Over the last 3 years I've bought an aluminium alloy, water heated intake made by "Flowtech", an exhaust manifold off a Marina (I think) and a 1.5 inch SU. You know how irresistible it is if you see them cheap; the whole lot cost only £45 - that's including the carb which was only £10 at the 2015 Breamore Classic Car Show! - and this year I fancy fitting them to my Trav. (The exhaust system should be fun!)
See here a mock up installation[frame][/frame]
My question is this; has anyone done this arrangement on a standard 1098, i.e. one with an unflowed head and standard cam? And if so, how did it go?
And if even you haven't, how do think it'll work anyway?
Regards, MikeN.
Morris Minor, the car of the future. One day they will all look like this!
I would just make the observation that no-one seems to stock off-the-shelf Minor exhaust systems to go with your manifold these days. You will probably have to get one custom made.
I could never work out why BL required to fit the exhaust manifold as pictured above because the Marina/Ital camshaft could not be called wild and so require the long pipes to stop the exhaust pulsating back up into the adjacent cylinder.
The camshafts fitted to the 1275cc Marina/Ital and 1275cc Midget/Sprite are one and the same and the Midget never needed the Marina/Ital type exhaust manifold.
I agree - that manifold is not worth the effort with the exhaust on a standard engine. And don't water heat the inlet manifold! Overall - I suspect there will be only a small improvement - you really need to fit a 940 head Mike !
I think that manifold is actually from a Metro - it's not a Marina one, as they are the same type as the Minor one, only larger. And the reason it wasn't fitted to the Midget is likely because it wouldn't yet have been designed when Midgets used 1275 engines. I know not everyone agrees with him, but Vizard speaks very favourably of the manifold, describing it as essentially being a 'cast iron LCB'. He says that 'changing this exhaust manifold for an LCB is almost a waste of time'. Granted, the 1275 Metro had a slightly more 'exciting' cam than the Marina, but it was hardly lairy. I would say that, with a different cam, that manifold would be an improvement over standard for sure. ESM used to do down pipes to match it - not sure if they still do.
It's very definitely not worth it for a standard engine! Yes - if better head/cam etc is fitted - it could help. But it is still just a 1098 engine with 6000 rpm rev limit - so it can only shift 'so much' air and better exhaust is not a huge priority..
All part of the 'evolution' i.e. it's in the shed and it's free Most of my old Cooper bits seem to be headed Ted's way - I wonder if the cam is any good
Thank you for your comments, but let's put the exhaust manifold to one side for a mo and consider just the 1.5 inch carb and inlet manifold. Is that carb too big for a standard 1098? (Please, please concentrate on that one first!) I should say that I'm interested in more mid range power rather than top end speed. Cruising at 65mph (true) is good enough for me which my 1098 will do already. (Any faster and I need ear plugs.) But when loaded or towing, the dear old Trav can do with more mid power when pulling out on to motorways or on long motorway rises, etc.
Now coming back to the exhaust manifold, I like the fundamental idea of separating the inner pair of exhausts from the outer pair because then the pulses cannot overlap and interfere. (Do they overlap on a standard cam?). However, while the standard manifold exit is only a single outlet of 28mm dia internally, the Metro exhaust is 32 mm internal dia and, of course, now paired instead of being single. As a result, the total internal cross-sectional area of the Metro exhaust system is some 2.6 times larger than the standard 1098 exhaust manifold outlet.
But if I use 22mm tubing for exhausts from the Metro manifold it'll reduce the total exhaust pipe cross-section to only one and quarter of the original pipe area - which I think might work. Why home in on 22mm pipe, I hear you cry? Well, that's a very common size for easily available copper central heating pipe which can be easily bent with internal springs, external benders, etc to any shape you want. And it's reasonably price, too. So here's the exciting opportunity of a weird but original homemade exhaust system!
But I'd especially like your advice on the fundamental question of whether a 1.5 inch SU is too big to work on a standard 1098. Regards, MikeN.
Morris Minor, the car of the future. One day they will all look like this!
My 2 cents. Mostly anything other than standard is a bit of a waste of time on a Minor (unless you have gone mad and done the brakes and suspension, the head etc etc). However that is kind of missing the point. If you will enjoy putting the new bits on and seeing if it seems a bit faster off the line then go for it. It's about having fun. If it makes no difference does it matter? It looks a bit different under the bonnet and you've had a nice little project.
That said in my experience the 1.5" SU does work well and you probably would notice the difference.
But first off make sure everything else is spot on. Timing, spark, valves...
Mike
To answer your question is a single 1.5" SU carb too big for a standard 1098cc 'A' Series the answer is 'No' provided you get the right jet, needle and damper spring.
