48 replies to this topic

[Robert1234]

Once the car is welded up and sprayed I'm looking to do an engine conversion on the manta B GT/E

What are the simple swap lumps available and what sort of power and costs am I looking at?

Thanks

Rob

[Kevin Abbott]

Xe redtop
Quick ( in both uses of the definition)
Cheap
Easy
About a grand should see you with a redtop in providing you do the work
160 horse
0 to 60 about 7 secs
It will drive off the clock

Hard engine? Anything not standard. YB, V8,S20DET and so on

[Robert1234]

Kevin Abbott, on 11 December 2011 - 08:35 PM, said:

Xe redtop
Quick ( in both uses of the definition)
Cheap
Easy
About a grand should see you with a redtop in providing you do the work
160 horse
0 to 60 about 7 secs
It will drive off the clock

Hard engine? Anything not standard. YB, V8,S20DET and so on

Ah cool, are they easy to find? And what car are they from?

[monzta]

On the other hand, spending a grand on your GTE engine will make the same power if not more. Enem Cam, ported and flowed head (preferably a 2,2 head), good exhaust system and a couple of 45´ weber or dellorto will see your old CIH lump make like 170bhp no problem. I can get you all those parts for a grand no problem

Theese engines are old tech, but they can really make some outstanding power for few ££ .. 100hp pr litre is not hard to reach on those old engines.

The good part about the CIH is that its so simple that anyone can take them apart at home and completely rebuild them and there are loads of options.. There are also some massive stroker kits available if you know what to look for. You can make a 2,5 litre engine that makes 220bhp and have a massive torque for about the same that a set of fast cams cost for the XE.

You can also make a 2,0 litre, using a lightweight 1,6CIH crank, H beam rods, and Toyota pistons (hardened) combined with the right head and especially the cam, you can get a engine build that way to make like 8000 rpm (like a rotary engine)..

Loads and loads of options and knowhow available as the cih has been tuned and modified for the last almost 50 years !!!

Edited by monzta, 11 December 2011 - 09:14 PM.

[Robert1234]

monzta, on 11 December 2011 - 09:13 PM, said:

On the other hand, spending a grand on your GTE engine will make the same power if not more. Enem Cam, ported and flowed head (preferably a 2,2 head), good exhaust system and a couple of 45´ weber or dellorto will see your old CIH lump make like 170bhp no problem. I can get you all those parts for a grand no problem

Theese engines are old tech, but they can really make some outstanding power for few ££ .. 100hp pr litre is not hard to reach on those old engines.

The good part about the CIH is that its so simple that anyone can take them apart at home and completely rebuild them and there are loads of options.. There are also some massive stroker kits available if you know what to look for. You can make a 2,5 litre engine that makes 220bhp and have a massive torque for about the same that a set of fast cams cost for the XE.

You can also make a 2,0 litre, using a lightweight 1,6CIH crank, H beam rods, and Toyota pistons (hardened) combined with the right head and especially the cam, you can get a engine build that way to make like 8000 rpm (like a rotary engine)..

Loads and loads of options and knowhow available as the cih has been tuned and modified for the last almost 50 years !!!

Hmm may be a possibility, I do like the the sound of the last idea.

It's running rather badly atm tbh, I'm not that good with engines if I'm being honest. My capri buddy says the timing is all over the place :s

Once it's running well what sort of things can I do (with a small amount of money) and some long hours in the garage to make a bit more power?

Thanks

Rob

[Alf]

Hi Rob,

I don't know if you're aware of the new I.V.A. regulations? I'm certainly no expert but the new MOT rules come into force on the 1st of January and it's my understanding that if you change your engine from the original, you need to submit for a VOSA test, they're getting really strict on engine changes, at the MOT I believe they will have to check the engine number against the V5 and if they don't match, you don't get an MOT!!

I was going to slip something different into my car but after reading all I could on the subject, I decided it's just not worth the bother, have a look on the DVLA and VOSA websites and see what you make of it, I must admit I got very confused by the time I finished!!

Cheers,
Alf.

[1900SR]

Engine swaps are fine, but you obviously need to inform DVLA. Once you start modifying the shell to fit something different you can run into BIVA or whatever it s these days. Simon P is well versed I believe in what is and isn't possible.

[monzta]

Robert1234, on 11 December 2011 - 10:03 PM, said:

Hmm may be a possibility, I do like the the sound of the last idea.

It's running rather badly atm tbh, I'm not that good with engines if I'm being honest. My capri buddy says the timing is all over the place :s

Once it's running well what sort of things can I do (with a small amount of money) and some long hours in the garage to make a bit more power?

