Thread: Series 2.25 petrol Power Ups

A smaller exhaust might actually help you on an engine that size. In exhaust systems bigger is not always better. If you go to big it reduces the air speed as the gases are cooling down an this can cause the cylinders to not scavenge properly. In a good set of extractors the length of each pipe should be the same. For a four cylinder engine a set of 4 into 1 that come together in the same firing order as the engine also helps the previous cylinder scavenge the next. All this really only matters for naturally assperated engines.

Cheers.

The easiest power improvement in this engine (apart from simply making sure everything is in good condition and setup correctly) is to increase the compression.

Most Australian 2.25 Landrover engines are 7:1, and provided it is the head with a square boss on top just outside the rocker cover next to the carburetter, compression can be increased to 8:1 or higher (over about 8.5 you will have problems on standard unleaded) by planing the head.

I don't think a two barrel carburetter has ever been fitted, so one has to wonder whether it is suitable. Other things to look at would be to ensure that the throttle linkage opens the throttle fully, and check the ignition timing. A compression check would tell whether any internal work is needed before doing anything!

John

You might be interested in what I have been doing for the last few months .

I have just finished setting up a fuel injection system on one of my Games. (Yes I know, a build thread will get posted eventually ) This has 4 individual throttle bodies and injectors off a Honda CBR600RR and also runs the Coil on Plugs off the same bike. Both fuel and spark is controlled by a Megasquirt ECU with a 36-1 crank wheel running batch fired injection and wasted spark for the ignition.

The engine has extractors fitted with the back half of the system being standard S3 SWB. It is also an 8:1 compression engine that is still standard in all other ways.

I am still tuning it and getting things running properly. The balancing of the throttle bodies is interesting but not impossible with a home made vacuum tool and I am still to properly work on the timing.

Generally though the engine is running well and it is great to have it automatically richen things up while it is cold so a choke is pretty much unneeded. I have noticed that it pulls much better up hills than it used to and I seem to be able to get up things in a higher gear. Haven't had a chance to see what the fuel economy is like yet but at 100kph I can put my foot down and it actually accelerates and it seems to hold 100 up a hill pretty well. Max revs I have seen while tuning is 4340 at 110kph so it certainly isn't over revving with the standard gears, but it would be nice to bring that down a bit and I will probably fit the Torro overdrive I have sitting in the shed.

So I would say that the proper control of mixture and timing throughout the whole rev range and the extra ability to breathe properly with the changes to intake and exhaust should help to get it running even better as I play with things. However, most of the series owners on here don't like any of that electrickery stuff so I think I am a little unusual .

I will have to take some photos in the next day or so and post a proper thread .

Cheers,

TimJ.

Great stuff, Tim.

We'll have to embrace some of this electrickery: not ALL of it was done just for the sake of marketing, I reckon even upgrading the plain old 3.5 V8 with a good sequential injection system, wasted spark ingnition and a good EFI manifold will transfer the characteristics of the old lump.

Well so far I haven't found another Landie with a twin barrel carbie. The only thing with changing the manifold is that I spent a lot of money buying the manifold thats on it now it cost me around $200 to get it from england.

hey mate, ive just had the head done onmy 2a and had it decked around 2.5mm! compression would be somwhere between 9.1 and 10.1. also had the ntake valves angles changed to 45' instead of the standard 30', also had the ports cleaned up too. Big difference. Now it drives better than it did with the standard wheels with my 35s, and doesnt die in the ass up hills.

and throw the diesel cam into it.

Dont try the oversized carby game on it it wont like you at low to mid range RPMS which is where the engine works best.

Originally Posted by Blknight.aus

and throw the diesel cam into it.

Dont try the oversized carby game on it it wont like you at low to mid range RPMS which is where the engine works best.

Well it's had that carby for a while and thats what I've got and it seems fine with it.