Mk1 1.6 1.8 differences
Discussion
Closely related, but quite a few differences.
Engine is physically bigger/longer - bores
are spaced further, not just bigger bore.
Position of CAS swaps from Inlet CAM to
Exhaust CAM, coil pack swaps to suit.
1.8 inlet manifold is horizontally aligned,
1.6 points downwards.
1.8 uses larger throttle body
1.8 uses different method for idle control,
warm-up, throttle body warming etc
1.8 has an oil pre-heater/cooler built under
the oil filter.
1.8 uses a hot wire MAF not a flapper type
air meter.
1.8 uses larger diameter flywheel and clutch
1 *think* that the later 1.8 uses sequential
fuel injection, or that may be from the Mk2
onwards.
Amongst others...
Anecdotally - its often written that the 1.6 is 'sweeter' in some way, by the same people who probably peddled that their 8V Golf GTi was better than a 16V.
Having owned and driven a number of them, its rubbish, the 1.8 is better in every way measureable way, just as revvy, same noise, etc.
Engine is physically bigger/longer - bores
are spaced further, not just bigger bore.
Position of CAS swaps from Inlet CAM to
Exhaust CAM, coil pack swaps to suit.
1.8 inlet manifold is horizontally aligned,
1.6 points downwards.
1.8 uses larger throttle body
1.8 uses different method for idle control,
warm-up, throttle body warming etc
1.8 has an oil pre-heater/cooler built under
the oil filter.
1.8 uses a hot wire MAF not a flapper type
air meter.
1.8 uses larger diameter flywheel and clutch
1 *think* that the later 1.8 uses sequential
fuel injection, or that may be from the Mk2
onwards.
Amongst others...
Anecdotally - its often written that the 1.6 is 'sweeter' in some way, by the same people who probably peddled that their 8V Golf GTi was better than a 16V.
Having owned and driven a number of them, its rubbish, the 1.8 is better in every way measureable way, just as revvy, same noise, etc.
Most of the above is correct.
We tune MX5's day in day out and the 1.6 is a better car! The engine is more tuneable, the 1.8 is no faster & engine is heavier so it doesn't handle as well.
A 1.6 can give very similar power to a 1.8 with an £80 tune-up but just slightly less torque; having said this these cars are all about the fun of revving them so the torque isn't that important.
Buy a 1.6 Mk1 import so it has all the bells and whistles.
The 1.6 is the chosen engine size for racing.
We tune MX5's day in day out and the 1.6 is a better car! The engine is more tuneable, the 1.8 is no faster & engine is heavier so it doesn't handle as well.
A 1.6 can give very similar power to a 1.8 with an £80 tune-up but just slightly less torque; having said this these cars are all about the fun of revving them so the torque isn't that important.
Buy a 1.6 Mk1 import so it has all the bells and whistles.
The 1.6 is the chosen engine size for racing.
Edited by nikpro on Friday 15th May 17:26
Wow thanks for the invaluable info lads.
Reason for asking is that my HSK turbo 1.6 suffered an actuater hose failure on a track day and the car stepped out pretty sharpish and blew the inlet servo pipe off.
Testing compression today I have found that 1,2 and 3 are 175 psi but 4 is only 75.
Repair is what its going to be then.
I guess then that you were at Brands last weekend as there was a grid of MX5,s of huge proportions! I was there to support my daughter who was racing in a 540 bhp Porsche 996 GTS and was lucky to chat to a few very decent MX5 drivers.
Reason for asking is that my HSK turbo 1.6 suffered an actuater hose failure on a track day and the car stepped out pretty sharpish and blew the inlet servo pipe off.
Testing compression today I have found that 1,2 and 3 are 175 psi but 4 is only 75.
Repair is what its going to be then.
I guess then that you were at Brands last weekend as there was a grid of MX5,s of huge proportions! I was there to support my daughter who was racing in a 540 bhp Porsche 996 GTS and was lucky to chat to a few very decent MX5 drivers.
