[Deathscythe]

Well, im MOT'ing and taxing the car at the end of the month and after 3 years of owning / tinkering i think its time to pass on the old girl. I've been looking around at a few other cars as im after something a bit bigger.

i'll always love corsa's, i'll probably buy another one to play with at some point when ive got some more money or as a side project.
So, im thinking about selling what is probably the only 1.2 8v Variable-Valve Lift and Timing corsa in the UK for around a grand (to fund the new car).

Reason for the low price is down to the bodywork, which to be honest needs a little work but nothing beyond the average person, i've already made a start on some things but i don't have the time anymore.
The engine runs beautifully (aside from the usual 8v reluctance to start in extremely cold weather, it always does start though) and has been religously fully serviced every 6000 miles by me. All the work on it has been carried out by me to a perfectionist standard.
The point of this is to see what sort of interest it'll get or anybody's opinions on it. Thanks.

 

[Matt]

any noticeable performance differences\?

 

[Lee]

Whatever you do don't abandon us when you move onto another car!

 

[mark330d]

So, im thinking about selling what is probably the only 1.2 8v Variable-Valve Lift and Timing corsa in the UK for around a grand (to fund the new car).

explain this bit please

 

[jim610]

wot you looking at for your next car?

 

[Deathscythe]

oh hell no, im not leaving the forum, like i said, i'll be hopefully getting another corsa as a project later on when ive got some more cash.
reason for selling it for a grand total of roughly £1000, because thats roughly what i need for my next car. im currently thinking about a bmw 318 or 320 while i save my money up.

I've put a staggering amount of work into it since i bought it, most of the rolling chassis has been rebuilt, the engine totally reworked, the brakes overhauled, the list goes on. the thing is, im not a greedy person, i bought it for £900 3 years ago and since then, the mate i bought it from has watched it get better and better. its time to let somebody else to take over from me i think. the VVLT feature is probably a good talking point at a show or something so it could possibly be a good show car if somebody was willing.

Which brings me onto the point that Matt asked, yes the VVLT does make a fair bit of difference, not extreme i.e. a honda VTEC system because it is a prototype version of it and i really didnt want to blow it up. There's noticeable power steps at 3200rpm and 4000rpm when the intake, then the exhaust valves begin opening wider with the cam timing retarding / advancing between the two valve sets to keep it operating smoothly. the biggest difference is actually at the bottom end, where the cam timing is at its most retarded, giving quite a useful torque increase up until the intake valves start opening further. between 3200rpm and 4000rpm its very responsive on the throttle, which is handy in traffic.

 

[mark330d]

how did you do this? diy? and has the rev limiter been raised? has the ecu been reprogrammed to allow more fuel in?

 

[Martin]

im currently thinking about a bmw 318 or 320

it was a sad day when i decided to sell my C. glad i got the BM thou. Like you said mate, I'll always have a thing for corsa's too, thats why im still floating around.

 

[mark330d]

bmw 330d for the win!

 

[Jonny]

bmw M3 all the way

 

[Deathscythe]

how did you do this? diy? and has the rev limiter been raised? has the ecu been reprogrammed to allow more fuel in?

yes, i did it all myself using a serious amount of maths and spent quite a while measuring the internal diameters of the head to make sure it would work.

the rev limiter hasn't been raised, it still tops out at 6200rpm. i didn't want to touch this as the 1.2 block is a long-stroke motor, which have a tendency to snap the con-rods at high rpm. If rpm's are what you're after, the 1.4 block is recommended, due to it being a 'square' bore/stroke ratio motor.

the ecu doesn't need reprogramming because it is the earlier 'self-programmable' ecu, which doesn't store or even use a preset fuel / ignition map, it calculates the required fuel / ignition advance constantly.

 

[Tim]

Didnt actually realise you had done that much to the engine. Congrats for doing all this to a 1.2 8v, just goes to show that with some effort you can get more power out of a 1.2.
And well if you decided to defiantly put your car up for sale for 1000 I would ask around for you since you live pretty close.

 

[mark330d]

how did you go about doing it all if you dont mind me asking, pm if prefered.

 

[Tim]

Yer I was thinking that as well mark, quite interesting to see how this was done.

 

[Deathscythe]

i really don't mind explaining it, its fairly simple really, the key was the design of the hydraulic tappets.
the original idea was from when i was having a quick read through the haynes manual when the head gasket popped and came across a cross-section pic of the valvetrain. the tappet and valve sit next to each other with a rocker over the top and the cam lobe acting on the top of the rocker between them.

this got me thinking, if the tappet was allowed to open further, then the cam lobe would open the valve further to compensate. while the head was in bits, i stripped the tappets down and removed the limit springs and valve from the bottom of the intake tappets, while punching the bottom of the valve seat in the exhaust tappets with a philips screwdriver. on the head, i carefully cut a trough into the side of the tappet bore to a measured depth with a dremel.
i then built up the valves while submerged in oil, which was tricky because its difficult to see small parts through the engine oil but neccessary to make sure the tappets don't pop shut when the engine first starts up.
after reassembling the head (after i'd done the porting and valve-lapping) i rebuilt it to the engine and cranked it over by hand to make sure the oil was there before turning the key.
after a few cranks it struggled to catch, but steadied down to tickover after a few tries. when it had warmed up i went on a lap round the estate and im still chuffed with the result.

 

[mark330d]

sounds amazing, well done for having the balls to try something different.

 

[Clutch]

Remember reading and asking mark about it, on corsacrazy i think, good stuff not sure but did you say that you think it puts out about 75BHP? (its not just VVLT which has been done before anyone gets excited lol)

 

[corsaJ]

Sounds very technical, would you say its about the same as a 1,4 now then?

 

[Deathscythe]

yeah it makes roughly 75-ish bhp, compared it with a pug 1.1 106 and it keeps up with that, despite being heavier but that makes little difference because of the extra torque available from the 1.2 block.
comparing it against the 1.4 is a little tricky, yes it does make around the same power and torque, but it can't spin up as fast so to keep up with the 1.4 it really needs to be revved hard.
swapping my head onto the 1.4 block should produce much better results, but it might have to have dampers in the oilways into the intake tappets to stop them surging to full open on full throttle, if that happens then the valves might not be able to close fast enough and end up de-compressing the chambers, with the valves burning out soon after. to do that, the head would have to be x-rayed to make sure the extra oilways were drilled precisely, which would cost.