Defender 110 Refresh & Modernise

[Defender Newb]

Hi,

Thought I would introduce myself given that I'm likely to start asking lots of questions shortly and in need of some help and input...

I've got an old defender 110 with me which belongs to a friend, he bought it a few years back at which point it was already running a 3.5 V8 Rover engine, however that ultimately died so he used a local garage at the time and they were instructed to fit a 3.9 V8. The car hasn't had much use and was used for plodding to the shops, nothing off road or adventurous. About 6 months ago it had problems, we narrowed it down to the coil pack which was replaced and new HT leads and plugs for good measure too. He is now planning to give it an refresh and update including some modernisation inside the cabin with custom centre dash/console, elec windows, elec heaters, sound system, etc, etc. My task is primarily electrical stuff, sorting the wiring mess in the bay, adding new circuits for planned gadgets along with some upgrades to handle the added draw and tidying up the engine bay and loom with a detailed finish.

I did notice that it wasn't idling as smooth as it should, almost sounded like an air leak so assumed split pipe or vacuum pipes loose etc and suggested we get it running 100% first. This is where I've potentially hit my first hurdle... From what I can gather the garage that installed the 3.9 V8 had to use some parts from the 3.5 V8 - What may have happened is they installed the 3.9 block and retained some/all of the 3.5 for the inlet and possibly heads. I aren't familiar with the engines so am trying to determine at the moment if that is the case, or not, but it would explain the poor idling and also it is reportedly very underpowered when driving.

I haven't any experience with any Defenders or Land Rovers, other than my daily drive being a Freelander 2. At this point I'm hoping someone can help to confirm/deny which engine this appears to be, and the easiest way to identify the block to confirm whether it is the 3.9 or 3.5 - Any help would be more than welcomed!!

Unfortunately all my experience is around Jap cars, primarily Toyota's and Lexus as I've done a lot of engine conversions over the years, but completely out of my comfort zone with this and due to the age of the engine I'm struggling to find reliable information online.

I've attached a couple of pics of the engine bay, from what I can gather the afm flapper wasn't used on the 3.9 but again I aren't 100%. To give an idea of what I'm aiming for in the engine bay as a finished look, I've also attached a before and after pic from a 1986 Mr2 Mk1 that I did a 3.0 V6 conversion on for wifey to do a trackday a couple of years ago.

[TD5toV8110]

Join the Rover V8 Appreciation page on FB.

https://www.facebook.com/groups/roverv8/

 

There are links there to diagnose the 4 CU system.

 

https://www.facebook.com/groups/roverv8/permalink/10160200267358265/

 

Engine number is near the dipstick. Use this site to ID the engine block (heads are the same)

 

Rover V8 Engine Numbers (rimmerbros.com)

 

Lack of power/poor running is most likely  worn cam.

 

The Rv8 is prone to cam wear from poor maintenance/age etc.

 

The 14cux (hotwire) is better than the flapper... Or Megasquirt....😁

 

Also is it on LPG?

Timing is critical for good performance, and I think gas has to be about 6 degrees different than petrol, so  if its timed for gas will be carp on petrol and vice versa....

 

Cheers

Dave

 

 

 

[smallfry]

Definitely a 3.5 injection system. Engine should run OK on it if its working correctly. No way of knowing if it is a 3.9 without the engine number.

[Defender Newb]

18 hours ago, TD5toV8110 said:

Join the Rover V8 Appreciation page on FB.

https://www.facebook.com/groups/roverv8/

 

There are links there to diagnose the 4 CU system.

 

https://www.facebook.com/groups/roverv8/permalink/10160200267358265/

 

Engine number is near the dipstick. Use this site to ID the engine block (heads are the same)

 

Rover V8 Engine Numbers (rimmerbros.com)

 

Lack of power/poor running is most likely  worn cam.

 

The Rv8 is prone to cam wear from poor maintenance/age etc.

 

The 14cux (hotwire) is better than the flapper... Or Megasquirt....😁

 

Also is it on LPG?

Timing is critical for good performance, and I think gas has to be about 6 degrees different than petrol, so  if its timed for gas will be carp on petrol and vice versa....

