Manta B Engine Swap

[farmerjack]

My 2.0l GTE with standard CIH engine is becoming difficult to get thro' MOT emmissions test.

I'm keen to keep to 8v to retain the ability to compete under road rally regs.

Wondered if a C20NE engine (Calibra 8v) would be a suitable replacement? What is the difference between C20NE and SEH?

Any thoughts or tips on this would be welcome particularly in relation to engine mounts, sumps and gearbox.

best wishes

fj

[Blockhead]

SEH engine has slightly different ECU, pistons and camshaft, camshaft being the main power difference. All parts are interchangeable though if you are going to be doing a rebuild on it.

You will have trouble mounting the engine to your gearbox though as the 20NE engine block (and SEH) are the same block as the 1.8L OHC engine fitted to the Manta. With a 1.8 gearbox (same used to convert to RedTop) you shouldn't have too much bother fitting although I don't know how much difference there is in engine and gearbox mounts- not much to my knowledge but somebody else on here will know more about that.

[Snowy]

SEH engine has slightly different ECU, pistons and camshaft, camshaft being the main power difference. All parts are interchangeable though if you are going to be doing a rebuild on it.

You will have trouble mounting the engine to your gearbox though as the 20NE engine block (and SEH) are the same block as the 1.8L OHC engine fitted to the Manta. With a 1.8 gearbox (same used to convert to RedTop) you shouldn't have too much bother fitting although I don't know how much difference there is in engine and gearbox mounts- not much to my knowledge but somebody else on here will know more about that.

The 2.0L SEH also has a compression ratio of 10:1 compared to the NE compression ration of 9.2:1

The NE has 115BHP and 124lbf ft torque.

The SEH has 130BHP the torque figure escapes me now??

The pre 1990 carltons had the 2.0L SE which was 122BHP and 129 lbf ft torque.

You could also plump for the 1.8 SEH from a pre 1990 carlton. This produced 115BHP and 118 lbf ft torque.

Or if you can find one the 1.8E from the mk2 cav sri or mk1 astra gte. this produced 115BHP and 111 lbf ft torque.

All these engines are the OHC family and will bolt up to the gearbox mentioned above.

All these engine make sense when you realise that the standard GTE engine only produces about 110BHP and 110 ft lbs of torque.

[Rick-Manta]

I was running the NE engine in my calibra a few years back and as has been mentioned it is just a lower powered 2.0 engine for some of the base model types and I assume was for higher fuel economy and cheaper insurance but while still being reasonably quick as you'd expect a calibra to be. If you did go for the NE you'd have a small power to weight advantage but the horsepower and capacity will be very similar to your original GTE CIH.

The sump, pick-up, gearbox and engine mounts (plus keep aside other ancillary parts and radiator hoses) you can get from the manta standard 1.8 OHC, they will let you fit all of the engines discussed but you're probably aware due to that fact it does make the 'conversion parts' of the manta 1.8 quite expensive, you'd be looking at £350 minimum plus you'll be unlikely to find everything you need from the same seller unless you find a rotten MOT-less 1.8S for sale.

As for fitting an Astra 1.8 instead of a 2.0 SEH or NE, although the outputs are similar and otherwise a good option, bear in mind that trying to declare a smaller engine has been fitted into your car is a right old pain. Keeping the capacity to 2.0 will be easier for the paperwork side of things and in fact declaring an increase is very easy to.

[mantasrme]

They changed the rules on Road Rally's 2 years back (or was it 3 )

Anyway you are now allowed to fit a 16v engine as long as you retain the standard inlet manifold for that engine.

So you can stick a c20xe 16v in without a problem

Thats what i did, its a massive improvement over the 8valve 2.0SEH i had in there before

Definatly the best way to go, and about the same cost as a SEH or NE

[dynamytedan]

i fited the 20seh .5mm bigger pistons with a stage 1 head , bike carbs and a 1.8gte cam shaft . definatly fast enough to satify my needs .

another member with a similar set up reached over 150bhp at the dyno .

as already said you would need the 18s gearbox and sump etc very sought after bits fetching a high price .

already talking hundreds without an engine .

cheaper options might be a 2.2 16v or a better GTE lump .

[mantadoc]

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Edited October 2, 2017 by mantadoc

[Snowy]

Any one into Ecotecs?

I still don't think Red Tops on standard injection and manifolds would beat the Ecotec 2 litre's 136 BHP (or is it 131?) after a minimum 20 years of use without a rebuild.

Plus there is the 140 SRI option.

