Best Way To Tune My 2.0 Gt/e Manta B

[ryancoupe]

hi guys im new here by the way, i have an 1985 gte manta b hatch and i was wondering how i could tune up the engine in her as i dont realy want to change the engine?

ive heard of getting a stage one head, cam, carbs etc, wat is your veiw? cheers

[madmantamik]

the first place to start is to get it to breath easier , you want to fit a 4 branch manifold , loose the middle box in the exhaust and fit a good quality cone air filter .then you want a new camshaft now this is down to your preference and what the car is going to be used for but a kent OP214 is a good allround cam you can go sillier but you may then start to get tickover poblems.flowed heads are a good way of getting power but can work out to be expensive and if you then end up running a 2.2 or a 2.4 head you will need new inlets aswell.hope this is some help.

[lamchop77]

hi guys im new here by the way, i have an 1985 gte manta b hatch and i was wondering how i could tune up the engine in her as i dont realy want to change the engine?

ive heard of getting a stage one head, cam, carbs etc, wat is your veiw? cheers

Do you want to keep the std injection system? If so then 150 bhp will be your max. CIH engines respond well to head porting, you can get fairly big increases will simple mods. Fit 45mm valve into the head to increse flow (2.2/2.4 valves) and basically smooth up the ports. Best if you can find a head thats been done by a reputable firm as a bad head can loose you power. 214 cam is ok but will only give 6-7 bhp. I would personally use a 234 kent or possibly a catcams equivalent. DBilas have a big range but trying to get one in this country is a nightmare. Regal are the supplier for them but when i rang they just weren't interested. With the 234 cam you may have valve to piston clearence issues, need to check on build. Std manifold is very good so for what you want i would spend the money elsewhere ie exhaust. Lighten and balance the engine, big differnece on the rev pickup. I have had steel flywheels made weighing in at 5.4kg compared to the 12kg std one but this will give a lumpy tickover. vernier timing wheel is a good idea as most engines will have had a head skim or will do if you pull it apart, this throws out the cam timing which you need to dial back in.

If you go the carb route go for 45's. 40's were on the limit with my 160bhp motor and had the chokes over bored. The CIH is a really good motor, alot of guys turn to the 16v but i'm a big fan of the CIH, they're just a gruntier motor. It can cost to make a high power motor but if you search around there are some bargains knocking around for what you want to do.

Think i've got a 214 cam and a couple of 234's in the loft wrapped up if you're interested. Also have a 1.9 ported head with std size wasted stem valves which i'm thinking of selling as i don't think i'll ever use it.

HTH

Chris

[ryancoupe]

the first place to start is to get it to breath easier , you want to fit a 4 branch manifold , loose the middle box in the exhaust and fit a good quality cone air filter .then you want a new camshaft now this is down to your preference and what the car is going to be used for but a kent OP214 is a good allround cam you can go sillier but you may then start to get tickover poblems.flowed heads are a good way of getting power but can work out to be expensive and if you then end up running a 2.2 or a 2.4 head you will need new inlets aswell.hope this is some help.

cheers mate im just trying to see what my best options are at the minute

Do you want to keep the std injection system? If so then 150 bhp will be your max. CIH engines respond well to head porting, you can get fairly big increases will simple mods. Fit 45mm valve into the head to increse flow (2.2/2.4 valves) and basically smooth up the ports. Best if you can find a head thats been done by a reputable firm as a bad head can loose you power. 214 cam is ok but will only give 6-7 bhp. I would personally use a 234 kent or possibly a catcams equivalent. DBilas have a big range but trying to get one in this country is a nightmare. Regal are the supplier for them but when i rang they just weren't interested. With the 234 cam you may have valve to piston clearence issues, need to check on build. Std manifold is very good so for what you want i would spend the money elsewhere ie exhaust. Lighten and balance the engine, big differnece on the rev pickup. I have had steel flywheels made weighing in at 5.4kg compared to the 12kg std one but this will give a lumpy tickover. vernier timing wheel is a good idea as most engines will have had a head skim or will do if you pull it apart, this throws out the cam timing which you need to dial back in.

