A Rover "Super Four"

C

chrisyork

Active Member
Whilst dozing gently in the hammock the other day I fell to thinking about what I might like to see done to a four cylinder P6 engine to bring it fully up to date.

This is partly triggered by knowing Richard's (webmaster) intention to do something dramatic to the drivetrain of his new coupe convertible. I've been a long time critic of his wish to use a T16 Rover on the grounds that it wouldn't suit the character of the car (not enough torque, too revvy), but I haven't come up with any really acceptable alternatives. So I started to think about modernising a 2200TC.

To start with we need to eliminate the engines current weaknesses. I certainly wouldn't have made the block or the cam follower arrangement like that if I'd been starting today, but there's nothing seriously awry with the result given that it's already made.

The engine is known to fail catastrophically by putting a con rod through the side of the block. I'm inclined to think this is mainly a symptom of old age and poor maintenance rather than an inherent weakness. Nevertheless, I'd be inclined to get the crank tuftrided, change the big end bolts for a modern high tensile steel and have the crank, pistons and rods properly balanced. All reasonably easy to get done.

The other engine killing failure is valve damage. The engine was designed at a time when it was normal to have the head off and do the valves at least every 40k miles so this shouldn't be a surprise. Today we'd be going to fit stellite seats and modern material valves as a matter of course, wouldn't we? So that should be that problem cracked. While we're at it a bit of cleaning up of the passages seems reasonable as well. If we're going to never disturb the head again after this, then I'd like to fit some modern material high tensile head studs and nuts. As with the big end bolts this will require some calculation to get the right tightening torque to achieve the same clamping force as the originals. The object of the excersise is not to do them up tighter, rather to use a material that doesn't relax with age.

My next target doesn't strike most people as a problem. The chain drive to the cam I think is a disaster. This is for several reasons. First I am not satisfied that Rover's production tolerences after the BL takeover were sufficient to get the cam timing correct. This is supported by the widely held belief that early (up to '67?) engines are much faster than later ones. Secondly, I don't like the effect of chain stretch on cam timing - the effect of the tensioners (if you're lucky enough for them to be working!) is solely to limit chain rattle, not to compensate for stretch. Thirdly there's no adeqaute method of fine adjustment of cam timing.

My solution would be to redesign the contents of the chain case to take a gear drive with a vernier cam adjustment. I'm pretty sure there's enough space in there to do this and it kills all the described problems at a stroke. A number of firms have done similar conversions - there's one for the 200TDI Land Rover engine for instance. It might be fun at the same time to raid the Piper archives and get out one of their sport profiles for the 2200TC.

So that's the known problems dealt with. What else would I like to do? Well in my archive of Rover Photos I have a particular favourite one of a fuel injected 2000 engine, probably from around late '66 early '67. So we know what Rover would have done if not swallowed by Leylands!

Fuel injection ought not to be too difficult to fit. Nowadays all the injectors, programmable ECU's, air flow meters, throttle position sensors etc etc are more or less off the shelf, and a guy like Richard ought to have no problem setting up the ECU. The difficult bit is actually creating the inlet manifold and air cleaner arrangements. The former I would see as four separate alloy tubes off the head - I'm not sure whether I'd want a balance pipe between them, probably not - depending on the space either straight or curved upwards. The latter is likely to involve a search of the scrappies for something that is likely to fit. The TC arrangement is severely restricted by the width to the side wall of the engine bay. I'd be inclined to pipe everything from a position in front of the engine where there's lots of space on the 4 cyl.

Now we've got an ECU on board I'd like to kill another of my sacred cows. That Lucas distributor. Hugely innacurate and very difficult to set and maintain. So lets lose that altogether and replace it with a blanking plate! W'eve been messing around at the front end of the engine so we've had plenty of opportunity to fit a crank position sender. W'eve already got a throttle position sender and a manifold depression sender from the EFI so all we need to complete the suite is a knock sensor and we are in business with proper ignition mapping. The results we can feed to a four pack of individual coils per cylinder and that's killed any arcing issues on the distributor cap.

I suggest we ought to liberate at least 20hp from the above upgrades without losing the low down torque which so suits the character of the car. And it ought to be a much more reliable engine to boot!

What else needs doing to match those extra horses? well I'd like to upgrade the radiator. As a general rule for every 10hp you win at the wheels you have to cope with another 20hp exiting via the rad! I'd be inclined to fit a V8 front slam panel and use one of Alan Ramsbottom's Aluminium Rads. You'd certainly need V8 front brakes, but that's simple enough, even vented if desired. And handling upgrades are simple and well proven. Only other real essential is a gearbox with an overdrive top (ie 5 or 6 speed) and a V8 back axle ratio. I know this has been done on the 4 cyl engine before but I'm not up to speed with the detail.

