How much can I get from the 2.25

[kidrover86]

Hey everyone, It's been awhile since my initial post. I've done alot of research since then (teri ann your site is great) and I've kind of boiled it down to two options... tweak the 2.25 gas motor or drop in a v8. It's a 109 3-door hardtop with Fairy overdrive.

My question is exactly how much can I get from the 2.25, I'm thinking the 2.5 camshaft, electronic ignition, ported and polished with 8:1 compression. The objective is to be able to drive a couple hundred miles with gear (think San Francisco to Moab and back). Any personal experience form people who have up-rated their 2.25 would be great. Obviously dropping a ford 302 would be awesome, but also alot more work.

The last time I drove the rover it was 9 years ago and I was 14 years old so my recollection of it's performance isn't really there haha. I understand with a v8 that the tranny, t-case axles and brakes will need to be addressed, so thats a whole different convo. Right now any input as to what to do with the motor would be great.

Keep it stock or pull it...question of the day! Thanks everyone, once I start the project I will be sure to start a build thread. Happy Holidays. -Jason

[SafeAirOne]

The objective is to be able to drive a couple hundred miles with gear (think San Francisco to Moab and back).

Two and a quarter liter engines have propelled loaded land rovers from sea to sea and continental border to conitnental border and back. A stroll from San Francisco to Moab should be pretty easy.

[kidrover86]

Thats true, sorry I forgot to say we will be putting a mild suspension lift on it to clear 33 inch tires. The increased resistance from the tires is what had me most concerned. This can be overcome to some extent with gearing but then that negatively impacts highway driving.

[scott]

i believe i'm getting about 100bhp out of my 2.25.

bored out to about a 2.3, 2.5 liter cam, 8.5:1 head, 1 3/4" exhaust, weber 2brl

[Bud]

Refocus

Stick with the 2.25, make it reliable, renew worn components, tune it well, and stick with smaller tires. This is cool, respectable, and peppy.

Do you want to drive it now? Do you want to drive it in a year with a hastily executed conversion? Do you want to drive it in three years having done your conversion well but still needing to do x, y, and z?

Staying original has many advantages, which become more apparent as time goes by. Resist the urge to do things to/with your Rover that it was not designed for. Maintain your classic car as a Classic and you will appreciate it later in life.

Travel at your Rover's pace. The whole point of driving old land rovers is to experience travel in a traditional manner, enjoy that freedom.

[kidrover86]

Yea I agree with all your points. We're trying to find the best middle ground of keeping the classic rover charm while being able to have fun with it offroad and going on extended camping trips. The v8 would give us more than enough power but is it necessary?.. probably not.

Whichever route we decide to take nothing will be done hastily. Everything will be planned out to work seamlessly. Were on no real time constraints so no need to rush anything. We would like some larger tires though, being the lwb that extra ground clearance is invaluable. Thanks for everyones input so far

Stick with the 2.25, make it reliable, renew worn components, tune it well, and stick with smaller tires. This is cool, respectable, and peppy.

Do you want to drive it now? Do you want to drive it in a year with a hastily executed conversion? Do you want to drive it in three years having done your conversion well but still needing to do x, y, and z?

Staying original has many advantages, which become more apparent as time goes by. Resist the urge to do things to/with your Rover that it was not designed for. Maintain your classic car as a Classic and you will appreciate it later in life.

Travel at your Rover's pace. The whole point of driving old land rovers is to experience travel in a traditional manner, enjoy that freedom.

[brucejohn]

Of folks here it seems TeriAnn has the most experience on extended travel in a series rover. Advice and following her example would likely be a good idea.

Having said that, I purchased my 3 door 109 specifically to have a vehicle that was easier to work on even in the field.

The allure of a return to more relaxed travel is a big plus. Taking the back roads, stopping to explore and enjoying life at a little slower pace sounds good. If I have the ability to blast down the highway at 70+ I will. The rover is a kind of forced relax and take it easy tool.

[TeriAnn]

Stick with the 2.25, make it reliable, renew worn components, tune it well, and stick with smaller tires. This is cool, respectable, and peppy.

Umm he is talking about going to 33 inch tyres. Stock for a 109 is 32 inches. An inch should not make a whole lot of difference and should not need a lift unless the springs are totally flat.

First lets look at what we are starting with:

Rover says stock for a 2.25L 8:1 is 70 hp @4000 RPM (less at lower RPM), 120 lbft @ 2000 RPM. I drove my 109 for about 15 years with a tach and SIII 8:1 2.25 engine and developed a sense on how the engine behaves at different RPMs.

The engine torque curve is very steep below max torque. While the engine can run smoothly under load down to 800 RPM or but there is almost no power there. If you are climbing a hill and need to down shift but want to keep your speed as high as possible you want to down shift somewhere between about 2400 and 2500 RPM. If you are almost at the top of a hill and you are feeling lazy, you can let the RPM slide down to around 2200 before the power starts to drop off quickly and you really need to down shift.

