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Discussion Starter · #1 ·
Hello. I've been kind of sold on taking a 1.9 and bumping up the displacement. So, most of the buzz surrounds the 2.4 but can you realistically go bigger, or would that stress the case to much? I want to stay away from the turbo/supercharger option for now (will revisit when my wallet is a bit fatter). Roller lifters, rockers, etc sounds very interesting. Basically I'm looking for strong street engine. Something with oodles of torque and wont fly apart after 20K miles. I have read up on several of the posts here, and the various articles around the web. I'm just looking for a good list of various 'performance parts' to consider things like possible bore and stroke combinations, etc. I already have found a local builder who is getting excited about building something, he can regrind cranks and everything (plus has opel gt experience). One final question, should I upgrade to 5-speed and a chevy clutch before or after I put in the new engine. I would really like to see 200 hp, with a carb, I know that’s a difficult goal and if its impractical, then I'll just have to deal with it, 200 is just my goal. Well, any suggestions on which way to go for my project would be greatly appreciated.…I also don’t really want to go the rotary, I just don’t have the time for a complicated conversion. Look forward to hearing from you.
 

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You are asking for a lot. A 1.9 litre engine won't make 200 hp with a single carb. I got a 2.1 litre engine to make 192 hp with a single carb, but it was a racing engine, and required 104 octane fuel, plus it had a powerband from 5300-9500 rpms. So the requirement for a 'torquey' engine would not be met! Also, you would not get 20k miles from any racing engine.

I suspect your best bet would be to get a 2.2 litre Opel engine, change the rods, offset grind the crank, and bore the block 2 mm. You can get 2478 cc's this way. Also, the 2.2 head flows TONS more air than the 1.9 head. But forget a single carburetor. Either you'll need to retain FI (programmable ECU), or go with twin sidedraft carbs. With this, you can meet your goals of high torque plus 200+ hp.

Bob

Oh, and as a side note, the stock clutch won't even take 150 hp, much less 200 hp! Also, with 200 hp, the Getrag 5-speed will be junk in no time. A 4-speed would probably break in a day. Getrag 240's are not that strong, 200 hp is about their limit. A Getrag 265 can take a lot more abuse, as can a ZF (about 300 hp).
 

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Discussion Starter · #3 ·
start with 2.2?

Hey thanks for the info, but you suggested that I started with the 2.2 and build on that engine? What are the differences between that engine and the 1.9....and by that I mean would you get a better engine taking the 2.2 and building it to a 2.4 or taking the 1.9 and taking it to a 2.4? If i port, and place bigger values in the 1.9 heads will it flow the same as a 2.2? Also, the carb I was looking at was a holley 500 or something of that nature, so I should be able to flow what I need it to (can get them really cheap). Now with the tranny you said the 4-speed will last a day? Wow, is that if keep dumping the clutch or normal driving? I have heard very little about the zf tranny but am interested...there is also a 6-speed varient of that tranny as well? What kind of work is involved with installing the zf, how does it compare to the 'complete' kit that OGS offers for the 5-speed getrag? And what kind of prices am I looking at? Thanks again for the info.
 

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Re: start with 2.2?

kmon said:
Hey thanks for the info, but you suggested that I started with the 2.2 and build on that engine? What are the differences between that engine and the 1.9....and by that I mean would you get a better engine taking the 2.2 and building it to a 2.4 or taking the 1.9 and taking it to a 2.4? If i port, and place bigger values in the 1.9 heads will it flow the same as a 2.2? Also, the carb I was looking at was a holley 500 or something of that nature, so I should be able to flow what I need it to (can get them really cheap). Now with the tranny you said the 4-speed will last a day? Wow, is that if keep dumping the clutch or normal driving? I have heard very little about the zf tranny but am interested...there is also a 6-speed varient of that tranny as well? What kind of work is involved with installing the zf, how does it compare to the 'complete' kit that OGS offers for the 5-speed getrag? And what kind of prices am I looking at? Thanks again for the info.
The 2.2 starts with a 95 mm bore and a 77.5 mm stroke. The 1.9 has a 93 mm bore and 69.8 mm stroke. The 2.2 also has a far better head, a raced prepped 1.9 head flows a little bit better than a stock 2.2 head, but a ported 2.2 can't be touched by a 1.9 head. A Holley 500 flows a decent amount of air, but NO amount of porting to the stock intake will allow the airflow from that carburetor into the head without restriction. That racing engine I mentioned had a 500 cfm Holley modified to flow 640 cfm, and the intake manifold had about 20 hours of welding, porting, and flow bench work to allow 192 hp to happen. Forget it for the street.

