B5 8 valve and 16 valve interchangeability?

[terribleone]

Hey guys

ive got a wf festiva (aussie car) with an 8 valve b5. The bottom end of the motor is dead and i have a complete b5 16v spare motor. will the short block from the b5 16v bolt up to top end of the 8v?

i dont want to bother rebuilding the busted bottom end or buy another engine.

[Larry Hampton]

I don't know, but why not run the whole B5 16V?

(I'll ask first 'cause everyone else will wonder the same thing...) ;p

[Nerd Racing]

I believe you need to run 16 valve pistons with a 16 valve head so they clear.

[terribleone]

whats involved with installing the 16v? i noticed the manifolds were different between 8v and 16v, the 16v also has a crank trigger and the 8v doesnt. will it need any custom work?

[getnpsi]

if it has a crank trigger chances are its a obd-2 type engine. you might have to run it using electronics of another b-series engine.

[Nerd Racing]

we didn't get them here in aspires (second gen festivas over there) so I don't know exactly.

[festyfreak39]

im almost certian it will work, put head gasekts side by side make sure the oil and water passages have the right way to go

im sure the only issue with the SOHC bottom end is a bit of a higher comp ratio and you loose the "non interference" ... ness. lol

im doing this with a sohc b6 8v bottom end a miata top end right now.

[terribleone]

Oh both of these motors are single cam, in australia the WD festivas came with a 16v single cam motor and the WF (later model) had a 8v single cam. kinda wierd. Im not talking about using a short block from a twin cam!

[getnpsi]

Again, if that 16v is a running engine don't crack it open. You want to swap the 16v head to another b5 so it's just as illegal as the whole engine as far as inspections go. I understand from reading they really check that stuff, more than strict California even.

Side note, what does the b5 engine computer look like?

[terribleone]

Hah no they dont check that stuff. The engine numbers are both "B5 ******".

I just need to know if the head will fit, if not I'll have to buy another short engine.

[terribleone]

so nobody knows?

[getnpsi]

The piston tops are probably different. I wouldn't risk it. I don't know if i am misreading your post but it says you have a good running spare engine?

The time to change a head/head gasket is almost the same as changing an engine on these tiny cars.