 

Cheers

Dave

 

 

 

Thanks for that. Will check out the Facebook group and understood on timing on Petrol vs gas. It does have LPG and I hadn’t even thought about timing differences tbh. 🤦🏻‍♂️
 

14cux - Am I right I’m thinking that’s the 3.9 ECU?

I have since checked and engine numbers are HRC2411 & CR9.35:1 & 36D68697C which from what I can tell is the 3.9 block and (assumed) heads

[Defender Newb]

18 hours ago, smallfry said:

Definitely a 3.5 injection system. Engine should run OK on it if its working correctly. No way of knowing if it is a 3.9 without the engine number.

Thanks for the confirmation on the 3.5. The engine runs but not as smooth as I would have expected either at idle or higher on petrol. (Not tried or compared to running LPG but will do later)

As yet though I haven’t checked timing which after a quick Google search looks interesting from what I can see.
 

I don’t think the engine is running as smooth or as well as it could or should. I would expect that it’s running lean with 3.5 injection and being 3.9 but if there’s any way to compensate without replacing with all 3.9 parts then I’d welcome any suggestions?

[geoffbeaumont]

14CU you'll find referred to as "flapper" engine management system - 14CUX is "hotwire". They take their names from the type of mass flow measurement they use. Flapper is definitely off the 3.5 engine (all 3.9s were hotwire) - probably swopped over to avoid any rewiring. Hotwire is more modern but both are pretty ancient now. As they adjust fuelling to suit the air mass entering the engine they generally compensate fine for the difference between 3.5 and 3.9 - it's unlikely to be the cause of it being underpowered. 

Number one cause of poor running on RV8s is dodgy ignition (the standard system on engines with distributors is pretty marginal to start with), but sounds like you've already looked at that. It's worth comparing how it runs on LPG, timing is likely to be set as a compromise between petrol and LPG and less than perfect for either, as you've no ability to run different curves for each fuel. LPG is best with a good deal more advance at low revs, but also likes a different curve.

As TD5toV8110 says, worn cam is a likely culprit.

[Defender Newb]

1 hour ago, geoffbeaumont said:

14CU you'll find referred to as "flapper" engine management system - 14CUX is "hotwire". They take their names from the type of mass flow measurement they use. Flapper is definitely off the 3.5 engine (all 3.9s were hotwire) - probably swopped over to avoid any rewiring. Hotwire is more modern but both are pretty ancient now. As they adjust fuelling to suit the air mass entering the engine they generally compensate fine for the difference between 3.5 and 3.9 - it's unlikely to be the cause of it being underpowered. 

Number one cause of poor running on RV8s is dodgy ignition (the standard system on engines with distributors is pretty marginal to start with), but sounds like you've already looked at that. It's worth comparing how it runs on LPG, timing is likely to be set as a compromise between petrol and LPG and less than perfect for either, as you've no ability to run different curves for each fuel. LPG is best with a good deal more advance at low revs, but also likes a different curve.

As TD5toV8110 says, worn cam is a likely culprit.

Thanks for that.

I was working on the assumption that it wouldn't be getting an accurate air reading and making it run lean, but that's a valid point that it should be reading more air and compensating or at least close to it. I don't tend to give the AFMs a lot of credit as haven't found them particularly accurate based on some of the ones used on old Toyota engines although it can depend on the ECU's too.

When we lost spark on it before we narrowed it down to the coil pack, replaced it and leads and plugs and there was a white spark but was a bit of a whimpy spark really, I just put it down to the age of the engine. Maybe need to revisit this given your comments. Wiring in the engine bay is messy, and theres loads of the push connectors which I hate with a vengeance and always prefer decent soldered connections. Is there any popular/recommended upgrades on the ignition system?

As far as overall running, I haven't driven it myself but have been told when it was a 3.5 it went very well, since having the 3.9 its slower both on fuel and LPG. I don't really want to be getting into the LPG side so was just aiming to get it right on petrol and from there he can pickup the LPG system with a local company if wanted, although hes happy to run it on petrol.

Understood on the cams, to be honest I was kinda hoping a new ECU, injectors, MAF, etc would solve without getting into stripping the engine.

