Just Another Damned Z Car Project Thread

[conedodger 1,081]

Thanks Yarb, 

I hear though that it isn't actually a 'bolt up' and I'm already building adapters and such so I think I'll just rebuild mine... Unless you have information that is contrary to that???

[Yarb 47]

Definitely 79-81, Bolt pattern 180 degrees out on 82-83. I purchased mine from Power Brake about 6 months ago. 

[conedodger 1,081]

Did a couple stops yesterday. I went to AutoZone and O'Reilly's. Both list the 79-81 online but neither can get it according to their counter staff. Motorsports Auto lists it and doesn't say it isn't available but they want a $300 core and I don't have one to send, though I can get a very rusty one on ebay for $60 shipped. 

Yarb, are you getting 'considerable' assist? Something you notice?

[Yarb 47]

Ok, Here ate some pics of my 1978 OEM booster. 
The dimensions are:

Top horizontal stud dimension left to right. center to center.  3 5/16”

Vertical center to center 2 3/4”

Overall booster diameter 9”

[Yarb 47]

Hope this helps. Let me know if there is anything else You need.

[conedodger 1,081]

I will check it when I get home. Thanks! 

[Yarb 47]

The dimensions you posted earlier were wider which is odd. Thought the 240 boosters were smaller in size. One other thought. The 15/16 booster sold by Cardone on Amazon is New and not rebuilt. Read a lot of reviews on other sites when combined with the ZX booster the pedal feels more like stock where the wilwood was a much harder pedal. Just a thought here’s a pic of what I purchased. $65. Not trying to persuade you by any means. Just a few options out there. Curious to what you find when you get home.

[conedodger 1,081]

Been waiting on this! Complete SS brake line set all prebent. Yeehaw! 

[conedodger 1,081]

Another piece of the puzzle arrived... 

BTW Yarb, I had already ordered this before you posted the above. Kind of weird though, I got it from Silvermine Motors and it came with no invoice for the actual transaction but there were two garbage invoices along with other garbage used to pack the MC in the box. 

Edited November 20, 2020 by conedodger

[conedodger 1,081]

It seems like I have my Master vac problem solved. I found one on EBay and Terrapin found one for me at a Pick and Pull. I'll send both to Power Brake Rebuilder and hopefully get one good one out of it. 

I have to wait to start putting the brake lines in as the master cylinder is the starting point. I'm so impatient! 

[Terrapin Z 194]

5 hours ago, conedodger said:

It seems like I have my Master vac problem solved. I found one on EBay and Terrapin found one for me at a Pick and Pull. I'll send both to Power Brake Rebuilder and hopefully get one good one out of it. 

I have to wait to start putting the brake lines in as the master cylinder is the starting point. I'm so impatient! 

I wasn't sure what you were talking about when you said make one out of two, but there it is. I'll have this one out tomorrow, should only be a couple of days to get to you. 

[conedodger 1,081]

Thanks David,

I sent you the Datsun Comp Distributor today.

[conedodger 1,081]

So, I've finalized the design for the throttle body spacer in my mind. It will be about 40mm thick with a bore big enough for the throttle plate (@70mm). It will be drilled for the 60mm square bolt pattern used to attach the stock throttle body to the inlet and countersunk so that the eThrottle body can mount flush. It will then be drilled and tapped so that the eThrottle body can bolt on. The eThrottle body will be clocked at 45 degrees so that the plug to the eThrottle body is down and right as you look at the front of the car. This is an important consideration as the bolt up pattern for the eThrottle body is not square. Kind of like i'm holding it in the picture below.

[Captain Obvious 2,364]

That sounds like it will work fine. Remember to keep the main bore concentric with the hole in the intake manifold. Only bringing that up because the holes in the new throttle body aren't in a square pattern. Make sure you get the center holes lined up and let the mounting holes fall where they fall.

Also, you're changing the diameter along the way... Are you tapering the bore hole in the adapter to account for the change in diameters? I don't think you want big step changes in diameter.

[conedodger 1,081]

13 hours ago, Captain Obvious said:

That sounds like it will work fine. Remember to keep the main bore concentric with the hole in the intake manifold. Only bringing that up because the holes in the new throttle body aren't in a square pattern. Make sure you get the center holes lined up and let the mounting holes fall where they fall.

Also, you're changing the diameter along the way... Are you tapering the bore hole in the adapter to account for the change in diameters? I don't think you want big step changes in diameter.

I know little of aerodynamic theory, though I am a pilot and a very small part of my career involved ‘considering’ the flow of air through tubes. Specifically endotracheal tubes. Most of what I’ve read about the spacers that are marketed out there involve breaking up laminar flow. They don’t expressly say that, but rather describe it. I highly suspect the marketers are not citing science on the spacers though. I am working with experts is all I can say right now. I will be keeping the concentrics of all three bores. 

[conedodger 1,081]

Many good things come from a drawing on a napkin. Though in this day and age, that napkin might be a program. I am working on learning Sketchup but my son uses something more sophisticated. Still, since I'm only learning Sketchup, I had to draw things out on a napkin so-to-speak. Before you laugh, Heinrich Nordoff and Dr. Porsche who were brothers-in-law and the Directors of Porsche and VW respectively, drew up plans for the production of the joint effort 914 at breakfast on a napkin. A real napkin! Sadly, Nordoff got sick and died and the new director of VW didn't recognize the agreement which ultimately made the VW/Porsche 914 too expensive and doomed it's production to 2/3 years for the 914-6 and 6/7 years for the 914-4. 