Yes, the 4-speed is that weak. I'm not talking about clutch drops (but that will split the case...have done it a few times). Just applying that much torque in 2nd gear is enough to break the gear while in gear, it's that weak.

The ZF is a direct bolt-in, but it's kinda rare. No modifications to the car to fit it, the shifter location is OEM, the driveshaft needs to be a factory automatic unit, the clutch can be stock, etc. Only need to modify the tranny mount crossmember to fit, but it will use the stock GT tranny mount.

Bob
 

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For 200HP normally asperated (especially a single carb), you are going to spend a small... maybe large fortune. For years we've been chasing the elusive 200HP number... we've done "money no object" efforts and can just barely "crack" 200HP... that's honest HP, not "advertised HP".
To get that kind of HP, plan on spending at least 10K and probably a lot more.

A better approach is to get a 2.2L from the Opel GT Source. Get the full FI system to go with it. Then go with either a supercharger (my favorite) or a turbo (more "sex appeal"). By the time you're done, you'll spend around 10K for the engine, turbo/supercharger, and engine management system, but you'll have over 200 HP (closer to 250 and more possible) and tons of torque (especially with the supercharger).

Yes, you'll need a transmission and rear end (Toyota Truck)to take the HP/Torque. We are currently working with Taylor-Race in Texas to develop a 300+ HP transmission that will be a "bolt in package for the Opel (and others). The transmission won't be cheap... but a Mustang/Camaro/Honda eating OPEL isn't ever going to be cheap.
 

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Discussion Starter · #6 ·
bigger bore

I'm really learning a lot...I love this forum. Well, if I were to reweld the crank for a larger stroke, and bore the case to take larger pistons...just how big could i go with the 1.9 case? Again, I need decent reliabtiliy, this is going to be a daily driver. I really don't have a ton of cash yet...I'm trying to swing $4K for the engine and tranny, and again, the mechinist here does work quite cheaply so that $4k should go a little farther. Since the zf is a bolt on tranny, what flywheel should i use...the chevy from UR? Also, what year make and model was both the zf 5 and 6 speed out of, figured I might start hunting junkyards for a tranny. The wow factor for the 6 is better than the 5 speed, but I would be happy with the 5 especially with the cash it saves, I'm going to price both and find out exaclty how poor I'm going to be ;) So, from most of the comments here 200 hp seems unrealistic for my budget, I'm just going to try and get as close I can then. Doubling the HP in the opel would definitly make a difference :D So, what is everyones impression with 150-200hp, seems to me that it would a huge difference. I know it all depends on how the engine is setup for where the powerband is and so forth, but from pracitlce experiance, what does this light of car feel like with that much power?
 

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Forget the junkyard search for a 5-speed ZF, they were never imported into this country. If you're in Europe, and happen to come across a 1.9 or 2.0 litre Kadett C model GT/E (about 1977-1978), it might have a ZF (they were an option, not a standard fitment). As far as the 6-speed ZF, it will definitely require modifications to fit...you're on your own there!

What will 150 hp do in a GT? Depending on traction, final drive, and tranny ratios, it'll hit 0-60 in around 6-7 seconds, and 0-100 in around 16-17 seconds. Top speed will again vary with ratios, but 145-150 is relatively easy to obtain.

To see the difference another 50 hp makes, I can't make an apples-to-apples comparison. But a 197 hp (dynoed) GT-4 road racing Opel GT hit 162 mph @ Road Atlanta a number of years ago. Can't comment on the acceleration though, the tranny was geared for road racing....it has a 1.91 first gear ratio, and a 1.00 4th gear ratio! Strictly concerned with rolling acceleration for specific track conditions, not 0-60 performance. But that engine cost about $7k to build, and is race-only. Best power is from 5800-8000 with the restriction imposed by the 45 DCOE Webers. The head flowed enough air for 221 hp, but there's no way it was going to make that much power with those carbs. Volumetric efficiency was as high as 112% at 6800 rpms, so it was using all it could for air.