With the cams I'm guessing its easy enough to do in the bay without pulling the engine as looks to be plenty of room? Any suggestions on sourcing replacement cams and likely budget? Also is there any other advisable maintenance for any other common problems?

[Defender Newb]

Here's me thinking I could pop off a cam cover and check the cams for wear..... 😂  On the plus side, I now realise I only need 1 cam, not 2 or 4 so thats good at least.

Is there any easy way to check for cam lobe wear, other than a teardown to get access to it? From what I've read, if I'm going to the effort of getting access to it then its a no-brainer to replace anyway but if theres any easy way to view/access it even with a long boroscope it would be appreciated.

With the cam I'm currently leaning towards real steel hurricane if replacement is needed, am I right in reading that sprockets, chain, followers, lifters, etc all advisable to replace at the same time?

I haven't done a compression test yet, but if I'm going down that route is there any common concerns around head gaskets, big ends, piston rings, etc that I should be conscious of? Just occurs to me that if I'm pulling half the engine apart am I better doing a full rebuild now? I am working blind in some ways as we have no history of this engine, so it could have done 20k miles or 200k miles for all I know.

Typically when I do MR2 conversions, I'll get the donor engine on the stand then do a full rebuild as I'd rather spend a couple of hundred on gaskets and parts to help avoid issues in the future. Possibly overkill, but just wondering if its worthwhile on the 3.9 lump based on everyones experience, or not? 🤷‍♂️

[Defender Newb]

Last question for the day, whilst the 3.5 bits should be ok running on the 3.9 lump, would reverting all parts back to the 3.9 ones likely offer any improvement?

If worthwhile going back to the 3.9 bits, what parts would be actually needed to get the 3.9 ECU, MAF and fuel rail working? Would it need the v-bank, inlet, plenum, and everything up, or are they common parts between the engines?

Edited March 14, 2022 by Defender Newb

[geoffbeaumont]

17 hours ago, Defender Newb said:

Last question for the day, whilst the 3.5 bits should be ok running on the 3.9 lump, would reverting all parts back to the 3.9 ones likely offer any improvement?

Maybe some, but nothing dramatic. Not worth it in my opinion.

17 hours ago, Defender Newb said:

what parts would be actually needed to get the 3.9 ECU, MAF and fuel rail working? Would it need the v-bank, inlet, plenum, and everything up, or are they common parts between the engines?

Injectors are different, so fuel rail may be (can anyone confirm?). MAF is different, hotwire has a stepper cold start bypass valve, IIRC flapper has either a simpler valve or none, and it also has a dedicated cold start injector which hotwire doesn't. I think other than that you can carry everything over, but I'm happy to be corrected  - I've only worked on the hotwire system, so I might be missing something.

Personally, I'd either keep the flapper system or go straight to a modern aftermarket ECU (plenty of off the shelf support for earlier versions of megasquirt for this engine, no real benefit to using the later, more expensive versions - probably other options that can be had with known good fuel maps to start from.

Assuming everything has been got into good mechanical and electrical order, the single biggest upgrade on these engines is distributorless ignition - Ford's EDIS system is generally considered the easiest option. The catch is you'll need an aftermarket ECU to control timing, and while there are spark only options (which saves some money), you might as well go the whole hog and do fuel as well.

If you do end up fitting a modern fuel ECU, the flapper injectors are low impedance, so either need to be replaced or adjusted for.

Basically, get what's there running properly first, and take note of the condition of everything you're retaining as you go, then decide if you're going to upgrade knowing you're starting from a mechanically sound engine.

[TD5toV8110]

These engines are known to eat cam lobes if they don't get fresh oil often.

A quick ish check is use a dial gauge to measure lift on each rocker by removing valve covers and turn the engine by hand.

It's not super accurate but you will see if one or more rockers are hardly lifting at all.

Then it's new cam/lifters/chain/sprockets...

Plenty of early TVR owners are happy with the "flapper" injection, (when it is all working properly)

So, go through the full diagnostics and replace any ancient sensors that are failing.

This is the cheapest/quickest option.

Bin the whole LPG system.....🤮

 

 

[Defender Newb]

Thanks for that Geoff.

