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Discussion Starter #1
I have been reading about these engines for over a year now. I finally took the time to explore all the "LINKS" from this site and the subsequent links from this sites links.

I don't know what the rules are about mentioning other websites on here so I will refrain from doing so. I will also suggest that the information I did find elsewhere is probably on here too, I just haven't seen it yet.

What I found were some articles suggesting power was engineered out of the lubrication system, whether on purpose or as a by process of engineering from parts on the shelf.
1) the oil pump pick-up screen is overly shielded and that relieving part of the shielding actually yields some usable power.
2) the oil pump supply orifice is oval and that the receiving block orifice is round; by matching the block's oil pump inlet to the oil pump's output, power is recovered/developed.
3) the oil pan system would benefit from a windage tray "device" in the oil pan.
4) the 2.2 and 2.5's equipt with balance shafts/chain/gears will do just as well without them and that they present a power loss to the power plant, and that their removal will provide for the volume of near a full quart of extra oil.

I procured a oil pump pick-up from the yard to give it a shot. (I would like to post the photos but still don't know how to post them on this forum). This isn't the most difficult task but is very easy to mess up. In addition to opening up the inlet to the pick-up screen, I put a chamfer on the outlet tube from the pick-up to the oil pump, may not do much but it will help. I won't be able to install these components until later this coming week unless I finish the heater core swap on Sunday.

If anyone has performed any of these changes I am interested in hearing how things went.
 

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The overly shielded pick up can be de-shielded to make the oil flow more efficiently with no ill results. I don't think it will make more power in its own regard.

Matching the oil pump inlet is a good way to free up lost power with no ill result as well.

The only benefit the windage tray provides is solving any oil starvation issues in corners. Such is the result when people remove their balance shafts and keep the deep pan. Simply switching from a 2.5 oil pan to a 2.2 oil pan will result in less sloshing oil when balance shafts are removed.
 

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Discussion Starter #3
bamman:

- the information I sourced regarding the "overly shielded" oil pump pick-up, suggested that reducing the shielding may result in as much as 3 hp at engine speeds above 3 k rpm.
- it also suggested that matching the block input orifice to the oil pump output would yield as much as 6 hp.
- I don't fully understand all the benefits from a windage tray but your comment is apparently true, in addition to "anti-foaming" action the sourced info suggests that in a Dodge 440 a windage system yields 16 hp (this is a dodge 153, not a 440; 25% of 16 = 4 hp).
- the balance shafts are claimed to rob the engine of 14 hp.

When all is said and done, for the cost of a make/shift windage system, a plug for the balance shaft oil supply and 2-4 hours under the engine, if half the claimed hp is realized I would be ecstatic:

3 + 6 + 4 + 14 = 27 x .5= 13.5, 13.5 hypothetical horse power reclaimed from a 100 hp at the crank system is huge in my book...27 is NUTS! If any of these processes yield power I believe they will in turn yield torque and the potential of fuel economy.

I by no means claim to know much, I am very pleased to read your responses. I have my oil pump pick-up ready and plan to match the pumps orifice to the block's inlet; my engineer buddy says to pull the balance shafts and that a windage system would benefit for the very reason you mentioned and the oil foaming action.

I believe the only way to substantiate power gains is on a chassis or engine dyno, so if after incorporating these changes, I feel a difference, I will mention it but unless I do before and after dyno time, no hp claims will be discussed by me: on the other hand If I can document an increase in fuel economy, I will gladly share the information.

Thanks again for the reply.
 

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Those numbers are BS. Please do put it on a real dyno before, and after. I guarantee you will not see gains like that. 14 hp because of the balance shafts? Then explain why the 2.2 and the 2.5 TBIs have virtually the same horsepower, with the 2.5 having balance shafts. And 6 hp by matching an orifice? I'd like to hear the explanation of the physics behind that.

If you want 27 hp gain, just convert it to a T1.
 

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Bob, that'll overshoot the mark.

I do agree and I've heard from other people that the balance shaft thing in particular is overblown.

