Head Swap

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EF9_Hatch

EF9_Hatch

Yeah
ok so i might be picking up this 91 Si head to put on my 89 D15b2. What do i all have to do for this to happen. I tried searching and i couldnt find anything. So sorry if this is a repeating subject for some people. Do i have to convert it to MPFI or I know i probably would want to, im sure of that. but i dont have the money right now and i got offered this head for $50 and theres 100,000 miles on it. I know i need a new head gasket all so...so which motor would i buy this for a D15b2 or D16Z6? thanks for any and all of your help
 
Just swap the camshaft. The heads are pretty much the same except the camshaft and the fact the B1 and B2 are DPFI. To swap the heads; just remove the valve cover, remove head bolts, swap head, install head bolts accordingly(use a manual), reinstall everything. If you want to run the D16A6 manifold, yes you'll have to convert to MPFI.

91 Si=D16A6. The head gasket should be the same as the D15B2, so it wouldn't matter what you tell them. You can always go with the D16Z6 gasket, which will bump compression up a tad also.
 
Ok. if i get the d6 head then i will have to use MPFI? or is that just saying i can use it? and if i get the z6 head i will not have to use it? is that what your saying lol...im kinda confused..I kinda get it but not really. I figured i would have to swap the camshaft...
O and y would a z6 head gasket give me more compression? j/w
Thanks for your help though
 
No. Whether you go MPFI or DPFI depends on which intake manifold you're using. If you get the Z6 head you have to go MPFI because the VTEC ECU controls four injectors. The D16A6(88-91 Si) head has the same head casting as the D15B1 and B2 engine. The 91 Si DOES NOT have a D16Z6, it has an A6.

A Z6 head will give you higher compression because the combustion chamber is smaller.
 
O ok i got ya now. I so have to get an A6 head for now because i dont have the money for the MPFI parts yet. I will probably keep my stock intake manifold and everything for now. If i do get the A6 head will it be any type of a power increase or will it be the same as what i have now?
 
The power increase will come from the camshaft. You can spend less and try to get just the camshaft from an A6 instead of the whole head(only reason to swap the whole head is if the D15 head is bad). If anything; I'd spend money on the MPFI conversion and a 88-91 Si(PM6) ECU, then upgrade the camshaft.
 
I need to find a damn junkyard around where i live lol
 
You will also have to wire for vtec if you go with the z6 head. go to rywire.com and get the complete rewire kit for like $380 if you decide to do so. Also will need a d16 dizzy, new timing belt and vtec ecu (p28) if you dont already.

-Carl-
 
I have a question near about the same...if I recall the D16Z6 Vtec motor out of the 92-95 civic coupe....is it possibleto swap the head off of that block onto a 91 civic Si block?
 
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