Thanks

Rob

Theres loads and loads of possible ways to make the CIH faster. The old school way of gaining 150+bhp is by simply installing a mild sportscam like the ENEM Y12 cam. This cam is made to go on road cars, and will raise your dyno curves a bit, but will bolt on to the original cam pulley wheel (non adjustable). You raise the oil level in the head (this is done by mounting a pipe in the oil return hole in the head), You fit a set of 40webers with 36mm venturi´s and a 2" sports exhaust system (do not use headers at this stage). Getting the flywheel lightened will also give some good power.
This will fetch you 150bhp in no time, and wont cost you much.

However, i would suggest you get hold of a spare engine and take it apart and start the real fun instead. Use your existing GTE as it is, but start building a engine that really rocks.. Loads of good info is to find on the opeltuners.com site, theese guys are hardcore geeks at tuning CIH, and they have loads and loads of tips and tricks for tuning the CIH.

I would either make it a 2,0 with a 1,6 crank (double cw´s) or stroke it to a 2,3 or 2,5. This is the way to start some serious CIH power outputs. You then will need to focus on the head. A 2,2 or 2,4 head would be very nice, but from time to time some special tuner heads are for sale as well. My brother bought a Mantzel 2,7 head on ebay some years ago for very few £´s and its really awsome. Gigantic intake ports, extremely agressive burnchamber and the valves are massive. A head like that, with a good racing cam will have your cih put out ALOT of power.

Alternatly you can also do it the very easy way and just fit 2,2 crank, pistons and rods in your original 2,0E block. Fit a 2,2 head, and a set of webers and you have 150bhp easy.

I once tested the 2,2 CIH and found out that the puny 115bhp they produce has to do with the EFI system. Its a real bottle neck! Fitting a 2,2 with a set of 45 Dellorto´s made the engine give 131bhp with no changes but the carbs. Exhaust was also stock. Then we changed the exhaust to a Simons 2,5" system, and the power was now up at 142bhp. And the most amazing part is that this was without even opening the engine !!!! A 2,0E cam followed next and even though i didn´t get it dyno´ed after mounting the cam, i could definatly feel the power had up´ped again. So my guess would be that i had added another 10-12hp... The CIH has a massive potential that has almost been forgotten

If you need any help sorting out parts, or finding out what you need just let me know. I have been fiddling with CIH engines for 12-14 years so i know alot about them

[ray70]

Hey Monzta!
You might be hearing from me too in the near future

[johnboy]

Hey Monzta, i have a 2.0s with twin choke weber(currently fitted) and a 2.0e gte injection motor with 5 speed box in the garage, was going to fit this (see my other post regarding fuel tank) but after reading this well??? what would you suggest?

[opel2000]

I must say that after fitting a modern 2.0 lightweight lump out of a Cavalier SRi into one of my old Manta's I was getting 150 BHP on the original injection with minor engine mods.
Car was crisp and smooth with no lumpy idle, would sit in traffic all day and would sit happily on the motorway all day, and return decent MPG with ridiculous reliability over the years too. Engine is still going strong in Mark Gunnings car now in Ireland
That was the 8 valve 2.0 SEH

Just finishing off a XE (Vauxhall 2.0 Twin cam) conversion, car is running smooth and pulls well and idles from turn of the key with no fuelling issues, and should be better than the SEH conversion power wise, and should be happy to sit in traffic etc etc.
Further down the line I'm hopin to whip out the XE and swap the pistons for LET Pistons and go about a turbo conversion on the engine, for little outlay I'm hoping to get 250 to 300 BHP.

A hell of a lot to be said for modern engines over the original CIH, in my humble opinion I would go for a modern twin cam powerplant with a good injection system over carbs on a CIH any day, especially with the price of fuel.

[monzta]

I agree with Opel2000 100%. If the car is meant as a daily driver, and you really rely on the car you should indeed go for a more fuel effecient engine. Modern engines will give you good power, and a much better fuel economy.

However, if the car is for show, and driving in the countryside sunday afternoons, i would strongly reccomend rebuilding the CIH. There is a good reason that this type of engine has been used by Opel non stop in 27 years with only minor modifications (66´-93´). What this also mean is that people has been tuning those engines since 1966, thats almost 50 years of tuning knowhow on the same engine type. This gives remarkable results, and even though the CIH construction is a bit ackward those engines was made back in the day where cars where ment to hold up for ever.