Wonder what running without balance shafts does to your engine's longevity, not to mention associated systems?

Gaining 3 hp over 3,000 rpm might be useful if you're racing -- but otherwise you will not notice it. You might not notice it if you are racing.
 

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I've owned two 2.2L and two 2.5L engines, and there is a very noticeable difference in smoothness in the 2.5L engines with the balance shafts. I would never want to give that up, myself. Once you remove it (most people reportedly cut the chain drive), it can be difficult to restore. There is an oil port to plug, but there should be no harm to the engine. It just won't be as smooth.
 

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Discussion Starter #8
hEY, thanks for the interest.

DaveAdmin: - while I have no aspirations of racing, I do find that I drive at or near 3 k rpm often; my tach doesn't currently read in the cabin but the engine rpm at 65 mph is reportedly 2,800 rpm. I often accelerate briefly to 70 or 75 to pass, usually not changing gears, so if there were some useful power to gain in the region, I would benefit from it near every day.

- while I have owned two, 2.5's and only one 2.2 so far, my time in the seat with a 2.2 has been very limited. I can tell you that of all the autos I have ever driven, no other has provided as much pleasure to drive as the 2.2 (bone stock, completely unmodified). I have driven across country several times with a 2.5 and can say that it is a very reasonably smooth power plant and that I don't necessarily embrace the concept of altering that. I do strongly desire to squeeze as much juice from the lemon as the lemon will provide.

BobLincoln:- isn't funny that BS is often the abbreviation used to identify the balance shafts?

- My engineer buddy did provide a readers digest explanation for power loss through bad design; the engine is providing the power for the lubrication system, if there are inefficiencies built in to the system, then those will equate to power losses or potentially use more power then necessary. In this particular case, oil is being feed through an oval hole into a round hole; a portion of the fluid is hitting a 90 degree "stop" and then having to find a way around it. If the passage were a smooth transition from the one area (component) to the other, then the power lost in the movement would be reduced.

- I have often wondered why the 2.5 engine with 12% more displacement only makes 1% more horse power? Perhaps the balance shafts are part of this mysterious power conundrum?

From everything I have read about the 2.2 and 2.5 engines one thing rings loud and clear Mr Iaccoca was H-bent on saving money, if it were cheaper and his engineers couldn't prove it would cost him more money in the short run he used it anyway (crappy intake and injector setup on TBI's). On that note, he wouldn't have O.K.ed the balance shaft gear if he hadn't had a super good reason to justify the cost.

I expect to find many power robbing components/areas in these engines, which, had I found 20 years ago, I may have kept to myself (to develop an edge over other owner/drivers). Today I believe everyone needs to benefit from any actual gain that can easily be incorporated if it can increase fuel economy!
 

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If the goal is increased fuel economy, there are far cheaper, even free, ways of getting more gas mileage. As I've said, the things that have the most effect:

1) Your right foot. Taking it easy (and they no longer teach it like they did in the 70s during the fuel crises) is the biggest gain. Coast as much as possible, anticipating stops and slowdowns. Obey the speed limit (that can be a 10% gain for most drivers). It was an eye-opener to install the navigator in my turbo and see the instantaneous gas mileage shoots up to 40s, 50s, 70+ mpg when coasting. Also, tiny changes in the slope of the road can change this reading by up to 5 mpg, as can tiny changes in your pressure on the throttle.
2) Idling. Minimize idling on startup and on your driving route. If sitting more than 10-20 seconds, shut it off. You use more fuel idling longer than 20 seconds than you do restarting. I have a red light on my regular commute that lasts 70 seconds, and I shut down if it's early in its cycle.
3) Keep tires inflated fully. You lose 1% gas mileage for each psi under optimal. I run 37 psi on tires rated for 44, instead of the 32 on the car's decal. It gives me better mileage and even, long tire wear.
4) Keeping the car in optimal tune. I replace plugs, ignition rotor, air filter and PCV valve every 15K miles, and remove and turn 180 degrees the prongs on the dist wires in the cap. The rotor and these prongs will char by 15K miles. I do a full tuneup every 30K miles, which includes also a gas filter, dist cap and new wires. It's cheap and the car runs better, engine is cleaner and lasts longer.
5) Wheel alignment. Keep it aligned, and keep the wheel bearings greased, and bearings and rear brakes properly adjusted.
 

