I have heard that the a6 pistons yield somewhere between 10.4:1 to 11:1 cr in a d16y8. With i/h/e i was wondering if anyone has a dyno sheet or has done this sort of mod. I'm just trying to find ways to make power with a very limited budget.

thanks

 

120+ atw, maybe...i/h/e and just pistons. why not purchase a1 pistons? more displacement and high CR for same loot! .050 avail from honda makes your y8 FUN....and streetable


[Modified by builthatch, 12:04 AM 6/17/2002]

 

would i need to do any mods to the block to fit the a1 pistons
also i am already planning to get the 59300 zex cam, but i wanted to know what would the cr be with the a1 pistons.

 

oohh that damned zex cam. alot of better choices in my opinion, anyway, you dont have to mod the block, you can get the stock bore size 75mm, but, honda offers .010, .020, and the .050-just bore it and go. the cr will....hold tiiite, be 13:1!!! with the y8 head BUT, it will not be a problem with the right plugs, tuning and fuel, even in cali...plus if your cam has alot of overlap, (which it should for an NA cam), itll kill some of that compression...


[Modified by builthatch, 12:36 AM 6/17/2002]

 

what cam would u recomend then?

I really want to do everything i my garage so taking the block to a machine shop is out question at this time. What would the cr be with the stock bore a1 pistons. My goal right now is 140 whp N/A

Thanks for the info

 

up

 

I've really not seen any impressive gains w/ the zex cams, 59100 or 59300...I have seen incredible gains with the crower stage 3 and the gude godzilla...although, i will admit, the numbers (spec-wise) on the zex 59300 look like they should make some real hp...I dont understand it. Im sure you know you will need springs and retainers with all these cams, for reliability. A tuned ecu also will need to be used to get the revs and tuning youll need. stock bore a1 pistons (75mm) will suit you fine, still 13:1 compression (as far as i know). its possible youll get 135+ out of this build w/o headwerk. REMEMBER, thats like 30 more hp that stock wheel hp! port the head and youll be making 50+ over stock...

the y8 head is nice, as is the manifold, but...in order to get a solid # like 150-160 out of the build, youll need to port it and match it all...

 

you might wanna keep an eye out for the new Skunk2 SOHC VTEC cam that's either out or coming out. I bet it wil make some good power...(fingers x'd)

 

I have a z6 with a shaved head( .025) would the crower cam clear my pistons or would I have clearence problems?

 

depends on what pistons...with a1 pistons, no way, you only have (stock deck and head w/ a1 pistons) .040 clearance...take away .025 and your waaaaay too close. BUT, if your running a6 pistons (more relief than a1) or even better, stock z6 (dishlike), your waaaay fine with up to .030 milled and a big cam like the crower3

 

thanks man...the motor is a z6 with stock bottom end, I was worried I wouldn't be able to run the big cam but thanks again for the info.


[Modified by 89civicdx, 4:17 PM 6/17/2002]

 

so with the a1 pistons the cr in a y8 would be 13:1. would i be able to run that on pump gas without a standalone ecu. (i.e vafc, fpr, bigger injectors, bigger fuel pump, dyno tuning)

[Modified by willyboyD16, 8:13 PM 6/17/2002]


[Modified by willyboyD16, 8:15 PM 6/17/2002]

 

just injectors and afc (or vafc) and pump...aklthough i know guys that ran stock pump, w/ just injectors and fuel controller...


[Modified by builthatch, 8:31 PM 6/17/2002]

 

hey man thanks for all the info. I probably have just a couple more questions, 1st will the stock rods be enough for that cr, and 2nd what would be the biggest cam i could run and not smack into the pistons.

 

up

 

you have got to be kidding. im running d16a1 pistons in my d16z6 and im no where near 13:1 c/r. i remember the y8 has slightly higher c/r than the z6. i dont remember exactly why it has higher c/r..except for one thing..the y8 headgasket is thinner. oh, im running the d16y8 headgasket on my setup. so other than the headgasket, im not sure off hand what else makes it have a higher c/r.

so what im saying is. how the hell is a d16y8 with d16a1 pistons going to yield a 13:1 c/r. if u have proof or numbers i want to see them. seriously have you looked at the domes on the a1 pistons... there is a pic on here...sonny van hook is doing a d-series piston project - mixing blocks and pistons to get ACTUAL c/r's - do a search - the domes are not that high at all. ctr pistons have HUGE domes compared to the a1's. but ctr pistons were DESIGNED for that..ie..the ctr was made for racing. the a1 pistons were found in mass produced integra engines. they dont have much dome displacement at all.

my d16z6 w/d16a1 pistons, d16y8 headgasket, stock cam, is running around 260psi compression on all 4 cylinders. i feed the thing 87 octane and it runs fine everyday on a stock pg7 ecu. i've made 0 fuel mods. i dont even have a fpr. the thing runs fine. last time i checked 13:1 c/r wouldnt fare that well on 87 octane with NO tuning and NO fuel mods.

im not disrespecting but i dont like when misinfo is spread around. i'd love to be proven wrong tho.