So, in short, you'd recommend either leaving the 3.5 bits as they are or, if going towards 3.9 hotwire then do it properly with aftermarket ecu, ignition and fuel mods to get best result. If I was going down the latter route then would likely lean towards MS anyway, especially as they can supply the 3.9 bits from stock which is very handy.

I suppose I just need to decide whether I want to get it running ok, or improve it and how much money we want to pump into it.

First things first I'll strip it down a bit to inspect the cam, will give me chance to have a better look at it and then see if I can get it running right as you suggest.

If I end up leaving it as is, would you think it's worth going for a better cam or the stock one if no other changes being made?

[Defender Newb]

TD5toV8110 - Thanks for that.

Good call on the measuring the rockers, appreciated.  Understood on the flapper setup too. Think I'm still torn between leaving as is or going the full hog with the MS setup and extras, that said though may feel different if I can get it running well as is. Part of me is reluctant to spend too much time on an engine I've never seen running right, been burnt in the past only to find out I've been sold an palletised engine with faulty ecu, botched loom or damaged AFM but worth spending a day on it and see how I get on.

The more I'm reading up on these V8 engines though the more I am liking them though, already been scouring ebay for a Defender project for myself... Never really played with anything other than Jap stuff before but think that is going to change in the future.

[geoffbeaumont]

Standard 3.9 cam will give perfectly satisfactory performance - remember most defenders have pretty modest diesels in them. If you do decide to spend the extra on an aftermarket cam, go for a high torque one not fast road - a 110 is a big heavy vehicle and you need low end torque not top end power for usable performance. The RV8 is good at this - it's an ancient design (with relatively minor updates over the years, it's still fundamentally a Buick design from the 50s), and it doesn't develop anything like the power of modern engines of similar displacement - but it's good at flexible low down torque, and very easy to work on.

[smallfry]

I dont mind the flapper system at all. Never really had any issues with it, and I have had quite a few. 3.9 will run fine on it in standard form, as it has a plus 25% fuelling capability. Only real issues with them is power resistor failure to one or more injectors, and the injectors sticking due to dirt or lack of use. Another thing now will be degradation of the little hoses that connect them to the fuel rail (due to modern fuels) AFMs can wear, but at high mileage/or due to carp air filtration.

Another thing now, due to age, will be a stiff and crusty wiring harness and poor connections. A hotwire setup will be no better in this respect.

If the cam is worn, it will never run properly, but is still forgiving in that respect. Remember though, all that worn metal end up in the oil. Getting a decent standard camshaft is quite difficult now, as are the lifters. My choice would be either Kent Cams, Crower, or Comp Cams. As Geoff says, you want high torque at low end.

[Defender Newb]

Thanks for that both.

If a new cam is needed I’ll stick with a standard one providing I can source ok.

Taking everything on board, current plan is a quick compression check (Just to confirm all ok) followed by measuring the rockers for indication of cam wear.

If a cam is needed will also be replacing all the recommended items too.

Based on the general opinion I don’t see any reason/benefit to swap out the 3.5 bits back to 3.9 bits providing get it running ok. I have put the option to the owner either leave as is or go for full overhaul along the lines of the MS1 v8 conversion kit as I think it would be better value for money.

Update shortly on the cam inspection. Thanks again for the input everyone. 🙂👍🏻

[Defender Newb]

Quick update, did a quick compression check which gave results between 168 and 178psi - Not sure if thats within normal spec but all plugs were removed and all pistons cranked 3 times for consistency. I haven't had chance to have a look for specs but will do later as got a disco workshop manual due to arrive. Engine appears quite clean internally so far, have also since been told that before being fit it had a big end refresh, head gasket replacement and valves cleaned and lapped etc but that was about 4-5 years ago.

I was hoping to check lift on all the rockers but was rushing before work so started with No.7 following Nigels advice which showed 0.238" (6.05mm) on the inlet rocker - Again, not sure if thats within spec of not, will be reading up later today though. Gauge looks balanced on the pic but it was stationary (Magnetic base) and tested several times for good measure.

[geoffbeaumont]

Compression sounds fine to me.

[Defender Newb]

11 minutes ago, geoffbeaumont said:

Compression sounds fine to me.