If you go the carb route go for 45's. 40's were on the limit with my 160bhp motor and had the chokes over bored. The CIH is a really good motor, alot of guys turn to the 16v but i'm a big fan of the CIH, they're just a gruntier motor. It can cost to make a high power motor but if you search around there are some bargains knocking around for what you want to do.

Think i've got a 214 cam and a couple of 234's in the loft wrapped up if you're interested. Also have a 1.9 ported head with std size wasted stem valves which i'm thinking of selling as i don't think i'll ever use it.

HTH

Chris

cheers mate that has answered alot of my questions! i may be interesred in some of those parts also. at the minute i want to keep the injection (untill i scrape up some more cash) but i like the idea of carbs. ive managed to sort out a four branch manifold from a man beside me

£30 second hand, not bad i thought!

[keith1200]

Std manifold is very good so for what you want i would spend the money elsewhere ie exhaust.

I have heard that a 4 brancher etc will increase BHP by 0.5! and I've also heard that; for once! GM were 'spot-on' with the standard manifold! yeah surprised me also

Porting is the way forward (i believe) if you go down that route? and while the engine is in bits? you might as well add goodies

As always; top advice 'above'

GL

Keith

[2908642343]

Keith;

You are quite right re the standard manifold over a 4 branch manifold, Opel got the manifold spot on, in testing a standard manifold v 4 branch the difference was less than 0.5 bhp, there is a good right up on the testing done in one of the motoring mags, for the life of me a cant remember which one.

One quite easy way to get more fromm the 2.0 ltr Cih is to swap the head for a 2.2 head and use 2.4 injectors and run the 2.2 injection system.

John

[lamchop77]

Keith;

You are quite right re the standard manifold over a 4 branch manifold, Opel got the manifold spot on, in testing a standard manifold v 4 branch the difference was less than 0.5 bhp, there is a good right up on the testing done in one of the motoring mags, for the life of me a cant remember which one.

One quite easy way to get more fromm the 2.0 ltr Cih is to swap the head for a 2.2 head and use 2.4 injectors and run the 2.2 injection system.

John

John the article you are thinking of is out of an old CCC and it was Dave Walker testing a Janspeed 4 branch against a std manifold on his rolling road. Why is my head so full of this sort of stuff.......i must be very, very sad.

Yes you can swap the heads, a std 2.2 flows about the same as a well ported 2.0, but try finding them nowadays. 2.2 injection seems to be just as hard to find and was also actually developed as an economy set up so why use as a performance upgrade. Guy i used to race against used a CIH 2.0 and used a 2.4 Frontera head and fitted the std 2.0 injection, can't remember which injectors he used, but he reckoned to have got 7-8 bhp more than with the 2.2/2.4 systems. Was going to try it but never got round to it. All you needed to do was drill a couple of new holes in the 2.0 inlet manifold to repositon it correctly on the 2.2 head then match the ports and fasten up with some bigger washers to hold the 2 manifolds to the head. Think you need a packer plate to attach the themostat housing as well.

HTH

Chris

[guysat]

Keith;

You are quite right re the standard manifold over a 4 branch manifold, Opel got the manifold spot on, in testing a standard manifold v 4 branch the difference was less than 0.5 bhp, there is a good right up on the testing done in one of the motoring mags, for the life of me a cant remember which one.

One quite easy way to get more fromm the 2.0 ltr Cih is to swap the head for a 2.2 head and use 2.4 injectors and run the 2.2 injection system.

John

Hi

Can you not just use the 2.4 head and injectors & 2.2 injection sysytem....?

Or is the combustion chamber different on the 2.4

Guy

[2908642343]

There is no particular problem with dropping a 2.4 head into the 2.0 ltr engine, except you will need a 2.4 manifold as well i beleive.

The 2.2 manifold and injection loom will work fine.

Another way to per look at this is to go the whole hog and put in a 2.4 lump with a 2.2 injection manifold and loom.

A good person to ask this question of is Andy Clears as he has done this before and so have several other members.