Here is how I'm communicating with my architect son. Don't laugh. There was no attempt on my part at scale! 

[Captain Obvious 2,364]

Heck no! I'm not poo-pooing a napkin sketch at all. I'd be SOL if it weren't for drawings like that!   Haha!

My question about the bore sizes goes like this... On your sketch, it's 70mm on the front side if your adapter. But what is the size of the hole on the manifold size (not shown on the napkin sketch)? If it's straight through 70mm, then you're going to have a step change in diameter when you hit the 50mm-ish hole at the inlet side of the manifold. You could probably open up the hole in the manifold some with a grinding burr, but I'm not sure you'd be able to get it all the way out to 70mm.

That's what I meant by tapering the hole from 70 down to 50ish.

[Captain Obvious 2,364]

And thinking about it some more and looking at your ruler measurements on the bolt holes for the new throttle body... I'm not sure there's going to be enough meat with a 100mm outside diameter for the adapter if you need to keep the center bores concentric. Maybe your architect to watch for that when he draws it up in CAD?

 

[conedodger 1,081]

Mine is already ported and extrudehoned. 😎

[Captain Obvious 2,364]

And here's what I was talking about maybe not having enough meat with a 100mm OD. Here's a quick sketch I threw together...

100mm OD, 70mm ID and two sets of bolt holes. One on a 60mm square and the other on a 60x70mm rectangle. All with the centers concentric. It looks to me like you might have some troubles with some of the holes being to close to the edge:

So I don't know if the bolt pattern for the 350Z throttle body is 60x70, but I just used what I could discern from your ruler pics earlier. It looks like trouble.

[conedodger 1,081]

Thanks Captain,

I guess we bump the cylinder out a bit...

[conedodger 1,081]

Ok, a little Sunday morning update. As I have mentioned, I'm semi-retired so I worked the last two days and was excited to see that I had boxes from David and Ebay. I haven't even figured out all of the stuff David sent me! It was packed so well, I half expected to find a live squirrel in there! 😎 The Ebay box was a Master Vac from a 79 280ZX. David also sent the same thing plus. Why two? I had already did a buy-it-now on the Ebay one, but I trust a member to send a serviceable part. David did. The Ebay one looks like it was bathed in saltwater 30 years ago and pulled out last week. Thanks David!

So what am I doing and why? There are two ways to increase the assist for your braking system. One is a larger power brake booster. Of course, you are limited by what will not interfere with other installations in your engine bay and what will bolt up to the existing holes, or, what you are willing to drill for. The second is a dual diaphragm booster. These can be smaller, but the problem is finding one that will bolt up. I haven't and I assume no one else has either but hey! It could happen! 

The plan is to pack them up today and send them off to a Power brake rebuilder in San Jose or LA. Same company, just two locations. Yes, I am sending both because there is a small possibility that one might not be rebuildable. If both are, I will sell the other to a member so they can do this mod as well. A note though, I have long been one who says that the stock brake system in good serviceable order is perfectly adequate for even autocross and track days. But, I am basically doubling the stock horsepower so...

A note to anyone thinking of doing this mod, you must uninstall your clutch master cylinder to fit the booster then reinstall the clutch master cylinder. 

[Terrapin Z 194]

40 minutes ago, conedodger said:

Ok, a little Sunday morning update. As I have mentioned, I'm semi-retired so I worked the last two days and was excited to see that I had boxes from David and Ebay. I haven't even figured out all of the stuff David sent me! It was packed so well, I half expected to find a live squirrel in there! 😎 The Ebay box was a Master Vac from a 79 280ZX. David also sent the same thing plus. Why two? I had already did a buy-it-now on the Ebay one, but I trust a member to send a serviceable part. David did. The Ebay one looks like it was bathed in saltwater 30 years ago and pulled out last week. Thanks David!

I must not have used enough tape on the box if the squirrel was able to get out. 😂😂. Glad to hear it made it there safely and you are happy with it. It did look to be in decent serviceable condition. I have worked in Shipping and Receiving for many years and understand packing makes a big difference. I have gotten so many things from eBay and FB that are packed so poorly. I am amazed they weren't just a bunch of pieces in the bottom of the box. Being I work in a large warehouse I have access to a multitude of boxes and packing for free, I know those items can be costly to buy. 

I'd be interested in hearing back on how the rebuild went, Rob. I am considering this Booster upgrade on my next project / build as well. That is a long ways off still. Just gathering info and a few parts here and there. 

I did also receive the trade item in the mail the other day but have not really looked at it much other than a once over. I have been on vacation this week and spent a lot of time reorganizing my parts hoard. Plus I tucked my car away for the winter. 

TZ

 

[conedodger 1,081]

TZ, I would probably rebuild that item but it worked like a charm. Just my obsessive nature I'm sure... The squirrel didn't get out until I unpacked. I wanted to just evict the little bastard from my garage but my wife named her. Now I'm stuck with the damned thing!!! Thanks David! 

[conedodger 1,081]

Ok, two boxes packed. Instructions enclosed. One box contains 73 240Z Power brake booster, the other contains two 79-81 280ZX Power brake boosters. I only intend to use one of course, but these are valuable vintage parts and someone should be bolting them on something so I am having them all done rather than putting them on a shelf where they languish and rust away.

If you need a 240Z power brake booster for your restoration or you need a 79-81 280ZX power brake booster for your restoration or upgrade, PM me. 

Oh! I also have a 15/16 master cylinder I took off that was in good shape. It isn't rebuilt and it isn't new but these are hard to find so PM me if you need it.

Edited November 30, 2020 by conedodger