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Re: What parts does disc-brake conversion use?
Posted by: lgoodwin ()
Date: May 12, 2008 06:56PM

Thanks, Craig and Kevin.

Barring results of someone else's successful conversion...
I was going the "prototype and test" route: Install the required parts and see how well it works in a safe test environment. Make changes/adjustments as needed and retest, etc., until I get the desired performance.

Someone (Rafee?) recently posted that they converted to disc brakes without going to the dual master cylinder and were happy with the results. My impression was that the original single MC generates the necessary pressure and flow to get the job done, and that the main reason for using a dual MC is for safety (if one half fails, the other half will still operate).

I just re-read the Scarebird instructions. They recommend using a '78-80 Monte Carlo or similar MC. Seems to me the one used on 80's vintage A-BODY would be a closer match (engine still in front, but lower gross weight).

Back to my original posting: What MC and PV do the LM front-disc conversion kits come with???

1962 Corvair 900 sedan1967 Corvair Monza 140/4-speed1968 Corvair 500 coupe1983 Mexican Mustang 5.0
1962 900 sedan needs a home1967 Monza 140/4-spd1968 500 coupe (now my son's)1983 Mexican Mustang 5.0

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Re: What parts does disc-brake conversion use?
Posted by: cnicol ()
Date: May 12, 2008 07:17PM

The 78-80 Monte Carlo IS an A-body (AG).

The other reason to use a dual MC is that as the disc pad wears, the master cylinder fluid level goes down. Disc-brake master cylinders have a larger reservoir to accomodate this requirement.

If your concern is about budget, why would you plan on multiple replacement master cylinders and FLAPS PVs instead of doing the math (which is free)?

There probably isn't an off the shelf disc/drum PV that does the job, given the Corvair's weight bias. The closest thing I can think of would be old VW stuff, but that's going to have European fittings, might as well go with an adjustable, which is cheaper than a single replacemnt PV, by the way.

I had a customer bring in a 57 Golden Hawk after he had a disc brake kit professionally installed. Nice kit, many sold, but in actual performance, it was rubbish! The car was scary to drive. Days and days (full days) later, I had changed the hydraulic ratio, changed the pedal stroke,installed an adjustable PV and verified the mechainical ratio.

If the kit had been fully engineered, rather than sold to a price, the owner would have saved many, many hundreds of dollars. I'm not saying that what's offered doesn't work, what I'm saying is that if they do work, it's a result of someone engineering them to work.
Just MHO,
Craig

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Re: What parts does disc-brake conversion use?
Posted by: lgoodwin ()
Date: May 12, 2008 08:24PM

I should have said "mid-to-late 80's A-Body, e.g., Chevy Celebrity, Olds Cutlass Ciera, etc.", but for all I know, the 78-80 Monte MC is the same.

I'm not planning on multiple replacement MC's.

I have no idea whether the Corvair vendors LM disc-brake conversion kits are "fully engineered". For all I know, they are just a bunch of stock parts that fit.

If the vendors provided more detailed up-front info about what they include (and why) and photos and why the kit is superior to the DIY route, I'd probably just get the kit. In the same vein, if Scarebird had actually tested their brackets on a number of LM Corvairs and determined the "ideal" set of parts, I'd just buy those parts.
All of the above might sell product more if they would do this.

BTW, my postings were on the weekend when the vendors were closed. When I take my vacation, I'll just call the source like I should have done.

Anyway, if/when I do this and get the correct setup, I will post details for anyone who might want to forego the trial-an-error.

Thanks for all the good input.

1962 Corvair 900 sedan1967 Corvair Monza 140/4-speed1968 Corvair 500 coupe1983 Mexican Mustang 5.0
1962 900 sedan needs a home1967 Monza 140/4-spd1968 500 coupe (now my son's)1983 Mexican Mustang 5.0

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Re: What parts does disc-brake conversion use?
Posted by: cnicol ()
Date: May 12, 2008 08:52PM

Vendors that have done the work don't want to reveal all the details or someone will just go and buy the parts and they don't get paid for the engineering and development effort. You just have to find out if they really did engineer their system.

Ultimately, the parts may all be "off the shelf" but there are many thousands of them on the shelf. Which parts do the job is the magic (and either the result of engineering or trial and error).

If you can do math, coming up with a likely solution won't take more than an evening.

