[twistedgold]

Just curious as to what horsepower I can expect from a 2.4L .

This question is for my friend Stephen who purchased my old Opel GT.

He wants around 200hp (I dont see the need for quite that much, but what do I know).

I know we'll have to upgrade the brakes, rear-end, and probably the getrag transmission he has.

I want the install to be easy as possible since I'm helping him, so I would prefer to stay away from FI and go with a dual sidedraft set-up just so we dont have a whole lot/as much wiring to do.

Will dual carbs support 200hp at the flywheel, or will he have to go FI?

If FI is needed would it not be better to just go with a 2.0L Turbo motor?

He would like to have under or around 10K in the drivetrain (Work will be spaced out over a couple years).

Also of consideration is we don't want to cut the car up so I dont think an engine swap to another brand is in order here. (Only rust on the car is a little bit in the battery tray).

Any information or help is appreciated,
Sean

 

[Old Hippie]

If I remember right, I think RallyBob said the uni-body was safe up to 180HP. Over that you got into the twisting realm. (Please correct me, R-Bob, if I mis-quoted).

 

[baz]

Also of consideration is we don't want to cut the car up so I dont think an engine swap to another brand is in order here. (Only rust on the car is a little bit in the battery tray).

Any information or help is appreciated,
Sean

if you fit duel side draft carbs you will have to cut and reform the area around the heater box as it will interfear with the last carb venturi

 

[davegt27]

go with a 2.2 instead of a 2.4
to start off with

davegt27

 

[RallyBob]

Just curious as to what horsepower I can expect from a 2.4L

A bone-stock Euro 2.4 makes 128 ps, or about 125 hp. In order to make 200 hp (60% more), there will be substantial modifications needed. You'll need higher compression (custom pistons), headwork, new valvetrain, bigger cam, custom exhaust, and either multiple carbs or EFI with a stand-alone programmable ECU. The OEM 2.4 EFI intake manifold won't fit under the hood BTW. As you suggested, the Getrag 240 will be marginal, and if the driver is hard on the car with 200 hp it won't last long.

Bob

 

[twistedgold]

Would a lenk style hood give enough clearance since he has one of those.

(Guy cut the hump above the carb off the original hood so I bought a lenk style hood for the car (couldn't find a local opel hood for less then $200 and picked up the unused lenk hood for $150 I think))

I'm trying to talk him down to around 160hp (@ flywheel), but he is dead set on the 200hp number.

I tried telling him with around 160hp he'd still be a heck of a lot quicker then most vehicles especially if he gears the car correctly and can get it to hook(this is going to be debatable).

I kinda follow the philosophy that it doesn't have to be the fastest thing on the road. Build it to do everything well.

What would you suggest Rally Bob, if you had 10K to throw into a drivetrain cause I know your kinda the go to guy around here for opel info.

Sean

 

[RallyBob]

10K to invest? In just the engine or the entire driveline upgrade?

I'd probably go with forced induction (turbo). Certainly a lot more driveable for road use. A 200 hp N/A engine will not be too practical, but it can be done.

For my money, I'd use a 2.2 block/crank, throw in some early forged 1.9 rods, some forged pistons (96 mm), a big-valve 2.2 head with porting, a modest solid lifter cam, roller rocker arms, and a custom intake manifold for EFI and stand-alone ECU. Throw in a modestly-sized turbo (say, Garrett GT28), and you could make 250-300 hp with no problem.

Then there's the rear axle, the flywheel/clutch, the transmission, and the necessary suspension mods and brake upgrades to keep a 170 mph GT planted.

Bob

 

[twistedgold]

I think he wants to put 10K into the drivetrain.

I wish he'd post here, would be a little easier if he came out and said what he wanted instead of me repeating it for him.

You know the more mouths something goes through the more likely it is going to get twisted some way or how.

so basically to make 200hp your going to need FI and forced induction to keep the thing streetable.

Sean

 

[opelgt692004]

I'm the guy that twistedgold is talking about. I'm not concerned with cost at this point. I just want my car to be the fastest thing on the road. I definately want a minimum of 200hp. Do you think that a 2.0L turbo would be a viable option in my case? Also, what can the unibody handle before it needs excessive reinforcement? I really appreciate all the help that you guys can give me.

 

[bear]

Unless you can put all your horsepower to the road, all the money in the world won't get you the fastest thing on the road. If you're going to run stoplight to stoplight, you'll have a problem with wheel spin. If you want only top end, forget about going quick. Take Rally Bob's advice seriously, he's been there, done that, and doing more. There is a trade off on doing serious modifications to engines for more horsepower, that trade off is longevity. The more horsepower you get out of an engine the shorter the life span of the parts inside. For serious horsepower the drive train has to be changed. That would require a lot of fabrication to install a rear-end that could handle the horses and keep the body stiff enough to not flex. Take some time and read the performance mod forum and you'll be able to see what others have done sucessfully. It may save you some grief further on down the road. JMTCW.