As regards the 1098cc and exhaust pulsating. With a standard cam fitted there is no chance that the valve openings will overlap so causing the exhaust pulsations to go back up to the adjacent cylinder. Only when you have a wildly overlapping valve openings will you require the longer primary exhaust pipes commonly called a LCB manifold.
The diameter of the exhaust primary and secondary pipes is crucial. To big and you will loose power as the speed of the exhaust gasses will be reduced - with too large a pipe the scavenging effect will be reduced which is what you do not want.
My preferred option with what you have is to fit the 1.5" carb and manifold, cut off the inlet manifold from the standard exhaust/inlet manifold and use the standard exhaust.
I would try the inlet manifold with the water connected and disconnected as some engines prefer to have a heated inlet tract and some take a total dislike to having the manifold heated.
If you are thinking of changing the cam the old 998cc Cooper camshaft (or a cam with similar timings) gives good all round torque and raises the power sufficiently without loosing the bottom end grunt.
Phil
I have the set up that Phil describes. I can confirm this offers considerable torque and power improvments compared to tjte standard set up than was previously on my car. I would recommend but I am still working on needle and spring set up.
The larger carb just means more air can get in to the engine when you floor the throttle....so consider now, how often do you drive with your foot on the floor? If that is 'often' - then yes the larger bore carb will allow more air in when you want it. It will do nothing much for 'torque' low down. The exhaust (as explained above) is not suitable and will probably lose power. I believe there is a 'ban' on using copper pipe for exhaust systems ? The 998 Cooper did NOT have a special cam - it was just the same as the standard 998 engine... The 997 Cooper had the 2A948 camshaft which has a little more inlet timing (which the MG Metro cam copied - but combined it with more exhaust timing) - and would be worth fitting - if you can find one now..... The BIGGEST improvement by far to a 1098 engine is to fit a 12G295 (998 Cooper) head - which needs 60 thou skimming, and are often 'well worn' these days, or the considerably better 12G940 1275 head - 'small' valve version which may need the exhaust valves sinking by 40 thou (but no skimming) and really opens up the engine to make use of a larger 1.5" carb, and possibly a better exhaust (but still not that 'twin' manifold) - although I noticed little extra improvement when I upgraded to a 3 branch larger bore with straight through 'S' silencer. Start looking for a good 940 head Mike !
My experince with improved torque and drivability is with a hif38 is at low revs and partial throttle opening. I rarley go above 30 in 3rd gear for example. I am not aware I ever operate he car with full throttle.
Swappong to this set up improved acceleration amd rorque in all gears. For example a nearby steep hill I can no go up in 3rd which I could not before. This is a standrad 1098 engine.
Call it what you may the 998cc Cooper camshaft has enough difference in valve timing from the cam shaft fitted to the 1098cc Minor to be used with benefit without losing that bottom end grunt and especially with a standard un-flowed 1098cc head.
Agreed it is not the same as the 997cc Cooper Pt No: 2A948 camshaft which when mated to the 12G295 head gives an appreciable boost in power.
Sorry about the 'Mini' hi-jack but I guess this could be of interest to others too. I'm pretty sure the original Rover Cooper (not RSP) cam I have is a standard A+ 1275 item and I do wonder if there would be any benefit in re-uniting it with the head I've already fitted to my traveller.
Could you please clarify as to whether you have a 1098cc or 1275cc engine fitted.
If you have a 1098cc engine with the standard cam and 940 head fitted you will gain a very small benefit in changing the cam to the 1275cc cam (AEG 577, AEG323 or AEG538) as the valve opening/closing and overlap degrees are slightly greater.
The effort to change them over may be greater than the benefit though.
You may have to pull the engine to change the oil pump as the 1275cc cam to oil pump drive could be slot or spider drive. The earlier 1098cc cam to oil pump drive is pin drive so cams are not straight forward to change.
Phil
Thanks Phil. It's a 1098, I realised the oil pump drive was different but was hoping for a bit more benefit for the work involved. I think I'll hang on, re-read Vizzard, gather some bits together and re-build my spare engine for a swap at some point - unless I trip over a 1275 lump that is Meanwhile I've got a very neglected Mini in the garage that due for my attention.
Just to throw in my completely unscientific observation.
I fitted a 948 then 1098 engine c/w box and 4.55 diff to my originally 803 powered GPO van. I later fitted an HS4 carb on C/T inlet manifld and a 3 branch exhaust manifold with a straight through Burgess silencer and exhaust out of the back.
I remember that there was a conciderable increase in acceleration and hill cimbing ability
Most of my old Cooper bits seem to be headed Ted's way - I wonder if the cam is any good