Edited by trackerjack on Saturday 16th May 00:40
Well Nikpro can I ask you a question? as you clearly have the credentials.
I hope you had a great weekends racing it was fantastic seeing all the clse racing of the MX5's.
The following pictures are of the offending piston and the engine was a Jap import and seems virtually new as can be seen.
Questions are as follows.
Head gasket quality varies and I use Payen or Reinz, where is the best place to buy them?
Piston rings are also varied so do you recommend any particular type or make?
The rest is straight forward as its a simple 4 pot lump but better made than the usual Triumph Sprint lumps I normally work on.
I guess heat has caused the following fail of ring breakage and land collapse that looks as if partial siezure has also broken the piston skirt.
Last picture is the car the engine is in, it took loads of hours to build and I damage it faster!
I hope you had a great weekends racing it was fantastic seeing all the clse racing of the MX5's.
The following pictures are of the offending piston and the engine was a Jap import and seems virtually new as can be seen.
Questions are as follows.
Head gasket quality varies and I use Payen or Reinz, where is the best place to buy them?
Piston rings are also varied so do you recommend any particular type or make?
The rest is straight forward as its a simple 4 pot lump but better made than the usual Triumph Sprint lumps I normally work on.
I guess heat has caused the following fail of ring breakage and land collapse that looks as if partial siezure has also broken the piston skirt.
Last picture is the car the engine is in, it took loads of hours to build and I damage it faster!
Edited by trackerjack on Saturday 16th May 18:45
I am not allowed to say what company I am a director of as the posts will get removed but we are the most succesful Mk1 engine builder in the UK - our engines have won more races than any other companies engines.
The only time we have seen ring/ring land damage is through detonation on the MX5 engine and the only parts we ever use in our engines are Mazda parts. What does the top of the piston look like or the edge above the top ring - has it got a speckled/sandblasted appearance?
Unlike most engines the det usually shows up around the inlet valves rather than the exhaust.
Has the cylinder head been skimmed?
We use Mazda pistons and rings and Mazda head gaskets - we have found all these parts extremely reliable where others have failed (Including Cometic)
Check ignition timing isn't to far advanced or a fuel injector is weak causing lean running on that Piston.
I assume you are running with aftermarket fuel & ignition mapping?
HTH
The only time we have seen ring/ring land damage is through detonation on the MX5 engine and the only parts we ever use in our engines are Mazda parts. What does the top of the piston look like or the edge above the top ring - has it got a speckled/sandblasted appearance?
Unlike most engines the det usually shows up around the inlet valves rather than the exhaust.
Has the cylinder head been skimmed?
We use Mazda pistons and rings and Mazda head gaskets - we have found all these parts extremely reliable where others have failed (Including Cometic)
Check ignition timing isn't to far advanced or a fuel injector is weak causing lean running on that Piston.
I assume you are running with aftermarket fuel & ignition mapping?
HTH
Edited by nikpro on Saturday 16th May 19:57
Edited by nikpro on Saturday 16th May 19:59
snotrag said:
Anecdotally - its often written that the 1.6 is 'sweeter' in some way, by the same people who probably peddled that their 8V Golf GTi was better than a 16V.
Having owned and driven a number of them, its rubbish, the 1.8 is better in every way measureable way, just as revvy, same noise, etc.
I've owned 2 1.6s and currently got a 1.8, and I did prefer the way the 1.6 engine revved, especially when you blip the throttle, it just felt slightly quicker to respond whereas the 1.8 feels a bit lazier, and perhaps when cruising on a motorway and then flooring it in higher gears the 1.8 pulls a bit better without having to drop a gear but really it's such a tiny difference that I'm not sure I'd be able to tell what engine was in there from just general driving if I didn't know.Having owned and driven a number of them, its rubbish, the 1.8 is better in every way measureable way, just as revvy, same noise, etc.
Given the option of the 2 I'd probably take the 1.6 over the 1.8 if all other things were equal (mainly how much rust they have!)
