tuning a 2.25 petrol

[n.r.g97]

Hi, I am currently in the process of tuning a 2.25 petrol, its for my trialer that im going to race next year but that besides, it may be of interest to someone.I am running LPG on the engine, which we think has given it a bit of a boost anyway (or maybe it was just the **** carb on it before was letting it down)I picked up an engine advertised in the free ads for a tenner , its a 5 bearing run of the mill 2.25 petrol, on strip down we found its been rebuilt before but thats not really important.The first step was to strip the ancillaries off until we had just the block and head, then the head was ground by 2mm and polished and ported the ports. the block has been re-bored 40 thou, new pistons, the high torque kent cam arrived last week. I cant get any reasonable priced 4 branch manifolds, so going to cut up some old manifolds and make our own. Aiming for around 120 hp, though maybe thats optimistic? so would be happy with 100, coupled with the torque increase, it should be good. just need to bolt it back together now

[Bowie69]

I would seriously look at getting megajolt on it, much better spark which will help the LPG, and programmable from the passenger seat, you would gain quite a bit from this.

The other option is LPG injection AND ignition run by Megasquirt, coupled with EDIS and you would have a bullet proof system, that is really nicely tunable.

Remember the Rover V8 went from ~125 to 155HP just by moving to injection... not saying you would get similar gains, but it does stand to reason that properly metered fuel will give better running than a big hole relying on passing air to pull the fuel in.

[rusty_wingnut]

nice to hear of someone tuning the 4 banger, there's a lot to be hard from the old school back of the shed tuning tactics. I made my own 4 branch for my 2ltr, a very satisfying job.

[Bowie69]

Also, what compression ratio are you aiming for with that skim? You can go higher with LPG...

ACR get 117BHP from a 2.8l conversion of the 2.25:

This unit is based on the 5 main bearing 2.25 or the

2.5 engine. It features 95 x 97 mm bore / stroke and

is supplied as a stripped unit with the Stage 2 Head,

Power Plus © SU carb and Camshaft. Where it replace

a 3 main bearing unit the parts (Fly wheel etc.) required

to convert can be added. For customers who have already

some or all of the Power Plus © system installed on their

Land Rover, in most cases this can be re used.

Power Plus © 2.8 Stripped Engine with Stage2 Head SU carb

and Camshaft produces the following output:

177 FtLb @ 2300 RPM 117 BHP @ 4100 RPM.

Torque is pretty nice though

[Soren Frimodt]

Sounds cool n.r.g, have done something quite similar to my 2,25 in the 80" Skimmed head 2,5mm and ported it. Also smoothed out the oil return holes in the head to allow the oil to return to the sump faster when at high RPM. Also you must round all the edges of water and oil channels on the gasket surface of the head after skimming. If left too sharp in can cost gasket failure, and it costs nothing to do

I have the complete manifold and carb kit from ACR on mine, was able to swap it for my stock set so was cheap Works really well and sure does give it a lot more power on the upper RPMs. That said though, I'm still on the stock cam which is a shame really, as I don't get all the potential, but someday you know..

Also, with all due respect, don't listen to the guys saying megajolt or whatever, keep it running points, properly setup they perform plenty fine for this old dinosaur of an engine, it's super duper cheap and reliable, can be fixed with a hammer and best of all, if you drop the clutch too hard it won't stall on you, every electronic ignition based on a trigger and wheel setup does not do this as the engine can be turning so slowly they don't get the signal properly. What could be good though was an injection system, have been thinking about this myself. Though I wouldn't go for the expensive and quite complex Megasquirt style setup. I'd go for a simple singlepoint injection system off a VW Golf or similar. much simpler (following the KISS system) and waaay cheap at a scrappy. One of my plans for doing this winter.

Just my input, but of course it is your build and I will love following it no matter what route you take

[Bowie69]

EDIS trigger wheel and VR sensor works to VERY low rpm, < 100. Cranking on my V8 is only about 150rpm IIRC.

[secondjeremy]

Have a look at the spec of the diesel camshaft - its considerably less soft than the standard petrol one. Rover fitted it to later engines.

[n.r.g97]

I would seriously look at getting megajolt on it, much better spark which will help the LPG, and programmable from the passenger seat, you would gain quite a bit from this.

The other option is LPG injection AND ignition run by Megasquirt, coupled with EDIS and you would have a bullet proof system, that is really nicely tunable.

