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opinions on D15B7 engine

Posted: Wed Nov 23, 2011 8:35 pm
by hondamake
Hi Guys. I've been offered a cheap D15B7 with manual gearbox to use as a short term replacement for my tired 177,000 mile D16Y7 with auto trans. My goal is to build a clever D14A4. Question I have is does anybody know anything about the D15B7? I've been told it will drop straight in, but we've all been told lies before! :o

Re: opinions on D15B7 engine

Posted: Wed Nov 23, 2011 11:04 pm
by saxophonias
Just bear in mind that the coupe weighs much more than ej9s. Moreover your tranny is way too long which is also to blame for keeping it slow. Why not build the d16y7?

Re: opinions on D15B7 engine

Posted: Wed Nov 23, 2011 11:56 pm
by Dodo Bizar
Leave it alone is my first guess. Reasons I tell later. Lets start with the engine itself.

The D15B7 is actually one of the best known engines in the D-series community. I think a quick glance at d-series.org will reveal many details. I actually wanted to spent some pages on it... but I never came around it. Though I've worked with many.

It's pretty much the predecessor of your D16Y7 engine. Its the basic engine for the 5th gen Civic coupe. Stock 102 bhp, low on revs (6800 I think it stops). Pretty long gear ratios on its S20 tranny.

The D15B7 si the MPFi version of the D15B2 (90 bhp). And the D15B7 is loved for the mini-me swaps, ESi heads which instantly raise compression around 1 CR.

Now for the reasons to leave it alone.
-it is the predecessor of your D16Y7, so on average 4 years older, and second hands often are not the best
-probably due to the same aging thing, I've personally had some problems with the oil pump, blown head gaskets (different, worse type gasket!) and seen a lot of them being blown up when 0.5 bar boost was applied for over 20 sec, not the most reliable engines sometimes

My guess would be you'd actually get a worse engine... it would really surprise me if it's still in mint condition. If it is mint though... you can hang it in pretty straight forward. I hang a D14A4 where once a D15B7 was. You just need to sort out all the engine supports, I think it fits in the original D16Y7 supports. Basic dimensions are equal between all D-series 1992-2000 and probably a little bit before and after.

Electronics are pretty straight forward. You can keep the D16Y7 ECU, it will get the engine round pretty decent. It would be a wise thing to keep the distributor from the D16Y7. It will fit right on the D15B7 engine if I am right, make sure you time it right.

On the subject of auto trans and manual trans I am less educated, what are yur plans for that?

Re: opinions on D15B7 engine

Posted: Thu Nov 24, 2011 1:19 am
by hondamake
Thanks for the info. Pretty much all I needed to know. The reasons for the swap to an older engine design: I want to keep using the car whilst improving it so the D15 is just short term, 2-3mths. The whole engine, box, ECU and any other bits I may need are £70 collected from 80 miles away. All of my cars are auto because I have arthritis, clutch and gearbox for a 1,000 miles a week is a literal pain. My aim is to build a high revving motor just for the fun of it. The D14 is nearer to square (bore x stroke) than the D16 thus keeping the reciprocating masses down. D12/D13 are better still but rare and old. It will then have a manual gearbox and become a weekend car. Yes the coupe has a heavier kerb weight but nothing that can't be fixed, I only weigh 64kg! :lol:

Re: opinions on D15B7 engine

Posted: Sun Nov 27, 2011 12:17 pm
by Dodo Bizar
If its just for interim engine, D15B7 is fine, you'll get it stuffed in and out easy enough without the need to make 'permanent' changes to any of the chassis.

Re: opinions on D15B7 engine

Posted: Thu Dec 08, 2011 9:46 pm
by hondamake
I've had to pass on the D15B7 but I've bid on a D14A8 with a manual gearbox attached. Couple of questions: I can't seem to find any info on the A8 variant, is it good or bad? Are the gearbox and diff ratios suitable? If I replace my auto with a manual box will I have to change the driveshafts? All contributions welcome! :)

Re: opinions on D15B7 engine

Posted: Thu Dec 08, 2011 11:14 pm
by Dodo Bizar
In generally D14A8 should be the same, however... from a performance point of view somebody in the Netherlands struggles to get it over 105~110 bhp. Same guy is trying to get more on Saturday on the dyno, but we'll have to see. It's only one case, and something else in his setup may be flawed, but perhaps the head/combustion chamber is slightly different making it less potent an engine.

Re: opinions on D15B7 engine

Posted: Fri Dec 09, 2011 1:26 am
by saxophonias
d14a8 tranny is very good. The d14a8 engine is different to our a4 ones as for performance. A little more torquier in the low and mid revs but lacks the pull on higher revs. I bet they have different cams

Re: opinions on D15B7 engine

Posted: Mon Feb 13, 2012 9:09 am
by sktaroins
hi , so i have a d15b7 with bisimoto cam/pistons + valve springs & titanium retainers.
with 1989 accord dx modified carb with auto jets that spray more fuel into carb after 80km/h
( something i am working on sounds like a computerized carb though ) anyhow its still mounted on the normal stock intake
still thinking about putting the 38size carb and then fitting it on the intake and then adding an OBX ITB ON THAT later on when i figure out my math if iam right.

but for now i kept the kn air intake on the carb and i rebuild the whole engine .

-should i replace the head to get more power?
should i get the d16z6 vtec head or the d14a2 head and does the bisimoto cam etc etc fit in both heads?

4 info - which block has more depth or length in the bore ?
iam looking into buying a block that has more depth in bore. so basically i am building on more on my engine.
is it the d15b7 or the d14a2?

deeper the bore higher the speed goes?

plz advice me regarding the heads and my question about the bore?
thx

Re: opinions on D15B7 engine

Posted: Thu Feb 23, 2012 12:58 am
by sktaroins
Hi all,

iam confused - so what if i wanted a longer block where the pistons move in the cylinders and what if i get bisimoto cams...
which block should i get ? well i want a deeper block to acheive more speed like over 200km/h.

but iam not getting anything anymore until i study this project of mine very well with those throttle carbs ans especially the new tech other than dyno's...!!

So iam talking about the block - some call it the bore some call it height of the deck well its the one which is under the head..
i call it the block and i like the bore to be deep too very deep :-) jk.

i want to find out which block has more height / longer or whatever it is but which block is deeper.
well yeah i have been watching alot between d14a2 and d16z6 but iam talking abt the blocks.

well i want to fit in a deeper bore is what i know now for my car.

Can i just change my d15b7 block and put either of them?
i know i asked something like this before but i need to know again..!
sry