2.6 Engine Improvements

I’m on the tail end of performing a frame off restoration on an ex military Australian Series’s III 109 utility truck. I chose to rebuild the 2.6l as its unique. The only worked I HAVEN’T done is rebuilding the Stromberg carb. Had that done by a specialist in the States.

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Originally Posted by Homestar

So, thought I'd start a new thread on this. The Series 3 is coming home tomorrow and I have cleared a space in the garage for it. Work will commence within weeks on its rebuild. The biggest part of the build is dumping the 173 Holden engine that is currently in it and returning a 2.6 into its rightful home. The main reason for this is to avoid having to get an Engineers certificate (it has never been registered in Vic with the Holden conversion).

As this will become a daily driver, having it capable of doing 100KPH easily on the highway. I'll be fitting 3.54 diffs to it (it won't be used much off road).

So, thinking I might need a few more neddies out of the engine. It will be completely rebuilt, and I'm thinking of some mods along the way. It will have to remain naupturally aspirated, but something I'm thinking of doing is fitting fuel injection to it. Now one of the big issues I think I'll have here is the integrated manifold on the head. Anyone ever fitted EFI to one of these? Also thinking I could machine the manifold off and TIG a flange onto the head so I can fit a custom bolt on manifold - sort of like the Westlake head, which would make mounting the injectors easier. Now having a look at the head, I'm not sure where the coolant runs through it and if this will get in my way of machining the manifold off? Anyone got a stuffed head they are willing to sell me cheap to test my theory?

Also, is it possible to increase the compression ration of these engines? I believe the Australian engines were a lower compression than others? Can this be done with different pistons?

A one ever had a new camshaft ground for one that allows it to breath a bit better?

Obviously not going for a budget build here, and I'm happy to throw some dollars at it if I end up with the right result.

Thinking around 120 to 130HP would be nice. Sorry if some of these questions sound dumb, but I've not worked on an engine like this before tha has challenges like the side valves and integrated manifold on the head.

Experiences from those in the know would be appreciated, or educated guesses from those that aren't.:)

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I bought and imported to the US a 1981 Series III 109 with the 2.6l engine in 2017. My question is if the military had modified the engine (valves and rings) to use unleaded gasoline. In the later years that this truck was owned, used and maintained by the military, did they run leaded gasoline in this vehicle or make the conversion?

many info would be very much appreciated

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Originally Posted by 101 Ron

This motor is not of a type which is good to play around with for performance.
If you can find a Westlake head would be good, only for the increased compression and alloy construction.
The breathing of this motor is not too bad as standard.
This motor is a F head....side valve exhaust and is a sort of enlarged version of the original 4 cyl rover motor used is series one landrovers which in turn was taken from rover cars ??????
Side valve motors do not handle higher compression well.
If you want to get the best from the 6 cyl rover motor I would just do a good rebuild to standard specs.
I remember a new series 3 exarmy landrover would perform well if distributor, and carby etc was all working as one in tune.
If injecting....... a single injector using the standard water heated intake would be easy, cutting the standard 2.6 head is not a option as the intake is surrounded by coolant as apart of the design.
If you want performance, play with the holden motor as the pathway to power on the holden is well known and all the valves are in the head.
The other option is later model...ie V8 rover/TDI running gear.
To spend money would be better spent on a later model of landrover...ie stageone series 3.

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I believe the ran leaded petrol the whole time. I don’t believe any of them were modified to run on unleaded. I’d use a lead replacement in the fuel - it’s cheap and easy.

The 2.6 has, unless I am mistaken, steel valve seat inserts, and hence unleaded should not be an issue.

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Originally Posted by Lionelgee

G'day Bacicat,

Thank you for starting this thread about upgrading the performance of the 2.6 Litre engine. I will be reading your developments and other people's responses with great interest. :)

I have a Series 3 FFR which is still pretty stock standard with its 2.6 Litre engine.

What type of Zenith Stromberg carburettor are you running the CD or the CD - 2?

Kind Regards
Lionel

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Are you aware of any ways to improve the connector that fits between the head and the water pump? Mine has always leaked and now the piece that fits in between the head and the water pump has broken off. Is there a retrofit that improves this awful design (IMO)??

