Who gives the best head?

[beavy69]

I have a 1.3L and want 2mod the head.

clearly (thanks to my poll "1.2 head") a 1.2 head will give better compression. But can it be shaved away for bigger valves as much as a 1.3 head before you hit the water mains?

doe anyone know, is anyone a head engineer (no pun)?

where's the best place (in the far south-yee haa) to get it done.

keep talkin

thanx,

[Dod]

Answer to the Title Question, Jenna Jameson, without a doubt.

Use the 1200 head and get 1600 Valves machined to suit, Stu did this before and reckons they're a good job. Wait for a few posts and he'll no doubt have a few lines to post. Port it and that should help you a good bit.

[Snowface]

1200 and 1300 head have same size valves.

You can put up to 39mm inlet and 33mm exhaust valves in nova heads i think.

(standard 1.2/1.3 are 31mm inlet and 29 exhaust)

if you wanted to use bigger nova valves in your 1.2/1.3, you'd have to use sri ones because the 1.6gte/gsi are shorter.

Standard sri exhaust valve is 31mm, inlet is 36/37mm

[Stuart]

we had "special" valves sourced that are 1.6 head diameter but 1.2 stem lentgh. V fooking pricey.



as for good head. Gary on MIG but he might be a tad busy at the moment.
try cylinderhead development or whoever they are in the back of PPC etc.

[Stuart]

oh and bigger valves + small capacity = fairly high rev occuring power..... more so with a performance cam added too

[beavy69]

Do you know that from experience Dod?

[S_Gault]

what size is your special 1.6 valves? as there is no way to fit a valve bigger than 35mm onto the std valve seat insert.

and no need to anyhow- ive had 80cfm from them with a 35mm valve and thats enough airflow for 135bhp

[Stuart]

they are "special" as in they ahve the same valve size as the 1.6 ones but have a stem length same as the 1.2 valves......

"special" meaning, not normal lol.


Or are you jsut being piccy about the words i use now? :P

[S_Gault]

no not at all, dont be so daft,

i know about the stem length.. since i think it was me who mentioned it originally, but a good 1600 head has a 37mm valve.. is that the size you are using?

[Stuart]

std 1.6 sized heads.

in a 1.2 thats fine imho. :P any bigger and they would be fecking close to caressing the bores lol

[S_Gault]

but they wont fit on the insert.

and if you take a std 1.6 and machine the tip to get the correct stem length , they wont last long as youve broken thru the stellite hardness

[Stuart]

they werent machined stems! they were fecking expensive items of the right spec.

they "seem" to fit the insert thats there lmao so meh

[S_Gault]

sorry, i thought they were machined, keep your pants on man,


Hows your engine coming along? any pics

Steven

[Stuart]

the engien has been "built2 since late july lol. but still nto started as the car isnt ready, and its cold so i cba till march

theres a couple of pics in the feature :p go find it lol

[Snowface]

http://img.photobucket.com/albums/v642/Snowface-85/day12.jpg

a GTE 1.6 Exhaust valve (32mm) on the Left and an SRi exhaust valve (31mm) on the right

if your after bigger valves in a 1.2/1.3/1.4 head then SRi ones fit (height wise).
They are either the same as or 1mm smaller diameter than GSI/GTE.

My 1.2 head Bill did for me he put 36mm inlet valves from a Vx Monza head (?) he had in he was working on.