[oldcivicjoe]

just tossing around an econo car build at the moment. have a few questions about the d14 and havent been able to dig up many specifics on them.

Whats the stroke length?
rod size?
piston used?
head used and chamber volume?
and most importantly is it the same main journal size as a d15b2 block?
and if any one knows what rod and piston i can use to get to 9.0:1 compressin with a d16z6 head?

 

[RedWabbit]

wow 5 years ago I could have helped you, I don't remember much about that stuff anymore. you will have a hard time finding that info it takes a long time scouring websites to find it too.

any reason to go with a 9:1 compression ratio?? what are you building the motor for? a higher compression ratio will burn the gas more efficiently.

 

[oldcivicjoe]

looking to run E85 with a turbonetics t3 turbo .48 A/R, f1-54 tubune,i thinks its a 40 trim compressor wheel, but may have to go to a 50 or even 60 trim, boost to about 14 lbs. mini me build with z6 or y8 head, make the vtec lobe into a thompson stroke lobe and switch vtec on whenever above 4 psi. reduces pumping losses and friction. then im going to put an hf trans in it for the higher gearing and see how many mpg i can squezze out of it. this is my answer to the chevy cruise eco.

 

[RedWabbit]

I definitely think you should run a higher c/r 10.5:1 would probably be best.

I'm pretty sure the cylinder size is the same for the d16 and the d14 just changes in stroke. if you are changing the c/r and using a z6 or y8 head then it would be easier and cheaper to just use a z6. I think most of your gains will be in head work not the bottom end.

 

[oldcivicjoe]

not really trying to make a ton more power. but for atomization purposes the head will be ported and flow matched, im also thinking the z6 head would be best, i can always get much more flow with better atomization with them vs the y8, guess if it comes to it ill just have to rework the combustion chambers to drop the c/r. was going to start at 9:1 and work my way towards 10.3:1 actually, just wanted to start low so i dont go blowing shit up, i figured i would work with cast pistons till i found the sweet spot then buy a nice set of forged pistons.

 

[RedWabbit]

tuning is much better than it was years ago, you can start off with 10.5:1 with no issues and it will help burn the fuel more efficiently. you can get better gas mileage with a higher c/r

 

[oldcivicjoe]

we will see. there is no knock sensor spot on the d15b2 block so kinda hesitant to run a cr that high from the start. plan to start close to 9:1 as possible then work my way up until i have had to retard the timing too much. also going to play with as few different fuel comp sensors and see if i can make it run well and get great fuel milage on gasoline as well as e85. with the aem ems system i should be able to set up a boost control that will drop the boost as ethanol content goes down.

 

[RedWabbit]

the amount of ethanol needed is greater than that of gasoline engines. and the afr is different as well then gas. so I don't know if you want to use it for a gas sipping eco car.

if you are really concerned about knock sensors then drill a blind hole on a flat spot on the back of the block and install one. it only uses the the resonance for knock.

honestly I find it kind of stupid to rebuild an engine after just building an engine just to up the c/r. its a waste of money. do your research and you will find that I am correct and you can run a 10.5:1 c/r with a turbo and tune it properly with todays technology. and if you can't with an overpriced tuning solution as aem then whoever is tuning doesn't know what they are doing.

if you look at vw. the newer 2.0t fsi engines have a compression ratio 10.5:1, have a K03 turbo, and I was personally getting 35-40mpg in a 3500lb 06 passat. so you could only imagine the mpg you would get from it in a little civic. higher compression ratio, turbo, head work, and some good fuel atomization will go a very long way.

 

[oldcivicjoe]

while i know its possible to run a 10.5 cr with boost the ring lands and the mains on a d series wont stand up to that kind of pressure for long. and going too high on the cr will force me to back timing off and thus lose fuel efficiency. yes i have boosted motors with 10:1 or above, but the gains are generally not worth it, it stresses the motor more than nessasary. and also a thompson stroke motor does not need that high of compression, it actually does better with around 9.5:1. or atleast thats where i made best fuel milage and emissions in previous testing. while granted that was with chevy small blocks and ford windsor motors the same principles apply here. this is why i am starting with a lower cr and working my way up.
and the motor was not just rebuilt, im going to start this build off with a d15b2 that has been sitting in my brothers garage for 6 years now and has 260k mi on it, the block will be going out to machine as soon as i find a place to get the d14 crank and rods.

 

[Darkness]

Honda D engine - Wikipedia, the free encyclopedia

 

[oldcivicjoe]

thanks darkness, i read thru that but had missed the rod length last read thru, and also the dome volume on the one where its listed. i came up with a chamber volume of 34.2cc, that means i should be able to find pistons for 9.1:1, 9.4:1. 9.8:1, 10.2:1, 10.5:1 and 10.7:1 thats just looking thru SRP's catalouge, if i search thru wiseco, mahale and a few others im sure i will get a few more options.
for the cam its looking like ill start out at valve closed 12 deg after bdc on compression stroke, that way can use the cam gear to go between 9 and 15 of compression bleed off, ill have a second cam ground to close at 18 degs. the best i could figure from my 10 year old notes is that i got peak power at 9 and peak fuel efficiency at 20 with the v8s. with this way under square boreXstroke it will probably be the first 12 deg cam that works best as it will bleed off more compression with less crank rotation.