My car is currently running a new built 2.2 with 2.4 injectors and 2,2 loom, it has done about 2k miles and drives like a dream, plenty of torque, but next year the 2.2 is coming out for a well balanced and CC 2.4 running the 2.2 inlet manifold.

The only real reason to run a 2.2 inlet manifold rather than 2.4 is the 2.4 manifold is taller andyou will need to cut a whole in the bonnet.

I am sure GTEPETE has used a cut down 6 cyclinder inlet manifold and bolted it to a 2.4 without any great proplems.

John

[lamchop77]

There is no particular problem with dropping a 2.4 head into the 2.0 ltr engine, except you will need a 2.4 manifold as well i beleive.

The 2.2 manifold and injection loom will work fine.

Another way to per look at this is to go the whole hog and put in a 2.4 lump with a 2.2 injection manifold and loom.

A good person to ask this question of is Andy Clears as he has done this before and so have several other members.

My car is currently running a new built 2.2 with 2.4 injectors and 2,2 loom, it has done about 2k miles and drives like a dream, plenty of torque, but next year the 2.2 is coming out for a well balanced and CC 2.4 running the 2.2 inlet manifold.

The only real reason to run a 2.2 inlet manifold rather than 2.4 is the 2.4 manifold is taller andyou will need to cut a whole in the bonnet.

I am sure GTEPETE has used a cut down 6 cyclinder inlet manifold and bolted it to a 2.4 without any great proplems.

Just out of interest, what else have you done other than put the 2.4 injectors in. Got a couple of sets of injectors off the 2.4s which i could use but cos i don't mess around with the injection system at all i'm wondering whether its worth trying them on a 2.0 set up on a well tuned 2.0/2.2. Did have a 2.2 engine that had run on 2.4 injectors but it was pretty much goosed, bores scored, bearings scored. Talking with my engine guy we came to the conclusion that it had been overfuelling and had thinned the oil down and washed the oil off the bores as it was running so i didnt want to risk using them on a decent motor.

The differences between the 2.2 and 2.4 heads are small. I think there is a small difference in the combustion chamber but the 2.4 pistons i have are dished and the 2.2 ones aren't so thats where any major change will be. The exhaust ports are slightly bigger and the valves are a better quality than the 2.2 ones.

HTH

Chris

[2908642343]

On the current 2.2 have done no other mods to the engine other than run 2.4 injectors.

The engine is as new as was stripped and rebuilt with new GM parts and GM gaskets etc.

Engine tuned and fueling set up on a rolling road.

The only other slight mod that has been done is that the car has A/C from a left hand drive Manta so has an additional ECU as a "Kicker" when you have the A/C on. The A/C takes a lot of power out of the 2.2 engine.

Other than that a standard well built engine in standard form, that knocks out about 137bhp on the rolling road.

Have changed the flywheel to a Monza flywheel with larger clutch, and clutch fork, the only reason for doing this was to make the clutch lighter and to be able to use a 2.4 at a later date. Some people have had problem with using the standard clutch when running 2.4's and some have not. I had the clutch chnaged as i based my decision on informaion from Andy, Nick, Paul, etc who are all running 2.4 Manta's.

The only reason for me to go to 2.4 is to get the additional torque and power to ofset the amount that the A/C takes from the engine and to give the car long legs for driving across Europe in. Parts for the 2.4's are also easier to find and are cheaper. I could have gone down the 16v route but this has been done by many people and i wanted the car to retain as much origanility as possible.

John

John

[ryancoupe]

On the current 2.2 have done no other mods to the engine other than run 2.4 injectors.

The engine is as new as was stripped and rebuilt with new GM parts and GM gaskets etc.

Engine tuned and fueling set up on a rolling road.

The only other slight mod that has been done is that the car has A/C from a left hand drive Manta so has an additional ECU as a "Kicker" when you have the A/C on. The A/C takes a lot of power out of the 2.2 engine.

Other than that a standard well built engine in standard form, that knocks out about 137bhp on the rolling road.

