spiffy_civic

I just took my d15b8 head off and upgraded to the d15b7 head bigger ports 2 more valves per cylinder and so on.. But i am currently using the d15b8 (hf style) intake manifold SMALL ports and throttle.. I was wondering if this is why my car is acting up or maybe its timing? I have it all set right and correct firing order and new dizzy/cap... Its a 1992 honda civic EG hatch CX.. d15b8 stock.. It runs like crap and cant go fast on highway i have to floor it to do 65mph.. At high rpm it does fine but lower it dont.. :/... Any idea's?? I know u honda tech people are smart.. I can usually figure it out but this has me completely confused... Let me know what all you think asap please!!!!! Thank you all.. ))

spiffy_civic

It ran amazing with the other head but slow as a turtle.. I was also wondering because i threw in the d15b7 ecu and did the 4 wire o2 so no CEL. It didnt make a diffrence it still runs the same just higher Rev limit and a little more power.. So could it be the intake manifold or more than likely timing...??? Or possiably the Coolant temp sensor or the 1 next to it? Could tho's mess with the way it runs? If so i can take the old 1's outta my b8 head and swap them out..

spiffy_civic

I was reading somewhere online that if i use the b8 injector's there only 180Flow Rate (cc/min) and the b7 was 235Flow Rate (cc/min).. You think my motor could be starving for fuel causing it to run like crap? I dont smell like running rich smells like it starving for fuel.. Problem solved? Let me know please
thanks for the help

bradley

Did you change the ECU? If you pop in a P06 it should run normal, even with the small intake and injectors. Ran into the same problem swapping D15Z1 head with D16Z6, it's mainly because the ECU expects to be dumping a lot less fuel in there.

spiffy_civic

Ya i forgot to add that thanks for the reply tho.. It has the PO6 ecu No O2 sensor but either way on both ecu's 1 wire o2 or 4 it dont run any diffrent.. At higher rpm DOES GREAT! But lower it cuts out but if i open her up she does perfect.. Makes no sence.. I installed the newer injector's235CC.. And i re-timed it and put new plugs in.. Made a little diffrence but still cuts out BAD.. Maybe the tiny tiny ports arnt allowing for a Good enough burn and at WOT it will run better cuz more air flow? Maybe go to the B7 intake manifold? Unless a bent valve or something but idk if thats what it runs like with a bent valve... Never had a head swap problem b4.. Always came out perfect so a little stumpd.. But the d15b8 head has TINY ports intake and exhaust so im thinking its the intake manifold screwing it up. This b7 head is a temp until i get my d16y7 head cuz im doing a HIGH COMP build NON vtec sohc ima try 2 do what i had 2 my old hatch.. d15b7 block,y7 head/timing belt,y8 headgasket,y8 intake manifold plus chipped ecu.. My old hatch was quick this 1 NOT SO MUCH

bradley

Have you not changed over to 4 wire? Running a D16Z6 head on a D15Z1 (which had the tiny ports too) and still using the 190cc injectors with a P28 and everything is working fine.

If you still have problems with P06, 4 wire o2, and it is a 16 valve D15B7 head on a D15B8 block, you've got SOMETHING wrong. That little port intake shouldn't make a difference.

spiffy_civic

No money for a 4wire o2 at the moment but my old Ej1 didnt have an O2 at all same ecu from that car thats in this car. And it ran fine so it must be timing issue or a vaccum leak from intake manifold or something.. Poss Bent valve? Idk im open to idea's.. It ran like crap at idle with the Po5 ecu with the O2 hooked up and it ran like crap with the Po6 Ecu No o2 hook up.. So im just gonna take a guess and say its not the o2 being Vacant. Has to be timing or something so simple..

24TEN

iTrader: (2)

https://sites.google.com/site/24teng...h-16valve-head

spiffy_civic

Thanks for the link.. I already seen that link tho.. I had the 16V pistons already thank goodness

DCRB

first off did u swap over crank pulleys? secondly u kind of need an o2 sensor so i'd get that put on asap, see if it makes a difference.

spiffy_civic

OK no i didnt swap it over I took it off to mechanically time the car with the lower timing gear mark on the block and the cam gear marks but i think i was using wrong marks on cam gear.. I was using the pointer which isnt used on a b8/7 its used on the z6 so ima set it again and see if it helps and the o2 thing im sure isnt helping it but it should still run and idle this car WONT idle if ur foot stays on the gas it will but other than that.. NO.. So ima go do that and see what i find.. Plus im tryin 2 get a o2 sensor i dont have a job so dont have a dollar 2 my name.. Ima see if a buddy with throw me his old 4 wire o2 from my old EJ1.

