1.8 BP from Astina into NA6?

emily_mx5 · Postby **emily_mx5** » Fri Aug 31, 2012 12:06 am

Hi all, I am looking into putting the BP engine into my Na6.
I know I will need a conversion kit like the one sold by flying' miata.
I have come across a BP out of an Astina gt for an insanely good price, but obviously it's mounted the wrong way in that engine bay.
I am aware that I will need an mx5 inlet manifold/throttle body/air intake and an mx5 exhaust manifold.
Is there anything else that I will need to swap over to make the Astina BP fit into my na6?
Or is this a really stupid idea haha.

Postby **NitroDann** » Fri Aug 31, 2012 12:15 am

Not a silly idea at all.

Ive had a few btw so... YMMV

Sump needs changing

Inlet manifold

Exhaust manifold

Double check crank angle sensor/cam angle sensor.

And ecu/whatever wiring is needed.

Dann

timk · Postby **timk** » Fri Aug 31, 2012 12:32 am

It comes with the coolant reroute already done too!

emily_mx5 · Postby **emily_mx5** » Fri Aug 31, 2012 12:42 am

and exposed cam gears

emily_mx5 · Postby **emily_mx5** » Fri Aug 31, 2012 12:52 am

ahhhhhh damn just realised the engine has a distributor meaning its too old and obviously wont work in an mx5
thanks anyway guys

jerrah · Postby **jerrah** » Fri Aug 31, 2012 10:01 am

Distributor comes off. Put your cam angle sensor in the hole.

jerrah · Postby **jerrah** » Fri Aug 31, 2012 10:03 am

http://www.solomiata.com/oneeight.html

Update 12/2/98 I get a lot of inquires about using the Ford Escort GT engine as an alternative as many seem to have found inexpensive examples. The Protege/Escort/Sophia/Tracer 1.8 long block is the same as the 1.8 Miata but all external things are different since they come from a FWD application. Items like the oil pan, thermostat housing pipe, heater core coolant pipe, intake manifold, intake manifold support brace, exhaust manifold, alternator & AC brackets, fuel rail, etc must be sourced from the Miata specific engine. Some items like the Miata valve cover and timing belt cover are optional only if you want the 'Miata' look. Addtionally, some of the 1.6 Miata parts will transfer such as the timing belt cover, cam angle sensor and thermostat housing. IMHO, unless you already have access to the Miata specific stuff it would be easier to just get a Miata motor.

Hjt · Postby **Hjt** » Fri Aug 31, 2012 12:04 pm

You can salvage the brakes as spares!

project.r.racing · Postby **project.r.racing** » Fri Aug 31, 2012 1:31 pm

sump
engine cover
timing cover
coolent inlet and outlets
manifolds intake and exhaust
cas

other than that, every thing else between a BP from a NA8 and a BG/BA Astina is the same. BP engines in Astinas from 10/96 had SOB and a 36mm base circle cams, same as NB8s.

if you already had a NA8, and was looking for a replacement motor, then a astina motor would fit the bill. worth it.

but if going from NA6 to NA8, then you'd almost need another whole NA8 BP just to get the parts that are missing. makes it not worth it.

emily_mx5 · Postby **emily_mx5** » Fri Aug 31, 2012 2:07 pm

ok thanks for all the help guys.
Rocker cover / timing belt cover does not bother me at this stage.

1) thermostat housing - can I use my NA6 one?
2) cas - can I use my NA6 one?
3) alternator/AC brackets - can I use my NA6 ones?
4) exhaust manifold - I already bought a set of NA8 headers

So I need:
5) sump
6) intake manifold
7) intake manifold support bracket

fuel rail

The coolant system seems to be different also?

project.r.racing · Postby **project.r.racing** » Fri Aug 31, 2012 4:49 pm

the FWD varient fuel rail is very close to a NB fuel rail. so just by moving and extending some fuel lines, you should be able to use the FWD version.

aux brackets etc will fit the same. dealing with a b series vs a b series engine here.

cas - gotta use the one for the correct ecu. heaps of NA8 CASs on ebay cheap.

coolent housings, again same with b series engines.

timing covers are different for a reason, FWD varients have no hole for the thremostat housing. so if you dont change them to mx5 ones, then you'll just have to run the timing belt exposed. although the lower and middle timing covers should swap.

sailaholic · Postby **sailaholic** » Fri Aug 31, 2012 5:46 pm

NA6 and na8 cas is interchangeable

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emily_mx5 · Postby **emily_mx5** » Sat Sep 15, 2012 2:52 am

Awesome, got the engine, now just trying to sort out the slight differences so I can get it functioning in my car

Could someone please tell me what this is called and where can I get one? (the red arrow, it unscrews from the head)

project.r.racing · Postby **project.r.racing** » Sat Sep 15, 2012 7:42 am

That is not a head from a Astina BP-05 engine. That is a NB head from a MX5 BP-4W engine.

The dead giveaway is the blocked off hole on the end of the ex cam where the cas/dissy used to be. Or the BP-4W casing letters on the end of the head.

edit/ Or are you just using the pic as an example for the part you require?