1.4 sr converted 1.2 head.. wat cam to use???

[James P]

so decided to fix the white nova.(1.4sr) J REG, it had 4 broken valves. so went down to this guy who breaks nova's. he only has 1.2 HEAD.

now this will fit and it makes them quicker. but has anyone done this before? because i need to know should i use the 1.4sr cam or the 1.2 cam? i know they will both work but want maximum performance output!!! thanx if you can help me.:thumb:

[Adam]

Im not sure about using a 1.2 head, its going put compression up.
1300 head may have been more suitable.

Use the 1400 cam, as the 1.2 cam wont fit your 1.4 dizzy :)

[James P]

im just using the 1.2 head. keeping the 1.4sr cam casing. surely it doesnt matter what dizzy i use does it????

if anything it will suite the 1.4 engine more because they have bigger valves thus letting gas's in/out quicker.
they have the same compresion chamber head so wont effect compresion.
the head is the same as the 1.4sr head just with bigger valve's.

[Adam]

Only the 1.4 dizzy will fit the 1.4 cam. So just fit the 1400 cam housing with the 12 head.
So you'll have to use the 1.4 dizzy.

It does affect compression because the chamber "depth" is different.

Valve sizes are the same, its the ports that flow much better than the 1.4sr ones.

[James P]

yer thats true about the dizzy.ill do that.. also you can clearly see the 1.2 valves are wider.

and if the chamber depth is different then its only by a fraction. i measured it. also thats a good thing.

[Adam]

Indeed, higher CR is a good thing up to a certain point ;)
And then it starts detting under load.

Perhaps i got it confused with the 1.2i heads that has small valves.
I dont have the numbers to hand

[James P]

oh yes thats probely what you've done. im getting it 2moz so will start putting engine back together. let you how it gets on. ill get some pics up to.