Nitrous

[JimCT]

Ambulance/camper

6200 lbs loaded for a month of camping with the two of us and our 115lb dog.

[yorker]

6200 lbs...

You are a prime candidate for a repower since that really is a ridiculously low power to weight ratio.

Generally speaking the torque-to-weight ratio is what really counts. In today's usage ≥ 20:1 is considered inadequate and < 10:1 is overkill.
Yours is around 52:1... using the 2.25's figures from TAW's page:

http://www.expeditionlandrover.info/enginePwrSpecs.htm

Neither a Turbo nor nitrous is going to make much of a difference for you.


Ask TAW- I think that summer trip she took to go to the ANARC Ralley @ Greek Peak in '98 was the nail in her 2.25's coffin.


A Ford 302 EFI like what she has now can vary widely in torque but figures of 300lb ft aren't uncommon IIRC (stock figures for the 5.0l were
150 hp (112 kW)270 lb.-ft. at 2,000rpm.

That renders a 20:1 ratio with your weight. Better than an unladen 88 with the 2.25 so that isn't bad by our somewhat eccentric standards.

TAW-have you dynoed your engine with the EFI? What are the engine's build specs now that you have swapped?

[TeriAnn]

[quote=yorker]how so? what diameter?

One diameter up from stock exhaust tubing plus a free flow muffler is your best bet. Your local muffler shop can bend you up a set. It will help over stock but considering how much an ambulance weighs you may not notice a difference.

[TeriAnn]

Ask TAW- I think that summer trip she took to go to the ANARC Ralley @ Greek Peak in '98 was the nail in her 2.25's coffin.

It performed just fine for that trip. Though I did have the engine floored for a lot of the trip. I had already made the decision to repower my Land Rover before that trip. I was exploring engine and gearbox possibilities.

The final nail was when I was driving South from Canada in Eastern Montana a few months earlier. It was a 2 lane highway with a long bend around a low bluff. I was floored at about 55. There was an oncoming 18 wheeler plus a 18 wheeler coming up behind me about 25 MPH faster than I was going. It had the space and passed me before the oncoming 18 wheeler got too close. It turned out that there was a second 18 wheeler behind the first also trying to pass me. There wasn't time for the second 18 wheeler. The driver thought better me than him and pulled into my lane alongside me to avoid a head on with the oncoming 18 wheeler. Rather than get run over I took this as an oppertunity to so some off roading at speed. I was able to safely get the Green Rover stoped out on the field. My poor dog was pelted by the few things not secured in the back (I had a net between the front & back) and I thought I was going to put my head through the roof on some of those initial bumps. But no damge was done except to my sense of safety. If there had been a drainage ditch along side the road the Dormobile would probably have tumbled head over tail a few times. When I stopped shaking I decided it was time to either sell my Land Rover or switch engines.

That was just the last of many close calls I've had by stupid impatient drivers just because I could not keep up with traffic. There are some highways in Utah where I could not even go the posted minimum speed limit on grades.

A Ford 302 EFI like what she has now can vary widely in torque but figures of 300lb ft aren't uncommon IIRC (stock figures for the 5.0l were
150 hp (112 kW)270 lb.-ft. at 2,000rpm.

The stock HP varied all over the place depending upon year and how it was built. 1970's 302s were pretty gutless, as were most truck versions & non-sporty passenger cars.

My base engine is from a 1970 Mustang. The EFI is stock 1991 Mustang 5.0 Mustang 302/5.0 (except the Mustang II years) typically were factory rated between about 205 HP and 240 HP with the limited edition sport version higher. I'd guess my engine is somewhere in that range. I know it will out climb a 4.6 P38 Rangie climbing the mountains going East to Reno

150 HP @ 2000 RPM sounds about right though.

TAW-have you dynoed your engine with the EFI? What are the engine's build specs now that you have swapped?

I never felt a need to pay someone o find out the actual HP. The engine does what I want it to do on regular petrol. I figure that's what really matters.

1970 Mustang motor, 1991 Mustang EFI, afer market 65mm throttle body (stock is 60 mm, the after market was cheaper than a new stock one). hooker headers, no mechanical fan (I have an electric fan off a Mercedes V8). When it comes time for a valve job, I will consider aluminum heads (makes the engine lighter than a stock 2.25L petrol) The heads I have in mind provide better power at the low end than stock. I'm also thinking about a special truck cam optimized for low RPM torque. But all that can wait until I have to pull the heads. It meets my needs right now.

[JimCT]

35K

Just for interest we have done over 35,000 miles in the ambulance as it is, so I would not consider it unuseable. That had included trips to cape Breton, PEI, NB....and lots of off-roading, it has been on it' sside once.

[yorker]

Well if you want to try nitrous- go for it. Let us all know how it goes.

[TeriAnn]

Just for interest we have done over 35,000 miles in the ambulance as it is, so I would not consider it unuseable. That had included trips to cape Breton, PEI, NB....and lots of off-roading, it has been on it' sside once.

I think you have hit on the single most important thing. Best to stay with what works and you are satisfied with.

I've seen too many people buy a series rig and trick it out without first learning where the vehicle handling boundries are. Sometimes the trick stuff can make the handling worse or the vehicle less reliable. A lot of times it becomes a crutch for not knowing how to drive a Series rig. I think Jim is taking the right approach. Buy a series rig and drive it. Learn where the vehicle handling boundries are, live with the ones do not feel a need to exceed, then selectivly make modifications to specific parts that will affect the boundries you wish to increase. It is usualy best to be conservitive with the modifications as long as the end results meets your needs.

If he can meet his needs by picking up 5 or 10 HP or straping JATO units to the roof of his ambulance ... Opps thats a nitro, er nitrous system isn't it, then that's the way to go.

Give you ideas a try & see if they met your needs.

[KingSlug]

Why I am re-powering...

I was pretty much satisfied with the power from my amby, but I found that it just wasnt driveable with modern cars. People would squeeze me out in passing lanes, cars were constantly causing me jumping in front of me as I was building speed causing me to slow. If I can get to 55mph I do fine. On hills I pull to the side and plug away at 15-20mph, from start on a hill its slooooow. I have decided to go with a 4BT Cummins, it just makes sense with the weight I am pulling. The problem with getting up hills is that your amby is giving all it gots to stay going forward, without a bigger engine you just have to enjoy the slow lane. Nitrous destroys engines, even in small amounts. The mods I currently have 8:1 head, Rochester, larger exhaust and I try to strip out extra gear when I am not going camping (I even rely on only one front fuel tank, instead of filling up all 3).