 

quote by dlric-"the domes are not that high at all. ctr pistons have HUGE domes compared to the a1's. but ctr pistons were DESIGNED for that..ie..the ctr was made for racing. the a1 pistons were found in mass produced integra engines. they dont have much dome displacement at all."

okay your missing the fact here...a1/ zc motors had huge cc, so much so that they had to make HUGE (maybe not as tall as you like to see, BUT DEF WIDE!!! domes on the pistons to get an accepatable C/R, now...when you take a piston designed for use witt a big cc head and install it in a motor with a SMALL cc, what do you have? a high C/R... http://a5.cpimg.com/image/39/4C/9239...-028001E0-.jpg ...these are big domes my friend. The z6 has bigger cc than the y8, hence the higher c/r (yours should be 12.5:1 as opposed to mine which is 13:1) the D16Y8 has 32.8cc and the D16Z6 has 34.6cc. for the record, my compression is 275+psi (a lil higher than 275) on all four cylinders, even across the board. the original information i got about a1 into a z6 was from nathan tasukon, crew chief for ed bergenholtz, when he was doing r&d for gude in the mid-late 90's. they determined that the z6 was about 12.5:1 and the y8 was .5 more, about 13:1 due to the cc difference. you have p29 pistons and run 87 octane? thats great! im glad you car was blessed so much more than mine! funny my car wont run on anything less than 93, even then it wants more octane...nathan when he had a z6 with p29 pistons that was featured in honda tuning and sport compact car, he had to run 92 octane (91? i ferget) with only 10 degrees of timing, heat range 7 plugs, and injectors, gude ecu and field fc. amazing that your car is soooo different from his too...i wonder where my 164 whp came from? according to you, not high compression...




[Modified by builthatch, 2:44 AM 6/19/2002]

 

i heard that tuning a motor with a high cr like 13:1 to run on 91 octane is basically the same thing as running an 11:1 cr but with less torque. it kinda sounds reasonable considering that if ur not using the full potential of having that high compression (13:1), then you will only be yielding the same power as a lower compression (11:1). i hope that made sense. what you guys think? just my $0.02..

 

ok so then im running 12.5:1 c/r on 87 octane with stock timing (im using my pm6 distrib on my z6 head so u cant really advance/retard it with the way its setup), stock d-series injectors, no fpr, and nothing to tune it? its been running like this for over a year now.

wow. so in currently rebuilding my b18c for 12.5:1 c/r w/aftermarket parts i wont have to tune it. it'll run fine on stock timing and 87 octane if this is the case.

 

IM conversation with nathan tasukon, who's resume includes-engineer with gude, then apexi, then AEBS, now with pactell engine management and TRD...also is crew cheif for ed bergenholtz racing...owned a 13 second NA street z6 in the mid 90's

builthatch609: can you tell me one thing, how did you know that z6 with a1's yield 12.5:1
builthatch609: how did yous find that out
nondee23: cc the head and pistons
builthatch609: o i c
nondee23: math my friend
builthatch609: rite..
builthatch609: this guy sez he runs z6 with p29, like your old motor- no fuel mods on reg and has no prob...
builthatch609: 87 octane
nondee23: lol cool good luck to him
builthatch609: i agree
builthatch609: rite on!

like i sed b4, my 164 whp NA must have come from somewhere magical, other than ultra high compression and the rite combo of parts......that is like almost 60 hp more than stock at the wheels. try to do that NA on a y8 w/o high cr.

[Modified by builthatch, 6:09 PM 6/19/2002]


[Modified by builthatch, 6:15 PM 6/19/2002]

 

ok basically you both are saying im blessed or something? my car just magically can run with zero tuning..stock ignition..no fuel mods..on 87 octane...and 12.5:1 c/r?

it runs strong too. so im just a honda god. ok. everyone should come to me to tune their 12.5:1+ c/r engines. everyone should actually just worship me. do you know how much time this would save ppl from having to tune their cars? just take my approach. throw in larger dome displacement pistons, a thinner headgasket, and call it a day folks. no need to tune.

what the hell am i missing here. remember i ran the stock d16z6 cam. what kind of crazy cam are you running? did you pnp the head? what ecu? what tuning?

 

ok..u say u have a1 pistons..but werent the 86-87 pistons weak compared to the 88-89?

 

d16a1 is 88-89 integra pistons. i went to acura and bought 89 integra pistons. new obviously. so i had to specify the year. the receipt is somewhere around here. i actually sent one to sonny van hook..he is/was doing the d-series piston project. this particular piston got scratched so i had to buy another. if you do a search for his post you will see it. he has a pic of several pistons, and i contributed a d16z6 as well as a d16a1. there's the proof in the puddin.

 

builthatch: you seem to know your SOHC D16 ****, so i figure you might be able to give me a good answer. what is my compression?
stock 93 DX bottom end
stock 98 EX head, milled 20 thousandths
stock 98 EX headgasket

thanks man!

 

thanks for the compliment, unfortunately, i don't know the answer, BUT, you can cc that combo and come up with a number...maybe check out the "d series ez board", i dont know the address off hand, i know one of those freaks has a number for you...BTW, strung out ROCKS i love fat wreckords