Have changed the flywheel to a Monza flywheel with larger clutch, and clutch fork, the only reason for doing this was to make the clutch lighter and to be able to use a 2.4 at a later date. Some people have had problem with using the standard clutch when running 2.4's and some have not. I had the clutch chnaged as i based my decision on informaion from Andy, Nick, Paul, etc who are all running 2.4 Manta's.

The only reason for me to go to 2.4 is to get the additional torque and power to ofset the amount that the A/C takes from the engine and to give the car long legs for driving across Europe in. Parts for the 2.4's are also easier to find and are cheaper. I could have gone down the 16v route but this has been done by many people and i wanted the car to retain as much origanility as possible.

John

John

cheers lads for all the help< any idea wer to get the lightened flywheel at?

[could not be happier]

hi guys im new here by the way, i have an 1985 gte manta b hatch and i was wondering how i could tune up the engine in her as i dont realy want to change the engine?

ive heard of getting a stage one head, cam, carbs etc, wat is your veiw? cheers

i used to run a gte, with 2.4 peter maiden engine, got a good deal from a mate on it after, i went through all sorts of tuning with the 2 litre, but ran out of money when i needed a set of webber 45 downgraught carbs, i did want to retain the original ( modded ) injection , down to cost again, puttin the 45 delorto,s on would have meant remote brake diaphrams, stuff all that,,

what i know now i didnt then, that a set of maybe GSXR 1100 ( or early model yamaha R1) examples ,, carbs and some sort of timed ignition advance, tuned to the carbs, will give a very good bhp and torque increase,, maybe using a flowed big valve head, 2.2 maybe with full rally ( is it kent 345 cam? ) cant rmemeber the actual one, but also the fast road gives better rev range, likely better with the bike carbs,,

you would have to fabricate a manifold tho,, wouldnt be too hard ,

[Kevin Abbott]

Don't bother spending lots of money trying to 'tune' an old engine, cut your losses, use the CIH as a boat anchor ( in fact buy a boat with the money you have saved by not tuning a nail) and put a more modern engine in. I'm not posting to piss you off mate i'm just hoping you don't chuck money at old tech. Been there, worn the t shirt, got beat by standard modern cars.

You wouldn't put more memory into a Spectrum computer, don't waste your money on a CIH.

If you have plenty of time then remove the head, port it out, radius the sharpest curve in the head ports, lose the guide bosses in the ports, match the manifold, buy a cheap big branch manifold, CIH engine isn't a crossflow engine so doesn't tune very well. They got cosworth to do a crossflow engine for the 400 for good measure and even that only made 140bhp in road trim

Regards

Kev

Oh yea, join the club

[Lesis]

The exhaust ports are slightly bigger and the valves are a better quality than the 2.2 ones.

So,this info is true?Found in opelgt.com

The 2.2 valves were fusion welded together, thats right, but he 2.4 valves are one pieced, they were better and stronger for undercut use, but many friends here will use also the 2.2 valves with undercut and it will work, with a 12:1 compression ratio, 7800rpm and 230 HP!

Do You undercut valve stems on stock 45/40mm valves?To what diameter?

[mantadoc]

Std head with 2.2 valves, or 2.2 head. Three angle valve seats and ported.

Careful with cams, anything wild usually means overlap with generally will push up your HC and could lead to emissions problems for MOT.

Don't forget the "oldies but goodies" to add to that, decent diameter cold air feed from the slot in the airdam to the standard airbox with a performance filter and marking the AFM spring and backing off 5 notches.

[lamchop77]

I wouldn't undercut the 2.2 valves and probably not the 2.4 either. Just stump up the cash and get a set of 214N stainless valves from Race Engine Componenets. May cost a bit but they are race proven valves.

Undercutting a std valve could cause the head of the valve to break off, which will cause cataclysmic damage!!!!

Just as a side note the 2.2 i had was set up onthe rolling road and witha 244 kent cam the hydrocarbons were at about 700 and dropped as you got up the rev range. The redtop 16v that was on before my car was over double that.

Chris