Regarding the maximum reliable displacement obtainable from a 1.9 block, I'd say 2.4 litres is about it. You can get a 2.7 litre from a 2.4 crank/block, but the 1.9 block can't handle that increase.

Bob
 

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BOB,
I know many people have asked you questions about the 2.4L conversion, including myself, but you say now that isnt the way you would go to get more power.
That was the engine that I wanted to build this summer, what kind of motor is your "new" prefered design?
 

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As mentioned above, I prefer to use a 2.2 engine as a starting point, and utilize a connecting rod with a smaller journal, thereby allowing you to offset grind the crankshaft to increase the stroke.
No welding involved, and all components are far lighter than stock.

Bob

Oh, and regarding the way to 'get more power'....enlarging an engine does not necessarily gain more power. You will gain more torque, and through slightly better pumping efficiency from a longer stroke, a little more power than a similar smaller displacement engine. Power is primarily a byproduct of airflow. So to increase power, you'll need more airflow through the head, the induction, and the exhaust systems.

Case in point: European spec 1.9 with FI is rated at 105 ps....the 2.0 litre is rated at 110 ps.....the 2.2 is rated at 115 ps. Even the 2.4 is only rated at 128 ps (though it has much better intake and exhaust manifolds). But, the primary benefits of these larger engines is the greater torque, and that's what you feel in the seat of your pants when you press on the throttle. But if you want power, you'll need a bit more compression, a bigger cam, headwork, better induction and exhaust, and proper tuning of the entire system.
 

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Well since the 2.2L are kinda pricey, I will probly stick to the 1.9L andI have two extras sitting around anyway.

Will that offset grinding/welding to the 1.9L crank significantly affect the strength of it?
 

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Discussion Starter · #11 ·
im in the same boat as 'opelgt73' its not really practicle for me to take a $1200 starter motor and then build on it. I just can't justify that within my budget. So, the plan still stands simply with using a 1.9. So, if I can achieve even 150hp I will still be very happy....did I mention I live at 7200 feet? Making hp here is kind of difficult. I definitly agree with many of the points you guys are making, but really wish to stick with a 1.9. What is the recommend size bore and stroke with that engine to go for the 2.4. And (sorry if this is a n00b question) can you bolt the 2.2 or 2.4 heads on a 1.9? I know the design is a bit different. Is there a way you could retrofit it? If the 2.2 is simply that much of a better design then I would like to take that route. Also, does anyone here just happen to have something with big hp/torque numbers that they would be willing to sell, like a used 2.2 or 2.4? Also, where can I get zf tranny's or find pricing on them? Thanks again, for taking time to answer this questions, I've done a lot of hot rodding with vw's but this opel addiction is still new to me.
 

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does anyone have any experience with tgsi's turbo kit? Is that still available? I'm tempted to go that route, since it seems that getting any decent power out of the 1.9 NA is very difficult (and expensive).

I thought I read somewhere on here before that the bottom-end of teh 1.9 couldn't handle it...but I'm curious, as I'd love to do my own turbo install (and yes, I'd intercool it)
 

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You can't use an intercooler for our "base" turbo system. It uses a "suck-through" system... which means that the turbo pulls air into the turbo from the carb. The output of the turbo (which would go to the intercooler) is a fuel/air mixture. Since the intercooler sits in the front of the car, if it were to be punctured with a pebble things could get real ugly.

There are other ways of running the turbo... but all much more expensive. The best way is to go to an FI system. Then you can get some serious HP... if you have the $eriou$ buck$.

By the way, we've only built 1 turbo sysetm for the Opel. It was our test "mule". We thought the Opel community would jump on it since a turbo is the cheapest way to get a respectable increase in HP. No one has... So we're concentrating on building stuff for the Hondas, Mazdas, etc. If you want one for an Opel, it is special order.
 

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JGard18 said:
I thought I read somewhere on here before that the bottom-end of teh 1.9 couldn't handle it...but I'm curious, as I'd love to do my own turbo install (and yes, I'd intercool it)
On the contrary, the bottom end is VERY tough. After 1973, Opel switched to cast steel rods (weaker), but with early rods and forged pistons, the shortblock can take a pounding. The weak link is the valvetrain.

Bob
 
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