SOHC -> DOHC

SpikeDerailed · Post by **SpikeDerailed** » April 23rd, 2006, 3:43 pm

Can you take the DOHC B6 Head and bolt it up to a block that was originally a SOHC? Or are there different bolting pattern & torque specs between the two?

mr1in6billion · Post by **mr1in6billion** » April 23rd, 2006, 6:34 pm

um... my vote says no.

Bochek · Post by **Bochek** » April 23rd, 2006, 6:52 pm

i allways thought you could, but thats just me, maby i was wrong, i uno, someone will know for sure tho.

Bochek

torpedan · Post by **torpedan** » April 23rd, 2006, 7:26 pm

The better question is which will take more time and effort. All in all I personally would spend less time just directly swapping in the newer motor than i would doing a head swap.

Boris · Post by **Boris** » April 24th, 2006, 1:55 am

I have a question... Do you mean swapping a 1.6L DOHC miata head (B6ZE) onto a 1.6L MX3 block (BPE)?

Sorry if this is a stupid question, I'm still kind of new to Mazdas. I would be VERY interested if I could swap a DOHC head onto my SOHC block too... I don't wanna do an engine swap because I've bought a clutch for my engine already and don't know whether it would fit on another engine...

torpedan · Post by **torpedan** » April 24th, 2006, 9:34 am

Boris wrote:I have a question... Do you mean swapping a 1.6L DOHC miata head (B6ZE) onto a 1.6L MX3 block (BPE)?

Sorry if this is a stupid question, I'm still kind of new to Mazdas. I would be VERY interested if I could swap a DOHC head onto my SOHC block too... I don't wanna do an engine swap because I've bought a clutch for my engine already and don't know whether it would fit on another engine...

The SOHC mx-3 block is a B6E a BP is a 1.8l.

For 94 and up Mx-3s the 1.6l head is DOHC, from what i understand it outflows the miata head as well.

Domnknpimp · Post by **Domnknpimp** » April 24th, 2006, 11:22 am

torpedan wrote:The better question is which will take more time and effort. All in all I personally would spend less time just directly swapping in the newer motor than i would doing a head swap.

well I dont think it should take you more than an hour to swap a head, if you think you can swap an engine faster than that, then i'm going to have to hire you to do mine.

Boris · Post by **Boris** » April 24th, 2006, 5:26 pm

err less than an hour to swap a head?? Took me like half an hour just to scrape the head and block... Maybe I'm slow, but it took me around 4 hrs or work in total...

SpikeDerailed · Post by **SpikeDerailed** » April 24th, 2006, 10:53 pm

Well seeing as how I could get a dohc b6 head cheap it would be worth it in comparison to swapping a new engine.

Besides im looking to try and drop a KJ-ZEM in when I find one.

Josh · Post by **Josh** » April 25th, 2006, 1:14 am

ok i will put it straight. now if you have the sohc you Cant swap the head from a DOHC MX3 without modification to some oil ports. but you can however swap on a 323 1.6L dohc head or a Miata 1.6L dohc head, but the miata uses a different bolt pattern on the intake manifold so you would be stuck using that manifold unless you have a custom one planned. honestly a 323 head would be good, but they are restrictive compaired to the MX3 DHOC head ports, and by putting two plugs in two oil ports you can solve the problem between the SHOC block and the MX3 dohc head swap. so all in all its easier and as far as power is concerened to just swap in a 1.8L BP. cause the 323 head will just not give you that much improvement.

the other option you have is to swap over the the SHOC 8 Valve head vs the 16valve head. it actually flows better and sounds beefy and lopey as hell. and all you have to do is go get some one to regrind you a cam and you could gaine some decent HP, at least as much as swaping on the DHOC 323 head would do.

Boris · Post by **Boris** » April 25th, 2006, 11:33 am

Thanks a lot Josh! Now I can consider going to dohc

SpikeDerailed · Post by **SpikeDerailed** » April 25th, 2006, 9:14 pm

I think im gonna try to get some free time tomorrow and get on alldata and start looking up everything for the dohc heads.