Opel OHC & GM Gen II Engines

[hammer man]

Maybe I am at the wrong place...

But I liked this forums a lot and I am visiting them more often...

I saw all this talk about flow numbers of the CIH engine, an engine that i've never even seen, because here we don't have them... But we do have the OHC... Actually I do have one!

I decided to port the head myself, and I think I need a little help now that I've ALREADY STARTED... Well, no big concerns, because I didn't go too far. I tried to be very conservative, only smoothening some areas. Not enlarging anything.

Does anybody have a less empirical way of doing it?

And I assume that this CIH engine is bigger than mine, isn't it? Comparing the flow numbers of the OHC (how do you guys call it anyway? It's bottom end is similar to the C20XE found here in the calibra and Vectra GSI only, but the head is 8v ohc)... Well, does anybody know the flow numbers of my head? It has 42mm intake and 36mm exhaust...

I am very curious about it and i just can't find anything...

[GTJIM]

Hammer man,

Your engine sounds like the one that Opel used to replace the earlier Cam In Head engine. It was (and still is) used in GM "J" series cars such as the Chevrolet Cavalier and also the Opel Asconas ( plus Vauxhalls). It is a completely different engine and many of the cars it was used in are front wheel drive.

I have a 1987 Opel Ascona 2.0i and it has a version of that "Gen II" engine that was made in Australia.

Brasil was were most of the "Gen II" engines used in the General Motors "J" cars were made.

Try puting "Chevrolet Cavalier" or "Opel Ascona" in to the search line on the home page of your search engine and see what turns up. I did that some time ago and there is a bit of info out there in cyberspace!

[opelbits]

Hammer Man-

You might try these guys for OHC experience:

http://www.mantapart.com/

[Jarl K]

Hi.
Try this, maybe this can be of some use.
http://www.opeltuners.com/

So you don't hace CIH engines in Brazil?
Too bad then ...lol
I think they are much better than the OHC.
Anyway, good luck with your project.

[West Coast GT]

Boy do I feel dumb.

What's the difference between cam-in-head, and over-head cam?

[namba209 (R.I.P.)]

Cam in Head is what our Opel engines are, the cam rides in a cavity in the head with the lifters above it and move the rocker arms which are above the lifters. The overhead cam engines are just that, the cams are above the rocker arms, or on the same plane as the rocker arms HTH.

Ron

[GTJIM]

THe Cam-In-Head Opel (also used in Vauxhalls and Holdens) is just like a conventional 'Push Rod" over head valve engine except the camshaft was moved up into the head. Thus eliminating the push rods and making the vavle gear remarkably compact (and unique!). It still has cam followers and rocker arms just like a standard push rod engine but the push rods themselves are very, very short bits that slide in a notch in the rocker arm as the mechanisim cycles.

Like this:

[GTJIM]

The "Gen II" or second generation Opel engine that replaced the CIH engine had a more conventional "Over-Head-Cam" design
with the cam shaft above the valves but still with a transfer bar with one end supported by a hydraulic device that looks like a lifter but does not ride on the cam.

Like this:

[hammer man]

Originally posted by GTJIM
Hammer man,

Your engine sounds like the one that Opel used to replace the earlier Cam In Head engine. It was (and still is) used in GM "J" series cars such as the Chevrolet Cavalier and also the Opel Asconas ( plus Vauxhalls). It is a completely different engine and many of the cars it was used in are front wheel drive.

I have a 1987 Opel Ascona 2.0i and it has a version of that "Gen II" engine that was made in Australia.

Brasil was were most of the "Gen II" engines used in the General Motors "J" cars were made.

Try puting "Chevrolet Cavalier" or "Opel Ascona" in to the search line on the home page of your search engine and see what turns up. I did that some time ago and there is a bit of info out there in cyberspace!

Thanks for the tips... I'll do some searching...

But when it comes to flow... Is CIH superior? I saw some people here talking that is possible and fairly easy more than 100 cfm... CIH...

Why dou you guys consider the CIH superior anyway? Flaws of the 2nd gen?

[baz]

hi hammer man
i dont think its looked @ much in the states as i think it was all front wheel drive there. in europe we had it rear wheel drive in the manta and ascona with a distributor adapter as the distributor comes off the end of the head driven by the cam
the adapter turned it round 180* and reversed the movement
this makes it unuseable in the manta/ascona without the adapter which is a hard part to find these days and will not fit the gt without body changes
engine itself is ok with up to 130 BHP when injected + more when you throw money at it

[hammer man]

Originally posted by baz
hi hammer man
i dont think its looked @ much in the states as i think it was all front wheel drive there. in europe we had it rear wheel drive in the manta and ascona with a distributor adapter as the distributor comes off the end of the head driven by the cam
the adapter turned it round 180* and reversed the movement
this makes it unuseable in the manta/ascona without the adapter which is a hard part to find these days and will not fit the gt without body changes
engine itself is ok with up to 130 BHP when injected + more when you throw money at it

I see...

