Ok guys...I've been researching for building a reliable all motor D and considering selling my turbo kit to do so. The P29's offer a nice bump in compression but no quench for the Y8 head. I've been trying to look into the PM3's because i have heard that they offer the compression bump and quench needed. Cant find too much info on this. Can anyone help me out?
Vantec89
http://www.d-series.org/forums/engine-building/140988-pm3-piston-d16-nonvtec.html
heres my old thread ^^^
researched this whole thing inside and out so read it up from front to back.
it can be done is the short answer, i didnt do it because i got a better deal on some custom pistons. keep in mind that for my thread i had .040" shaved off the head. so dont use that in your calculations
install pm3 pistons and use a shim (mock headgasket) that is .060" thick and cut the cylinder holes in it so the pistons will pass through. torque down the head and crank it over by hand with some clay on the piston domes. this will tell you a ton!
endyn engine building articles recommends .040" minimum piston to HEAD clearance (this is an issue since pm3's will come out of the hole up into the combustion chamber so make sure your pm3's will fit up into the CC) keep all of that in mind for the final size of the headgasket.
the clay will tell you the piston to valve clearance.
if youre good and within recommended building margins then use a .060" headgasket, if you need more room to clear p2v then go thicker. cometic or bisimoto can set you up with a custom thickness gasket.
other issues:
-the valve reliefs on the piston dome will need enlarged because the valves in a d16 head move down toward the piston in differently than in a d15 (which the pm3's are designed for).
-account for some rod stretch in all calculations (.040" for forged rods, .045" for stock with ARP rod bolts)
-account for the higher lift and duration of the aftermarket cam you will need to bleed off some of the compression.
-check final compression readings a few times on the calculator
-measure and make sure the ring lands wont be too close to the flame inside the CC
get a good set of rings, have them coated, piston dome and skirt coating would be great insurance as well.
finally...when using a thick head gasket take into account changes in timing as well as the fact that ARP head studs should be used for more clamping power. when the head is moved further from the block, warping can occur. the best bet would be to have the head and block decked the absolute minimum so you have solid flat surfaces to start with.
sorry so long of a reply but theses are the main issues with the build idea
good day
rep if you feel like it
heres my old thread ^^^
researched this whole thing inside and out so read it up from front to back.
it can be done is the short answer, i didnt do it because i got a better deal on some custom pistons. keep in mind that for my thread i had .040" shaved off the head. so dont use that in your calculations
install pm3 pistons and use a shim (mock headgasket) that is .060" thick and cut the cylinder holes in it so the pistons will pass through. torque down the head and crank it over by hand with some clay on the piston domes. this will tell you a ton!
endyn engine building articles recommends .040" minimum piston to HEAD clearance (this is an issue since pm3's will come out of the hole up into the combustion chamber so make sure your pm3's will fit up into the CC) keep all of that in mind for the final size of the headgasket.
the clay will tell you the piston to valve clearance.
if youre good and within recommended building margins then use a .060" headgasket, if you need more room to clear p2v then go thicker. cometic or bisimoto can set you up with a custom thickness gasket.
other issues:
-the valve reliefs on the piston dome will need enlarged because the valves in a d16 head move down toward the piston in differently than in a d15 (which the pm3's are designed for).
-account for some rod stretch in all calculations (.040" for forged rods, .045" for stock with ARP rod bolts)
-account for the higher lift and duration of the aftermarket cam you will need to bleed off some of the compression.
-check final compression readings a few times on the calculator
-measure and make sure the ring lands wont be too close to the flame inside the CC
get a good set of rings, have them coated, piston dome and skirt coating would be great insurance as well.
finally...when using a thick head gasket take into account changes in timing as well as the fact that ARP head studs should be used for more clamping power. when the head is moved further from the block, warping can occur. the best bet would be to have the head and block decked the absolute minimum so you have solid flat surfaces to start with.
sorry so long of a reply but theses are the main issues with the build idea
good day
rep if you feel like it
Thank you sir! I'm glad someone posted on this for one and you actually posted some really useful info instead of "search harder" or "searching owns you" i appreciate that a lot and the fact that you can take the time to share info alone, motivates me to dig deep into this build idea and run with it! thanks again! rep for sure....i'd give you double rep if i could, lol.
anyone else with any info on this type build would always be amazing and appreciated. thanks.
anyone else with any info on this type build would always be amazing and appreciated. thanks.
thanks. i like to help if i can and this is a unique build so i hope you go through with it.
