Will a Miata head bolt onto a 1.3 block?

[Chetcpo]

Hello everyone. I'm building a Locost 7 (Lotus 7 replica) to autocross in SCCA Dmod and I'm exploring potential engine choices. Has anyone tried to bolt a twin cam miata head to their 1.3l block?

They are both B series engines so I was hoping to get the lower displacement of the 1.3 while running the better flowing twin cam head with a turbo.

Right now the car has the Miata 1.6 in it, but that leaves me outgunned in the power department. The limit on displacement in DMod is 2.0 liters naturally aspirated or 1.4 liters with forced induction. I decided it was cheaper to bolt the head up to a lower displacement block (the 1.3) and turbo it than bore and stroke the 1.6 (or a 1.8) block out to a 2.0.

This hasn't been done as far as I know, so I fear I'm in uncharted waters. Does anyone have a used 1.3 headgasket laying around that they could send me? (I'll reimburse for shipping) I think I could lay it on the 1.6 head and get an idea of whether or not this will work. Can anyone point me to some pictures of the block?
Thanks.

BTW-here's a link to my thread on this topic over on locostusa.com. In it I have a picture comparison of the miata and festiva heads.

[muscle_Car1]

I dont think they interchange, different oil & water passages.

[Chetcpo]

I dont think they interchange, different oil & water passages.

Hmm, Oh, well I thought in this pic side by side they looked pretty similar, the block is supposed to be the same.


Maybe some creative welding and grinding is in order.

[5.0zone]

Wow they do look a lot alike.
You could try taking a head gasket for each and compare the water/oil passages.

[muscle_Car1]

it does look alot alike.

[Chetcpo]

You festiva guys may be able to make out as well if this proves to work. You could bolt a 1.6 head to your 1.3 and run the Miata's twin cam timing belt system and engine management system. (no distributor) I'll bet you'd pick up power just with the headswap.

[IdealSociety]

it does not work.

the block on the b6 is physically longer

[Kraig]

I thought a B3 and B6 block had the same external dimensions....can't you put a B6 head on a B3?

[IdealSociety]

er perhaps im thinking b8 block...

ive never heard of it, for what its worth though, it would take less time to just swapin the whole b6 than to change the head over, better power gain also.

besides, who only gets the head?

[Chetcpo]

er perhaps im thinking b8 block...

ive never heard of it, for what its worth though, it would take less time to just swapin the whole b6 than to change the head over, better power gain also.

besides, who only gets the head?

It's for a turboed Dmodified autocross car. I have to keep displacement below 1.4 liters, thus the 1.3 block. I guess I'll make a trip to the boneyard and get a 1.3. That's the only way to know for sure I guess.

[IdealSociety]

b6 is identical, nobody would ever know the difference

[Chetcpo]

b6 is identical, nobody would ever know the difference

Probably not until I started smoking the field anyway.

[festivaWES]

with 83hp...i doubt it

beside the coolant passages will not line up, it's more hassle than what its worth.

[quaddawg]

What does that Locost weigh??


I would like to build a REAL DM car....


you think you are at a disadvantage... lol.. try running a Festy in DM.... HAHA

[quaddawg]

with 83hp...i doubt it

beside the coolant passages will not line up, it's more hassle than what its worth.

eh... my B6 puts close to 100 to the wheels, and his Lotus clone doesn't weigh as much as a Festy... AND he is talking about turbo'ing it... SO... A turbo'd SOHC B6, would put 120-150 easily to the ground, in a 1500 or less package, with Lotus 7 handling...

True DM classes are VERY competitive

Bottom line, a B6 is stamped B6, and losing due to being disqualified at a impound, would just suck..



Forget the miata head, it won't work easily.

I think you could build the b3 to what you need... or....


To be honest, I think a Swift GTi Twin cam, 1.3, turboed, would be JUST THE TICKET... Sorry Mazda fans, but that 1.3 Suzuki motor would be BAD-ASS in a light DM car...



OR, you could always do what the National DM car did this year... get Cosworth to build a one-off engine for $12K.... did you SEE his Lotus?? Not a 7, but just friggin AWESOME!!!