spiffy_civic

Ok so im a total NOOB aparently. Cuz i have timed a d15b7,b1, D15b7w/y7 head.. Iv done Z6 and everything and i some how managed to screw up timing a a B8/b7. lol So in other words its runs alot better!!! Still has a miss fire but i think ima tooth off or so but much better and idc if im off by a hair it runs perfectly fine for me and my daily driving until i get my d16y7 head

Thanks for all your guys help!

24TEN

iTrader: (2)

This is really what I was trying to get at without having to spell it out for you, I explained what is different in the link provided. I did the exact same conversion as you and experienced the same issues as you have been experiencing. If you READ you'll understand.

spiffy_civic

Well sorry i missed that LITTLE thing.. I didnt use the crank pulley to time it anyways so i didnt even need to change pulley's out... I took it OFF then timed it again it was a few teeth off cuz i was using wrong timing marks on cam pulley so MY BAD.. But thanks for the help

24TEN

iTrader: (2)

Honestly it sounds like you are missing the entire point. I don't know how in the world you are going to adjust ignition timing without a crank pulley not to mention the correct crank pulley. It's kind of a BIG thing.

spiffy_civic

Im NOT missing ANY point no neeed to be cocky I DONT have money to buy another...And i set timing by ear when it comes to the dizzy, If it sounds good and rev's fine its good enough for me.. And i set timing on my B7/Y7 and NEVER used a timing light only thing i used on crank was the TDC mark after that all done by ear.. So i think your missing the point i asked for help i didnt ask to be picked on and pretty much called stupid on my own post. If i wanted that id go to facebook man.. Im not tryin 2 be mean but all i did was ask for advice to get this going Cuz its my DD car. Its not permanent. Just temp until i get a job/money to get the correct stuff.. but this is history now so let other people learn from my stupidity

24TEN

iTrader: (2)

I didn't miss any point and I wasn't being cocky, you asked for help and I gave you some insight. I wasn't picking on you, just pointing you in the right direction. Like I said I did the exact same conversion (that's the whole reason I made that link I provided) and I know exactly what you are experiencing. Now that you have stated you don't use a timing gun to do ignition timing, there's nothing more I can add.

I can say a whole lot more based on your reply but I choose not to. Good luck with your DD car, getting a job, getting money to get the correct stuff, your stupidity, etc.

spiffy_civic

Thanks.. Iv just had a rough time with this and i have learning issue's and what not so i dont always understand sometimes i need it spelled out for me.. Thanks for the help tho.. It just seemed like u were being cocky cuz uk the answer and wouldnt tell me lol.. Sorry for blowing up.. Just stressed out and all.. Went and applied for jobs today so hope i get it.. As for the stupity well thats gonna take some time I drive a SOHC honda with 100Hp lol In time. I will learn to be less stupid

spiffy_civic

Btw ended up NOT being timing it was the lack of O2 sensor got 1 installed and runs 10X'S better plus timing was off by a hair nothin to big

spiffy_civic

so it was timing but not the biggest issue lol

Garritt Oberjat

I have a 1995 dx civic with a d15b7 I just pulled my 16 valve head off and picked up a d15b8 8 valve head.I can't find any information on this is there any thing I need to look out for? Will my p06 ecu run the d15b8 head fine? Or should I return that head and try to fine a 16 valve head

mk378

D15B7 or other 16-valve non-VTEC heads or complete engines should not be hard to find. I think you could bolt on an 8 valve head and use all the other parts that came with the DX, but the question is why. It's going to have less performance.

Garritt Oberjat

​​​​​​​the only reason is I couldn't find a 16 valve and only paid 60 buck from a junk yard for the 8 valve but I have 30 day to take it back and it would be the same price for a d16y8 head non vtec would that head bolt on just as well?

TomCat39

d16y8 is a vtec head. a d16y7 is the non vtec head. There would be mechanical timing challenges with these heads as the cam key index is half a tooth off from the previous generation heads.

You want the D15B7 head as your ECU would run the B8 head too rich anytime in open loop which is anytime you are 3/4 throttle or more and when not up to temp.