10 replies to this topic

[mcaville]

Hi there,

Just putting my 94 Sprite back together after swapping out the 1275 auto fro a 1293 manual. I have also bought a 2nd hand hif44 on a Howley manifold to go with this. What i hadn't considered is that previous Minisport manifold allowed the brake servo to connect, whereas the Howley manifold won't. Is this a major problem? The Howley manifold does have a bolt where the servo pipe would go, however when you remove this bolt the aperture is far smaller than that of the Minisport one.

Is there anyway that i can use the Howley manifold? If i can't will the Minisport manifold, which previously had a hif38, work with the hif44?

[minidaves]

just swap the manifold

[liirge]

Drill the Hole out and Tap it, and then use the bolt from the minisport manifold?
Just an idea, taps can be bought at a very low cost, and a howley manifold is very nice, good find!!!

[mcaville]

Drill the Hole out and Tap it, and then use the bolt from the minisport manifold?
Just an idea, taps can be bought at a very low cost, and a howley manifold is very nice, good find!!!

Nice suggestion. Has anyone else done this before, or have they found another solution? our right about the Howley. If i can help it i'd much rather use that than the minisport one. Also, i'm guessing that the minisport one will be ported for the 1.5" carb as opposed the 1.75".

[liirge]

its not a hard job to do at all, its done alot to add vacuum take off's to twin manifolds they are smaller and from scratch, in fact if there is a smal take off already it will be slightly easier as it acts like a pilot hole.

Edited by liirge, 15 October 2009 - 07:43 PM.

[mcaville]

Rightyo, i'll go and get myself a tap tomorrow. Any idea what size i want? I guess i could just take the adaptor from the minisport manifold to the shop with me.

[Dan]

It should be 5/8 unf and it'll cost you a fair bit. Before you rush into doing that though just check that it's going to work. The late type of servo connection is a banjo fitting, it doesn't seal to the thread but seals onto a flat on the manifold around the thread with a copper washer. It's the same banjo as the early oil transfer pipe. If the manifold doesn't have a large enough flat around the thread, or a large enough area that could be machined flat it won't seal. If there's anything sticking up in the air near the fitting it won't work either because the pipe has to lay flat for the banjo to seat. If it won't work for any reason you need to use the early vacuum adaptor as fitted to the Cooper S and in fact this might be what it is currently machined for, I can't remember if the thread is the same as the late type or not. This screws in and leaves a stub of pipe, you then need some flexible vacuum rated hose of the right size. Remove the plastic hose from the engine side of the one way valve and replace it with the rubber hose.

Adaptor.
Hose.

[liirge]

Rightyo, i'll go and get myself a tap tomorrow. Any idea what size i want? I guess i could just take the adaptor from the minisport manifold to the shop with me.

Yup best idea, also alows you to find the size of the hole you need to drill for tapping

[bmcecosse]

Just get rid of the servo! It's a bl**dy nuisance !

[mcaville]

It should be 5/8 unf and it'll cost you a fair bit. Before you rush into doing that though just check that it's going to work. The late type of servo connection is a banjo fitting, it doesn't seal to the thread but seals onto a flat on the manifold around the thread with a copper washer. It's the same banjo as the early oil transfer pipe. If the manifold doesn't have a large enough flat around the thread, or a large enough area that could be machined flat it won't seal. If there's anything sticking up in the air near the fitting it won't work either because the pipe has to lay flat for the banjo to seat. If it won't work for any reason you need to use the early vacuum adaptor as fitted to the Cooper S and in fact this might be what it is currently machined for, I can't remember if the thread is the same as the late type or not. This screws in and leaves a stub of pipe, you then need some flexible vacuum rated hose of the right size. Remove the plastic hose from the engine side of the one way valve and replace it with the rubber hose.

Adaptor.
Hose.

Thanks for the advice. Just ordered the adaptor and hose. I'm surprised that no one has made an adaptor that will take the banjo bolt on the original hose.

[Dan]

You are using a very old manifold, when it was made the Cooper S type system was standard on many cars. All the newer manifolds are cut for the new fittings.