How much is too much....

Jul 04, 2006 10 Replies

A little while ago, my 75 Spitfires engine had a vacuum line that was split. After the obligatory vacuum line joke from my local auto store employee, he procured a length of the correct size and I managed to get the engine running again.



I was pondering this weekend while I was on a road trip (Sadly, not in it) just how much of the lines and bottles up there are really necessary?



You can get away without a bottle - my Triumph 2000 hasn't got one, my PI has. But if your Spit has a bottle fitted, I would keep it.

The difference is that if the engine cuts out, the vacuum stored in the bottle will give 4 or 5 fully power assisted stops, but without it you get one stop that is nearly power assisted and after that, no assistance. You can't do cadence braking on slippery surfaces without a bottle either because the vacuum doesn't have time to recover before you reapply the brakes.

Jim

Does a Spitfire really need a servo at all? My Vitesse's brakes feel fine without one, so I wouldn't see it as essential on the lighter Spitfire with the same brakes.

"Howard" realised it was 3 Jul 2006 17:59:00

-0700 and decided it was time to write:

Judging from the e-mail address you use and your IP-nr, I'm guessing you're posting from the US. That probably means you're talking about a US-spec Spitfire with all manner of smog control equipment, which was thankfully lacking on UK- and Euro-spec Spits.

Now you have some of the inhabitants of this (UK) newsgroup confused, as they seem to believe you're talking about vacuum for a brake servo - which was never a standard fitment on any Spitfire.

Anyway - if you want to talk about the smog control stuff on Spits, this really isn't the best place. I suggest you get yourself subscribed to the Spitfires mailing list, which is full of helpful Americans with similar cars, some of which still have their power sapping US-spec pumps, bottles, hoses and what have you.

Go to this web page for more information:

formatting link
to the mailing list is a matter of e-mailing to snipped-for-privacy@autox.team.net with 'subscribe spitfires' or 'subscribespitfiresdigest' (without the quotes) in the subject line. You'll beasked to confirm your subscription - read the instructions. It's a busylist from what I remember, but worth it. Just tell'em I sent you. ;-)

I would have to double check, but I don't think I have vacuum assited brakes. Which migh explain all the capped and plugged lines at the valve cover.

Thanks Jim.

R/ Howard

Jim Warren wrote:

Yippee,

Yes, I am in the US. Columbus Ohio.

The vacuum line I replaced ran from the carburater to a filter in front of the radiator.

As for the smog control, Well, the air pump was gone when I got the car, and it runs fine. I would like to simplify as much of the car as I can.

As I mentioned in an earlier post, it did not come with vacuum assist breaking. But there have been a few days where I could have used it.

I will visit the web site you suggested.

Thank you again.

R/ Howard

Yippee wrote:

Yippee,

Thanks again. They are hammering away on all sorts of topics. I might be able to get an word in.

For the non- US cars is there a schematic/diagram for what it should and should not have. I have a Haynes manual, but I think it is about 20 years old.

Thanks again.

R/ Howard

Howard wrote:

I wouldn't worry unless the manuals older than the car...

"Howard" realised it was 5 Jul 2006 19:01:02

-0700 and decided it was time to write:

The original Spitfire 1500 workshop manual has diagrams and drawings fo the engine compartment for both US-market cars and for other markets. You should be able to deduce a lot from that.

The youngest Triumph Spitfire is 26 years old now, so that's OK. ;-)

_Some_ of the US market Spits ("50 state" ? version) are described. Californians had even more kit in there, some of which isn't listed. If you're working on a re-imported Californian Spit, this can get confusing.

Has anyone ever seen a vacuum bottle to provide vacuum for a servo on a car as light as a Spit? I haven't - I've had plenty that powered ancillaries such as aircon flaps or doorlocks, but the only brake vacuum bottles I've seen were on older Jags with Dunlop brakes.

DISCLAIMER: I'm in the US with a US-Spit('79)

There's no vacuum brake assist in the Spitfires(correct). on the GT-6 they do offer an aftermarket vacuum brake assist, which is of course pricey.

As for smog equipment, I am no stranger to that. Since emissions testing stopped in my state, I removed the air pump, switched to a 4-2-1 exhaust, and a plain intake manifold(for a Weber DGV). I do have the 2 carbon canisters and the breather system to go back to the fuel tank, however.

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