense. I haven't been able to work on it at all this week, had a plumbing emergency and have been on the back hoe, or in the mud all week....fun! I paid $40.00 for the master, $5.00 for the forged link, $10.00 for a extended linkage rod to extend the mc rod, the rest was strait forward fab on the pedal and mc mount. Mine mounts to the cross member, but rpm and others have mounts that weld to the frame. There are pedals available also. My big deal was with the clutch, the brake was pretty simple.
I am also reinforcing the cowl with a cage, sort of. There is a angle that goes across the inside top of the dash that is welded to brackets I cut to fit in the corners where the windshield post mount, they are welded to 3/4 x 1-1/2 unitsrut that is welded to plates that are routed into the floor and will be encased in glass. The posts will also reinforce the door jambs. The cross angle has flat plate welded from it to a plate that I cut to fit the top inside of the cowl, and the Ss firewall bolts to it and ties everything together. There is also a bracket that the column mounts to. It is as strong and rigid as I could make it, and it will be glassed into the tub and will lift off with the body. The front body mount bolts go through the plates that the front door posts are welded to. I also built a similar support for the rear door jambs and front seat mount that serves as my center body mount. I wanted more than just glass on the sides just in case. I hope it's strong enough to allow the car to be slid rather than collapse in the event of a side impact....?

 

[Zandoz]

Frame height is 4". There isn't any trick linkage, the pedal is mounted on a post through the frame, sticks up through the floor, the mc rod mounts to the bottom of the pedal and goes directly back the the rearward facing mc. You can make the rod however long suits your particular instal. I will try to get some decent pics. I posted some a while back, but they were blurry, I think my garage camera got dust on the lense. I haven't been able to work on it at all this week, had a plumbing emergency and have been on the back hoe, or in the mud all week....fun! I paid $40.00 for the master, $5.00 for the forged link, $10.00 for a extended linkage rod to extend the mc rod, the rest was strait forward fab on the pedal and mc mount. Mine mounts to the cross member, but rpm and others have mounts that weld to the frame. There are pedals available also. My big deal was with the clutch, the brake was pretty simple.
I am also reinforcing the cowl with a cage, sort of. There is a angle that goes across the inside top of the dash that is welded to brackets I cut to fit in the corners where the windshield post mount, they are welded to 3/4 x 1-1/2 unitsrut that is welded to plates that are routed into the floor and will be encased in glass. The posts will also reinforce the door jambs. The cross angle has flat plate welded from it to a plate that I cut to fit the top inside of the cowl, and the Ss firewall bolts to it and ties everything together. There is also a bracket that the column mounts to. It is as strong and rigid as I could make it, and it will be glassed into the tub and will lift off with the body. The front body mount bolts go through the plates that the front door posts are welded to. I also built a similar support for the rear door jambs and front seat mount that serves as my center body mount. I wanted more than just glass on the sides just in case. I hope it's strong enough to allow the car to be slid rather than collapse in the event of a side impact....?

Sorry to hear about your plumbing emergency. Whenever there's a back hoe involved in fixing plumbing, it's a serious bummer.

It still comes down to not really wanting anything requiring maintenance or repair under the floor, if reasonably avoidable. Until something about that pedal & master setup becomes unworkable, I'm going to stick with it.

Other than the tubular hoop, I'm not planning anything extensive enough to be remotely considered a cage. At this point I'm planning on a piece of T-Slotted extruded aluminum running the width of the firewall, parallel to the top of the hoop, and a pair of T-Slots tieing the top of the hoop and the firewall T-Slot together. I'm hoping to use the pair of front to back T-Slots to carry the sliders for an under dash drawer to carry the electrical stuff...fuse panel, relays, etc...and in the face of the drawer the auxiliary gauges.

I've approached this build from the beginning as a 4-wheeled motorcycle. The body is just the equivalent of an elaborate motorcycle fairing. When it comes to safety, thinking the body is going to provide any real protection, is just wishful thinking. It would take something like a sanctioning body approved full racing safety cage to get real safety in one of these cars.

 

[fletcherson]

Sorry to hear about your plumbing emergency. Whenever there's a back hoe involved in fixing plumbing, it's a serious bummer.

It still comes down to not really wanting anything requiring maintenance or repair under the floor, if reasonably avoidable. Until something about that pedal & master setup becomes unworkable, I'm going to stick with it.

Other than the tubular hoop, I'm not planning anything extensive enough to be remotely considered a cage. At this point I'm planning on a piece of T-Slotted extruded aluminum running the width of the firewall, parallel to the top of the hoop, and a pair of T-Slots tieing the top of the hoop and the firewall T-Slot together. I'm hoping to use the pair of front to back T-Slots to carry the sliders for an under dash drawer to carry the electrical stuff...fuse panel, relays, etc...and in the face of the drawer the auxiliary gauges.

