Brake Master Cylinder and Fuel Pump Questions

[SLOroadster]

Its interesting, you claim you have a 510 master cylinder, yet the bleed valves are on the opposite side (correct side for a roadster) I think your real issue is that the firewall has been modified. I thought I had a roadster master cylinder, but the bleed fittings are on the wrong side making it a 510 one. It might be worth removing the firewall reinforcement part, and going with the more traditional one that mounts under the dash buying you the space you need.


Roadster MC is on top, 510 on the bottom.


Will

[RCMike]

Really good looking car. You removed the fiberglass fenders?

[Datsun.David]

Hey Will -
The 510 master you show is totally different than the one on my 72 510, which is almost the same as the one on my roadster... The second port on both the 510 master I have and the race car master is much closer to the static end of the master. I did just notice however, that the 510 master is only 3/4, where the race car master is 7/8. 510 has bleeders on passenger side, race car has bleeders on drivers side... sooooo chances are good that the race car master is another Datsun solution... pick up maybe? I will see what I can find out... I think the 510 master you show would work no problem on my car, but all the 510 masters I saw online were like mine - with the much wider spaced ports.

Regardless, it seems that with the parts I have on hand, I can eliminate any potential conflict with the banjos by using a top feed cover instead. Conveniently, this will also let me run the fuel lines out board of the intake manifold without having to throw out $100 worth of braided hose...

[Datsun.David]

Hey Mike - Thanks!
It is coming along. Unfortunately, I didn't have any choice on the fibreglass. The fenders were already gone when I got the car. I looked all over for a set of salvageable Japco fenders, but to no avail... Honestly, it might have been a blessing - I think it will have an easier time getting into vintage races without having to go through too much jurying... It was a race car for 20 ish years, but not quite in period by most standards.

Ross Mullen had the original quarters that were cut from the car 20 years ago stashed in his attic... so we welded one of them back together, and I bought a NOS quarter for the driver side.

The front fenders came from two different 68 donor cars and actually fit pretty good after 60 hours of fiddling... (probably not quite - it just seems like it.) It hasn't been an inexpensive endeavour to get it back together, as we have gone through and tried to remove all the rust (of which there was very little) but also tried to bring back the true roadster lines - even though it is a race car, I want it to be nice. Not concours nice, but nice. I have a couple fun little details that I am planning too that should make it a bit unique... I am trying to come up with a cool solution for interior door panels as the doors have been gutted, but the door bars protrude into the door cavity making a Skillard(Z) or Futofab(510) style aluminum one a challenge...

[Datsun.David]

Considerable Progress!
Replaced the side mount fuel inlet lids for my Mikunis with top mounts, thanks to Dave Premo, Will, JT for the insights that led me to the conclusion that would work... this allowed me to turn the previously cock eyed MC to its proper position. Bonus is that the top mount configuration allows me to route the fuel lines outboard quite easily. The fuel lines aren't perfectly straight due to the adjacent screws, but should look sharp enough and work well when finished. I need a couple extra AN fittings to make my way.

Any insights on the fueling system?

The car previously ran a surge tank with a couple of pumps. I have just cleaned up the surge tank and am contemplating best strategy from here forward... I am relocating the surge tank from under the car to the trunk and re routing fuel lines to place pumps in the trunk immediately adjacent the cell as well...

[Gregs672000]

I'm pretty sure the 280z master I recently bought to replace my 510 master is 7/8, which was the reason I bought it. I posted some pictures a while back showing the 510 vs the 280 as I recall. I'll see if I can find the post. Also, the early 510 master (say 68-70 or so) appears to be different and has a different part number than the later one (see '73) per Rock auto. As noted, the 510 bleeders are on the other side vs stock Roadster. The 280z however is 7/8ths and has the bleeders on the outboard side like a Roadster (see '78 280z image on Rock auto). Looks to me that this is what is on your race car.

[Gregs672000]

Not to hijack this thread, but what would be the result of putting a 7/8 master on a stock Roadster with disc/drum set up (assuming the rest of the brakes are stock)? I see the race car is running larger front brake calipers and what I would assume are stock rear drums/cylinders. What about if one is running similar larger brakes as I am (Toyota 4runner 4 piston calipers on Maxima vented discs) and RX7 discs/calipers in the rear? I had heard/read that the larger master should work better with my set up and give more stopping force, thus the reason for the intended swap. Wonder what it would do to a stock Roadster as well.

[Datsun.David]

Interesting info Greg. I will check with a local Z buddy... My 260 isn't here for me to compare to...
I am far from an authority on the effect the master plays, recognizing enough to know that bigger isn't as important as balanced...

[Gregs672000]

Ya, I hear you on the balance issue, something I am concerned about. Right now, the 3/4 master works pretty well with the set up I have, but I think it could be better. I will install the 280z master and give it a try this spring.

[Gregs672000]

Attached is the pic of the 510 master next to the 280z. Looks to me that the 280z matches what you have installed. It also appears my 510 master is different from the one Will posted, which again makes me think about early 510 vs somewhat later. Based in the limited pics I can see for early 510 masters, it looks like the one I posted is used until 1970, and the one Will posted is the later from 1971 on. I think if someone is running Mikuni style carbs and wanting to run the 3/4 510 master they should get the early one to avoid clearance problems, especially if having to use adapters.

[Datsun.David]

Hey Greg
That early 510 master looks a lot like the roadster master with regards to where the ports come off on the bottom... agreed that one would have worked in my situation.

I have confirmed with the guy that built my car that it is a Z master. And as such, I am ordering a new one on Rock Auto for $53. Thanks for the tips guys. I took a good luck at the discs and drums and they all look really good.

[sports imports]

240Z also use 7/8 brake master cylinder. David, I would phone Jeff R as he is the one that installed that brake master.

Ross

[Datsun.David]

Thanks Ross. Talked to Jeff. Z master for sure. New one coming from Rock Auto!

[Linda]

Per Parts Interchange, early Datsun 510 master #11-1538 fits Roadster. Must use adapter noted or change out the bolts.
Linda

[Datsun.David]

Hey Linda -
Thank you for this. Where did you get this interchange? This master (the 11-1538) would fit my car. The 510 master on my 72 would not. I would love to help clarify this for future owners...