Rear non-vented Rotors for 5 lug conversion, Looking for part info... Options

[jim_hoyland]

What non-vented rear rotor for a 5 lug conversion shouldI be looking at when, say, search Pelican Parts?

[DRPHIL914]

@jim_hoyland

check with PMB and Eric Shea, they have the drilled rotors for front and rear for easy conversion and using your stock brakes, might have the 914/6 rear 5 lug stud hubs , if not Bruce Stone probably does.

Phil,

[jim_hoyland]

What year/model Porsche used a rear non-vented rotor ?

[Steve]

What year/model Porsche used a rear non-vented rotor ?

70/71 914-6 90135240118

[mgphoto]

What year/model Porsche used a rear non-vented rotor ?

Early 911’s used non-vented rotors, but if you are adapting 5 lug conversion using 914 rear brakes you will need to cut the rotor diameter by 3mm (if I am remembering correctly). Be advised that the screws to stabilize the rotor to the drive flange doesn’t line up, be careful when mounting the wheel to center the brake disk on the studs as off center rotors will be out of balance causing a shimmy in the rear.

[DRPHIL914]

What year/model Porsche used a rear non-vented rotor ?

Early 911’s used non-vented rotors, but if you are adapting 5 lug conversion using 914 rear brakes you will need to cut the rotor diameter by 3mm (if I am remembering correctly). Be advised that the screws to stabilize the rotor to the drive flange doesn’t line up, be careful when mounting the wheel to center the brake disk on the studs as off center rotors will be out of balance causing a shimmy in the rear.

not if you get the stock rear solid rotors from PMb that are drilled for 5 lug, but you have to pull and replace the hub that has the studs in it. IF you want to go thru the full expense of replacing the calipers, then do that and get the 914/6 caliper and rotor. Or full out 911 parts. its a slippery slope and one not necessary to slide down unless you have a bunch of cash burning holes in your pocket. and Jim i know you are not planning on racing. do you already have 5 lug and you are just changing the rotors? not sure what your starting point is and what your end goal is.

Phil

[ndfrigi]

Jim’s car is already 5 lug with fuch wheels.

[jim_hoyland]

What year/model Porsche used a rear non-vented rotor ?

70/71 914-6 90135240118

Is that the same diameter as the stock 4 lug rotor ?

[DRPHIL914]

Jim’s car is already 5 lug with fuch wheels.

gotcha! well then he is probably asking because he wants to upgrade.
i'm sure he can do what mgphoto suggested and trim a 911 rotor to fit.

every time i think about doing something like this i get sticker shock. Also evey during AX or mountain driving i have never felt i didnt have sufficient braking power. now if i added more HP and was doing to do more serious ax or DE driving then i guess it would be worth it. .

BTW Jim, great Car of the Month Pic!! i really like the look of having your top color the same as the body!!

[Steve]

What year/model Porsche used a rear non-vented rotor ?

70/71 914-6 90135240118

Is that the same diameter as the stock 4 lug rotor ?

That I don't know. i would call PMB.
I have only used the above part number with a 914-6 rear caliper and currently with boxster rear calipers.

[horizontally-opposed]

Have used both 914-4 rotors (drilled for five-lug) and 914-6 rear rotors.

Both work great, and I've seen no downside to the former so long as the wheels are on and covering the ugly. (IMG:style_emoticons/default/biggrin.gif)

[jcd914]

What year/model Porsche used a rear non-vented rotor ?

70/71 914-6 90135240118

Is that the same diameter as the stock 4 lug rotor ?

No the 4 cylinder rotors are about 4mm smaller outside diameter than the 6 cylinder rotors.

I'm in the middle of a 5 lug conversion right now.
The 4 rotors measure approx 281mm and the 6 rotors measure 285.
Measurements are approx since I measured with a cheap tape measure.

Jim

[Montreal914]

If you are using stock rear calipers, I would have stock /4 rotors drilled to 5 lugs. I would assume PMB sells those.

The /6 rotors are not only larger in diameter, but also thicker. I will post the actual dimensions later when I get home.

[jim_hoyland]

What year/model Porsche used a rear non-vented rotor ?

70/71 914-6 90135240118

Is that the same diameter as the stock 4 lug rotor ?

No the 4 cylinder rotors are about 4mm smaller outside diameter than the 6 cylinder rotors.

I'm in the middle of a 5 lug conversion right now.
The 4 rotors measure approx 281mm and the 6 rotors measure 285.
Measurements are approx since I measured with a cheap tape measure.

Jim

Thanks, just what I wanted to know; will the additional 2mm of radius still fit into the stock caliper ? 2 mm doesn’t seem like much….

[mgphoto]

What year/model Porsche used a rear non-vented rotor ?

70/71 914-6 90135240118

Is that the same diameter as the stock 4 lug rotor ?

No the 4 cylinder rotors are about 4mm smaller outside diameter than the 6 cylinder rotors.

I'm in the middle of a 5 lug conversion right now.
The 4 rotors measure approx 281mm and the 6 rotors measure 285.
Measurements are approx since I measured with a cheap tape measure.

Jim

Thanks, just what I wanted to know; will the additional 2mm of radius still fit into the stock caliper ? 2 mm doesn’t seem like much….

No, the photo to the left shows a 1mm error using the vented rotor and a v-ed /4 caliper.
That 1 mm caused the rotor and caliper to lock up, if there is a problem it will find me.

[jcd914]

Thanks, just what I wanted to know; will the additional 2mm of radius still fit into the stock caliper ? 2 mm doesn’t seem like much….

It seems that the 6 rotors work and clear the caliper for some and don't work for others.
The 5 lug hubs I am installing are converted 4 lug hubs that I pulled from some used trailing arms I have, two sets. Both sets of arms were converted to 5 lug, both use stock 4 calipers, 1 has redrilled 4 lug rotors and 1 has the 6 cylinder 5 lug rotors.

Jim

[DaveB]

I am keeping the 914-4 brakes in the back, having a new solid Sebro rotor drilled for the 5 lug then had a 5-lug 914-4 spline pressed into the training arm. PMB rebuilt the 914-4 calipers I sent in. I changed out the front for a '71 911 Boge strut, drilled rotors and the 3" Brembo. BTW - PMB did the work and I would go to them for any 5 lug conversion.




4 lug drilled to 5 lug.




5-Lug 914-4 spline







I had the trailing arm modified by PMB with the spline pressed into it.





This is my rear caliper rebuilt by PMB





Rt brake and suspension as I pulled it off the '75. Above the can of Blaster is the rear caliper. What I sent in was pretty rough and what I got back looks better than new.



DaveB