I think we've got ourselves a 2200 with the same performance as a V8!

Chris



Edited By chrisyork on 1206351513
 
Apart from the issue of timing chain stretch, I can't see there is any problem with cam timing, there is only one setting if you peg up the crank and camshaft, and if that is incorrect IIRC there is a spline adjustment in the top chain gear to reset it, which if you had a mind to alter the timing from standard you could use.

As for using crank sensors etc. they're always failing on moderns, so why would they perform any better on an oldie.

Don't get me wrong, I'm all for upgrades, but a lot of the modern gear can be a lot more trouble that it's worth.

I personally wouldn't use studs and nuts for the head either.
 
What gives the 2200 TC engine it's torque characteristics ? Presumably the stroke : bore ratio. Is it that much more undersquare than any modern engine ?
 
Does anybody have a nice graph of the standard 2.2TC torque / power curves ? I never found my TC to be particularly torquey. Even with fully mapped distributorless ignition. I never got round to fitting injectors to the inlet manifold, but I was intending to simply use the standard manifold drilled to take injectors, replace the SU's with throttle butterflies. Not the greatest layout for power gains though.

Harvey, I've never had a Rover crank sensor fail on me, and one of my engines is 20 years old with nearly 200k on it, that level of unreliability I can cope with ! The great thing with the moden gear (assuming it's well made) is the lack of maintenance required, one of my 820's did 70k on one set of spark plugs / dizzy cap / rotor. The electronic ignition gives such a powerfull spark that old knackered plugs still work well. They were in a right old state when I did finally replace them :D

Compare that to re-timing and adjusting the points on the TC on a regular basis, especially after "enthusiastic" driving.

I'm not saying the modern stuff is perfect, some gear is rubbish, 800 ABS sensors are useless, fail left right and centre, and cost about £100 a pop.
 
Chris,

you know well how to stir up the forum!
I 've been always thinking about improving old motors myself, although not at exactly the same lines.
To be honest i don't find much wrong with timing chains. Of course they wear out and stretch but so do the timing belts too. I thing it is quite normal to expect to replace timing chains after 60K miles. In comparison timing belts will need replacement with almost just as much hassle, and with the added peril of snapping leaving you with a very expensive repair job.
Also like Harvey, i don't feel very comfortable with electronics. Yes, they can do miracles when they work OK, but they are sensitive devices that can give you a heck of a time when they fail, usually without warning.
What someone must take advantage of, are the modern materials and alloys. Fancy lightweight pistons, running on liners that will last a lifetime, stronger and lighter rods and crank, balanced as you said, will be very nice.
Camshaft design is very important and if someone is prepared to pay for some research, the results will be impressive in improved power and torque without sacrificing a smooth idle. Unfortunately there's not much to do on the induction side due to the restricted space, but exhaust system design has moved on further all those years. I am sure there must be something that flows better and be more quiet at the same time.
The Rover 4 pots owe their torque characteristics to their displacement and to the fact that they have only 2 valves per cylinder, something that promotes breathing at low revs. Undersquare engines are famous for low down torque but in truth the 2000 is actually square, and the 2200 oversquare!
I just want to note here that moderns feel slow not because they have inferior engines, but because they are so much heavier! Believe it or not a modern mid sized family car is heavier that our Rovers! I drove a new 407 a few days before with the 125 bhp 1.8 engine. It felt disappointing in comparison with my worn out 2000 TC.
Last but not least please do not make comparisons with the V8. You can make a 4 pot just as much fast, or even faster, but it will never deliver the output with the same manner as a V8.
They say that there is no substitute for cubic inches, but i believe that there is no substitute for cylinders too. The more the merrier! (Well, sort of...)

cheers,

Demetris
 
I think it's just a case of finding the reliable modern stuff and using that, and there's no doubt that modern cars are more reliable than cars of the P6 era, it's just that most of the times when a modern does break down you don't get them going again roadside, and the electronics can be pricey.
I take a cynics view 'cos I tow plenty in with crank sensor failures. (Amongst other things!)
 