Here we have it longitudinally mounted in the omega and S10 Pick up truck... I think either way it doesn't have distributor...

Some people here achieve a little bit more than 130 hp... The Kadett GSI had 121 hp stock. With some minor modification it reaches 140 + hp, because we have pump alcohol here, and it allows much bigger compression ratio.

Chevrolet (opel) RWD here we have the OPALA, that is an Opel Commodore with an american 250 cu in engine, the much more modern OMEGA (same as yours from the early eigties, here produced till late nineties), with the same engine "tuned by lotus" (slightly, I suppose) and the 2.0/2.2 8v OHC and the chevette ( i think u call it some kind of older Kadett) with another engine (1.4/1.6) with iron heads (crossflow).

All the rest is FWD. KAdett, Astra, Vectra, Corsa and so on. All except the corsa family have this 2nd gen engine, some with 16 valves though...

But I am trying to understand if the engine itself is inferior or superior to the CIH...

Thanks.

[hammer man]

Originally posted by GTJIM
Hammer man,

Brasil was were most of the "Gen II" engines used in the General Motors "J" cars were made.

What is a "J" car anyway?

[GTJIM]

The "J" (Jay) is a GM shorthand term for the tpye of chasis that a model line has. Like "F" is for Camaro/Firebird RWD the "J" is for the transverse engine FWD chasis used on Opel Ascona series C (1982-87) ; Vauxhall Cavaliers (1982-87) Holden Camiras (1984-89) and all the Chevrolet Cavalier/Buick Skyhawk/Cadillac Cimarron/Oldsmobile Firenza and Pontiac 2000 Sunbirds and Sunfires (1982-96) plus the FWD range you have in Brasil.

Much easier to just say .... GM "J" Series

Incidently, the 2.0i and 2.2i engines were built in Australia (3.2 million of them) and also in Brasil ( don't know how many).

The "J" car platform also used 1.8 Litre Isuzu motors plus 2.8 and 3.1 Litre V6 motors.

As to which is superior - they both are! Just depends if they were made in Brasil or not!

[hammer man]

[i]Originally posted by GTJIM
As to which is superior - they both are! Just depends if they were made in Brasil or not! [/B]

Thank you funny guy...

But my curiosity is because the engines seem to have similar dimensions 1.8 - 2.4 liter and similar valve sizes 42mm. But one has square portings and the other round porting. One is crossflow and the other isn't (or am i mistaken?)

Knowing that the 2nd gen is a newer model will surprise me if I eventually discover that the older CIH is similar in size but superior in power...

The normal path would be the engines EVOLVING... Not going back...

And it seems to me that the CIH is a very good power source...

p.s.: My engine is 1.8 and it is brazilian, not ISUZU...

P.S.2: Thanks for the "Brasil" with an S.

[azzi]

Originally posted by baz
hi hammer man
i dont think its looked @ much in the states as i think it was all front wheel drive there. in europe we had it rear wheel drive in the manta and ascona with a distributor adapter as the distributor comes off the end of the head driven by the cam
the adapter turned it round 180* and reversed the movement
this makes it unuseable in the manta/ascona without the adapter which is a hard part to find these days and will not fit the gt without body changes
engine itself is ok with up to 130 BHP when injected + more when you throw money at it

The dizzy conversion is on similar lines to the 1800 Manta OHC engine and even uses some of the parts. The Exhaust Cam Pulley has an extra pully fitted to it that drives the External Dizzy via a rubber belt. The 16v Dizzy is made into a Hybrid as its Oil Fed in normal form, but with the 1800 Base its converted to sealed bearings.

You could go for the DIS dystem from the later engines, but they came on naturally Aspirated engines only, I'm fitting the Turbo in my GT so I've decided on the dizzy conversion to prevent my having to cut into the bulkhead. (Thus having to change the dashboard to fit a normal stereo)

[azzi]

In similar lines, I've heard about a CIH engine with a cross flow head, but they are THAT RARE, I've never even seen a picture of one. And I don't mean the Manta 400 16v head either.

Here a quote from Opel Tuners



Yes there is (was) a crossflow head...
Heads and parts are very rare.
It´s called "Schwedenkopf" (sweden head).
The head looks a little like a BMW M10 head (central cam, rocker arms...). The rocker arms have "needle-bearings".

[RallyBob]

The crossflow alloy head was homologated for Group 2 rallying in the early 1970's, Walter Roehrl (sp?) used an Ascona A with a crossflow CIH to win the European rally championship in '74-'75. Conrero also used them on the revised Conrero GT's for Group 4 racing. HP ranged from 210-225 with these heads, but they're a bit fragile too.

[kwilford]

Is this the Crossflow CIH 16V head?

[Gary]

*Drool*

Is that Gil Wesson's GT?

[azzi]

Originally posted by Gary
*Drool*

Nice, Looks like the 400 engine though.

I was assuming the CIH head was 8v and not 16v.