turbo sprint engine

[GrahamFountain]

And yes I did get the "face that launched a thousand ships" reference, just not entirely sure it's a joke!

It's exactly like a joke; just not funny.

Graham

[GrahamFountain]

"how hard can it be?"

About 50-60 quid off fleabay and a few hours fitting. And, at 330 Watts or so (claimed), they might give some power boost on tickover.

Some of them give the thrust value, and there's obviously an area given by the outlet throat size, but I have to go cook sausage and mash for the horde of the things now.

But one of them looks exactly like the extractor fan I put in the loft to vent the en-suite. That didn't cost 50 quid though. So these must be more powerful.

Graham

[Carledo]

Then a mile must have grown, Jonners. A fair pace for a tall modern man is about 3 feet or 1 yard. A mile is 1760 yards not 1000! that would make a pace about 5 foot 3 inches, try it sometime! Oddly here, that mille passum definition quoted much more nearly fits a kilometer!
(note that my head still works in Imperial measures)
And the difference between half a litre and a pint would only matter if you were paying the same for both!

I can think of many and better reasons to leave the EU, I don't need metrication to be one of them!

Steve

[GrahamFountain]

Then a mile must have grown, Jonners.

Before you argue with someone, you should walk a mile (or 1000 paces) in their shoes. Then, you'll be a mile (or 1000 paces) away from them, and they'll have no shoes.

Graham

[Carledo]

But one of them looks exactly like the extractor fan I put in the loft to vent the en-suite. That didn't cost 50 quid though. So these must be more powerful.

Graham

That is not logical captain, the household one is cheaper because they are not selling it to gullible fools but hard headed builders!

Steve

[tony g]

I always find it amusing that young engineers I work with are talking microns and Im talking thou. When they say whats with the imperial thing I tell them that the thou thing IS metric! Its the only part of imperial that makes sense to me. A thousandth of an inch (or anything else) is proper metric lol.

I still tease them with 0.1 being 4 thou (I know its not exactly but Im happy with it ) and doing clearances with feeler blades makes more sense in thou than the metric equivalent lol

Tony

[Karlos]

Off the original thread topic I know...

A metre is three feet three. It's just longer than a yard you see.
Two and a quarter pounds of jam weigh about a kilogram.
A litre of water is a pint and three quarters.

I remember reading this on the back of a Cornflakes packet back in the 70's. HATED the rhymes. Awful putrid ryhmes. Still HATE them.

Made little sense as I had no idea what a pound of jam looked like, but I did know what a pint was because milk was delivered daily in glass bottles that had "1 Pint" on them. Only came across yards on road signs, I have never noticed yards being used anywhere else other than in conversations describing the size of your garden or the boxes on a football pitch. Did football pitches go metric i wonder?

Litres is an odd one as everyone knows what it means when used for engine displacement. I was only aware of cubic inches being used to describe the displacement for American V8 engines. How do they manage to get so little power from such enormous dispacement? 265cubic inch V8, produces 98 BHP, top speed 83mph, 14 mpg.... Ok I made those figures up but you get the idea.

Doesn't sound right does it - my Dolomite has a 3 1/4pint engine.

[GrahamFountain]

one of them looks exactly like the extractor fan I put in the loft to vent the en-suite. That didn't cost 50 quid though. So these must be more powerful.

Well the extractor fan is 230 v, but is less powerful than most of these 12 v ones sold as superchargers. So that's no help.

I'm not sure about anyone else, but I'm sufficiently convinced that an electric supercharger is too hard to make work with any fan and power store I could easily get.

I know that the calculations were only rough - a 2 litre engine probably wouldn't draw 0.1 m^3/s at 6000 rpm, probably not even with 7.5 psi boost at the start of the inlet channel. But with, perhaps, 25 percent efficiency from the fan, it's still going to need 20 or 30 hp to boost peak power by anything much, and that's far too much power for a 12 volt system to supply. And even if I could get some boost from one, it would have to be at low rpm and short term. I already was convinced of it's being too hard before we stared, to be honest, but I'd forgotten how much too hard.

And anyway, the Sprint engine will give more than I could ever want on the road without resort to any kind of forced induction – I know I've had 145 bhp at the wheels of a TR7 Sprint, and about 190 at the flywheel (by Dave Boggs' measure) –, just for it being professionally blueprinted and balanced, etc., and adding a set of 45s, a Kent road cam, and a tube manifold. I reckon with more effort on the carb setup, I could have got a bit more - I just used the venturi tubes that came with the SH Delorto carbs, and hoped.

That setup mightn’t have given quite 190 with the Doly Sprint manifold, but I've never believed that a tube manifold gives a TR7 Sprint 15 hp on its own. It might, but only with several other improvments that also are claimed to give 15 hp on their own. So I doubt it would lose that much. I know the inlet manifold and the carbs are expensive, but, especially if you don't mind second hand, a lot less money and effort than a turbo or supercharger setup.