Way back when (no seriously I can't remember!) I experimented with a supercharger on a 2000. I achieved a reliable 148HP with more torque than a full sitting of Government! The issue was that it made the engine prone to breaking, usually in a spectacular fireball fashion (stronger con rods were needed).
I have contemplated the whole injection thing, but have come to the conclusion that if you want a smooth, reliable fuel injected car then buy a modern car. Damn sight easier than fooling around with adapting stuff.
Having said that I have converted V8s to EFi simply by throwning the EFi system off a modern version of the Rover V8 onto an old car. Not as easy as it sounds, but helps.
My next trick will be to sort my 2000TC racer out (rusty, blown up and living(?) in a shed on Dad's farm) with a tasty set of 40DCOE Webers. I fully expect it to not run below about 2000 RPM, but when it goes it will REALLY go :p
I am looking at new piston designs, but with the combustion chamber in the crown of the piston there is suprisingly little you can do to make the engine breath better. Flat valve angles dont help either. I have just had to admit that the 2000 engine, gem that it is, is just not really cut out to be a performance engine. Not that its going to stop me trying to make it go faster..........I have an old Sprintex supercharger in the shed and some spare carbs and bits of plumbing and other stuff..............Finish one project at a time? (Rubbish you can never have enough old cars in the workshop)
Curses, now you've got me thinking!!!!

Cheers

GUY :D
 
I've seen a picture of a SC engine with a turbo on it, can't remember where. I think it was on that website that catalogues all known P6's. Can't remember the URL off hand.

Ah found it.

b989.jpg
 
I agree with Guy on the subject of Heron head breathing!

I think my main thrust was to liberate the best the engine was capable of through modern precision in fuelling, cam timing and ignition timing.

The supercharger route has alway been very attractive where pure power output is the driving criteria. It's always struck me as cheating though - calvanist upbringing perhaps? The neatest modern version of this is the Mercedees combined turbo and supercharger. At high power outputs the compressor is driven by the exhaust gases as in a conventional turbo - so you get the economy benefits that implies. At low outputs what would otherwise have been a huge hole in the torque curve is filled by engaging a mechanical clutch onto the turbo so that its compressor becomes engine driven rather that exhaust turbo driven. Very clever trever! I wonder if a complete set up from a 200K would transplant?

I have considerable sympathy with the keep it smiple so you can fix it at the roadside school of thought. Against this, you will sacrifice some of the performance and economy that could be available. And I'm with Richard (webmaster) in thinking that if you know what you are doing modern systems can be both reasonably easy to set up and very reliable. Its just that if you don't they can be a nightmare on both scores. So my proposal is definitely strictly for the electronically competent!

I'm afraid I still disagree strongly with Harvey on the cam timing. Whilst what he says is true, I still maintain that doesn't get you to where I want to be with a truly precise cam setting.

I was intrigued that there have been no challenges yet on the basic robustness of the engine.

Chris



Edited By chrisyork on 1206672969
 
Good idea for a thread Chris!

It brought back a memory from when I was 18, and had my first V8 P6. I was still living around the Clacton area at the time, and I had this ratty looking black 2200TC pull out in front of me. He booted it when he saw a V8 in his mirror, and I could not catch him!! I went round the next corner, just in time to see him pulling into a petrol station, so I pulled in for a chat. It turned out that this thing had got a high lift cam, gas flowed head, and the carbs and distributor had been played with as well. At least I didn't feel quite so embarassed!!

I agree with Chris's thoughts on poor camshaft timing, and dodgy distributors, although I have no experience of the Rover 4 cylinder engines. These two things I have found to be very common on the old Ford "Kent" engines, especially when they have the Motorcraft (or Motorcrap as I call it) distributor fitted. When using one of these posh Snap-On type timing lights which can be used to work out the advance curve, they're all over the place! The best results seem to be achieved by fitting the Bosch distributor from a Fiesta, and then setting up the timing "by ear". Years ago I had a Mk2 Escort 1600 Sport with a slightly warmed up engine. My mates dad was a touring car racer in the 70's, and a chat I had with him one day resulted in said Snap-On timing light coming out, followed by the distributor, and a large box of dizzy parts! We had the distributor in and out of the car about three times, and different springs were swapped around until the advance curve was spot on. What a difference!
 
I was intrigued that there have been no challenges yet on the basic robustness of the engine.
Click to expand...

Well, I could go on about my original 2.2TC engine which ate it's big ends at 52k. Plus I seem to remember the Haynes manual lists the big ends as a 30k mile service item !! A far cry from the 200k you'd expect from a modern engine.

However, on my replacement engine I gave it a lot of stick, did quite a few timed 0-60 runs where I took it clean off the end of the rev counter in 2nd ( which required re-timing and points adjustment afterwards ), and plenty more similarly bad treatment. And the basic lump took it all, even the gearbox, that to be honest had always sounded like it was on it's last legs, didn't break. I was running modern 195's on the back too.