So what has happened those 50 years. Well, so far the Swedes hold the world record on tuning the 8 valve CIH´s. This was done on a 2,4 liter frontera/carlton CIH engine and this engine makes (grab a hold of something) 270bhp normally aspirated ! ! !   That is more than a 2,4 liter Phase 2 i400 engine !!!  If you want to see a vid of this follow this link;
http://www.highspeed...elGrHKitcar.htm
Go about 1/5´th down the page until 4 links marked with light blue text on yellow background appear, and select the first link (this will ask you to save a WMV file on your computer wich is the movie sequence).

I love the modern tech, but you have simply just got to admire the old CIH lumps.

RAy70 you just write if i can help

Johnboy, i have sent you a pm

[costasa]

monzta, on 12 December 2011 - 07:49 AM, said:

Theres loads and loads of possible ways to make the CIH faster. The old school way of gaining 150+bhp is by simply installing a mild sportscam like the ENEM Y12 cam. This cam is made to go on road cars, and will raise your dyno curves a bit, but will bolt on to the original cam pulley wheel (non adjustable). You raise the oil level in the head (this is done by mounting a pipe in the oil return hole in the head), You fit a set of 40webers with 36mm venturi´s and a 2" sports exhaust system (do not use headers at this stage). Getting the flywheel lightened will also give some good power.
This will fetch you 150bhp in no time, and wont cost you much.

However, i would suggest you get hold of a spare engine and take it apart and start the real fun instead. Use your existing GTE as it is, but start building a engine that really rocks.. Loads of good info is to find on the opeltuners.com site, theese guys are hardcore geeks at tuning CIH, and they have loads and loads of tips and tricks for tuning the CIH.

I would either make it a 2,0 with a 1,6 crank (double cw´s) or stroke it to a 2,3 or 2,5. This is the way to start some serious CIH power outputs. You then will need to focus on the head. A 2,2 or 2,4 head would be very nice, but from time to time some special tuner heads are for sale as well. My brother bought a Mantzel 2,7 head on ebay some years ago for very few £´s and its really awsome. Gigantic intake ports, extremely agressive burnchamber and the valves are massive. A head like that, with a good racing cam will have your cih put out ALOT of power.

Alternatly you can also do it the very easy way and just fit 2,2 crank, pistons and rods in your original 2,0E block. Fit a 2,2 head, and a set of webers and you have 150bhp easy.

I once tested the 2,2 CIH and found out that the puny 115bhp they produce has to do with the EFI system. Its a real bottle neck! Fitting a 2,2 with a set of 45 Dellorto´s made the engine give 131bhp with no changes but the carbs. Exhaust was also stock. Then we changed the exhaust to a Simons 2,5" system, and the power was now up at 142bhp. And the most amazing part is that this was without even opening the engine !!!! A 2,0E cam followed next and even though i didn´t get it dyno´ed after mounting the cam, i could definatly feel the power had up´ped again. So my guess would be that i had added another 10-12hp... The CIH has a massive potential that has almost been forgotten

If you need any help sorting out parts, or finding out what you need just let me know. I have been fiddling with CIH engines for 12-14 years so i know alot about them

Hello Montza,
In your opinion the 1.6 crank is better than the 2.0?
I have a 1.9 cih and i'm collecting parts to spiceing a little, in your opinion what will be the best crank to the 1.9block larged to 2.0?
Until now to my engine i have:
kent cam op244
hard valve springs (lexmaul)
2 40 dellorto dhla (i will put 36 or 37 venturi chokes)
kent vernier pulley

Thanks

Edited by costasa, 21 December 2011 - 03:07 PM.

[robah]

This is what I like about the Forum. Good honest debates on the pros and cons of engine swaps and modding the CIH. Reading the thread upto now it has been very interesting and informative.  I had already choosen my path, the XE conversion, as I hope to use the car as a daily drive.........

Thanks Guys

[611]

Im with you on that, good to get some different opinions one the best way to go.
I ran twin carbs on mine and as it wasnt a daily drive, found i quite often had to have them adjusted to keep them in balance. Aslo found it very had to get it setup with a smooth power curve, allways seemed to have a bit of a flat spot somewhere ;-)

Going for a diferent option this time as plan to use it more and dont want to put in a redtop as like the look of the old CIH, going full webber injection with twin 45 throttle bodies! will let you know how it comes out when i get it finished :-)

Andy
www.theopelproject.com

[mantadoc]

£ per BHP winner is 3.0 12 valve Monza / Senator engine.

180 BHP for £200 including engine, fitting and all bits if you are handy.

Heavy engine but a great relaxed cruiser without the expense of big wing sumps and 1.8 gearboxes to fit the Family II 16 Valve engines.  Even plugs into the cars loom to run fuel pump etc.

