no they increase fuel pressure therefore they make the injectors inject more fuel. will do funk all on a carb carQuote:
Originally Posted by turbojolt
Printable View
no they increase fuel pressure therefore they make the injectors inject more fuel. will do funk all on a carb carQuote:
Originally Posted by turbojolt
o right well i heared wrong then lol
would a 1.3 carb need to be down jetted to match the 1.2 engine
Dont think so mate, I'd try it without rejetting first. Should be ok iirc
what other mods do you have planned?
List of stuff I'm thinking of doing....to make a kind of stealthy engine.
- Skimming.....both Head and Cam carrier.
This would cost me around 60-80 quid I rekon. Giving higher lift on cam, theoretically, and increasing compression ratio. Need to measure CR first to make sure everything's hunky dorey.
- 1.3 SR camshaft kit.
Cam and followers to be installed.
- GTE/GSI exhaust system, from manifold back. This should give good exhaust flow, much better than standard system. May then try out a Eurorallye exhaust system mated to the front end of the GTE/GSI system.
- Either SR or 32/34 Weber carbs. This will probably be a bit further in the future.
- Eventually might try the 1.3 crank and rods in it, however 1.3 engines are like rocking horse **** so I'm not holding out hopes, unless I can find one which needs rebuilding, so I can nick the relevant parts.
I'm hoping to get close to SR performance. I know it would be much more advisable to XE the thing, but I fancy doing some of this stuff just as an exercise. Plus I think I would be lethal with 150 brake lol
i didn't know this, very interesting. would work well with the other goodies i have goin on my 1.2.Quote:
Originally Posted by Riggy
hence sri inletQuote:
Originally Posted by burgo
just bare in mind that altho yes it does give you a 1.4, it achieves this by having quite a large stroke and therefore a lazy engine. you'd be better off with a normal 1.4 bottom endQuote:
Originally Posted by MattyW
is the sr crank and rods the same as in the 1300 mk2 astras
any one thinking of doing the 1.3 crankshaft and con-rods should have a look here clicky there is a set of balanced and polished 1300 sport con-rods for only £60
also before tuning a 1.2 8v engine would it not be a good idear to change all the oil and filters timing belt maybe run a bottle of engine flush through the system maybe flush the cooling system change the dizzy the spark plugs and ht leads just to make sure it was in really good condition before spending money on it
but i want to keep my 1.2 head, i was under the impresion that only the 1.3 bottom end would fit.Quote:
Originally Posted by burgo
oh and its a well maintained engine, dizzy, leads, oil is all pretty new.
why do you want to keep your 1.2 head??
because of all the bits i already have on it, (manifolds, cam.)
what manifold ans cams do you have on it already mate
Only got a four branch mani and full mongoose system on it at the moment.
But got an irmcher inlet with twin carbs, kent fast road cam and vernier pulley goin on in the next few weeks.
I'm getting the head polished and stuff and set up by my local rolling road.
Got my mot this month so wanna get it through that before i carry on playing.
ps, i know i could change the engine for the money im spending but its my money to waste :D and i have coilovers. strut brace and gsi brakes for the people thinking i should be consentrating on handling first.
did you notice much of a diffrence when you put on the manifold and exhaust or was it just manily a sound diffrence
are you or have you had it on a rolling road yet
so your not changing the head because of the bits connected to it!!! thats stupid imo. 1.2 valves are tiny. hopefully by tonight i should know the cc of the combustion chambers of 1.2, 14sri and 1.6 heads so can advice you which of the other two is best to fit
is a 1.6 or 1.4 sri head going to be a direct fit
also i might be wrong but arnt the 1.4 sri heads a bit of a rarity
no they are redily available on mk3 astra's and as i said ill let you know later
what so dose the 1.4i astra have the same engine as the sri i never knew this
the 1.4 mpi yes as they do the spi in them aswell
right results are. if you use a 1.4 sri head you get a compression ratio of 8:! and a 1.6 head you get 7:! both of which are miles off the mark. if you can remove 7cc from the 1.4 head volume then it will take it back to 10:1
so could that be a easy way to have a low compression engine for maybe a turbo
or am i muppet for thinking this lol
yes exactly that turbojolt
what im a mupet or it would be good lmao
both :thumb:
lmao so how did you work it out mate are you a engine builder or just really smart when it comes to engines
i think we are going to have to make another article to add to this one now as options have just opened right up for the 1.2 engine from a little conversion
dose or can anyone work out what compression ration a 1.2 with a 1.3sr crank and rods would be roughly as i have no knowledge on how to do this
im just very smart :P. basically i measured the cc of the 1.2, 1.4 and 1.6 heads then use stu's calculators
well i must be stupid then, is just a bit of fun, just want to see what kinda power i can get out of the engine.Quote:
Originally Posted by burgo
if i wanted amazing power gains i would've kept my 200sx on the road.
not much diferrence if any, maybe a tiny bit more responsive but nothing to get excited about.Quote:
Originally Posted by turbojolt
havent put it on the rollers yet, but am kinda tempted to do it before i fit the other parts so i can get a before and after figure.
sorry to be very dim but is the cc the amount that the ports can flow
Quote:
Originally Posted by MattyW
it would be very interesting to see the differences seems as you are going to be caring out a far amount of work
thats what im thinking, it seems everyone gets shot down when they ask about tunning the little 1.2, so would be good to have some concrete figures for people to refer to instead of 'dont bother its not worth it' from the big block brigade.
the rolling road im using is proper old school and is good with carb vauxhall engines, his rollers are only good for about 200bhp so think i'll be safe to use him throughout this little experiment.
i will get a power run as it stands and another one after he's tuned it up then we'll have some base figures to start from.
any constructive suggestions on this are welcome. :thumb:
Quote:
Originally Posted by MattyW
to be honest i cant wait lol
i hate all this you could put a xe in it and get more power at the end of the day they could convert it to a space frame chassis and run a twin turbo mid engined 5.0ltr v8 but they don't i hate all the negative comments on the tuning of the smaller engines
i hope it all goes well for you mate any idear when you will be getting this all done
cc is a measurement of area
Quote:
Originally Posted by burgo
im with you now :thumb:
lol
i'll pop in to the rolling road this week and book the first run, and hopefully the next stage of tunning will be done next month.
volume ;)