I've approached this build from the beginning as a 4-wheeled motorcycle. The body is just the equivalent of an elaborate motorcycle fairing. When it comes to safety, thinking the body is going to provide any real protection, is just wishful thinking. It would take something like a sanctioning body approved full racing safety cage to get real safety in one of these cars.

Yea, not much safety, I wasn't planning on doing anything like I ended up doing, but I like things to be rigid and it just made sence once I started trying to mount the column, seat, seat belts, and I want the seat to hinge forward to access the battery, and whatever else I put under there, then planning on functioning doors. I want to be able to grab the column or windshield frame without breaking them loose, lol. And the doors... I couldn't imagine the body holding its shape once they are cut out.... One thing lead to the next... It really wasn't that bad, other than trying to measure and fit the under dash stuff in the mirror, my daughter was hanging out watching me try hard not to swear too much...I used Steel that I had lying around with the exception of some flat stock I bought. It may have added 100lbs, probably much less. I doubt the 427 will notice. It will still all come off with the tub, so with the exception of a roll bar that I want to fab that will likely be a bolt on, nothing will be attached to the frame once the body mount bolts are removed. It should be simple to service.
Not sure how much easier floor mount masters will be to service verses under floor with a door. The remote reservoir will make adding fluid easier to reach, but not sure where they would fit(on mine) and it's not something that should need much attention. Your car, your call, I am just adding my thoughts. If I can offer any pics or anything to help your decision process, I will do what I can.

 

[Zandoz]

Yea, not much safety, I wasn't planning on doing anything like I ended up doing, but I like things to be rigid and it just made sence once I started trying to mount the column, seat, seat belts, and I want the seat to hinge forward to access the battery, and whatever else I put under there, then planning on functioning doors. I want to be able to grab the column or windshield frame without breaking them loose, lol. And the doors... I couldn't imagine the body holding its shape once they are cut out.... One thing lead to the next... It really wasn't that bad, other than trying to measure and fit the under dash stuff in the mirror, my daughter was hanging out watching me try hard not to swear too much...I used Steel that I had lying around with the exception of some flat stock I bought. It may have added 100lbs, probably much less. I doubt the 427 will notice. It will still all come off with the tub, so with the exception of a roll bar that I want to fab that will likely be a bolt on, nothing will be attached to the frame once the body mount bolts are removed. It should be simple to service.
Not sure how much easier floor mount masters will be to service verses under floor with a door. The remote reservoir will make adding fluid easier to reach, but not sure where they would fit(on mine) and it's not something that should need much attention. Your car, your call, I am just adding my thoughts. If I can offer any pics or anything to help your decision process, I will do what I can.

Providing sound door hinge and steering column mounts were my original intents for the hoop. Initially I had no other plans for it. Then I got the idea of using it as partial support for the electronics drawer. Finally, I got the brainstorm of moving the hoop 6" or so to the rear, and covering it with roll bar padding...making it a full width grab handle. Not having to rely on fiberglass for support while getting in and out is HUGE for me.

Yeah, in the scheme of things an additional 100lbs for a 427 to push around is not a big deal...for my little 170 to push around it is significant. I am biting the weight bullet when it comes to seat and seatbelt mounting. I'm using a 2"x3" 1/8" wall crossmember, with a 1"x2" driveshaft loop, for those duties.

What makes the floor mount pedal and M/C assembly work better for me, is that the masters end up totally exposed on the engine side of the firewall just above the frame rail. That is done with no additional linkage, and the only bracketry being 2 simple flat plates with some holes


Any work needing to be done on the M/Cs can be done while sitting on a stool. With the remote reservoirs mounted on the firewall (not shown), fluid levels can be checked from my wheelchair.

 

[fletcherson]

Providing sound door hinge and steering column mounts were my original intents for the hoop. Initially I had no other plans for it. Then I got the idea of using it as partial support for the electronics drawer. Finally, I got the brainstorm of moving the hoop 6" or so to the rear, and covering it with roll bar padding...making it a full width grab handle. Not having to rely on fiberglass for support while getting in and out is HUGE for me.

Yeah, in the scheme of things an additional 100lbs for a 427 to push around is not a big deal...for my little 170 to push around it is significant. I am biting the weight bullet when it comes to seat and seatbelt mounting. I'm using a 2"x3" 1/8" wall crossmember, with a 1"x2" driveshaft loop, for those duties.