Remember the Rover V8 went from ~125 to 155HP just by moving to injection... not saying you would get similar gains, but it does stand to reason that properly metered fuel will give better running than a big hole relying on passing air to pull the fuel in.

I would definatly be interested if i was running petrol, and i will have a look at megajolt, but due to spending too much on other areas of the landy at the moment, I am happy to stick with clockwork, it has very rarely let me down, and thats only ever been due to neglect.

nice to hear of someone tuning the 4 banger, there's a lot to be hard from the old school back of the shed tuning tactics. I made my own 4 branch for my 2ltr, a very satisfying job.

Thanks! I am looking forward to seeing how much of an increase i get.

Also, what compression ratio are you aiming for with that skim? You can go higher with LPG...

ACR get 117BHP from a 2.8l conversion of the 2.25:

This unit is based on the 5 main bearing 2.25 or the

2.5 engine. It features 95 x 97 mm bore / stroke and

is supplied as a stripped unit with the Stage 2 Head,

Power Plus © SU carb and Camshaft. Where it replace

a 3 main bearing unit the parts (Fly wheel etc.) required

to convert can be added. For customers who have already

some or all of the Power Plus © system installed on their

Land Rover, in most cases this can be re used.

Power Plus © 2.8 Stripped Engine with Stage2 Head SU carb

and Camshaft produces the following output:

177 FtLb @ 2300 RPM 117 BHP @ 4100 RPM.

Torque is pretty nice though

Aiming for 9.5:1 compression with the gas, having looked at the ACR engines, maybe 120hp is optimistic, but id be happy with 100 really, and its still a 2.25 (even if nothing else on it is standard )

Sounds cool n.r.g, have done something quite similar to my 2,25 in the 80" Skimmed head 2,5mm and ported it. Also smoothed out the oil return holes in the head to allow the oil to return to the sump faster when at high RPM. Also you must round all the edges of water and oil channels on the gasket surface of the head after skimming. If left too sharp in can cost gasket failure, and it costs nothing to do

I have the complete manifold and carb kit from ACR on mine, was able to swap it for my stock set so was cheap Works really well and sure does give it a lot more power on the upper RPMs. That said though, I'm still on the stock cam which is a shame really, as I don't get all the potential, but someday you know..

Also, with all due respect, don't listen to the guys saying megajolt or whatever, keep it running points, properly setup they perform plenty fine for this old dinosaur of an engine, it's super duper cheap and reliable, can be fixed with a hammer and best of all, if you drop the clutch too hard it won't stall on you, every electronic ignition based on a trigger and wheel setup does not do this as the engine can be turning so slowly they don't get the signal properly. What could be good though was an injection system, have been thinking about this myself. Though I wouldn't go for the expensive and quite complex Megasquirt style setup. I'd go for a simple singlepoint injection system off a VW Golf or similar. much simpler (following the KISS system) and waaay cheap at a scrappy. One of my plans for doing this winter.

Just my input, but of course it is your build and I will love following it no matter what route you take

At the moment I will stick to points, this should keep it basic and easy to work on, I agree alot has to be said for moving with the times, but if i was doing that i wouldnt use a rover engine

How do you get on with the 2.25? It is interesting to hear from other people what to do and what not to do- saves time and money in my experiance

Have a look at the spec of the diesel camshaft - its considerably less soft than the standard petrol one. Rover fitted it to later engines.

I would have a look, but my cam is back from kent cams luckily it cost very little (£60)

[Soren Frimodt]

Is it a regrind then? Does it have enough or do they add material?

Well I get a long just fine with it, a lovely smooth engine, and it is just enough tractor-ish that no matter how much you fiddle with it, it'll always have low down grunt, and nice flat power curve. So lovely smooth engine for 90% of the time. BUT it is no V8 and on long loose hills I do lack the power and the last few thou's of revs that the V8 offers. Also it is quite heavy compared to the power it delivers. But very reliable and definitely worth fiddling with as noticeable power is easy to gain.

[rusty_wingnut]

You might wish to consider cam timing if you wish to make gains in the upper echelon of the rev range.

For comparison, my 2ltr will pull from barely rolling 3rd gear happily, that is in a 109 with 7.50 tyres. I can comfortably pull OD top on the motorway but longer hills do force me to change down. Nice bit is that there is no horrid diesel rattle and I can hold a conversation! 28mpg on a steady run as well.

