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View Full Version : 1200 Bottom with 1300 Head Anyone?



Sola
08-12-14, 10:59 PM
I've had a look around but cannot find the thread that I'm sure I saw on here a while back. I'm planning on putting a 1300 SR (Gt) head, cam etc on a 1200 NV block as I want to keep the small block look under the bonnet.

I know it seems like an odd frankenstein creation but I want to keep all the numbers matching.

Can anyone cast any light on doing this please? I know the engines share the same architecture but I would be grateful to hear from someone that has done it.

Many thanks.

jimbob-mcgrew
08-12-14, 11:23 PM
youll be best off just using the cam, inlet and 2e carb from the 1.3

the 1.3 head has a larger chamber, so youll loose a bit of compression power.

out of curiosity... what parts have you got to play with ? ... do you have 2 complete engines, or just the 1.2 at the moment

Royston
09-12-14, 06:35 AM
add 1.3 crank and conrods = 1.4!

CR may be a little high, would like to know myself if anyone has calculated the CR (not summised)

I will check it myself when I get chance.

Sola
09-12-14, 07:02 AM
Thanks for your answers. I have the 1200 engine up and running quite nicely in the car. I have a tuned 1300 head and top end currently on its way to me. At the same time I have a DMTL Weber carb in the middle of a rebuild and a suitable inlet on its way as well.

Just hoping these can all be brought together and actually work.

mowgli
09-12-14, 09:29 AM
if you fit the 1300 head to the 1200 bottom end, it will work fine, but the carb might run a bit rich.

Sola
13-12-14, 05:20 PM
Thank you for your replies, I am looking forward to giving this a try.

mowgli
14-12-14, 09:14 AM
add 1.3 crank and conrods = 1.4!

CR may be a little high, would like to know myself if anyone has calculated the CR (not summised)

I will check it myself when I get chance.

pm me when you are ready.... remember, i did this when most current nova owners were not even born.

mowgli
14-12-14, 09:18 AM
Thank you for your replies, I am looking forward to giving this a try.

sola, is the 1200 being kept for insurance purposes? or originality?

seriously, as lovely as a 1200st engine is (i did some huge miles in one back in the day), a 1300 or 1400 bottom end will make your nova go a lot faster.

the 1300 head will not make any extra power over the 1200. the carb will, as long as you fit a decent exhaust to it, even the stock 1300 one is better than the 1200 stock one, but you are looking at maybe 2 or 3 hp..

a stock 1300 bottom end will give you a 20hp improvement for no external physical changes (apart from the engine no.)
and a stock 1400 (carb or spi) bottom end will give you more like 25hp.