What makes the floor mount pedal and M/C assembly work better for me, is that the masters end up totally exposed on the engine side of the firewall just above the frame rail. That is done with no additional linkage, and the only bracketry being 2 simple flat plates with some holes
View attachment 11871

Any work needing to be done on the M/Cs can be done while sitting on a stool. With the remote reservoirs mounted on the firewall (not shown), fluid levels can be checked from my wheelchair.

I didnt realize that you had room to put them out in front of the fire wall. I was thinking in terms of mine, there just isn't any room. Sounds like you have it figured out. I also need to correct something I said earlier, my frame is 3", not 4". I don't know what I was thinking. The master does hang down a little, maybe an inch or so, but the channeled body more than covers it, and it's much higher than anything else. The cross member that it is attached to is lower, so there will be no issue with ground clearance as long as I don't go off roading.... I was looking at it last night, I finally got to get back in the shop for a while.

 

[Zandoz]

I didnt realize that you had room to put them out in front of the fire wall. I was thinking in terms of mine, there just isn't any room. Sounds like you have it figured out. I also need to correct something I said earlier, my frame is 3", not 4". I don't know what I was thinking. The master does hang down a little, maybe an inch or so, but the channeled body more than covers it, and it's much higher than anything else. The cross member that it is attached to is lower, so there will be no issue with ground clearance as long as I don't go off roading.... I was looking at it last night, I finally got to get back in the shop for a while.

Yeah, those roll of quarters sized, Wilwood compact masters give more positioning options...especially with 2 sizes of reservoirs, plus the remote option. Once it was determined the 5/8" bore M/Cs I have were insufficient, those Wilwood units were no-brainers. I'd love it if there were remote tandem units with right side outlets...that configuration would have given a bit more wiggle room...but right now there seems to be no such beast.

It sounds like you have the issue covered, that I'd have with an under-floor master...the master being exposed to impact from below. For me to go that route would require linkage to get the M/C back under seat. Back there, the M/C could be raised to the point that the reservoir would be above floor level.

 

[fletcherson]

Yeah, those roll of quarters sized, Wilwood compact masters give more positioning options...especially with 2 sizes of reservoirs, plus the remote option. Once it was determined the 5/8" bore M/Cs I have were insufficient, those Wilwood units were no-brainers. I'd love it if there were remote tandem units with right side outlets...that configuration would have given a bit more wiggle room...but right now there seems to be no such beast.

It sounds like you have the issue covered, that I'd have with an under-floor master...the master being exposed to impact from below. For me to go that route would require linkage to get the M/C back under seat. Back there, the M/C could be raised to the point that the reservoir would be above floor level.

My car has lift bars that connect to the cross member at the low point, where it bolts to the tail shaft housing bolts. The master is also mounted to the cross member, but at the top, so if I did encounter a off road or similar incident, the lift bars would protect the master, there is no way it would be contacted barring a freak event. Knock on wood! When I was struggling with deciding how best to move the pedals and make them functional, I looked at many options. I looked at the type you have, but I just have no room on either side of the firewall on top of the frame. The engine is close, and the column. It would have been too cluttered. The only viable options were under floor or up in the cowl. The cowl setup was very entising, but I had already had pieces and parts to build the under floor setup and I like being able to remove the body and leave all of it in tact.

 

[Zandoz]

My car has lift bars that connect to the cross member at the low point, where it bolts to the tail shaft housing bolts. The master is also mounted to the cross member, but at the top, so if I did encounter a off road or similar incident, the lift bars would protect the master, there is no way it would be contacted barring a freak event. Knock on wood! When I was struggling with deciding how best to move the pedals and make them functional, I looked at many options. I looked at the type you have, but I just have no room on either side of the firewall on top of the frame. The engine is close, and the column. It would have been too cluttered. The only viable options were under floor or up in the cowl. The cowl setup was very entising, but I had already had pieces and parts to build the under floor setup and I like being able to remove the body and leave all of it in tact.

For the most part, them not being cookie cutter creations, our cars are mixed blessings. Things like master cylinders, that are no brainers for most cars, for ours frequently require a good deal of creativity, fore thought, scrounging, and sometimes trial & error.

As small as those masters are, I still have a clearance issue... I'll only have about 1/2" clearance between the master and the block & transmission. The block and transmission housing are structured so that depending on the vehicle type, the starter can be mounted on either side. That makes for a wider than necessary package, at a bad point for me.

I'm planning for body removeability. Sandwiched between the floor and the frame rail, will be a 1/4" plate, bolted to the top of the frame rail. The floor will have a large enough cutout for the pedal assembly to pass through...but small enough that the perimeter of the cutout will be supported by the plate. The pedal assembly will mount on the plate, instead of the actual floor.