Mind you, I sometimes get the impression that interest on this forum in a task is directly proportional to its difficulty. And as an inherently lazy bugger...

Graham

[Carledo]

Tuning a stock engine for big BHP increases is expensive and usually unreliable.
Adding forced induction of any sort to a stock engine is difficult, expensive and ultimately will probably grenade the engine.
NOS will almost certainly grenade the engine.

This is why I subscribe to the American theory, "there ain't no substitute for cubes". Find the biggest and most reliable unit that will fit and shoehorn it in. This only takes time and a little enginuity, donor engines are usually pretty cheap and donor CARS can often be an even more practical and cost efficient solution. I often hear the "but it ruins the originality/character of the car" argument but in terms of bang for your buck, there's no other method that comes close! And the car you CREATE, you will love more BECAUSE you created it and pretty soon you realize that it has a character of its own and (mostly) you love that too! It's YOUR car, why worry what others think?

Steve

[tony g]

AS I have a turbo and a supercharger in stock cost wouldnt be like a bolt on bought kit for me and I would only boost the sprint engine to about the same level as an engine with cam and 48's but without revving the ring hole out of it, so could even be more reliable if the gasket stays intact

Tony

[GrahamFountain]

"there ain't no substitute for cubes".

Well, I understand the sentiment, but I don't think a tuned Sprint engine, even up close to 200 hp, is necessarily that much of a problem in terms of reliability – though I've no use for one at the moment. And I think it's a lot less cost and effort to get to that sort of power from the existing engine than through any engine swap (other than to a TR7 2 L or Doly 1850/1500/1300 engine; but where would be the point in those).

I think that bigger capacity engines are almost necessarily lazier – they store more energy, and take more power to spool up or down, and thus generally longer - though I did toy with the idea of building a Morris Doxford at one time in my youf; but my parents were "vertically opposed" to the idea.

I think modern bike engines underscore that responsiveness issue. I have a number of special problems with the Rover V8 - but stock, that laziness is definitely one of them. It's a lovely engine for towing a sub-post office with, but not a sports car engine as it comes out of an SD1 or even a P6. The cost of the installation, even in the TR7 where you can/could get all the bits off the shelf, is another. They say that "torque is cheap", but I know that "careless torque cost lives".

And I am someone who's got a Doly Sprint because I fell in love with the engine upgrading TR7's. I'd still be driving one, 'cos they're fun. But I need something with more seats. I've seen 2+2 TR7s, but other than Mike Collins' Tracer, I'm not impressed much. And even there, Martha reckoned it a bit tight in the back – a truly dirty laugh, that woman.

So, on the whole, I couldn't possibly agree. Sorry.

Graham

[Dolly-Washer]

It's quite possible to locate the turbo elsewhere, therefore taking away the large problem of engine bay space. it's quite common in some applications and works surprisingly well with a lot less lag than anticipated by most people! Saw a car for sale recently (albeit a v8 merc) but the turbo was literally in the boot!

Rob

[cliftyhanger]

to get 200bhp from a sprint engine would not exactly be a budget build. I am guessing 3K+
A duratec can be done for way less than that.
In fact, I intend buying a brand new, crated from the factory, Zetec for £800. With my existing EFI setup and an exhaust tweek, I am expecting 180bhp (duratec would cost more, but break 200bhp)
I would expect the Zetec to run for approx 80-100k miles with a hard life. Require no unusual maintenance either other than oil changes and a couple of cam belts. And a genuine touing mpg of around 35+ (we exceeded that on teh 10CR this year, including some 100mph autobahn stints, where you could almost see the fuel gauge move)
A sprint engine at 200bhp I would expect no more than 20k tops (that figure may be hopeful. Anybody got real experience?) without a stint in the garage. And bills to match. And half the economy of a modern engine.

Really modern swaps are the way to go if you want a car that just works and produces good power. Honest.
But it has to be a compromise.
Saying that, stick proper EFI on a sprint engine would see some mild power gains but a good increase in economy A good path to tread I would say.

[GrahamFountain]

to get 200bhp from a sprint engine would not exactly be a budget build. I am guessing 3K+

Not that I accept that estimate, but the costs of having a none standard engine, and presumably gearbox, propshaft, and exhaust system, fitted at £40 an hour or so must be fairly high, surely - even if you get the engine for nowt.

Graham

[cliftyhanger]

Anybody seen the cost of rebuilding a std 4 cylinder OHV engine recently? About £1500.
A std sprint engine? more, probably 2k?
And at 200bhp I am sure std internals would not be adequate. Let alone substantial headwork, a proper cam (not cheap) etc etc.
Plus you would be wanting a bomb-proof propshaft, radiator etc etc. They all cost, and alternatives would be the same cost (maybe cheaper)

Yes, fitting an alternative engine would not be cheap.
But over pulling out and replacing like for like? maybe 2 days extra?

But this is pointless, as most of us are capable of doing this ourselves.

owever, I stand by my comments on EFI. Probably the same cost as fitting a pair of decent webers...