Thanks nikpro for the extra help.
No the head is standard and unskimmed.
I will make sure timng is not too advanced.
The HSK comes with a piggy back addition to the ECU and is connected and when I was getting car through IVA had to prove the mixture was about right.
I am running with a Saab 900 intercooler and Aquamist water injection.
I will keep the actuater pipe secure as it was this coming off that caused the failure I think.
I was giving it some beans on track at the time so must be expected though the temperature on track never went above 90deg.
Finally I have just had the fuel pump fail and have bought a new one, it is possible that it might have fluctuated with supply which would not help.
Cheers
Jon
No the head is standard and unskimmed.
I will make sure timng is not too advanced.
The HSK comes with a piggy back addition to the ECU and is connected and when I was getting car through IVA had to prove the mixture was about right.
I am running with a Saab 900 intercooler and Aquamist water injection.
I will keep the actuater pipe secure as it was this coming off that caused the failure I think.
I was giving it some beans on track at the time so must be expected though the temperature on track never went above 90deg.
Finally I have just had the fuel pump fail and have bought a new one, it is possible that it might have fluctuated with supply which would not help.
Cheers
Jon
Edited by trackerjack on Monday 18th May 23:49
JimSuperSix said:
snotrag said:
Anecdotally - its often written that the 1.6 is 'sweeter' in some way, by the same people who probably peddled that their 8V Golf GTi was better than a 16V.
Having owned and driven a number of them, its rubbish, the 1.8 is better in every way measureable way, just as revvy, same noise, etc.
I've owned 2 1.6s and currently got a 1.8, and I did prefer the way the 1.6 engine revved, especially when you blip the throttle, it just felt slightly quicker to respond whereas the 1.8 feels a bit lazier, and perhaps when cruising on a motorway and then flooring it in higher gears the 1.8 pulls a bit better without having to drop a gear but really it's such a tiny difference that I'm not sure I'd be able to tell what engine was in there from just general driving if I didn't know.Having owned and driven a number of them, its rubbish, the 1.8 is better in every way measureable way, just as revvy, same noise, etc.
Given the option of the 2 I'd probably take the 1.6 over the 1.8 if all other things were equal (mainly how much rust they have!)
I started off with a 1.6 mk1 an believed all the crap about the 'the 1.6 is revvier and the sweeter engine".
Now the the 1.8 I have is admittedly an R limited, so it comes as standard with a lightened flywheel, 4.3 Torsen and an optimised ECU. This engine revs to an indicated 7900rpm, it's far more lively than the 1.6 and as a car its out an out better than the 1.6.
Now the the 1.8 I have is admittedly an R limited, so it comes as standard with a lightened flywheel, 4.3 Torsen and an optimised ECU. This engine revs to an indicated 7900rpm, it's far more lively than the 1.6 and as a car its out an out better than the 1.6.
towelie said:
it's far more lively than the 1.6 and as a car its out an out better than the 1.6.
Not ragging the beans out of it round the back roads it isn't.I liked all my 1.6's and 1.8.The 1.8 just feels like an ever so slightly more mature 1.6.
It's like it has grown up a bit and doesn't require quite so much input to be able to make quick progress.
Richyvrlimited said:
Indicated yes. in reality that's not what it's revving to. the HLA's can't really cope with more than 7400rpm and you end up with valve float.
The OEM ECU redline for all, (import or UK) MK1 1.8 cars is just shy of 7000rpm
I know what a 7k redline feels like an the r ltd is definitely not 7000rpm redline. My 1.6 is set to rev to 7400rpm with the megasquirt and the 1.8 is very obviously higher, probably not 7900 as indicated as like you I know the stock rev counters are optimistic.The OEM ECU redline for all, (import or UK) MK1 1.8 cars is just shy of 7000rpm
Some of the special editions r ltd & rs ltd have a higher rev limit from the factory. So no, ALL 1.8 engines do not have a 7k rev limit
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