im still convinced that this kind of set up would be one of the best performance wise using the stock piston options that are availabe. With the awesome quench characteristics of the flat top pm3 and being above deck you can and will up the compression pretty heavily, run on 93 and assuming you do your homework and get a solid tune it should make good #'s and be reliable. quench is like free octane.
whats your full set up going to be? throw up a full build thread and some of the other parts you are using or planning to use. that would be helpful.
im still convinced that this kind of set up would be one of the best performance wise using the stock piston options that are availabe. With the awesome quench characteristics of the flat top pm3 and being above deck you can and will up the compression pretty heavily, run on 93 and assuming you do your homework and get a solid tune it should make good #'s and be reliable. quench is like free octane.
whats your full set up going to be? throw up a full build thread and some of the other parts you are using or planning to use. that would be helpful.
This been covered in a few threads, I know I posted in them.
The valve relief issue is the only major issue.
What to do with my 75.5mm PM3's.......
The valve relief issue is the only major issue.
What to do with my 75.5mm PM3's.......
Yes, this build idea has me going...I was rolling around all night with ideas stewing in my head. Lol. So even though being that I'm gonna have to mod the valve reliefs and be extra careful and look at every detail for this build. The mock up headgasket/spacer has me intrigued. I haven't heard anything of this in any other build. Would using something like this hurt reliability at all? Im trying to go with something that is powerful and reliable! Of course I'm not trying to be the god of n/a D power or anything, nor do I have the funds. Truly I want a learning experience and a lot of fun to come from this.
I thought about running pm3 but considering they come out of the block .028 that really worries me with how close that makes the top ring to the top of the cyl. That to me would cause a lot of other issues with clearance and what not possibly causing more money than using the slightly dished a6 pistons.
Why not use PG6s and not worry about any of the rest of the stuff? As long as you don't go crazy with the cam, it'll be fine. You'll have to notch if you want a big cam, though.
PG6s don't stick out of the block (much) as opposed to the PM3s that have valve reliefs in the wrong places and will drastically lower your compression when you notch the pistons to clear you valves.
PG6s don't stick out of the block (much) as opposed to the PM3s that have valve reliefs in the wrong places and will drastically lower your compression when you notch the pistons to clear you valves.
Where can you find pg6s. The dealer for sure but eBay only seems to have p29s. Plus domes kinda suck it's something the flame front has to try to climb over and doesn't help with quench.
I did consider running the PG6's.....however, do they offer the quench needed for the Y8 head to make the compression bump worth while?
If you go to FJ and look in the all motor D series section you can buy a whole bottom end kit or just the pistons alone.
If you go to FJ and look in the all motor D series section you can buy a whole bottom end kit or just the pistons alone.
pg6's are good and proven over and over in n/a builds
my only problem with them is with running a bigger cam. pg6's require the same kind of valve relief cutting that the pm3's need anyhow. if youre making higher compression (which is obvious here) then you will need a larger cam to help maximize power gains, burn effiency, and driveability. the stock cam is about all your gonna fit on unmodded pg6's.
bottom line: what compression are you set on running?
start there when deciding what pistons to run.
select a set of pistons that then fits that range of compression + the desired quench characteristics youre looking for + all machine work that may be needed ($)
then get a suitable cam to match it.
my only problem with them is with running a bigger cam. pg6's require the same kind of valve relief cutting that the pm3's need anyhow. if youre making higher compression (which is obvious here) then you will need a larger cam to help maximize power gains, burn effiency, and driveability. the stock cam is about all your gonna fit on unmodded pg6's.
bottom line: what compression are you set on running?
start there when deciding what pistons to run.
select a set of pistons that then fits that range of compression + the desired quench characteristics youre looking for + all machine work that may be needed ($)
then get a suitable cam to match it.
well, just all kinds of lost on what pistons to run.....seems like there is some issue with any high compression OEM piston...lol.
it just depends...
what compression are you shooting for? 12:1? 11:1?
we can suggest several set ups that will allow for ideal compression and quench (especially since the y8 head is a high quench design anyhow)
what compression are you shooting for? 12:1? 11:1?
we can suggest several set ups that will allow for ideal compression and quench (especially since the y8 head is a high quench design anyhow)
Im personally planning on running the pm6 pistons and shaving .020 off the block for zero deck with either a .030 cometic or a y8 2 layer to get a tight quench.. Just a thought...
This thread sucks.
Until the OP learns WTF compression height is, how to calculate (or what resources to use for figuring) piston to deck, and finds out how thick the OEM MLS headgasket is, this whole thread is just full of useless fluff.