Re purchasing multiple master cylinders: MCs are sold in 1/16" increments from 3/4" through 1 3/8". When it's done by the seat of the pants method, (which I have done many times) it typically takes three to get it right. (too much, not enough, and just right.) BTDT

Craig

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Re: What parts does disc-brake conversion use?
Posted by: 1bad67 ()
Date: May 12, 2008 09:10PM

Being cheap (owning a Corvair I guess that's like repeating myself), I did them myself. Drew up the brackets to mount the calipers, had a buddy burn them out, then welded them up myself. The calipers I used were S10 4x4's (they are different from the normal ones only because the bleeder screw & hose are mounted differently. They have the same mounting dimensions, and take the same pads though. I used '86 Camaro rear rotors. They worked great for the rear, but the S10 4x4's have less offset, and would have left more room on the inside between them and the big bolt at the top of the spindle.
For a master cylinder I got an '86 Camaro one. It is already set up for 4 wheel brakes, and the pedal effort is acceptable. The nice thing about it, is the ports are on the right (passenger) side, so plumbing was easy. While I was in the wrecking yard getting the Calipers & rotors (like $10 each for Calipers & $5 for rotors) I grabed an S10 Plastic reservoir for the Master Cylinder. The Camaro has an angled firewall, whereas the S10 is vertical like the Corvair. All in all I'm pleased with the results, but....
If your not into bending & flaring brake lines, grinding & filing things that almost fit, and the extra time it takes for the extra trips to the FLAPS for the last little bits & pieces, I'd say buy a kit. There's a reason they cost what they do. Where are you gonna get the extra fittings that tie the second side of the master cylinder into the brake line? do you know what length brake hoses to get?
I did it because I could, and because I wanted to. Doing things yourself rarley turns out cheaper. Unless you cut some serious corners.

Eric

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Re: What parts does disc-brake conversion use?
Posted by: lgoodwin ()
Date: May 12, 2008 11:54PM

About the kits... The one Corvair Underground sells does not come with a master cylinder. I don't recall if the one Clark's sells does. So, even if I buy a kit, looks like I need to decide whether to stay with the stock MC or locate the "properly engineered" replacement that's best for the disc/drum combo.

According to CU, my '68 has a dual MC. I've never even bled the brakes on this car yet, and seldom look in the trunk, so did not even know it was a dual unit.

Seems like the vendors expect this MC to work with the kit. Guess I'll call Lon and see what he says.

1962 Corvair 900 sedan1967 Corvair Monza 140/4-speed1968 Corvair 500 coupe1983 Mexican Mustang 5.0
1962 900 sedan needs a home1967 Monza 140/4-spd1968 500 coupe (now my son's)1983 Mexican Mustang 5.0

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Re: What parts does disc-brake conversion use?
Posted by: cnicol ()
Date: May 13, 2008 12:50AM

I looked at the catalogs for both CU and Clarks, plus Rafee's ebay listing. It looks like those vendors feel a stock MC does the job, though CU recommends a dual MC, but you already have that. If you got one of the kits, it looks like it would pay to run 14" rims, 'cause the kit is almost $200 less, but then your NAPA total is far less than that.

I haven't heard any complaints about any vendor's kits, though truthfully I haven't heard anything positive either. It would be interesting to hear from a performance guy who has installed one of the kits, especially regarding which end (if any) locks up first. In the absence of a proportioning valve, my bet is on the rear by a fair margin.

The plan for the Scarebird brackets and NAPA parts looks like it will only cost you in "figure-out-the-hardware" and run-around time, assuming the calipers are the same as their kits (which gets back to your original question). Clarks lists the piston diameter as 2 3/8", which is a good place to start comparing.
Craig

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Re: What parts does disc-brake conversion use?
Posted by: lgoodwin ()
Date: May 13, 2008 02:36AM

Ah, thanks for the extra research, Craig. I'm sure you are right about the balancing issue and that changes would be a necessity for the racetrack.

Factors that I hope will minimize rear lockup in my case:
The rear tires are a lot wider than fronts (235 rear, 195 front).
Drive very conservatively, especially on the freeway, which is rare.
I'm used to driving my Chevy C10 pickup with front discs and drum rears -- rears lockup all the time when not carrying a load.

My car has 14 inch wheels.

The main benefits I hope to get from going to front discs are no more pulling and lower maintenance. The front brakes currently alternate between stopping straight to pulling right, to pulling left. I could resolve these issues, but then I'd still have drum brakes. I like the simplicity of disc brakes.

If the stock MC does not do the job, I'm willing to buy an adjustable PV and/or a different MC down the line. Thanks for all the great tech info!

1962 Corvair 900 sedan1967 Corvair Monza 140/4-speed1968 Corvair 500 coupe1983 Mexican Mustang 5.0
1962 900 sedan needs a home1967 Monza 140/4-spd1968 500 coupe (now my son's)1983 Mexican Mustang 5.0

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Re: What parts does disc-brake conversion use?
Posted by: Ed Dowds ()
Date: May 13, 2008 02:52AM

A bolt on disc brake master would be one from a '69 Camaro. The drum brake '69 Camaro master is the same as a '67-'69 Corvair master so the Camaro disc brake should work ok. The only problem is that it is 1-1/8" versus 1" for the stock drum brake master. It would require a little more pedal pressure.