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I have often wondered why the 2.5 engine with 12% more displacement only makes 1% more horse power? Perhaps the balance shafts are part of this mysterious power conundrum?
2.2 = 93 horsepower, 123 lb-ft as I recall
2.5 = 100 horsepower, 132 lb-ft as I recall

The 2.5 largely gave more torque "down low."

I calculate the 2.5 had 15% more displacement and 8% more horsepower with 7% more torque, going by the "new-old divided by old" method.

Again, though, you have to look at the torque curve. The 2.2 was definitely more "peaky." Nothing wrong with that.

If you really want to have a blast, get the T1 if you can. That was a great package - multiple port injection for better mileage and smoother operation, and a good 40-50 horsepower more (93 -> 147, I think?). The 2.5 Turbo I is probably my favorite, believe it or not (keep in mind I've only driven the 2.2T1, 2.5T1, and 2.2T3 -- I suspect the T4 was best to drive and T2 was close). The 2.5's low end grunt coupled with the turbo... made a difference.

Supposedly, the turbo models had better gas mileage in real driving.
 

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I average 32 mpg with my 2.5L TBI and 33 mpg with my 2.2L turbo. On trips to Carlisle, the turbo gets 35 mpg due to long areas with 55 mph speed limits and cruise control. I can't get the 93 to beat that, although my 92 did.
 

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I have removed plenty of balance shafts and the way I see it, if you are going into the motor like a rebuild or changing a oil pan gasket then do it, but I wouldn't go out of my way just to do it.

As for vibration, all cars will be differnt. Some motors are put together good and some not. Case in point my 91 Spirit ES 2.5TI 5speed and my friends 91 Daytona 2.5TI 5speed. Both motors were smooth, both had about the same mileage on them and we both had poly motor motor mounts and a soild bobble struts. We both removed our balance shafts and vibration wise the Daytona was the same with the balance shafts my Spirit was different it vibrated alot, I had to change and go back to stock mounts. Plus you don't really feel and differnce in seat of the pants driving. We also but 2.2 oil pans on the cars.

As for which is the best for overall driving, it depends on the car. I thought my old 92 Spirit ES 2.5 TI auto was the best. Good torque and snappy. I felt alot better than my 91 Spirit ES TI 5speed. That 92 had what they called it a high torque motor. Put out more torque than the 5-speed.

As for "Real world Driving" on the Interstates at 65+mph expect about 26-29mpgs out of a Turbo unless you lower the boost and timing and run 87 octane and you can get over 30mpgs with it on the Highway.
 

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Discussion Starter #13
1991spirites:

-I do have a near complete T1 system; my intentions are to install it on this 2.5 with the "high torque" 2.5 liter turbo computer, then once the bugs are worked out, perform the T1 to T2 change and add an intercooler. If that is asking for a headache then I will use a T1 computer(s). I am missing a couple of components (fuel lines, fuel pump and computer) and can't do the change until spring as I need the auto as my daughter full time transportation to school.

DaveAdmin:

-When I looked up the specs for the 2.2 and 2.5, I found 99 for the 2.2 and 100 for the 2.5. I know that there are different values but seemed to be the newest. Using your numbers the difference is less severe, for certain.

This 2.5 is very smooth and I do not desire to give up any longevity in the engine. I like the appeal of the turbo for power much better. I am not sold on the LOG intake though. It just looks sad compared to the T2 one piece and the newer 2 piece intakes. I will however, make use of what I have, which is an 87 T1 system minus the aforementioned components.

I am looking forward to trying the unshielded oil pump pick-up and the port matched oil pump to block changes; I am going to keep the BS's for now as I still need the highest reliability this engine may have to offer.