Don't know if the Ecotec inlet clears the servo though.

Obviously an XE on standard injection is an easier fit with only a few wires.

I tend to think if swapping, and not totally performance motivated, picking a standard engine that meets your requirements is the best way to go.... keeps your maintenance easy and parts off the shelf, plus none of the usual expenses of modding which may not deliver without proving on a dyno.

Basically predictable horsepower, torque and reliability.

I will let you know as i have a 2L ecotec to fit in my mk1 cavalier.

[Leon]

Any one into Ecotecs?

I still don't think Red Tops on standard injection and manifolds would beat the Ecotec 2 litre's 136 BHP (or is it 131?) after a minimum 20 years of use without a rebuild.

Plus there is the 140 SRI option.

Don't know if the Ecotec inlet clears the servo though.

Obviously an XE on standard injection is an easier fit with only a few wires.

I'd have thought the Ecotec head will clear the servo as I'm sure the Ecotec head is a little bit narrower than the XE?

I've got plenty of love for the Ecotec, a friend ran a Cavalier SRI with an Ecotec for years and it pulled like a train. The engine is nowhere near as bad as some people would have you believe, lots of it is just internet forum hysteria.

I've heard stories about the Manta 1.8 sump not fitting the Ecotec block but I don't know if this is true or not. Puts me off a bit though. Not sure how the wiring compares either, if you are keeping the injection system.

[yellowhusaberg]

on the subject of ecotect 2.0 or red top 2.0 engines i would go red top and rebuild it,i have 2 manta's with red tops in and the cost of parts to rebuild to standard spec is not bad if you use either autosprint or autovaux for the bits,they sell genuine vauxhall stuff a lot cheaper than vauxhall dealers ie genuine cam followers from autosprint £81,vauxhall dealer £160+.i'm also a welder by trade and welded quite few ectec heads with bad water way corrosion the last one was only made in 2003?they seem to be build down to a price compared to the red top.

[mantadoc]

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Edited October 2, 2017 by mantadoc

[yellowhusaberg]

thought the the red top use the same block/crank as the head from a ecotec will bolt on a red top and vice versa,so the only major difference is the emission control stuff and surly you have to do something sbout the lamba sensor/cat?if you run with out the lamba sensor you have to wire the up the ecu to think it's still there or the emmissions are crap and what about the cat as the ecotec was designed around them anyway?yes you can do away with the injection/ecu completely and not have that problem but you are surly back to the argument that cheaper to use than a red top?

yer you are right about not just thinking opel/vauxhall,somebody i know is looking at a saab 9000 2.3 turbo as a possible fit if a gearbox can be sorted ,instant 235bhp and a load of torque.

[Snowy]

thought the the red top use the same block/crank as the head from a ecotec will bolt on a red top and vice versa,so the only major difference is the emission control stuff and surly you have to do something sbout the lamba sensor/cat?if you run with out the lamba sensor you have to wire the up the ecu to think it's still there or the emmissions are crap and what about the cat as the ecotec was designed around them anyway?yes you can do away with the injection/ecu completely and not have that problem but you are surly back to the argument that cheaper to use than a red top?

yer you are right about not just thinking opel/vauxhall,somebody i know is looking at a saab 9000 2.3 turbo as a possible fit if a gearbox can be sorted ,instant 235bhp and a load of torque.

The later saab engines will bolt up to the omega gearbox. Have a read of practical performance magazine. They are fitting one in a mk2 escort using an omega gearbox.

When i fit the ecotec into the mk1 cav i will be keeping the standard injection, using the lambda sensor. You do not need to keep the catalytic converter to make the engine run properly.

[mantadoc]

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Edited October 2, 2017 by mantadoc

[farmerjack]

What a great resource this is - thanks for all your helpful comments.

Looks like I should be quietly trying to gather up 1.8 sump and gearbox and a standard redtop -

ecotec appears to be an option but is there some doubt about sump compatibility?

I remember there is something about the distributor - I don't want to lose my heater.

I really like the idea of reducing some of the weight up front!

best wishes

fj

[Snowy]

What a great resource this is - thanks for all your helpful comments.

Looks like I should be quietly trying to gather up 1.8 sump and gearbox and a standard redtop -

ecotec appears to be an option but is there some doubt about sump compatibility?

I remember there is something about the distributor - I don't want to lose my heater.

I really like the idea of reducing some of the weight up front!

best wishes

fj

The ecotec uses the same block as the XE, so no worries with the sump or gearbox.

