Early 2.25 gas 90

worldofinflation

Active member
I've come across a nice Swiss Military 90 sitting in a field in Malawi. Looks to be an '84 or '85 and has the 2.25 gas motor with a 5-speed gearbox. Are these exactly the same as the late Series 3 engine? General opinions on the robustness of these late 2.25s appreciated. thanks.
 

evilfij

Well-known member
It’s a 2.25 petrol, if it’s not a 2.5 petrol, this all applies. Its a 5 main bearing engine (like the late SIII) which makes it, in theory, even better than the earlier series 2.25 Let’s just say, it’s a great engine, but you won’t get anywhere fast. I have seen 2.25 petrol engines run with all manner of faults like a broken con rod, the intake packed with nuts, etc. everyone like the 200tdi and 300tdi, but a 2.25 petrol will run.
 

FLY CUBS

Well-known member
2.25 is bullet proof and will take a LOT of abuse. Like the previous post said, you wont make it anywhere fast but it's also not terrible around town. My 109 with a 2.25 petrol will easily do 50+ without an overdrive.
 

mgreenspan

Founding Member
You can expect to get to 60mph easily. It’ll accelerate to 65 nicely and cruise there happily. You can push it to 70, but any uphill will drop that back down to 65. I daily drove and commuted from Cambridge to work at Mildenhall in the UK with this exact setup in a 90 van. It works but you’ll be filling up frequently if you drive on the highway. The tank isn’t very big and you’re really revving the engine to go that fast. I loved it, but swapped to a 200tdi for fuel economy. The conversion all in with labor and a warranty in the UK was under £2000 at the time so it made sense. For a weekend ride or for running around town a 2.25 will be perfect.
 

LR Max

Well-known member
Not *the* same but pretty darn close. Same architecture.

Will be metric fittings and a few other differences. Intake and cooling system will be different but not anything ground breaking. Its a decent engine if its in good shape.

If you want to tow your 4000lb airstream over the pass at 70mph, she ain't going to do it. But if you just using it for general use, no worries. Actually a decent engine in a 90. I'd build one up, ACR builds these engines and they can put out some respectable numbers.
 

hillstrubl

Founding Member
2.25 is bullet proof and will take a LOT of abuse. Like the previous post said, you wont make it anywhere fast but it's also not terrible around town. My 109 with a 2.25 petrol will easily do 50+ without an overdrive.
Is this the motor that was basically designed as a diesel but as a petrol is a bulletproof for that reason?
 

evilfij

Well-known member
Correct. Rover built the 2.0 and later 2.25 diesel and basically put a 7:1 and later 8:1 compression petrol head on it. That’s why it is a tank. The early one have problems if you run without lead additive as it eats the valve seats. Not sure when that got fixed if ever in production. They make lead additives if you don’t want to convert the head.
 
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