Amazing!
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Amazing!
Following the fitting of the solid lifters, I was out again for a weekend of racing.
Unfortunately, all was still not well with the engine, power was way down on what it should be, so this week it has once again been delivered to, and now stripped down at BTEC Racing.
The news is not good.........
Cylinders 1 to 3 have between 70 and 75% leakage, and the best one, Number 4 has 35% leakage.
I'm told the acceptable figures would be about 25%.
One of the pistons shows signs of damage. Two of the spark plugs have been clipped by the pistons, suggesting that the strain of 8,000 rpm is too much for the bottom end (maybe a bit of whip from the crankshaft?).
So I am looking at a minimum of the bores being honed, and 4 new pistons.
But of course whilst it's in pieces anyway, it would make sense to fit some forged pistons, and if you're going to do that, then better con rods would be nice, plus a steel crank and maybe a different cam.
And I could pursue one of my other plans, which is to use a 16v head.
Of course it all depends on money, and as I have a miniscule budget left for it this season, all my ideas are largely irrelevant.
None of this is a great surprise really, the engine was getting old (over 10 years of competition work), and forcing a lot of boost through standard components was only ever going to go one way.
So the bottom line is it really needs a new engine building, if it goes back together with standard components I can't see it surviving long. The problem of course is funding it! And justifying the funding is even harder.
Following the fitting of the solid lifters, I was out again for a weekend of racing.
Unfortunately, all was still not well with the engine, power was way down on what it should be, so this week it has once again been delivered to, and now stripped down at BTEC Racing.
The news is not good.........
Cylinders 1 to 3 have between 70 and 75% leakage, and the best one, Number 4 has 35% leakage.
I'm told the acceptable figures would be about 25%.
One of the pistons shows signs of damage. Two of the spark plugs have been clipped by the pistons, suggesting that the strain of 8,000 rpm is too much for the bottom end (maybe a bit of whip from the crankshaft?).
So I am looking at a minimum of the bores being honed, and 4 new pistons.
But of course whilst it's in pieces anyway, it would make sense to fit some forged pistons, and if you're going to do that, then better con rods would be nice, plus a steel crank and maybe a different cam.
And I could pursue one of my other plans, which is to use a 16v head.
Of course it all depends on money, and as I have a miniscule budget left for it this season, all my ideas are largely irrelevant.
None of this is a great surprise really, the engine was getting old (over 10 years of competition work), and forcing a lot of boost through standard components was only ever going to go one way.
So the bottom line is it really needs a new engine building, if it goes back together with standard components I can't see it surviving long. The problem of course is funding it! And justifying the funding is even harder.
it sounds like that upgrade was a step too far on the old bottom end.
the trouble with the 12st bottom end is that there isn't much available from later models to use, as in newer cranks/rods etc...
maybe its time to brush up on your portugese & go on brazilian eBay for a 1.0 ohc 4pot....
A 1.0 ohc ? What were they fitted in ?
brazilian spec corsa b & c, 8v. it runs 12:1 cr on corn alcohol.....70 odd hp & revs like hell......
Sounds awesome. So in standard form its spi? Same head as 12st?Quote:
Originally Posted by mowgli
That is certainly an option Mike, and you beat me to it as I was going to contact you about it.Quote:
Originally Posted by mowgli
Where was it you found out about this engine/car combination? A specific website/magazine? Or was it just General Knowledge for you?
I need to do some more research on it.
BTEC Racing were keen to build me a 3 cylinder Corsa motor, but I don't thing there's a way I can get away with that under our Regulations;
12.6.1. The engine block must be externally identifiable as that fitted to the original model or specified option.......
Thinking out loud, the other option is to abandon the turbocharger, and stick a N/A 1400cc 16v engine in there.
But that doesn't really appeal to me, a lot of the fun of this car is it being a tiny capacity turbo.
Plus a high spec. baby XE will cost an arm and a leg, and even the best of the best is maybe 210bhp tops.
see below
i was looking at corsa variants on the web one night & then found a youtube link to a turbo 1.0 4cyl corsa in brazil, then sort of went to look for that, as i didn't think they still did a 4cyl 1.0...Quote:
Originally Posted by novarally
and i found this