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Opps! Double post.
Posted by: Ed Dowds ()
Date: May 13, 2008 02:52AM

Opps! Double post.



Edited 1 time(s). Last edit at 05/13/2008 02:53AM by Ed Dowds.

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Re: What parts does disc-brake conversion use?
Posted by: freeulster ()
Date: May 13, 2008 07:38AM

Didn't Rafee the vendor in Oklahoma post about this in the last few weeks?

Kent Donnelly
Living in sunny Brigantine Beach NJ
64 Vert
Philadelphia Corvair Assoc and CORSA
"EM's are faster than LM's because we don't have all those extra lug nuts weighting us down"

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Re: What parts does disc-brake conversion use?
Posted by: Tom Z ()
Date: May 13, 2008 12:45PM

..on the 65-500 that's slated for a mid-4.3,I've got an s10 master cyl stuck in the original hole,fits like it was made for it,no cutting;rod needs to be longer,but that's later..it may be one from power-assisted system,I haven't found the rest,there's 2 '88-ish manual masters around (smaller bore,like 1"..),plus several s10 prop valves..right now,tho,I'm re-doing the front drum system I did a couple years ago that will likely be 'for sale' soon (cleaned+ Xtended backing plates w/whl cyl's,shoes loaded),,as Craig is "leading the blind" on mounting the (Granada/ Fairmont) rack correctly,I'll be posting on this soon w/pix,when I get the 'mount it here' measurements..Meanwhile, the disc brackets I got from Dave Clemens will get loaded,ready to swap on,and start attacking the front floor 'repair'and rear susp re-build...

Tom Z,,Rochester NY


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Re: What parts does disc-brake conversion use?
Posted by: Michael C ()
Date: August 26, 2008 04:58AM

Im reading through the meassages and im seeing a lot of information on late model vairs. Is there anyone out there that can tell me about any disk conversions for a early corvair. 60-64? im trying to find any information what so ever. i know they sell a 4 lug front conversion, but its not quite what im looking for. Is there anyone that can let me know any 5 lug conversions? Or anything out there for the rear brakes as well? Disk, and 5 lug for the rear on an early?

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Re: What parts does disc-brake conversion use?
Posted by: MattNall ()
Date: August 26, 2008 05:18AM

Mike, you just swap LM Spindles to your EM suspension up front

Rears? no possible.. the swingaxle design moves the flange around..

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Re: What parts does disc-brake conversion use?
Posted by: steve goodman ()
Date: August 26, 2008 12:53PM

Is there anyone reading this that was at the fan belt toss the year it was at Indio in the fairgrounds? There was a fellow there who had a mock-up of rear discs on an EM trailing arm and was trying to market it. I went back later in the weekend to look closer at his stuff and he was gone.

Best, Steve
Golden, Co.

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Re: Indio FB Toss
Posted by: MattNall ()
Date: August 26, 2008 02:59PM

I beleive it was 1989? When I had my boat at the entrance?

It had the true " floating caliper! IIRC

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Re: What parts does disc-brake conversion use?
Posted by: ccpinc ()
Date: August 26, 2008 04:04PM

We sell new front disc brake conversion brackets for 1960-64 and 1965-69 Corvairs. The early set uses Colt hardware and the late set uses the same parts mentioned here in previous posts.
The brackets are $89.95/set early or late. With a little time and effort getting the other obtainable parts locally you can save $$$$!

Jeff Williams

CALIFORNIA CORVAIR PARTS

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Re: What parts does disc-brake conversion use?
Posted by: steve goodman ()
Date: August 27, 2008 02:29AM

Hello Jeff: Thanks for that but Michael C was asking about REAR for EM. I was asking if anyone remembered Indio fan belt toss where someone was selling the rear for EM too. Matt is probably right on the year and I remember the boat.

Best, Steve
Golden, Co.

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Re: What parts does disc-brake conversion use?
Posted by: ccpinc ()
Date: August 27, 2008 04:42AM

Sorry about the misplaced advert and the HUGE photos. I'm not sure how I did that.



Jeff Williams

CALIFORNIA CORVAIR PARTS

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Re: What parts does disc-brake conversion use?
Posted by: ccpinc ()
Date: August 27, 2008 04:45AM

Sorry about the misplaced advert and the HUGE photos. Not sure how I did that.



Jeff Williams

CALIFORNIA CORVAIR PARTS

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