mx5 engine in tr7

[JohnTR7/6]

hi im thinking of putting a mx5  engine in my tr7 for reliability has anyone done this please get in touch any help anyone

[Beans]

Alistair Flack from Hamilton Motorsport has done it and can supply a conversion set.

But for reliability it is probably cheaper to sort the original engine and wiring properly ...

Or sell the TR7 and buy an MX5 of course 😜

[RobPearce]

Hmm... kludge together an untested combination of bits that were never designed to go together... "for reliability"... yeah. I agree with Theo, sort out the years of neglect and return it to how the factory developed over substantial testing and expense.

[thescrapman]

I can see the appeal. 150hp out of the  box and improved fuel economy.

And probably a lot cheaper than a rebuild on the original engine.

Not sure any more reliable, 

[Clive]

Been done to dolomites, so no reason it wont work in a TR7. One thing to watch is sump position, dolomites have a front bowl so use the 1600 engine.

The mk2/2.5 MX5 engine is bombproof and a complete engine/box or even rusty car only a few hundred quid.

 

Rob, taking the whole engine/box/loom/ecu means no mixing about. Only thing is routing stuff, fuel pump and so on. 

Colin, may not be more economical! (we have a TR7 powered Toledo and MX5 1.8 here, so direct comparison)

[RobPearce]

Quoted from cliftyhanger-

Rob, taking the whole engine/box/loom/ecu means no mixing about. Only thing is routing stuff, fuel pump and so on. 

That depends on the engine. A LOT!

Is it a mass air flow meter, or a speed density system? If the latter, merely putting it in a place where the exhaust and inlet piping are different could throw the mixture way off. And I've come across Japanese production engines (admittedly not Mazda) where that would be enough to risk piston failure.

Don't get me wrong - if the OP wants to fit an MX5 lump for the experience, the extra power, the revability, or just the challenge, I say go for it! But don't think it's a magic pill for reliability.