It's the early XE's that have a dissy on the back of the head which would cause you to loose/modify your heater. The late XE's and all ecotec engines have coil packs so no dissys to worry about.

[lamchop77]

Farmer Jack

Whats the problem getting the manta through the mot with the emissions? Worn engine or injection not set up?

Here's something i've picked up from some of the other opel forums, the 16v Red Tops are only marginally lighter, if at all, than the CIH. One guy (Hiro) has weighed the motors at the individual component weights and it turns out if you decide to run a turbo version it's definately heavier.

If you want 150+ bhp in your manta get a 234 cam, vernier wheel, 40's and fit 45mm inlet valves with a bit of a port "clean up". Add a 2 1/4 exhaust and get it set up on a rolling road you should get 150-160 bhp. add a light steel flywheel and you will be quicker than a std red top.OK the fuel economy comes down BUT a mate of mine had an Astra 16v (150bhp) which he drove enthsiastically shall we say and he got that down to 19-20 to the gallon.

HTH

Chris

[mantadoc]

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Edited October 2, 2017 by mantadoc

[farmerjack]

Not sure why my MOT man is concerned - some people are glass half emtpy people - It might turn out o.k.

In respect of engine mods I'm technical but not that technical! i.e. I much prefer to leave things std if I can -especially engines - certainly would prefer std injection to twin 40's and remember road rally regs. (petrol consumption not an issue on the miles I put on it.)

I remember reading a thread on this site sometime ago which had the CIH cast lump at 375kg and an XE etc at somthing under half that! Was I mistaken or were we mislead? Certainly drives like there's something substantial at the front end.

best wishes

fj

Farmer Jack

Whats the problem getting the manta through the mot with the emissions? Worn engine or injection not set up?

Here's something i've picked up from some of the other opel forums, the 16v Red Tops are only marginally lighter, if at all, than the CIH. One guy (Hiro) has weighed the motors at the individual component weights and it turns out if you decide to run a turbo version it's definately heavier.

If you want 150+ bhp in your manta get a 234 cam, vernier wheel, 40's and fit 45mm inlet valves with a bit of a port "clean up". Add a 2 1/4 exhaust and get it set up on a rolling road you should get 150-160 bhp. add a light steel flywheel and you will be quicker than a std red top.OK the fuel economy comes down BUT a mate of mine had an Astra 16v (150bhp) which he drove enthsiastically shall we say and he got that down to 19-20 to the gallon.

HTH

Chris

[mantasrme]

Here's something i've picked up from some of the other opel forums, the 16v Red Tops are only marginally lighter, if at all, than the CIH. One guy (Hiro) has weighed the motors at the individual component weights and it turns out if you decide to run a turbo version it's definately heavier.

I don't think either his scales (or his adding up) are anywhere near right. The 16v is considerabley lighter than the CIH.

After i changed from my old cih to 16v the front of my car is riding approx 20mm higher (with 400lb front springs)

[rutts]

farmerjack

you can get a steel sump off yukspeed in yorkshire for less than an alloy one for the 16v, gearbox from a carlton/manta. use a manta gte uprated clutch/spinner plate and 16v cover. dont forget a spigot bearing for the crankshaft. as snowy said you need a calibra/astra dis pac engine(no distributor).

[mantadoc]

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Edited October 2, 2017 by mantadoc

[yellowhusaberg]

i agree with your comments about the weight difference between a red top and a cih engine,a mate and i picked up red top engine between us no probs but had no chance with the cih engine

[lamchop77]

i agree with your comments about the weight difference between a red top and a cih engine,a mate and i picked up red top engine between us no probs but had no chance with the cih engine

I can carry the CIH short motor up on my own me and my mate can lift the complete moters pretty easily. Any way enough of the macho stuff!!! Here are the weights of the separate components for the CIH (These are approx until i can get the stuff on the calibrated scales at work):-

BLOCK 35KG

TIMING GEARS 7KG

EMPTY HEAD 23KG

VALVES/CAM/COVER 10KG

CRANK 20KG

PISTONS/RODS 6KG (My forged pistons/balenced rods are now 4KG)

PULLEY 2KG (New pulley is 0.465KG)

FLYWHEEL 10KG (New flywheel 5.2KG)

SUMP 3KG

CLUTCH 6-7KG

Thats vitually all the components for the motor which comes to 123kg with no ancillaries.

Has anyone else done this for an XE, or can any of you guys weigh the parts and post. For me it would be interesting to find out the weights for the XE to compare.

HTH

Chris