Honda D Series Forum banner

1 - 20 of 27 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter #1
Has anyone used the high compression p29? pistons from ycp, any ideas on the actual compression ratio these pistons can produce? And I'm needing to know the dome height aswell
 

·
BATSLOMAN GIVES NO FUCKS.
Joined
·
4,194 Posts
I believe you may be thinking of the pistons. When you turbocharge an engine you need to put lower compression pistons in place of the stock ones so the motor doesn't blow from so much power.
he is asking about pistons.....what are you reading? and low comp pistons mean its a slug when not in boost.
 

·
Brokedick Millionaire
Joined
·
40,351 Posts
I believe you may be thinking of the pistons. When you turbocharge an engine you need to put lower compression pistons in place of the stock ones so the motor doesn't blow from so much power.
That was 20 years when tuning knowledge and options were limited.

Now, 10.5:1 on pump 93 is doable, but E85 with 11.5:1 is way more fun.

12.5:1 on E85....it will run like a "Snot Rocket" and on should "DILYSI" on low boost. It was for sale on here I believe and now wish I had it. It was running the cylinder head I was going to run on "D15Baby8" as well as the transmissions I'd built for it a few times. It shredded teeth due to TQ once.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #6
Got the motor together , will the higher compression need a different tune or will it run under the factory tune? The car doesn't seem to want to run, if I advance the timing with the distributor it will start for a few seconds but as soon as I try to give it gas it dies ? Will I need to do an ecu conversion?
 

·
BATSLOMAN GIVES NO FUCKS.
Joined
·
4,194 Posts
stock build? you might need to run higher octane, but should
be ok. check your timing and grounds
 

·
Brokedick Millionaire
Joined
·
40,351 Posts
I'm laughing at stupidity right now. Maybe because of the knowledge I and others gave input on the Zealworks calculators and have been reading and tuning for 40+ years.

You might wanna pick up a book before searching on the internet.
 

·
BATSLOMAN GIVES NO FUCKS.
Joined
·
4,194 Posts
12.22:1 compression
 

·
BATSLOMAN GIVES NO FUCKS.
Joined
·
4,194 Posts
Im currently running 93 octane. Stock y8 head with D16a1 high comp pistons shouldnt need an octane higher right ? Also from what I can tell timing is right
After doing a bit of research on the Zealworks Calculator D16y8 with p29 pistons will have a estimated compression ratio of 12.22:1 so I'm thinking I need higher octane
d16a1 pistons are listed as pg6.....you keep saying p29.....

if you did your "research" that 12.22:1 was with pg6's....your p29's bring it up to 12.64:1

do you even know what youre doing anymore?
 

·
Registered
Joined
·
12 Posts
Discussion Starter #12
I never truly had a clue on what I was doing😂 This is why I came to the forums for help. The box my pistons came in says they are p29 and so did the listing I bought them on , but the dome is 7.20 cc which is the same as the pg6

I'm new to the Honda world , but im trying learn. from what I was told this site was best for getting help with building a D-Series motor
 

·
BATSLOMAN GIVES NO FUCKS.
Joined
·
4,194 Posts
if theyre p29s with the 7.20 cc.......that puts the compression at 14.36:1.......


post pictures of the piston spec sheet or box they came in
 

·
Registered
Joined
·
12 Posts
Discussion Starter #15
After tediously rechecking everything I found out that the distributor was not firing right 😭 Replaced the distributor with a salvage yard one and the car runs great on 93
 

·
Registered
Joined
·
12 Posts
Discussion Starter #16
For anyone actually following this build , the car made it a little over 500 miles before spinning a main bearing because of the oil pickup failing and losing oil pressure , so back off with the pan and in with a new set of main and rod bearings
 

·
BATSLOMAN GIVES NO FUCKS.
Joined
·
4,194 Posts
yeah just slap some new ones in there, don't check the crank to make sure its still in spec
 
1 - 20 of 27 Posts
Top