My problems with the standard engine are that a) it's a boat anchor, and b) it isn't already fuel injected etc..
The effort involved with converting to fuel injection would far outweigh the trouble involved in just sticking a modern ready-prepped engine in. I noticed the other day that vauxhall did a 2.2 version of the Omega, probably an ideal engine swap being already RWD and the omega being roughly the same size / weight as a P6 (probably a bit heavier than a P6), although it only makes the same power as the 2ltr T16 (820) engine (144bhp). Plus of course there is a Turbo version of the ecotech available which can produce very good power.

The Turbo / Supercharger option is interesting, however again you really need to be running injection for these to work properly. Same thing applies to the ignition timing issue, this is the main reason they swapped to electronic mapped ignition. Engines often require varying ignition timing throughout the rev/load range, sometimes requiring the timing to retard slightly at diferent points depending on things like inlet tuning / pulses etc.. A simple distributor just can't do that, so you end up with a compromise, especially when you start messing with cam timing and porting etc.

Have a look at this ignition graph. It would be nigh on impossible to get a distributor to produce this.

ignition.gif


Plus a little light reading..
Basics of Engine Management



Edited By webmaster on 1206697915
 
My thoughts based on what I would do and have thought of for a while now. The goal would be to lengthen the engine life and better MPG. Having mechanical fuelling (SU CARB) and ignition must effect engine life, when cold starting up at high revs for example. With EFi car runs at normal tick over from cold. Also poor timing must put extra pressure on the big ends as well as the small ends. My bro had an allegro that just would not stop pinking, after two years the small ends were shot!

Ignition:
There are a few choices. One just replace the points with non contact fancy ones. Ok so the timing will not wonder from warn points but the advance curve will still be effected by the dizzy being worn.

The second choice is the replacement dizzys that look like the old ones but are supposed to be fully electric. I've not looked at these yet but they may be but the ones I've seen still have the vacum tube. This could be just to a load sensor or still a mechanic connection? Hope its the former. But these don't look like you can reprogram the map, seem to only have a fixed set to choose from.

The third will give the best results. Remove and blank off the dizzy and fit a timing wheel and a proper ECU that we can recode. This is fine but don't look so good as you have to use a coil pack, or do you? I've wondered if you can customise it to run a single coil and use the old dizzy just for err distributing the spark. BMW did this with thier M40 EFi engines. Full electric ignition but still had the dizzy.
This will also have the benefit that it can take more readings from the engine and also drive an option fuel injection system.

The first two are easy a few hours work, the later is going to be a few weeks and a trip to the rolling road. The best option for the goals but I would only do if fuel injection is the next stop.

Fuelling:
This is where I feel the biggest gains can be had and also where i'll suggest something radical. I would use an SC head! I would mount the injectors into the cover that is over the inlet tract. This will allow the fuel pipes to be hidden in a pipe that would run alongside the water pipe. You could then build the throttle body from an old SU carb to keep the look and also keep the original connection to the throttle, more important for people like my self with autos.
The Mass air flow meter can be placed into the air filter box, maybe.

So that's my penny's worth. As i've said to other people on the PC forum when talking about the car they put EFi on. I would have gone for MPG and not a massive 30% hike in power. No surprise they cooked the poor old engine.

:)
Thanks,
Richard e Collins.
 
Excellent ideas Richard, I especially like the SC idea, if you weren't looking for ultimate power you could just use a single point injection unit to replace the SU. For years I had considered making "injection SU's" where the internal body was sleaved to produce a throttle body and an injector could be mounted within the top or underneath in the float chamber, the end result being visually identical to a standard SU. Most systems these days don't use airflow meters, simply rely on a vacuum sensor (MAP sensor) and the throttle pot.

As far as the ignition goes, I had mine set up with it triggering from the front pulley, single coil and then sent the sparks through the old dizzy cap and leads. Not ideal but it does look faily standard, and the important thing is it made it fully mapped. That type of setup is very common in late 80's & 90's engines before wasted spark and individual coils took off.



Edited By webmaster on 1206701695
 
Chris, Richard, et al,
What modifications did the factory make to the four-pot engine when they made a brief foray into the rally scene (if any) ?
Regards, John.
 
webmaster said:
Excellent ideas Richard, I especially like the SC idea, if you weren't looking for ultimate power you could just use a single point injection unit to replace the SU. For years I had considered making "injection SU's" where the internal body was sleaved to produce a throttle body and an injector could be mounted within the top or underneath in the float chamber, the end result being visually identical to a standard SU. Most systems these days don't use airflow meters, simply rely on a vacuum sensor (MAP sensor) and the throttle pot.

