Datsun Roadster Forum-311s.org

mklotz70 wrote:

I just went back and looked at your thread again......your calipers are 2 piece......have you considered or looked into spacers between the caliper halves? I've seen it done on other rotors....an 1/8" spacer plate in there would save having to cut the thickness down on the rotor. Just a thought.

They make a wider caliper for a 25 mm rotor. I think it starts in 87 or 88

Gregs672000 wrote:Reviewed your posts regarding thickness of the various rotors. I do see that minimum is 20 for the Maxima, and that is the starting thickness for the toyota! Well, again, not sure if I had it turned that far down or not. Also not sure why it would be ok for the toyota to be 20mm and the Maxima to be "maxed out" or minimally thick at 20mm. But I do hear what you are saying. For the record however, I have no problems with cracking, fading, warping, etc. Perhaps the 20mm thickness is in relation to how far it can be turned down until it is "unturnable" again but still useable? Either way, I'm not worried. If we're talking about mm here (which we are), and one was concerned the pad themselves could be shaved a tad to accommodate the larger disc I would imagine, unless the rotor itself would not fit within the caliper.

I'm pretty sure the min thickness would be determined by the construction of the rotor itself. If the center is more open for cooling, it couldn't be cut as thin. Maybe it's a "mass" thing....with the smaller diameter, it had to be thicker to have the same mass. The braking efficiency is based on how much heat the rotor can absorb....the vents are to cool it back down quickly. From what I've read, the vents don't help much to cool while the heat is building up.....that's handled by the mass of the rotor. So, for a one time braking event, a solid rotor could absorb more energy(in the form of heat), but it would take forever to cool back down to be useful for repeated events.

Cutting down the pads would work, but I don't know if you'd sand them down(too much dust) or mill them down. Or...like fj20 pointed out...use a wider caliper.

dbrick wrote:Have you looked at Pagasus racing for the bolts?

Geez....somehow I keep missing posts. I guess the forum only sends out one notification, so I get on here and only look at the most recent....anyway.... Sorry Dave.

I just looked at their site. Looks like that have a great option for bolts with a drilled head.

AN8H-15A 1/2-20 x 15/16 Grip Airframe Bolt, Drilled Head 1 to 4: $6.99 5 & up: $6.25 In Stock

found on this page..... https://www.pegasusautoracing.com/produ ... oduct=AN8H" onclick="window.open(this.href);return false;


Luckily, only this morning did I see some info on AN sizing.....the number corresponds to the number of 16ths. So, AN8 is 8/16's, or 1/2".

If the kits go into production beyond the 4 I'm making, I'll definitely consider using those bolts. I've already bought the hardware for this set. If I use them in the future kits, they'd add $20-25 to the price. For guys that are racing, the drilled head may be a necessity, but I may just leave it to them to buy their own.

Also....keep in mind or notice that the length of bolt I picked above is based on the "grip length" they show at the upper right corner of their page, so at first glance, it would look too short. The 15/16" grip + .680" of thread makes for a bolt that is only .008 shorter than the 1-5/8" bolt that would be perfect. I still don't want extra hanging out the backside. The 1-1/16" grip bolt would end up .118" too long.....which I'm nearly positive would hang out the backside far enough to hit the rotor.

Great stuff Dave! Thanks!

Dave.....I've ordered 4 bolts to "check out". $34! I enjoy the prototyping, but the $'s add up pretty quickly sometimes. If they work, I'll sell them with a "special" kit. If they don't........ oh well.

mike... i can easily send you that 34$ i will be needing to wire my bolts. let me know if you need more prototyping $

hhhmmm.....that just might work out perfect since I'm going to be sending you another box anyway. Thanks!! let me make sure I got the size right!

Another note about Pegasus Racing.......when it comes to the shipping page, take note of the note at the bottom that says they can do USPS for small or over weight packages. I'm pretty sure they're using flat rate priority. It only cost me $5.40 instead of the $9+ for UPS.

This just occurred to me as a point of confusion - The correct calipers are the Girling calipers for a 1985 Volvo 244 or 245... But do we need the calipers designed for vented rotors, or solid rotors? Mike's picture on page 4 shows pictures of calipers for the solid rotors... but the rotors we're using are vented, and I assume thick enough to justify the vented-type calipers.

Sorry if this seems like a boneheaded question; I just want to make absolutely sure before I put the order in.

corey.vixie wrote:This just occurred to me as a point of confusion - The correct calipers are the Girling calipers for a 1985 Volvo 244 or 245... But do we need the calipers designed for vented rotors, or solid rotors? Mike's picture on page 4 shows pictures of calipers for the solid rotors... but the rotors we're using are vented, and I assume thick enough to justify the vented-type calipers.

Sorry if this seems like a boneheaded question; I just want to make absolutely sure before I put the order in.

Vented Caliper

You can convert a solid rotor caliper to work with vented rotors by building a space, but that has not been covered. It is common to install spacers to change the width of a caliper.

In case anyone is interested the Caliper manifolds are still being made . This is the E-mail i recieved from Breck Meyer
his e-mail is breck1969@yahoo.com



Good morning Daryl,

I do still make the Volvo Caliper manifolds and it would cost $100.00 US for the 2 manifolds and banjo bolts, crush washers plus 3 day priority mail shipping in the U.S.

If you don't need the banjo bolts and crush washers, the total would be $60.

I'm waiting to hear how soon the machine shop will have the next batch of manifolds done, and I'm hoping they can machine them within the next couple of weeks.

Let me know if your still interested and I'll give you my Paypal info for sending the payment.

Thank you,

Breck

corey....thanks for catching that....I just went back and created new images for that thread.....they come up bigger now too. Whoever can, please double check that I have them right now!

Spider...thanks for the info....I've gotten a question or two on that and didn't have an answer.

Spider - That sounds right, I bought some from him recently and they were $60. You can get the bolts and washers for MUCH cheaper than $40, though. That sounds like a 'hassle charage' to me.

Mike - Not a problem, just want to get all my info correct for the write up (and for my car )

mike did you figure out whether the bolts are correct?

corey.vixie wrote: You can get the bolts and washers for MUCH cheaper than $40, though. That sounds like a 'hassle charage' to me.

true.... but cheap hardware is hit and miss on actual quality... and since i will be racing my car i want the bolts wired...sure i could drill the bolts myself... but these are hardened after all the holes/threads are cut.... so no weak spots.

http://www.rockauto.com/catalog/raframecatalog.php" onclick="window.open(this.href);return false;
so 17428 and 17429 are the correct ones? are they really left and right?

fixitman04 wrote:cheap hardware is hit and miss on actual quality... and since i will be racing my car i want the bolts wired...sure i could drill the bolts myself... but these are hardened after all the holes/threads are cut.... so no weak spots.

...You're going to drill the heads on your banjo bolts? That seems ill advised, somehow. I can see it for the caliper mounting bolts, but these are just banjo bolts that hold the brake manifold to the caliper.

I think that high grade caliper mounting bolts are absolutely worth it, but as far as what I'm pumping brake fluid through, I don't need to spend $40 on two banjos and 4 copper washers. My two cents.