The engine seems happiest cruising in the 2800 to 3200 RPM range. I'm guessing best fuel economy around 2800 RPM on level roads under most normal driving conditions (The slower you are going the better the fuel economy). Basically you have a truck that is happy going 55 MPH all day. SF bay area to Moab, you are only talking about half a day to a day (depending upon your path) extra time to get to Moab in a stock 109 vs a vehicle doing the speed limit.

Running a fairly fresh SIII 8:1 engine with Rochester carb I found 3800 RPM about as high a shift point as I wanted to use for maximum acceleration. Most of the time I up shifted at around 3500 RPM. I think that while the peak HP may be at 4250, the power curve is mostly flat above 3700 RPM and the added RPM doesn't give you anything to write home about.

How well all this works out depends upon how heavy your truck is, the altitude you drive at, how steep the roads are in the hills and what is an acceptable driving time & speeds.

I've found that on Interstate 40 climbing towards Flagstaff (He specifically asked about going to Moab) that 45 to 50 MPH was my best pedal to the metal speed and on some Utah highways I could not go as fast as the minimum posted speed limit. But I have a heavy truck (5700 lbs fully loaded). You can do better with a lighter weight truck.

Here's the common options:

stock engine in good shape: Good compression healthy engine should be the base. No compression = no power. If you have a 7:1 head replace it with an 8:1 head (not enough metal to shave it without much higher risk of cracking head). Going from a fresh 7:1 head to a fresh 8:1 head is good for about 6 HP. A fresh distributor might be a good idea if yours has any shaft wobble. You get your 70 hp. It can push an overdrive in fourth on the level at lower altitudes or with a good tail wind (Overdrive is most useful for splitting 3rd & 4th gears in the hills). Expect to be driving slower than traffic most of the time.

Common modifications Good condition engine as a base. New distributor with more performance advance, 2.5L cam, 9:1 compression head, Rochester B series carb, K&N air filter for highway use, go one size larger diameter exhaust tubing & free flow muffler. Some people might suggest a header. I had one for a few years and could not feel any difference other then the truck was more finicky when the engine was cold in cold weather. Maybe bore the engine out some. You are basically looking at a complete engine rebuild, and if you do everything right you can pick up maybe another 20 HP. If you have deep pockets you might go shopping at ACR (Automotive Components Remanufacturing) for bolt on high performance options.

Start with a 2.5L engine & add performance mods The stock 2.5 engine is factory rated at 83hp @ 4000 RPM & 133 lbft @ 2000 RPM. You get about 15% more power in stock trim. Add the modes listed above and you might end up with something in the neighborhood of 110 hp. and still look stock from a casual engine bay inspection. = happy purists.

A modified 2.25 or a 2.5 engine should provide enough power to push fourth overdrive under most levelish highway conditions and allow you to go faster in the hills. Beyond that you start making the purists cranky.

Find a Scottys adapter and install a sixties Chevy four cylinder engine. A Chevy cast iron four is lighter weight that the LR four, has more hp & torque and usually gets better fuel mileage. minuses are that it may take a bit of an effort to figure out the flywheel/clutch set up. Also parts are getting harder to find for many of these engines. But the conversion is fairly simple and can easily give you a 140 HP vicinity engine and other than the flywheel the conversion is pretty straight forward.

Contact Robert Davis and buy one of his pre engineered 4 cylinder conversions http://www.lrfaq.org/Series/FAQ.S.op...onversion.html It will cost somewhere in the 3-5K region but will net you a clean nearly turn key pre engineered solution that will give you enough highway power for most of your driving while pushing 4th over in a lightweight 109.

Convert to a 200tdi engine and be the envy of all but the purist of purists: The stock 200tdi is rated at 111 hp @ 4000 RPM, 146 lbft @ 1800 RPM. This is the general range of a modified 2.5L engine but less than most GM 4 cylinder conversions.

This conversion is well documented but like the 2.5 engine you would need to import the engine. It would take a similar amount of effort as a Scottys adapter conversion if you are starting with a 2.25L diesel LR. With a LHD truck you would save a lot of conversion headaches if you do a power steering conversion at the same time. You will need Defender version manifolds. You can stay with your stock drive train behind the engine.

Six & eight cylinder conversions: These take a lot of effort and engineering to get right. Short cuts or poorly engineered or executed conversions will usually result in a headache vehicle that is nowhere as reliable as a stock truck. A good conversion is not cheap. You can buy several early drivable Rangies & Discos for the price of doing one Series conversion right. You need to be very good or hire someone who is very good at fabrication to pull this off properly. A good conversion is beyond the capabilities of your average home mechanic. Think twice or more before proceeding on this kind of a project and make sure you have a lot of ready cash.

