Whuddup HT.

I recently completed a swap, and the new d15b2 is sluggish compared to the old d15b2.

The newer motor I put in was blueprinted by a machine shop, had a rebuilt head w/new seals, new bearings on the crank/rods, new everything.

I was told that the new motor would produced the most power possible from an OEM spec d15b2, because everything was checked, re-built, and replaced to perfect OEM spec.

The only thing different about the new motor is it has an adjustable cam gear which is set on 0* (no advanced/retarded timing.)

I suspect that the aftermarket adjustable cam gear is slightly off and that's why the motor has less power than the old beat-up and abused motor.





What's the procedure for setting an adjustable cam gear? Do I just advance it one degree, set the ignition timing (w/timing light), and go for a drive to see if it has more/less power and keep tweaking things from there?


I need to know how to properly set an adjustable cam gear.

(Car is dpfi, has oem un-chipped ecu - can't tune it.)

 

other info.....

blueprinted d15b2
manual trans
new distributor/cap/rotor/plugs/wires
new radiator/battery/axles.... all kinds of stuff
dpfi
88' civic wagon (4-door)
all fluids flushed/filled/clean oil, trans fluid etc.

 

1.) You will only move the power band around with an adjustable cam gear. A Dyno is needed to truly see if the curve is where you want/need it.

2.) "Blue-printing" means absolutely NOTHING. If the wrote all the specs down on a sheet that would be considered "blue-printing". Now you can build an engine on the tighter or loose end of the specs to get that last .01% of power...

3.) The true pre-procedure for setting an adjustable cam gear would be to have the head off the block and to measure everything. Feeler gauges, dial indicators, clay, ect... The works. There are plenty of write-ups on how to do this so I am not going to repeat it all.

 

thanks dude.

1 - this answers my question. i was thinking the adjustable cam gear may be a little different than oem honda cam gear, and causing the motor to be more sluggish than the older more beaten up and abused d15.

similar to being a tooth off on the timing belt, and havign the car run but not quite right - i figured the adjustable cam gear may not be identical to oem.

i figured messing with it (it's currently 0* adv/retd) might give the motor the power i was expecting.

2 - what I meant when I said 'blueprinting' was merely checking that everything was within spec/tolerances and reassembling the engine (after replacing anything that was not precisely how it should be.) I believe I used the wrong word.

3 - when i dial in my other motor with these complex procedures, i'll also revisit this d15 which isn't running with as much power as it should.









in other news - could having an aftermarket header be causing my loss of power? it's slightly larger than oem cast iron, but it's stainless 4-2-1 with long primary and secondary runners.

from my research this would tell me the header is best suited for higher rpm, which corresponds to the motor feeling sluggish down low in the powerband.

this is NOT a performance build of any kind, i just put that header on because i thought it might improve power and i had it laying there. (silly me thinking I could improve honda's oem designs?)

i will put the oem cam gear back on, reset the ignition timing, and report back to check for replies about the header situation.

thanks much!

 

Absolutely, especially if it's a cheap one.

 

it's probably a no-name cheapy.. i see no markings.

the welds look good *inside as well as outside

i will measure the tube diameter, but they are bigger than oem by maybe 20% or so, it's hard to say from memory.



looking back... what was i thinking putting that on an oem motor..... especially with the old oem cat back tiny piping....