Ok - Thanks for confirming.  To be honest it is a bit higher than I expected but no red flags so I'm happy, trying to find definitive specs on cams at moment so hoping the WSM has arrived when I get home and that it is stated.

[smallfry]

I would be hoping to get about 190 psi on a newish engine, but what you have is fine , I would not be concerned about that.

Remember that valve lift figures are misleading. The rocker ratio is 1.6 to 1, so for example, if you have valve lift of 16mm, the cam lobe will give a reading of 10mm, if that makes sense. Also, you have to factor in some of the valve lifters may have lost some oil, so may not give the same reading. 

[Defender Newb]

1 minute ago, smallfry said:

I would be hoping to get about 190 psi on a newish engine, but what you have is fine , I would not be concerned about that.

Remember that valve lift figures are misleading. The rocker ratio is 1.6 to 1, so for example, if you have valve lift or 16mm, the cam lobe will give a reading of 10mm, if that makes sense. Also, you have to factor in some of the valve lifters may have lost some oil, so may not give the same reading. 

Understood on the compression test thanks.

With the lift figures, this is exactly what I'm tying myself in knots with at the moment. Specs from an online WSM (PDF Page 20 - legionlandrover.com/manuales/manual%20de%20taller%20discovery%20(95).pdf) state valve lift of 9.49mm with most places online confirming the 1.6x lobe to get to that figure (Although some are stating 1.5x). If I use the 1.6x formula then I end up at 9.664mm at the valve - Appreciate that's close to the factory specs but my reading was if anything slightly out as it was just over 0.238" meaning its still likely more than the factory specs. So, either oil is causing the variance or it had a new cam (Standard or uprated) fitted a couple of years ago and its like new.

At the moment I'm thinking rather than taking the time to measure all of the rockers (I've only measured inlet No.7 so far), I may aswell just strip down to get access to see the cam. Engine needs detailing anyway so will make it easier/neater and hopefully a visual inspection will either confirm its a new/recent cam and likely ok, or it needs replacing. I think the only way I would get a rock solid measurement otherwise is by pulling the cam and measuring it on the bench.

Given how clean the engine is internally, and that a professional garage did the heads I would like to think they replaced the cam if it needed it, but just don't want to assume so would rather rule it out given it seems to be a common issue before looking at anything else.

[smallfry]

I wouldn't assume anything done by a professional. That only means they do it for a living, not that they are any good or have done it right.

They only way you could get anything like a correct reading on the clock, would be to get the stylus on the outer rim of the lifter if possible. With a visual inspection you will only see if its quite badly worn and/or pitted. Its normally the third and fourth and sometimes the second lobe from the back that go first and are the most worn. Why ? I have no idea, but there must be some sort of fundamental problem.

No point in measuring the actual valve lift and trying to work backwards from that either, there are too many wear variables in the rockers, shafts and valves themselves to get accuracy.

This is the problem with "standard" aftermarket camshafts. There is no way that you can get the exact specs, and they are usually a one size fits all sort of thing. Treatment and hardening can be somewhat hit and miss too.

Whereas a good quality aftermarket upgrade manufacturer will be able to give the exact specs, but once it has been fitted by someone else (like yours) you dont know what you have to start with. However, if you are lucky, you might find some info stamped on the rear end.

Same with lifters. Do NOT buy any from random ebay sellers either. Must come from an established supplier with a good reputation.

[Defender Newb]

That's a valid point really on the pro side, I've seen work from pro's at both ends of scale! Understood on the lifter and good call on keeping an eye for stamps on the cam, that would be nice.

For some reason I had a picture in my head of a hat type rather than cup type lifter 🤷‍♂️ but good call again thanks, I'm hoping to be able to rule out the cam and any alignment issues and at least I know I have solid platform to work off, all being well. Owner waiting for me to update on the CAM before deciding on an MS kit, he's planning to keep it long term so seems a good course and should give less chance of any issues in the future if he goes with it. 

[TD5toV8110]

[Defender Newb]

16 hours ago, TD5toV8110 said:

Thanks. 👍🏻 I’m hoping if it is worn that it’s fairly obvious, or at the other end of the scale that it’s still new and shiny and I can see some markings. 🤞🏼