I've got a single SU, four branch manifold, rebuilt distributor, high compression pistons and a nice new cam.

[bill van snorkle]

Going off on a slight tangent here, but I have heard that the supercharger from the BMW Mini has been used with some success on 2,25/2.5's over there. Anyone know details about them?

[Phil Price]

I hear all this talk of skimming heads to 9.5-1 and increasing bhp but it is a flawed concept for a Landrover engine. I have followed this debate online and read online posts made by  world acclaimed experts including, David Turner of Turner Engineering.  Landrovers need low level torque. When you skim a head you up the compression, Which will increase the bhp at high revs which are not good news for an old plodding engine which rarely gets beyond 3500 rpm, What it also does is reduces the low rev off road valuable torque Landrovers need more than unobtainable high revving bhp. They are not racing cars. Keep it at 8-1 especially if your starting with a 7=1 head as the metal on them is very thin and skimmed it can cause it to crack. 8-1 heads have a raised rectangle of cast under a center head bolt with a funny figure 8 cast that looks more like 2 zero's pushed together.

Low compression heads are also less likely to blow a head gasket.So are more reliable.

Also they will run on very poor, low octane petrol as found in Africa and Australia in the 50's and 60's that's why series 1's have 6.8-1 and series 2's 7-1 compression heads.

Enjoy driving your slow Landrover and take time to enjoy a slower safer pace of transport.

If this is alien to you and you want to drive fast you bought the wrong vehicle.Sell it and buy a Subaru. The insurance will be more expensive though as driving fast is never a safe option. Phil  Price 

[lo-fi]

Holy thread revival, batman! 

Also, with respect, absolute nonsense:

21 hours ago, Phil Price said:

Which will increase the bhp at high revs which are not good news for an old plodding engine which rarely gets beyond 3500 rpm, What it also does is reduces the low rev off road valuable torque Landrovers need more than unobtainable high revving bhp. They are not... 

Increasing the compression ratio does not shift the power band or trade torque for bhp. It improves just about every aspect of performance throughout:

http://www.imedpub.com/articles/influence-of-compression-ratio-on-the-performance-characteristics-of-a-sparkignition-engine.pdf

Agreed that low compression does allow running on poor fuel, the likes of which likely aren't available anymore. 

 

[FridgeFreezer]

You can have low torque, good power and better than factory MPG in a Series quite easily...

[Bowie69]

56 minutes ago, lo-fi said:

Increasing the compression ratio does not shift the power band or trade torque for bhp.

Thank you, I though I was going mad for a moment, and I was going to come back and re-read this and research before lambasting 😛 

[Gazzar]

There is a point being missed here. A series is a versatile vehicle. It's a farm truck, a passenger car, an expedition vehicle, cherry picker, missile carrier, armoured car, builders van, green lane toy.

It's a platform you start from.

No one has the right to say what engine should be what.

As long as it's safe, and road worthy and legal. It's fine.

I did 250 miles in mine yesterday, mostly on the motorway. I need a vehicle that's safe at those speeds, because it's what I want to do. Why shouldn't I drive it at the speed that's safe for my use?

If you want to bumble along country roads, that's your business. I do that, too. But I also go long distance at 60+ mph and no one has the right to stop me, my car, my business, my hearing.

It's not the wrong vehicle. It's my vehicle. If I choose to fit a high compression head, and a fancy cam, and fuel injection, that's my business.

It's cleaner, more efficient, more hp, more torque, more reliable, but that's irrelevant, what relevent is that I can do what I will with it, so long as it's legal and safe.

[Quagmire]

8 hours ago, Gazzar said:

There is a point being missed here. A series is a versatile vehicle. It's a farm truck, a passenger car, an expedition vehicle, cherry picker, missile carrier, armoured car, builders van, green lane toy.

^This is spot on.

My LR's are the best tools I own, but also the most fun for me and my young family. They are whatever their owners want or need them to be and that's the appeal of them, and why we have such a wide, varied and therefore interesting community on here. I personally love all the threads where people are doing things just because they want to try, and that they can see some benefits for them at the end of it. Your thread is one of those, and similarly, this one is too for different reasons! 

Carry on! 

 

 

[Snagger]

15 hours ago, Gazzar said:

There is a point being missed here. A series is a versatile vehicle. It's a farm truck, a passenger car, an expedition vehicle, cherry picker, missile carrier, armoured car, builders van, green lane toy.