BobLIncoln:

-Thanks for the tips on conserving fuel. I prescribe to a well tuned engine myself (whenever possible). I haven't looked at the PCV yet, I will address that. I agree VERY MUCH, that "driving style" has a huge effect on mpg. I am currently teaching this to my daughter. I haven't given up though, I still want 41+ mpg, by any normal means if possible.
-upon dropping off the parts for the port/polish job, the porter, shared some of his plans for the intake/exhaust; he is confident that I will see over 40 mpg and possibly 45 with a custom cam and headers (he also has a good reputation for usually being correct). I am not saying you are wrong, I am simply saying that I haven't given up yet.
 

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The heads on these cars are rubbish, although I think that 45 is a bit of overkill. There is a lot to be gained by doing work on the head; as you mentioned, these cars were designed to be built cheap and durable, not necessarily high-performance. So the head castings are quite bad in terms of flow and restrictions. I really haven't heard much of people doing head work on TBI cars, they usually see it as less work to go turbo. The 2.5 has more than enough displacement to make very good power, it's just crippled by getting the fuel and air in and out fast enough to make that power. I would like to see this beast dyno'd when it's done. Beware, though, a cam is not a miracle device, all cams are compromises, and must be tailored to how the engine is used to see any appreciable gain. You won't see anything with, say, a race cam that comes into its powerband at 4500rpm if you're just driving around town.
 

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Discussion Starter #15
B10alia:
-where my porter reported good gains andprogress in the TBI exhaust manifold, he was stimied upon first and second inspection of my donor turbo head. Appearently it saw too high of temperatures at least once. So dispite having valves and springs of usable quality, the head is dead. He wants to do the intake just the same; when he is done and I have a weekend free to install them I will. We have several local, reputable dynos and I expect to skip the baseline test but will spring for a run with the mocked up stock intake and exaust. Later after I resolve the "donor" head issue and port/polished/flow benched to the manifolds, I will have it dyoned before and after the cam. For the cam I am going to take my porter's recomendation, to use a later model roller cam and have it reground to his specs. There is always hope of a full engine rebuild. I usually make the most of available stock parts, but alwys have it. Balanc ed, cdebur, and polish the crank, debur and peen the rods, rework the oil passages with at least good bearings/gasket-seals and and hardware. What I have been taught is that a solid rebuild is good for an additional 15% performance without going with the exotic. I installed the boost gage in the dash after the pulley was installed to see what my daughter might have to say. She thought it was making more power from a turbo! She wasn't paying pull attention to the gage and noticed later that it wasn't functioning yet. She was surprised at the power, had to do a couple of mid left hand turn, wide open throttles to clear the yellow! She would let out a surprised WAOH! Anyhow thanks for the thoughts any shared enthusiam.
 

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Discussion Starter #16
Purhaps a bit of good fortune has ammassed, I went back to get another head from the yard, the owner let me have another head at no charge since tha last one was not usable! This puts me back in the game!
 

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When I looked up the specs for the 2.2 and 2.5, I found 99 for the 2.2 and 100 for the 2.5. I know that there are different values but seemed to be the newest. Using your numbers the difference is less severe, for certain.
You have to be careful with 2.2 power numbers. The TBI 2.2 was generally 93 horsepower, plus or minus one. I believe your 99 figure might have been from a Shelby or similar "warmed-over" carbureted version. It was not typical -- nor a good comparison point. It would be like pulling out the Turbo III as "typical" for 2.2 turbo cars. (Well, not that bad, but 99 hp 2.2s are a small percentage of all 2.2s.)
 

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2.2 TBI is listed as 99 hp in the 1985 catalog, and turbo as 146 hp. Can't find my 1992 catalog, but I think it also called out 99 hp for the 2.5L TBI.
 

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The newest book i could find was 1993 and is shows the 2.2TBI as 93hp and the 2.5 TBI at 100hp
 

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What book? I'm looking at the sale brochures, which have the hp and torque of each engine at peak RPM. Sometimes the ratings are different for each model of car, since they are net hp at the wheels, and losses are different.

1992 2.5L TBI was 100 hp.
 
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