Ron

 

[kmon]

'fatest thing on the road' is a pretty hefty goal. I personally would rather have the extra displacment. A 2.4, 2.5, or clear up to a 2.7 engine especially turbo'd are going to be interesting to say the least. As Ron said, traction is something that will give you problems with high hp. The larger the budget the more options you have. You need to ask yourself several questions, first what kindof of driving do you really want to do...drag racing, driting, agressive street, road racing. You can squeaze over 500hp out of a cih but it woudnt be too streetable. The forums have great info on my driveline conversions, and their are a few members who are currently building up some crazy gt's (rallybob has a great thread going with pictures of a cih turbo). I'd speed a few days going through all the articles, and threads on this site you can get your hands on. A few things that I would suggest, lsr rear end (toyota is a common conversion), getrag 265, s10 or large opel clutch, and a near infinite amount of patience. These projects take time, but are completly doable. If you dont want to go the 4 banger route their have been v6 and v8 conversions (even a few v12 conversions but those pretty much butcher the car), all are disscused in the forums but they are definitly more work then a cih 'bolt it'. Good luck to you.

 

[RallyBob]

Another concern is that with a 200 HP NA engine, the power band will be a bit tighter, so the standard Getrag 265 ratios won't cut it. You'd have to invest in either a ZF gearbox (rare and expensive), or something along the lines of an adapted Quaife Ford Sierra 5-speed with close ratios. Big cams and dual carbs suck without the appropriate gearing.

In fact, I'd go out on a limb and say at that level it's the single most important factor for making the car go the way it should. Professional-level motorsports tend to agree here, for example a BTCC touring car from about 4 years ago had a 40-45k engine, but a 65k transmission. Current WRC rally cars run gearboxes costing upwards of 80k.....

But yes, a 200 hp streetable NA engine is doable, it just costs more money to make it driveable. My friend Gregg, the guy having me build his turbo Manta right now, has a 2.5 roller-cammed CIH Opel engine in one of his cars. I'd estimate it at about 185 or so hp right now, with a single carburetor. It will easily go over 200 with sidedraft throttle bodies, programmable ECU, and a custom header. It is very driveable as far as a normally aspirated engine goes, has torque a 1.9 can only dream about, but revs hard to 7500 rpms.

However getting to this level requires some money, such as the basic 2.4 core engine (about $2200 back when he bought it), the roller cam (about $750), roller rockers ($600 a few years back), stud girdle ($115), a fully professionally ported head with 1.94"/1.60" stainless valves (about 2k), custom intake ($600), custom high compression pistons with Total Seal rings ($550), billet flywheel and custom clutch ($630), then all the little bits and pieces, the machine work, assembly time, etc. It'll cost another $500 or so for the header, and about 2k to build the custom EFI. Should be right around 215-220 hp, and more even more streetable thanks to the EFI, plus it runs on 93 octane pump gas. Eventually it's getting a Volvo close ratio rally dogbox ($4500), and a 4.88 Toyota rear axle.

Oh, and you'll have to try to avoid Gregg for that 'fastest thing on the road' honors, his 2.5 turbo Opel should run about 450 hp! Then there's my own plans for a 550+ hp CIH Opel engine in a Manta......

Bob

 

[opelgt692004]

Isn't there a 2.0L turbo opel engine? Do you think one of those would fit the bill for my project?

Thanks for all the good information guys.

 

[RallyBob]

Yes, it is a 2.0 litre engine with cast iron block (not related to the CIH block), an alloy 16v twin cam head, and of course the turbo (turbine housing is cast into the exhaust manifold BTW).

It makes 204 ps in stock form. You would need to use a Getrag 240 from a 1.8 OHC Manta B. They share the same bellhousing style (bellhousing is integral with tranny case). Of course, this means you have the weak Getrag 240 still. You will have to make custom engine mounts. I'm not sure on the cutting/welding aspect, but it IS a crossflow head with a turbo, so it will be much wider, and therefore a tighter fit.

HTH.

 

[opelgt692004]

Is there anyway to beef up a getrag 240?

 

[GTJIM (R.I.P.)]

Opel Motors

The Chevrolet Cavalier FWD 2.0 and 2.2 motors are Opel designed Motors.....
Lots of development has gone into them for drag racing!

 

[twistedgold]

Stephen
(Since I don't know when I'll catch you in person)

Since we (I say we since your going to con me into helping) are considering a swap that involves cutting anything I suggest you pick up a cheap (highly rusted gt). To test fit everything into to see what to cut etc. What to fab up etc.

Sean

 

[opelgt692004]

I kinda like the idea of a Cavalier engine. How much hp do you think I could get out of that? Also, how difficult would it be compared to the 2.0L turbo Opel engine? Would the Getrag 240 transmission work with that?

These are really good ideas. I appreciate it. The guidance is extremely useful as this is my first Opel.

 

[RallyBob]

The new Ecotec engines in the Cavalier are available in a 2.2 litre version here in the US only, starting this model year. However, that same engine has been in various versions of Saturns for about 3-4 years now. It's all aluminum construction, has 140 hp stock, and GM Racing has tweaked them to over 1000 hp and 10,000+ rpms for drag racing use (turbocharged and on methanol). However, those with lesser budgets can get 300-400 hp without too much trouble!

You'll find this engine was never used in a fore/aft installation, only transversely, so I don't know of any transmissions that will just 'bolt up' to this engine.

Still, if I were to stray away from the CIH engines for an old Opel, this would definitely be the engine I'd modify and install.....

 

[baz]

the only car i know of with the eco tec in rwd is the opel omega
comes with both 5 speed man and 4 speed auto boxes