It's a platform you start from.

No one has the right to say what engine should be what.

As long as it's safe, and road worthy and legal. It's fine.

I did 250 miles in mine yesterday, mostly on the motorway. I need a vehicle that's safe at those speeds, because it's what I want to do. Why shouldn't I drive it at the speed that's safe for my use?

If you want to bumble along country roads, that's your business. I do that, too. But I also go long distance at 60+ mph and no one has the right to stop me, my car, my business, my hearing.

It's not the wrong vehicle. It's my vehicle. If I choose to fit a high compression head, and a fancy cam, and fuel injection, that's my business.

It's cleaner, more efficient, more hp, more torque, more reliable, but that's irrelevant, what relevent is that I can do what I will with it, so long as it's legal and safe.

You missed out hovercraft - they did that and it need high revs and bhp.

I may be mistaken, but I thought higher compression ratio was better for all aspects of performance and efficiency, but was ill advised where fuel quality was poor as it increases detonation and all the problems that brings, so export LRs tended to keep the 7:1 heads while home market later switched to 8:1 as fuel quality improved, but never going higher as the nature of most LRs meant they tended to lay about unused for long periods and suffer fuel degradation or contamination, or use fuel from storage that suffered the same in commercial/industrial applications.

[Bigj66]

I notice that ACR are selling a Stage 2 BVH with 9:1 CR.

Would that be a bit overkill for a daily driver?

[Snagger]

If you need a new head, then it would be worthwhile doing that at the same time as it’ll save a bit of fuel or give you a bit of extra go.  It’s probably not worth doing if the current head is OK unless you’re fairly unhappy with the performance.  But all these tuning mods are incremental - they don’t make a big difference in isolation, but they do once you start adding them together.

Edit: I misinterpreted the post as a question about a 9:1 head, not a complete engine.  I think it would be quite transformative.  Plenty of acceleration, which allows you to pull out in traffic rather than wait for big gaps, no more slowing down on hills or headwinds, and possibly some reasonable fuel savings because you’ll be spending a lot more time in higher gear.  I’d now fit one of those rather than a Tdi - similar performance without the deafening noise and vibration.

[Bowie69]

Not overkill at all, be a nice improvement.

Best thing I ever did though, was stick a 1.75" SU carb on it instead, that and electronic ignition, ran superbly after that, and went so much better.

[FridgeFreezer]

Bear in mind 9:1 is very low-compression by modern standards, ISTR some fancy stuff is pushing 13:1 and a lot are around 11:1 which used to be race-car territory.

You're bang on about doing what you want with it - sure 7:1 is for "poor fuels" but Land Rover being what they were in the 1960's, it's for thrashing across the desert driven by a squaddie running on 62 octane / low-grade vodka and towing a trailer.

If you're not going outside Europe in your series you'll struggle to find any fuel that's less than what would be considered staggeringly good quality in 1960. Biggest problem with modern fuels is the ethanol content E5/E10/E15 which disagrees with some older seals.

[lo-fi]

7 hours ago, FridgeFreezer said:

Bear in mind 9:1 is very low-compression by modern standards, ISTR some fancy stuff is pushing 13:1 and a lot are around 11:1 which used to be race-car territory

... but (as a point of discussion because its interesting if you're an engineering geek like me) with very clever combustion chamber designs and mixing strategies. 9:1 is probably about the sweet spot for a stone-age 2 valve single plug design. Having said that, would be interesting to see how it behaves at 9.5:1. 10:1 you're probably pushing it to get enough advance in to get decent power without detonation. The "pent roof" design of modern 4 or 5 valve high compression chambers needs far less advance as they're only really compensating for flame front speed, not asymmetrical placement of the spark plug and an odd shape to fill. They will ping badly if you go past the sweet spot, not that there's any advantage in doing so. As another point of interest, there are some relatively modern, high output engines which don't use bonkers compression. Some of the Honda I-Vtec engines (civic type R) were a meagre 9.8:1. 

Turbo?

[Bigj66]

ACR do two versions of the 9:1 head but one has the larger valves in it. I was wondering how that might affect things like a smooth idle even though it will in theory flow better? Would it be more suited to a 2.5 than a 2.25 for instance? Or would it need a ‘wilder’ cam to really see the benefits of the larger valves?

[Gazzar]

Which then moves the focus to the fuelling of this extra flow. 

G.