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Originally Posted by Lotz-A-Landies

Hi Andy

The Rover 3 litre rover car engine block is basically the same as the Land Rover 2.6 at least the last 2 versions of the 3 litre. The Land Rover has a different water pump and the head is different to accommodate the pump. The 3 litre crankshafts have a longer stroke and are 8 bolt instead of 6 on the Landy. The shape of the 3 litre and 2.6 pistons are slightly different although the same bore size swapping pistons will change the compression ratios, making the Landy even lower compression than it already is,

The Land Rover RHD and Mk1 P5 3 litre have an inlet manifold integral with the head. The Mk2 and Mk3 have a detachable inlet manifold (Weslake head) but the carby and steering box on the Landy are incredibly close making the air plenum difficult. Remember you can't use the Land Rover water pump on a Weslake head, meaning Australian conditions may be too much for the capacity of the 3 litre cooling system.

If your mate is talking twin carbies he's likely talking about one of the P4 engines and not the P5 3 litre.

Clear as mud?

Diana

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Any chance you know of a work around to the terrible design of the 2.6l engine and I’m specifically referring to the way in which the head attaches to the water pump. Part 564165 is no longer available and I really don’t want it anyway as I said before that this design is awful. No matter how I fix this connection it leaks.

Looking for someone who has had to work around this. Surely, I can’t be the only person who has encountered this. Thanks for any and all advice.

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Originally Posted by matthamilton

Any chance you know of a work around to the terrible design of the 2.6l engine and I’m specifically referring to the way in which the head attaches to the water pump. Part 564165 is no longer available and I really don’t want it anyway as I said before that this design is awful. No matter how I fix this connection it leaks.

Looking for someone who has had to work around this. Surely, I can’t be the only person who has encountered this. Thanks for any and all advice.

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Re-fitted the head on mine years back and no leaks.Part number 564165 was firmly attached to the head from memory.
The only problem I've had is that there should be a protrusion on the water pump to keep the fat O-ring centralised.
This was originally a thin spring steel band (I have one somewhere) but aftermarket pumps sometimes have a machined lip.
I'm in the process of reconditioning a couple of 6-cyl pumps and will machine a tube to press in and provide the location for the O-ring.

Colin

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Originally Posted by gromit

Re-fitted the head on mine years back and no leaks.Part number 564165 was firmly attached to the head from memory.
The only problem I've had is that there should be a protrusion on the water pump to keep the fat O-ring centralised.
This was originally a thin spring steel band (I have one somewhere) but aftermarket pumps sometimes have a machined lip.
I'm in the process of reconditioning a couple of 6-cyl pumps and will machine a tube to press in and provide the location for the O-ring.

Colin

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My water pump which is a new old stock OEM doesn’t have the protrusion to hold the rubber seal in place. And when trying to remove the water pump (instead of removing the head) to get to Part 564165, part 546165 broke with the threaded piece still in the head.

So now I’m trying to determine if I can extract the thread piece of part 564165 out of the head and use the threads for a brass connector that can be threaded into the head. Then press in a brass fitting into the water pump and use some sort of Fernco type hose to connector the two brass pieces and prevent leaking.

Otherwise, it’s tapping the head and the water pump and I’m not sure how smart that idea is since I’m sure heads for this 2.6l are hard to come by.

Thank for your reply!!!! At least I feel like I’m in this predicament with others!!! :)[bigsmile1]

Just following up and letting everyone know how I worked around the issue. First, the issue, is that part 564165 which is a cast piece that fits between the thermostat housing and the water pump housing is no longer available. This is an awful design and this area always seems to leak. I decided to tap the head at the thermostat housing with a 1/4 brass threaded fitting and tapped the water pump outlet with an 1/8 inch threaded brass fitting. I connected the two brass fittings with silicon hose and clamps. This solution held pressure at 15+ psi and eliminates Part 564164.

I’ll post pics if anyone is interested.

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Originally Posted by matthamilton

Just following up and letting everyone know how I worked around the issue. First, the issue, is that part 564165 which is a cast piece that fits between the thermostat housing and the water pump housing is no longer available. This is an awful design and this area always seems to leak. I decided to tap the head at the thermostat housing with a 1/4 brass threaded fitting and tapped the water pump outlet with an 1/8 inch threaded brass fitting. I connected the two brass fittings with silicon hose and clamps. This solution held pressure at 15+ psi and eliminates Part 564164.

I’ll post pics if anyone is interested.

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Yep, post a pic or 2 please.