As far as the ignition goes, I had mine set up with it triggering from the front pulley, single coil and then sent the sparks through the old dizzy cap and leads. Not ideal but it does look faily standard, and the important thing is it made it fully mapped. That type of setup is very common in late 80's & 90's engines before wasted spark and individual coils took off.
Click to expand...
The thinking behind the four injects mounted next to the ports is to correct in some part the poor port design, have a single port design does not negate the worst design part of the SC head. I've always been surprised that Rover did not drop the SC head all together when the TC came along. Then could have just had a different inlet manifold.

But saying that if mounting the injectors where I suggest would work I think that the SC head is better suited for a 'stealth' injection upgrade. :)

Of cause this is always day dreams like the ones that started this thread. :;):
 
I have just had a brainwave (that explains the smell of burning then!). The 2008 model range of Triumph motorcycles are all fuel injected, but they are made to look like carbs! :p
How about FOUR of these on a custom 2000TC head? Looks mad, gives the fuel injection and best of all, they are designed to feed a piston of 400 plus CC, so room for improvement (ie supercharger, I told you I had a one track mind) :laugh:
Possibly only two would be OK if you are just driving normally.
Any takers........

Cheers

GUY :D
 
chrisyork said:
I'm afraid I still disagree strongly with Harvey on the cam timing. Whilst what he says is true, I still maintain that doesn't get you to where I want to be with a truly precise cam setting.
Click to expand...
We're going to have to agree to disagree on this Chris, there's a vernier in the camshaft sprocket which enables A) a way to compensate for a worn chain, B) set the valve timing to any variation of (at a guess at the moment 'cos I haven't counted the teeth yet) I would say one degree, & C) vary the timing from standard by any amount less than a tooth.

Tensioners are noisy, but do work, and if they fail they are fixable, and the cam carrier design (OHC working directly on buckets with shims under) is not prone to faults,and short of DOHC (or desmodromic) is about as good as you'll get.

The biggest drawback of the engines basic design is the bowl in piston set up, which is why the Ford "KENT" engine could always be tuned to a higher degree in the Pre Crossflow design, as soon as it went Crossflow the pistons limited it.

It was mentioned in passing (somewhere) that very early engines seemed better and more powerful than later ones. The only reason I can think for this is that initially they had open crankcase ventilation, before moving to a closed system, so moving down the slippery slope of emission controls and all the power sapping that that entails. It was a mod to change the breathers IIRC to change the early ones to later spec by blanking off the open breather on the side of the sump, and some may have escaped the process.



Edited By harveyp6 on 1206873036
 
You can tell I've been having a major Rover read today, triggered by Demetris's gearbox problems. Along the way I've re-read the James Taylor book on the P6 and it's amazing the things that jump out at you that you hadn't spotted before!

From having previously started this Topic I was tuned in to aborted upgrades to the 4 cyl engine when I re-read the book.

I already had registered the fuel injected engines from '66. What I hadn't taken much notice of previously was the explanation of how the 2200 engine came about. I'd always thought it a strange thing to have done so late in the cars production with other engines around in the BL parts bin.

Taylor refers to the Rover P10 project as progressed by Rover to replace the P6 and Triumph 2000. (It later moved to the new BL Specialist Division design office and became SD1) Apparently Rover did what you might expect them to do and developed a new engine for P10 based on the existing P6 2000 unit. It was intended to build it on the P6 engine line, so it had the same bore spacings, stroke and deck height as the 2000 engine. But it had a DOHC cylinder head and in order to get big valves in, needed a bigger bore taking the capacity out to 2200.

So we can be pretty sure it had a pent roof combustion chamber and flat or domed pistons rather than the 2000's Heron head design with the combustion chamber in a well in the piston and a flat head. Apparently it had Bosch L Jetronic injection as well for 170HP on the dyno (that would be around 145 - 150 installed in a car).

Taylor also says it had a redesigned "lightweight" and slightly canted block, which is one of the things I had proposed, to take advantage of more modern casting technology (so it almost certainly lost the side plates!).

Inevitably as SD1 grew it got cancelled in favour of the reworked Triumph sixes, so Rover used the new bore to size to give the P6 a bit of a refresher!

So what engine is out there most resembling the P10 2200? I'd personally plump for the Ford 2300 twin cam seen in late Granada's. How about it Richard?

Chris
 
How much similarity is there between a SDI 2600/2300 engine and a Triumph 2000/2500 ?
It's a change from OHV to OHC and from chain drive to belt drive.
And not a very reliable engine as the oil feed to the cam blocks causing the belt to snap
 
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