Help me pick an engine to use!

Hi folks, put on your thinking caps for a moment.

Here's my problem. I am designing/prototyping an industrial machine (stationary) and need an engine. The typical industrial engines are VERY pricey new, especially the newer injected, high efficiency ones. SO, my thought is to use rebuilt, zero hour automotive engines. I will machine a drive adaptor that bolts to the flywheel (not an automatic flex plate), so the engine will have to come in at least one model that uses a standard clutch. My initial production run is 10-12 units.

Here are the requirements:
Physically as compact as possible - probably means a straight-4
readily available in the US - a model with high production numbers
NO exotic engines - parts MUST BE INEXPENSIVE AND AVAILABLE
60-90 HP - a little more is OK, but not higher than 120 or so.
operating RPM 1800 - 3500
average torque

prefer EFI - TBI probably best for lower cost, I would adapt the ECM and sensors from the same vehicle. This probably rules out very late model cars where the ECM is tightly integrated into the trans and body. I would consider carbureted engines too, but prefer FI for obvious reasons.

water-cooled (I actually considered the old air-cooled VW 1600, but the air ducting was a nightmare)

fuel - prefer gasoline, but would at least consider diesel. Unless you know of a nice powerplant that runs on sugar water :cwm27:

Oh, it would be nice if the starter mounts to the engine instead of the bellhousing, but that would not be a showstopper.


I don't want much, do I? :icon16: I have considered a few engines, but can't quite put my finger on the right one. I figure with all the experience out there you all will have some great ideas that I would never think of.

Thanks!
Dan

As far as cheap, plentiful, low-powered engines go, I'd say you might want to try the 2200 from a Cavalier. They had 105 hp and seem pretty reliable, although they have some head gasket issues.

If that's too much power, I think the 3 cylinder engine from the Geo Metro is rated at 55 hp. I see plenty of them running around, so parts shouldn't be too expensive.

Not exactly compact, but if you want cheap and reliable, the old Buick 3.0L 4-cylinder is super plentiful in marine applications and parts are widely available at the parts store. There isn't much different between most automotive and marine engines, but the 3.0 has proven crazy reliable in boats. Most are 120 hp at 5000 rpm, so at 3500 you're probably right on your 90 hp target. They're also built to run at wide open throttle and 5000 RPMs all day so they should be up to it. They don't readily come with EFI (except the new ones) but adapting a TBI from something like a 4.3 V6 should be a breeze.

The 2.2 GM engine is also a good idea for simplicity and parts operation, but they aren't what I'd call heavy duty.

Ford's Ecotec would make a nice one. VW's 1.9L TDI would work. Avoid the Quad 4. They have some head cracking issues that are worth it in a car, but the heavy use might accelerate the problem.

Do a search on Ebay for Hercules engines. They make some gas I-4s that are top notch for your application. Parts are cheap and available, but not at the local parts store.

Given your operational RPM range, make sure you choose one that has a supremely low-rpm torque peak. Operating at 1800 rpm and heavily loaded (more than 1/2 throttle) should only happen if you are at or above the torque peak at 1800. That's really hard to do with a small 4-banger. Loading an engine for work when its below its peak torque can cause overheating, excessive stress on internal components, and generally not a good idea. Most peak around 3500. That's why my first suggestion was the 3.0. Its torque peaks very low.

If you're just trying to get quick power for the prototype, don't worry about it, but in your final design make sure the engine will be at or above the peak torque point while under load.

Wow, some geat ideas already. both of you mentioned the gm 2.2, that one had crossed my mind too.

Ford has an Ecotec motor? I thought GM did.

A Hercules G1600 would work for my application, but I haven't seen any for sale.

A marine engine. now I hadn't thought of that one. I know one is based on the old 151cu in Iron Duke as well. Hmm....

Cool!

I would also say go with a 2200 GM. I think they improved them (HP wise, I remember mine being 120 HP) starting in '96. The head gasket problem on them lies in the alignment studs they use. They are exactly the same length as the hole they go into, so heating up and cooling down causes loss of pressure on the head gasket which causes leaks. When the head gasket is replaced, the pins are ground down slightly and the problem is resolved.

You're right, the Ecotec is GM. They are a good engine, coming very close to the quad-4 in terms of torque and HP. They are still a bit on the costly side, however.

How much is this machine going to run? If it's just for testing a prototype then a petrol engine would do fine. But if it's a in a machine to run hundreds or even thousands of hours then a diesel is the go for fuel consumption alone.

Cummins 4B (non turbo) would do most of that. Rev range is on the lower side but they can be set to run up to 3200rpm apparently quite simply.

Kiwi -

I looked up some data on the Cummins, it would do. It's a heavy bruiser, with nice torque. Max speed for continuous operation is 2500, but I can adjust the drive ratios for that. What US vehicle(s) would I look for to find one? I also have little experience with reuilding diesels, what is the parts cost compared to a gas motor? Does it use a plain mechanical injection pump?

I am leaning toward the GM 2200 so far. What would be a good year to target? I'm thinking something like a 98 S10 pickup- RPO code LN2 engine? Sequential fuel injection, OBDII, roller lifters, composite intake. 140 lb/ft torque peaks at 3600 RPM. I have done some rough calcs, my torque will never exceed 75 and is pretty linear with speed.

Thanks for all the great replies!

Kiwi -

I looked up some data on the Cummins, it would do. It's a heavy bruiser, with nice torque. Max speed for continuous operation is 2500, but I can adjust the drive ratios for that. What US vehicle(s) would I look for to find one? I also have little experience with reuilding diesels, what is the parts cost compared to a gas motor? Does it use a plain mechanical injection pump?

The cummins 4B is primarily a stationary industrial engine. You might also find it in forklifts, tractors and the like. The turbo versions are/were fitted to step vans. Check out www.4btswaps.com for info on these engines. Injection is via mechanical pump.

I am leaning toward the GM 2200 so far. What would be a good year to target? I'm thinking something like a 98 S10 pickup- RPO code LN2 engine? Sequential fuel injection, OBDII, roller lifters, composite intake. 140 lb/ft torque peaks at 3600 RPM. I have done some rough calcs, my torque will never exceed 75 and is pretty linear with speed.

Thanks for all the great replies!

Check into the years for HP ratings (I think torque stayed the same), but they should be the same between the S-10s, Berettas, Corsicas, Cavaliers, etc. The only difference between the car and truck is the exhaust manifold; the car go straight down, the truck agles toward the rear of the engine.

True, but he needs his target HP at 1800-3500 rpms. The chances of a 2200 making 90 hp at 3500 rpms is a little slim considering that most only make 125 at 5500-6000 rpms. Its possible, but without a dyno sheet its tough to know.

Dgardner - If you could find all the specs on it I could try to reproduce it on a few dyno simulators and we could closely approximate it.

Thanks Curtis for the offer. My initial numbers were pretty worst-case. I'm now realizing they were a little high, so my real max is actually closer to 70-75. Is that more reasonable for a 2200 at 3500 rpm?

J-Ri, your info is great. Knowing the exhaust configuration will really help. The straight down will be much easier to shoehorn in to the machine.

Thanks to all!

Yeah, I think 70-75 is spot on. I was picturing the curves in my head based on what I've seen with the 2200 and 75-80 is my guess at 3500.