But done right you end up with something like a more powerful leaf sprung Defender that gets better fuel mileage, uses inexpensive easy to source parts and that most US mechanics know how to work on. There are a whole lot of options available but figure at a minimum engine, cooling system, gearbox, rear axle assembly & power steering needs to be addressed. But with a small block EFI conversion you can have a very reliable truck with an engine that weighs less than the 2.25L engine, has more power at idle than the 2.25 has a peak and gets better fuel mileage.

You could end up with a reliable truck that goes the speed limit under all road conditions, gets better fuel mileage than a stock Series, has one finger steering and is much nicer to drive than a stock Series truck. The purists will say bad things about your truck, but that's their problem. Done wrong and you have a sometimes mobile headache that you might have trouble giving away.

So anyway that's the common range of options for American Series owners

[kidrover86]

Thanks Teri. For some reason I was thinking the rover had 31's stock. 1 inch shouldn't make much of a difference, probably wouldn't even need to swap gears. I'm going to look into the 2.5 a little, I hadn't really considered that.

[JimCT]

255-85's

We are running 33" 255-85 16" Truxus tires on the Ambulance and they fit and work great. Of course we have the military frame. Not that much difference in gearing either. Jim

[NickDawson]

I've got a 2.5 an 32" tires - can do 60mph easily on the highway

[TeriAnn]

i believe i'm getting about 100bhp out of my 2.25.

bored out to about a 2.3, 2.5 liter cam, 8.5:1 head, 1 3/4" exhaust, weber 2brl

The stock 2.5 engine is factory rated at 83hp @ 4000 RPM & 133 lbft @ 2000 RPM. It has a larger swept volume than your engine, the same cam, a Weber 2 brl, 8:1 compression. You seem to be estimating and additional 17 hp out of a half a point more compression, a slightly larger dia exhaust pipe and slightly smaller engine.

Is there a secret you are keeping? Reshaped combustion chamber? different valves? reworked ports? Turbo? low restriction air intake? reworked distributor curve? What are your tuning secrets? Have an ACR reworked head you didn't mention?

Or I guess conversely I can wonder why Rover got so little power out if its larger engine, same cam & 2 barrel Weber? Crappy distributor curve?

[Eric W S]

The stock 2.5 engine is factory rated at 83hp @ 4000 RPM & 133 lbft @ 2000 RPM. It has a larger swept volume than your engine, the same cam, a Weber 2 brl, 8:1 compression. You seem to be estimating and additional 17 hp out of a half a point more compression, a slightly larger dia exhaust pipe and slightly smaller engine.

Is there a secret you are keeping? Reshaped combustion chamber? different valves? reworked ports? Turbo? low restriction air intake? reworked distributor curve? What are your tuning secrets? Have an ACR reworked head you didn't mention?

Or I guess conversely I can wonder why Rover got so little power out if its larger engine, same cam & 2 barrel Weber? Crappy distributor curve?

Or the reader can also wonder why you've gone from providing good information to being petty in the matter a few posts...

[scott]

...Is there a secret you are keeping? Reshaped combustion chamber? different valves? reworked ports? Turbo? low restriction air intake? reworked distributor curve? What are your tuning secrets? Have an ACR reworked head you didn't mention?

Or I guess conversely I can wonder why Rover got so little power out if its larger engine, same cam & 2 barrel Weber? Crappy distributor curve?

gee terri why the hate? i based my estimate on info and parts i got from one of your employers/clients. you're listed as the webmaster for the folks who sold me my new head, cam and a bunch of other parts. his claim was, if i recall correctly, 110 bhp from his 2.25. i'm just a novice and did what they suggested bought what they sold and figured i wouldn't end up with what pros did but maybe i'd get another 20+. some day i'll put it on a dynamo and get an accurate reading of bhp at the wheels and will post and if i exaggerated, an apology to the mbrs of this board for misleading them. i do know for a fact (measured w/ a garmin gps) on a flat hwy i was easily turning 33" rubber at 65 mph in o/d with throttle to spare. i wouldn't hesitate to drive it like this all day and was just trying to let that dude know a 2.25 with a little bit of work will easily cruise from the bay area to moab. the pegged speedo in my avitar was taken, head'n east into albuquerque on the i 40. yes it's was head'n down hill but again i had lots of throttle left. badvibes has a rmfctr stock 2.25 w/ less than 4000 on it, from these same folks, stock exhst, and rochester and tells me he struggles to keep up as i cruise down the hwy towards some of our favorite off roads sites. excuse my long windedness, it's just me saying i ain't a liar just an optimist.

[kidrover86]

It's looking more like we'll try tuning the 2.25 and see if it can provide us with the power we require for our trips. If it's not I'm sure some members on here would be interested in an uprated 2.25 if we decide to do a conversion .