1.2, 4 speed

[PicklesSE8]

I bought my Nova as a cheap runaround and my drive into work doesn't usually get above 60mph, problem I'm finding is because its a 4 speed I'm revving the nuts off it at anything above 50 so dual carriageways are a bit of a no-no. All I'm wondering is will I be doing any harm to the engine running it at what I would consider to be higher revs, even though it came with a 4 speed? It's done about 130,000 miles. It's ok on fuel, I worked out that its doing about 38mpg. I've also possibly got the option to buy a 1 owner, 45000 mile 1.6 8v Cavalier and wondering if it would be worthwhile getting the engine and box swapped into the Nova? Any comments welcome :)

[Novasport]

Use the Cav for the commute and have some fun with the Nova

[PicklesSE8]

Not an option unfortunately, we also have a Vectra Estate (which I sometimes use for work) and a Calibra (which only comes out in the summer) so no space :)

[therealnovaboy]

other option is to fit a 5 speed box out of a nova/corsa.

I cant see the cav being much better on fuel and putting the cav engine into a nova would be a false ecconomy as its a big block 1.6

you could pick up a f13 box for about £50.

I used to do 300 motorway miles a week in my 1.2 4 speed and never found it much of a problem. my 1.2 used to get roasted from the minute i turned the key for about 60000miles of its life. never once did the engine let me down nor did i change anything other than the oil and filter.

let it rev they like it.

[PicklesSE8]

Cool, I guess the main thing I wanted to know is if it'll do it any harm as I'm used to driving a 6 speed diesel, if they like to be revved then fair enough :) I'm quite happy with the fuel economy, but if fitting a 5 speed box will be beneficial then I'd definitely consider it. Just been looking on Ebay, would any F13 box be suitable?

[marc69]

Your 4 speed will only be doing 3000rpm at 60mph, a lot of small modern 5 speeds rev higher due to being under powered. It probably sounds like more because you can hear the engine due to less road noise intrusion.

Unless you are continually over 60mph in 2nd gear all day, if your car is well maintained it should be fine.

I drive my 1.0 up to 70+mph all the time, does it no harm, they were designed for it.

[marc69]

A 5 speed box would either leave you slightly underpowered if it is low revving in 5th or, as in the case of a F10 in my 1.4, 5th is the same in it (due to a closer diff) as fourth is in the others, therefore more gear changing (but better for higher revs racing).

I doubt you'll notice a big difference in fuel economy, if any. Compared to the cost of gearbox, gaskets and gear oil.

[PicklesSE8]

That's good to know, other thing is the exhaust is pretty (very) loud which probably doesn't help either. If it's not doing any harm and I'm not going to get much of a benefit then I'll stick with it for now, maybe just get a quieter exhaust :D

[marc69]

If your not bothered about noise and if the car is on normal cam/carb etc, you are just as well with a standard exhasut.

Is it a 1.2 carb or injection?

[PicklesSE8]

It's a 12ST, injected, with a cat but no O2 sensor (so presumably I can lose the cat). I'd like it to sound a bit better than standard but at the moment 50mph plus and you can't hear anyone talking

[therealnovaboy]

you probably want an f10 5 speed with a 3.94 final drive. or an f13cr with a 3.54 final drive.

an f10 with a 3.94 final drive will give you 70mph at about 3700rpm
an f10 with a 4.18 final drive will give you 70mph at about 4000rpm
an f13cr with a 3.53 final drive will do 70mph at about 4200rpm
an f13cr with a 3.74 final drive does 70mph at about 4500rpm.

the f10 4 speed does 70mph at about 5000rpm.

take your pick

[therealnovaboy]

It's a 12ST, injected, with a cat but no O2 sensor (so presumably I can lose the cat). I'd like it to sound a bit better than standard but at the moment 50mph plus and you can't hear anyone talking

Im pretty sure the SPI 1.2s had the shorter final drive (3.94) compared with the carb (3.74) so it will be quite revvy.

[PicklesSE8]

Thanks for all the info, would this work?

http://www.ebay.co.uk/itm/VAUXHALL-F10-F13-CR-GEAR-CLUSTER-2-13-AUTOGRASS-RALLY-track-day-/251266300089?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3a80a378b9

[therealnovaboy]

Yes but youll need a 3.5 final drive out of a diesel nova. if you used the final drive you have got in your 4 speed youll end up with exactly the same speed in 5th as you would with your current 4 speed. I.E 72 MPH at 5000rpm

[marc69]

It's a 12ST, injected, with a cat but no O2 sensor (so presumably I can lose the cat). I'd like it to sound a bit better than standard but at the moment 50mph plus and you can't hear anyone talking

Must be a leak or something with your exhause, they are not very noisey cars.

I ran a Kreg 1.2i 4 speed standard engine and 70mph was just above 3500rpm in th gear, the same as my 1.0

[_Jake]

That would make the gears closer meaning youd be at higher revs at 70 for example. I wouldnt worry about going above 50 in your 1.2, i used to cane the daylights out of mine regurlarly topping it out at 90 lol

[therealnovaboy]

Must be a leak or something with your exhause, they are not very noisey cars.

I ran a Kreg 1.2i 4 speed standard engine and 70mph was just above 3500rpm in th gear, the same as my 1.0

Hmm seams a bit low rpm. you sure you were doing 70? 3500rpm is about 50mph with an f10 and a 3.74 final drive.

[PicklesSE8]

Wrong link, I meant to put this one up:

http://www.ebay.co.uk/itm/VAUXHALL-F10-13-CR-GEAR-CLUSTER-2-13-3-7-cwp-/261216040933?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3cd1b077e5

Forgot to mention it's got a cat back aftermarket exhaust...

[therealnovaboy]

thats exactly the same as the last one but with a 3.74 final drive, the same as what is in your 4 speed.

My mate had a 1.2i with an aftermarket exhaust. it used to make a loud humming noise that resonated through the car. if you ditch the CAT it might be less monotonous.

[jimbob-mcgrew]

nova's are generally pretty crap on the sound deadening front.
check you don't have a blow in the exhaust too.

an f10 5 speed's probably what you want for a little extra top end. altho don't expect it to work miracles, it'll still be kinda loud compared to your 6 speed diesel. and depending on what final drive you currently have, compared to the replacement gearbox, you might notice a bit of a knockdown on the acceleration

[therealnovaboy]

I think the 1.4I corsa Bs had an f10 with a 4.18 CWP that would be a pretty good compramise.

too be honest probably not worth the hastle just let it rev and turn the radio up.

[jimbob-mcgrew]

youll have to check which final drive you have (there are markings stamped on the lower edge of the gearbox housing end, behind the passenger wheel)

if your currently running a 3.94 in the 4 speed, a 5 speed with a 4.18 wouldn't really be any different (longer 5th gear with a shorter final drive would be v.similar)

a 5 speed f10 with a 3.94 would be the next step up, or if you want a little more, with a 3.74 final drive would be about as good as your gonna get. on the flipside the acceleration will be poo tho. but depending on how long the drive is everyday, maybe your ears and your sanity are more important lol

[marc69]

Hmm seams a bit low rpm. you sure you were doing 70? 3500rpm is about 50mph with an f10 and a 3.74 final drive.

yes, both cars run at these revs at 70 in 4th as does my sr in 4th(3200rpm in 5th) and my 5 speed 1.4 also runs just over 3500rpm at 70 mph in 5th gear.