MX5Ireland

As the subject matter says above.....

Hi Fergus.Is it not the Jap 110 bhp as the Euro ones are 90bhp.?? Short nose/long nose identity thingy?? Are you looking for 110bhp jap engine as we have lovely one

Jap and Euro were the same engines.
89 - 93 is 115/116hp
94 - 98 is 88hp (were there 1.6 japanese imports from those years for the mk1? I'm not so sure)
The '91 M2-1001 special edition had 132hp (only 300 of these made I think).

Well, my '91 Jap Eunos was always down on power even before I put the turbo in it (if yee ol'timers in the club remember back all those years when I got it and I was saying it was slower than my mothers '89 Honda Civix 1.3 )
That was way back when we just had the mailing list and no forum.

And to make matters even more confusing - the USA Mazda Miata '90 - '94 has the following specs...

Displacement....1597 cc, 97.45 cu. in.
Compression ratio...........9.4
Power output........116 bhp @ 6500 rpm
Torque.........100 lbs.-ft. @ 5500 rpm

I did have a PDF showing all the differences in all of the 1.6 & 1.8 cars by year, but it's lost somewhere

(edit) Didn't a club member have an Auto that was around the 88bhp mark until he put in a Link ECU and was able to raise the BHP to 128/130BHP in that block ? I forget what year that Silver car was though

Hi ,from my understanding were the Euro cars not restricted from 116bhp ??to 90ish bhp.All the imports were 116bhp as they were not restricted.Thats what I am told but Its not the first time I might be wrong........I know the Auto engines tend to be faster from 1 not being revved as hard due to auto box and 2. they have different cmas or something to compensate for slowness/lag in the box.Any I converted to manual we much faster than original manuals.

Hi ,from my understanding were the Euro cars not restricted from 116bhp ??to 90ish bhp.All the imports were 116bhp as they were not restricted.

yep the Euro engines were but only after '94 I believe as it was competing with the 1.8

Looks like there were 1.6 imports through all the years according to this :
http://ox.mx5oc.co.uk/guide_eunos.htm

Spotted this on another forum re the 88hp engine :
"Taken from the Mazda Workshop manual (12/94)

Engine
The purpose of the modification is to increase the low speed torque by changing the valve timing and compression ratio.
The following parts have been modified

The configuration of the camshafts have been modified
Valve timing
IVO 5* BTDC
IVC 40* ABDC
EVO 55* BBDC
EVC 5* ATDC

The configuration of the pistons have been modified
Compression Ratio - 9.0:1

Fuel & Emission Control System
According to the readoptaion of the B6 engine model, the following changes have been made.

◦Injection method has been changed from the two-group injection to the sequential injection.
◦IAC load correction has been added according to the addition of the rear window defroster signal input to the ECM.
◦IGF signal input to the ECM has been discontinued.
◦Signal names have been changed as follows. NE = SGT & G = SGC
◦Diagnostic trouble codes No. 01 have been discontinued.
◦Vehicle speed sensor input have been added.
◦In the exhaust system, the front pipe and the parts after it are the same as that of the BP engine model.
◦The heated oxygen sensor has been adopted and its instulation position has been changed.
◦The fuel tank capacity has been enlarged and the cruising range has been increased accordingly.
Features - Excellent drivability and improved engine performance due to Squential mulitport fuel injection"


Re the Auto engine :
"The 116 HP Miata 1.6 DOHC motor from 1990-1993 is a normally aspirated version of that 323 turbo engine. It mainly differs from the turbo counterpart in higher compression pistons (to 9.4:1), lighter connecting rods and a lighter flywheel. This means that the NA version of the motor is quite over engineered for its applications. (how many NA motors do you know have oil spray cooling for the pistons). The automatic transmission version of the 1.6 DOHC engine has lower compression pistons to 9.0:1 and the camshafts have less duration. These changes were done for the automatic version to gain torque at a lower rpm and minimize detonation from the torque eating trans. The tradeoff is a less peak HP rating of 100. "

Lots more nerdy stuff here : http://web.archive.org/web/200702161555 ... ngine.html

Interesting,every day is a school day.

autocheck wrote:Hi Fergus.Is it not the Jap 110 bhp as the Euro ones are 90bhp.?? Short nose/long nose identity thingy?? Are you looking for 110bhp jap engine as we have lovely one

Is that a 116bhp block and not a 110bhp ? What year is it ? Short/long nose ?
How many miles are on it and would it be possible for you to do a leak down test as I'll be Turbo'ing it ?

I have a block here that I think came out of a '95 or '96 but it's defo not restricted. I just don't trust the piston rings in it.
My original engine is still here and in perfect nick but it's one of those 90bhp block's I'd have to say.