Inlet manifolds?

[greg1.4]

i am running a 1400cc nova and its engine re-build time..

i am wanting a bit more go aswell. i have a 1400 sri block with 1300 head, enem 300deg camshaft and webber 40 dcoe's..

i also have a 1400 sri head sitting, which i believe has bigger valves as standard and round ports, so is this better than the 1300 head?

and if i was getting a gain by using the 1400 sri head would i need to use a round port inlet manifold?

Can i also fit bigger valves with double springs to a sri head?

thanks

Greg

[greg1.4]

what would be better?

a 1400 sri head with bigger valves (from kent or whoever makes them), ported and polished with round port manifold and 40's?

or

a 1300 sr head with bigger valves, ported and polished and a sqaure port manifold with 40's?


also where can i buy 'bigger' valves and double springs for the 8v engines?

[mikey14sr]

A standard SRi head with round-port manifold can easily give a 10bhp improvement over a 1300 head and T40 inlet, and it allready has bigger valves in it.

[Adam]

SRi head and a round port inlet.
It has bigger ports and valves than a standard 1300 head.

[MC]

If you are going to put larger valves in either head, use the 1300 item.

Both heads have the same amount of room for valves so in theory can be modified to the same extent. The 1300 head will raise compression and it has larger ports than the 1400sri head. The cathedral shape has the same profile at the top but opens up more at the bottom.

Valves will be supplied by whoever does the headwork.

[greg1.4]

thanks guys..

yes i am wanting a decent spec head..

think i will go with the 1300 head and get it ported and polished with big valves as this raises compression too..

what is the best inlet manifold to use with the 1300 sr head? the cathedral type i take it?

[MC]

Yeah, I once had an irmsher sport one and to use it on my 1600 filled the lower half with weld and matched it to the head! Doh.

[greg1.4]

ha ha, thanks for the quick help, much appreciated!

Greg

[garyc]

what carb do you want to run?

[greg1.4]

webbers..

[garyc]

ther are lots of weBers!!!!!!!!

[MC]

Read the very first post garyc and all becomes clear! lol

[garyc]

ah I see, I thought all 40 manifolds are more or less the same. I guess he needs one that matches the ports on his head then! then carefully matching everything up for full performance.