[mantadoc]

Something in my mind says the 1.6 crank had less main bearings than the 1.9 + so wasn't as sturdy

[monzta]

mantadoc, on 15 December 2011 - 09:10 PM, said:

Something in my mind says the 1.6 crank had less main bearings than the 1.9 + so wasn't as sturdy

Youre dead wrong mate

See this is something only us old crackers know The 1,6, 1,9 and 2,0 has the same amount of bearings, largely the same engine block, the same stroke on both crank and rods. Only difference to those 3 engines are the bore of the block.

So why use a 1,6 crank ?

Here´s why. The 1,6 crank is very similar to the 2,4 crank, except for the stroke. It does however have double counterweights, and this is a BIG advantage. The reason for this is that you have a smaller circumreference, therefore also a smaller inertia torque, and you get less vibration when in the high revs. A standard 1,6 crank that has been weighed in and balanced by todays standards will handle 7-8000rpm no problem. Over that, you will need some forged parts instead.

This is a 1,9 or 2,0 crankshaft:



This is how a double cw CIH crank looks like (when redone a bit )



You can clearly see the difference.

The not so good part is that if you want to stroke the engine the 1,6 crank is out the window. The maximum you can do with a 1,6 crank is 2,1 liters with a 97mm bore. For bigger displacement you will need the 2,2 or 2,4 cranks.

Regarding the 1,9 engine block, this is the ideal block to tune on when tuning CIH´s. It can take a overbore to 2,0 liters displacement, but the real advantage is the cooling channels in the block. They are much closer to the cylinders than on the 2,0, 2,2 or 2,4 block. That is why most still use a 1,9 block for tuning today. Especially in historic motorsports where they are often regulated by homologations to run a maximum of 2,0 liters displacement.

The 2,0 and 2,2 block seems to have some problems with the cyl 4 cooling. When theese engines break, its always cylinder 4. I have had one that pushed out the rod and piston through the engine block knocking off my starter engine   and a racing buddy of mine had one that pushed the piston up the cylinder sideways

Bearings are also a problem on the CIH when tuning, so when you are in the process of tuning a cih you will need to get the crankshaft bearing locations downsized to 1/10th of a mm more than the book says. This will make enough room for clearance as the crank sits on a layer of oil and should never touch the bearings. It will not sound that good during startup but as soon as there´s oilpressure you will have an engine that purrs

I agree on the 3,0 12V part. Those goldtop engines are really gold.. Had one in my previous Monza A 78´. Replaced the old 2,8 unit with a goldtop, fitted a mild streetcam, and a set of tripple 40 Dellorto´s + a modified 3" single tube sports exhaust system from a Carlton GSi. It showed 240bhp on the dyno, so pulling some massive power from those engines are VERY easy.

If i ever go to work on a B series Manta again, this is the engine i will use. The weight ratio problem can be fixed by lightening the front end, and using fibreglass parts like they did on the A series TE2800 where they actually succeeded in getting a weight ratio the same as a original GT/E

Regarding the best way to go, XE or CIH, i´d say XE if your car is a daily driver, or if you have a big engine budget. The XE is a fast 150bhp, but if you want more than the 150bhp it will get VERY expensive VERY fast. A set of racing cams for the XE will cost you the same as a complete tuneup of the CIH head (porting, larger valves, flowmeasuring and the sickest cam out there, steel gaskets etc).

If your car is not a daily driver and you dont need more than 200hp i will take the CIH any day., They sound absolutely fantastic, and they can make some serious power. The whole retro thing should also be considered.  

My guess is that if you can assemble the engine yourself, you can rebuild a standard 2,0E so it is brand new, and tune it to around 150bhp for the same money that a XE build will cost you. And then you will have a 150bhp XE that has driven god knows what miles, vs a brand new 2,0 CIH with the same 150hp

Edited by monzta, 16 December 2011 - 11:49 PM.

[costasa]

Hello Montza, thank you , the pictures show cleary the diference, if i find a 1.6 crank i will go for that route.
I don't know that 1.9 block was better in terms of cooling, that is good news, but if the chanels are close to the cilenders i have to be carefull doing the bore, i was thinking only boring to 95mm in your experiencing what is the maximum bore that 1.9 block can handle?

Thanks

[monzta]

No prob mate

The maximum bore of the 1,9 to be safe is 95,25mm wich is an exact match for Chevy 265 cui pistons

There is however 2 different 1,9 blocks but you cant really tell the difference. Some of them can actually be bored to 96mm without problems, while others are borderlining. So as i said to keep it safe, i would recommend the 95mm or 95,25mm for the chevy pistons as they can propably be bought cheap.