1.7 Engine 1.4 Box

[PaulZ]

Hi all
Quick question for guru's of mechanics.

Iv got a 1.4 at the moment and i want a 1.7 in the next couple of months when/if i can afford it.
I know my car pretty well now so if possible i was thinking of buying a good low milage 1.7 engine and have someone stick it in my car rather than buying a new puma that may well just bring me a lot of hassle.

Obviously car needs updating with the DVLA etc after this but my question is 1.4 gearbox or 1.7 gearbox.

Iv spent most of last night and this morning trying to work out which is best but to be honest i cant work it all out. I know the 1.4 box has shorter ratio's than a 1.7 but are they to short for a 1.7 engine.
Also how will rpm be at certain speeds on a 1.4 box and 1.7 engine compared to a 1.4 complete car.

If i have gotten myself muddled up with all the number's and understanding of gearbox ratios can someone please help me out

Cheers
PaulZ

 

[corley]

the 1.7 box is matched up nicely for the engine, regarding shorter ratios depends how you like to drive but i really like the FRP box with short ratios as the acceleration is really nice over standard. but other get upset about running at 3700rpm at 70.

I don't know if the 1.4 has shorter ratios maybe someone can confirm?

 

[pumad]

it will make less revs on 70 ... (3200 RPM) Only the first 2 gears are noticebly shorter then the 1.7 box...

Will be a great highway car with less rpm than a normal 1.7 will do!

 

[Ginger Tom]

Should be quicker to 60 aswell

 

[pumad]

Should be quicker to 60 aswell

don't think so... because you barely hit 60 in second with a standard 1.7... Which has slightly longer gearing in second than a 1.4 does.

so you have to shift to 3

 

[stumc]

Mate it will be exactly the same as your current 1.4 in terms of revs:wheel speed. Whatever the engine revs to at a given when speed now, it will be exactly the same with a different engine if you use the same gearbox.

I'd go for it, a lot to be said for lower ratio gearin in my opinion!

 

[SkyHighatrist]

Should be quicker to 60 aswell

don't think so... because you barely hit 60 in second with a standard 1.7... Which has slightly longer gearing in second than a 1.4 does.

so you have to shift to 3

I dont know, until i had the engine transplant last year, my millie hit about 73 in second on std 15"s. Now she does barely make 60 in 2nd :/

 

[PaulZ]

Thanks everyone for your inputs, valuable information

Cheers
PaulZ