13 replies to this topic

[Mini Man Dan]

Hi,

I currently have a 998cc A plus engine with a stage one kit and a high lift cam. I am considering getting a different cylider head but not sure which would give me the best performance. Would a 12g295 head be best?

What work would i need to do to fit this head? Would it be worth it? I dont want to go for a 1275 as insurance costs are an issue so i was thinking of just modifying my current 998. I know i would need to declare all modifications to the insurance company.

Thanks for all help!

P.s. I have spent the past hour searching before posting this topic

[stef]

yeh 12g295 is best. you dont need to mod anything to fit it either i dont think.

either that or buy a stage 3 from morspeed or the likes

and yes. to get the best out of your cam you need a modded head

Edited by stef, 03 April 2007 - 10:24 PM.

[minivanman]

like stef says, the 12g295 is the one to get - its the best flowing from standard. I've got one sat on my desk waiting to go on my car. I would do a cam change in it as well but I cant be bothered to take the engine out. One project at a time! It will probably need work doing to it though, because they have been abused for the last 40 odd years. I've got new springs, valves, a bit of light porting and unleaded seats in mine. So far its cost me £50 for the head, £200 for the work at morspeed, then all the studs, thermostat and head gasket kit etc. So looking at around £300 in all.

[Mini Man Dan]

Are there 9 stud and 11 stud 12g295 heads or did they only do them as one size if that makes sense.

You say to get the best out of my cam i will need a modded head but what modifications would i need to do to get the best performance? I dont want to buy a morspeed stage 3 as they cost around 800 if i am correct. If i get a 12g295 head what could i do to it to improve my overall performance?

Cheers
Dan

[Nic]

the 12g295 head was fitted to the coopers and so none were 11 stud as far as im aware. it will have to be skimmed to get the correct compression ration for your engine. other than that it is a bolt on and go. of corse bigger valves can be fitted and the head can be gasflowed etc to get more performace.

[Jimmyarm]

Alternatively you could go down the 12g940 (1275 head casting) route. Its more work - have to get the block pocketed, mess about with the heater plumbing, possibly shave a bit off the water pump, but it will give you better results.

Whichever head you choose, consider doing a cam change at the same time to maximise the benefit of both mods.

[Clubby1275GT]

i have 1 currently attatched to a 998 engine that i will sell! its had bigger valves as far as i know and has been ported, dont quote me though as im going buy what ive been told.

i can whip it off for u if u want it, postage would be high as its heavy but i live in brum if its any good to u

if u do a search on the topic "found a head" or something like that u will see pictures, its got double valve springs and cast rocker gear on IIRC

[Mini Man Dan]

Thanks for all of your replies the are very usefull!

How much would i have to have skimmed off tog et the best compression or does it vary from engine to engine? I have heard a lot of people talk about getting an engine pocketed but what does this actually mean/involve?

Jimmyarm i have already got a different cam. just spoken to my dad and he think he bought a fast road cam from mini sport

Cheers
Dan

[blacktulip]

for a cam i would go for a kent 266 for the road.

[Mini Man Dan]

After doing another search and reading more topics i have another question.

What modifications can i do to my current head to improve it and how good would this be compared to a 12g295 head?

Cheers
Dan

[stef]

stage 3 heads were around 350 last time i looked.

you can get your head ported, flowed and polished, double valve springs etc.

if you look in the faq section, im sure there is a post where it shows you what heads have what size inlet and exhaust valves.

at the end of the day its a 998, around stage 3 spec would be fine for you really. and i would advise a kent cam or an sw5. the one you have probably isnt gonna get thes best out of your engine. depends what you want. you can go for a mental cam but it'll do your head in round town.

[stef]

http://www.theminifo...showtopic=19385

[Big_Adam]

12g295 should come with double springs as standard.

As for improvements you can do to your current head,

David Vizard: Tuning The A-Series Engine

Just buy it and read it. It will tell you (almost) EVERYTHING about making your engine work harder and go faster.

And seeming as I'm hear, pocketing the block is were a cut out in the block is made to stop the valves in the head smashing into the block at high speed. The cut out allows for valves to get to full hight without smashing into the block and buggering the engine in a massive and expensive way.

[Sammy D]

Buy my Slark race engine and use your current bits and make a monster..

http://www.theminifo...showtopic=45065