The Triumph Dolomite Club - Discussion Forum

Has anyone tried modifying alloy Dato 240z brakes to fit a sprint?

I know it's been done on the larger saloons, also found an article here:
http://www.triumphowners.com/resources. ... nID=111025

Thinking about doing it if it works out comparably with buying (and shipping) new Sprint drums.

Garth, I like the idea.

I have a good contact with brake supplies, so I will find out if they are available locally (Australia) and what sort of price they are talking. I will see if i can get my hands on a drum to see how much machining is required to make them fit the rear of a Sprint.

Mark

would finned drums fit under sprint wheels? the standard ones are already quite close to the wheel.

When you are looking for more cooling why not drilling the backplate and the std drum?

The finned drums maybe a problem under standard Sprint wheel, but I don't have standard wheels, (13" BBS), and I can't drill anymore holes in the brake drums or backing plates or they will fall apart, and I have ducting feeding there as well. The alloy drums should be considerabley lighter than the standard cast iron.

Before someone says, fit disc brakes to the rear, I am happy the way that the drums stop the rear of the car, and by my calculations, a disc brake conversion will be heavier than the drum brake system.

Mark

Ahh too late....., fit disc brakes to the rear. You can buy those very expensive lightweight calipers with plastic pistons in it. Make yourself a alu hub/disc carrier and only your disc is metal. This is maybe a littlebit heavier than the drilled out brakes but lighter than than the std drum and backplate. Sprint drum is very heavy.

By the way, what's wrong with the rearbrakes anyway and why don't fit std drum when they need replacement.

Hey Mark, glad you like the idea! I think it should be an easy mod as the Sprint PCD is smaller than the datsun, so just a case of re-drilling further in.

I think the finned bits won't be a problem as they are on the inside (back) edge of the drum as the wheel "spokes" slope backwards.

There's nothing wrong with standard sprint drums apart from the fact that in my case they have been machined oversize so i need custom brake linings and my rear brakes make Hammond's car look like it stops well on hills...
Also trying to find NOS drums in Aus is very difficult, they're cheap to buy from Rimmers but prohibitively expensive to ship.

Mark i'd be interested to know what you can find.

Cheers,
Garth
(SPRINTPARTS "Ideas man" )

PS Any luck with those carbon-fibre bonnets?

carbon bonnets, sounds interesting

I now have a pair of new 240z finned brake drums. As we thought, they WILL NOT fit inside a stardard Sprint alloy wheel, but will fit inside my BBS wheels.

Will now get them drilled to match Dolomite PCD and enlarge centre hole. When done will post a photo for all to see.

Mark

So ... an enterprising individual might put the drums in a lathe and remove the fins to make them fit under standard wheels...?

....and the result???

Hey Mark, have you had a chance to look any further at this?

Cheers,
Garth

Hi Garth,

Below is a photo of alloy drum inside my 13" BBS wheels. It only just fits, and to make them fit inside a Sprint alloy I would imagine that most of, if not all of the fins will need to be removed. I think that I can get some second hand drums if interested, but a fair bit of machining will be required. I have not used the alloy drums as my car now runs a disc brake rear end, but it is also not a Triumph axle assembly. I am tired of trying to use 30+ year old parts so have gone for something a bit newer, and hopefully it will be indestructible.
Mark

PS. I should add that these discs are 250mm, almost the same size as the fronts. I used this setup for the first time last weekend, seems to work OK, just learning to get the best from them at present.

Looks good! Race regs allow non-original axle then? What axle are you using?

David

The basic diff is a Borg Warner assembly, locally (Australian) made in in numerous Aussie built cars. This particular housing is from a Nissan Skyline R31/Nissan Pintara.

It has had all original brackets removed and Dolomite brackets welded on so that it bolts up to standard mount points. It uses a 4.1 LSD (numerous ratios available from 3.08 to 4.1), and using standard Nissan disc/caliper setup. It is 100mm wider than a Sprint, so now flares are fitted to the 'guards and the front track has been widened.

The only downside so far is that it would weigh at 10-15kg more than the Sprint unit. The axles are about twice the diameter of a Sprint axle, so hopefully no axle flex or oil leak problems ever again.

Mark