Leave your engine alone before you blow it to heck.
Until the OP learns WTF compression height is, how to calculate (or what resources to use for figuring) piston to deck, and finds out how thick the OEM MLS headgasket is, this whole thread is just full of useless fluff.
Leave your engine alone before you blow it to heck.
Ok. Let's play this game . . .
Why did you decide to achieve an 11.5-12:1 static compression ratio?
If your answer doesn't involved a well though out reply about quench, camshaft selection, and expected powerband, you are likely just plain wrong.
Why did you decide to achieve an 11.5-12:1 static compression ratio?
If your answer doesn't involved a well though out reply about quench, camshaft selection, and expected powerband, you are likely just plain wrong.
@ least he wants to build around the cam. thats a decent enough start.
FYI good quench lowers the temperature of the gasses that are trapped between the pistons dome and the cylinder head. It basically prevents a second flame from occurring. You get more efficient combustion.
have you considered y7 pistons and then milling the head?
FYI good quench lowers the temperature of the gasses that are trapped between the pistons dome and the cylinder head. It basically prevents a second flame from occurring. You get more efficient combustion.
have you considered y7 pistons and then milling the head?
run a 3 layer y8 headgasket...when its torqued down and compressed its .028" thick. i assume you are using the zeal calculator? if not heres the link:
Honda D-Series Compression Calculator by ZealAutowerks
you dont want to screw with a headgasket issue down the road. OEM is best imo.
Leave the block alone. whatever you take off the block is exactly how much it will come out of the bore. y7 pistons sit @ zero deck. if you MUST deck it go the ABSOLUTE minimum just for nice flat surfaces...like .005" off of it.
take what you want off the head for compression. clay it to check clearances between the pistons and valves with the bigger cam. its much safer.
Honda D-Series Compression Calculator by ZealAutowerks
you dont want to screw with a headgasket issue down the road. OEM is best imo.
Leave the block alone. whatever you take off the block is exactly how much it will come out of the bore. y7 pistons sit @ zero deck. if you MUST deck it go the ABSOLUTE minimum just for nice flat surfaces...like .005" off of it.
take what you want off the head for compression. clay it to check clearances between the pistons and valves with the bigger cam. its much safer.
oh ok, that'll work....the .028" changes it to 11.38:1...ill take that. lol
and yes, im using the zeal calc. oh ok...you think the head will be ok taking .040 off?
and yes, im using the zeal calc. oh ok...you think the head will be ok taking .040 off?
you never know unless you check it with clay.
many have taken alot more than that off a head and still been fine.
search around the site (maybe showcase and d-series build threads) for other people running that set up or .040" off a y8 head y7 block combo and get their take on it.
i have .040 off my head (all y7 build) i dont expect to have many problems. if there is i'll do what i have to in order to get it back to safer clearances.
many have taken alot more than that off a head and still been fine.
search around the site (maybe showcase and d-series build threads) for other people running that set up or .040" off a y8 head y7 block combo and get their take on it.
i have .040 off my head (all y7 build) i dont expect to have many problems. if there is i'll do what i have to in order to get it back to safer clearances.
what stg3 cam are you planing on running? 11.38 isnt really that high in my opinion it may be over cammed with a stg3 from crower or bisi, crower 2 and bisi custom 2 maybe a better choice, being over cammed will make less power then being under cammed. this is just my opinion some may say its fine but i like to be a little light on cam then way heavy
Using that compression calculator doesn't work with the Y8 head.
I know you want to learn, but, quite frankly, you're going about things the wrong way. Building around the cam is a good thing, and I am happily surprised about that, but, just picking some cam isn't even the bet way to do things.
1. Power goals for a particular range.
2. Cam spec'ed to get you to #1.
3. Select the chamber configuration to get you enough quench and compression to work with the cam.
4. Work the head, and make sure there is enough in and out velocity to meet your goals (intake and exhaust).
5. Put everything together checking clearances.
6. Break in.
7. Tune.
Measure.
I know you want to learn, but, quite frankly, you're going about things the wrong way. Building around the cam is a good thing, and I am happily surprised about that, but, just picking some cam isn't even the bet way to do things.
1. Power goals for a particular range.
2. Cam spec'ed to get you to #1.
3. Select the chamber configuration to get you enough quench and compression to work with the cam.
4. Work the head, and make sure there is enough in and out velocity to meet your goals (intake and exhaust).
5. Put everything together checking clearances.
6. Break in.
7. Tune.
Measure.
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
