I am doing an all motor build and used cspeedracings compression guide and found that with my USDM (DAMNIT!) ITR pistons I get a wopping 10.6 c/r with a 3 layer OEM gasket. I also calculated it with a single layer gasket and got 11.1 I am wondering should I go with the 11.1 or the 10.6? I have also thought about breaking out my USDM Si pistons and dropping them in.... Where should I go with this? How much difference in HP does compression make should I even be worried about this? Plus with my valvetrain I should be able to rev up to 10,000rpm should I run an 11 c/r when going that high?

 

What block, head, cams, ect.
For a good all motor, you should be looking at least 11.4 or higher, just my .02
More compression = More power

 

Good luck reving to 10k with OEM parts. You should look into getting some forged internals if you plan on reving that high. Lots of headwork will be needed too. You will also want a cam that can make power that high because it's pointless to rev your car to 10k if the power drops off way earlier.

I also agree with what the guy before me said, go with more compression. Talk with your tuner to see how high to go, if he is comfortable tuning really high compression on pump gas while keeping it safe, then go for it.

 

Crower stage 2 camshafts and corwer valve springs/retainers.... B16 head B18c1 block Arp hardware.... Will the GSR rods support this power?

 

I sure wish I could get some assistance here....

 

i wouldn't rev to 10k on gsr rods sure it will do it but they wont hold up. besides with the cams you have they probably wont make power past 8500.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2-logicl &raquo;</TD></TR><TR><TD CLASS="quote">I sure wish I could get some assistance here....</TD></TR></TABLE>


I think you'd get more assistance from everyone if you had a better defined goal for your car. Talking about reving to 10k is one thing, but what is the car's intended usage? Once you figure that out and come up with a power goal, the proper parts combinations and comp ratio can be suggested to you.

 

Sorry I have been shifting back and forth between forums that I thought I had made that clear.... For one thing I don't care what RPM's I go up to I just knew that the Crower cams and valvetrain can hold it..... I plan on retaining streetability but be able to drop the hammer when I need to. I have a set of si's and a set of USDM ITR's but I think I may be able to get a set of CTR's..... Which I want more that either set I own..... What I am trying to find out is an optimal compression that I should be looking at with CTR head GSR block Crower stage 2 cams/valve springs/retainers...

 

What do you plan on using for tuning? I would aim for anywhere between 11:1 - 11.8:1. That would give you a decent compression ratio for the street and still give you lots of room for the average tuner. To an extent, more compression is better but tuning and the fuel you use, becomes ever more important as it increases.

 

I was thinking I may use Uberdata or chrome as my roomate has the chip programmer and I may get a VAFC as well.... I have an FPR and an AEM fule rail also have an SCI-L for increased and better spark... I was wondering what neccessitates the need for ugraded injectors but right now my main point of concern is the pistons? Someone told me to always use OEM stuff and a set of CTR pistons will put me near 11.6 compression...

 

Like I said earlier, talk with your tuner and use the highest compression he is comfortable tuning on pump gas. More compression will get you more power, but like the guy before me said the fuel, tuner, and engine management you use will make a big difference.

If your going with uberdata or crome then you won't need the AFC.

 

I knew I wouldn't NEED it but well what I didn't know is if they can work hand-in-hand... IE making somewhat permanent changes with the uberdata chrome and then instant changes with the VAFC while I am out driving around but that is the least of my concerns... What is the highest compression you have heard of with CTR pistons in a b18 w/ stock head gasket...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2-logicl &raquo;</TD></TR><TR><TD CLASS="quote">I am doing an all motor build and used cspeedracings compression guide and found that with my USDM (DAMNIT!) ITR pistons I get a wopping 10.6 c/r with a 3 layer OEM gasket. I also calculated it with a single layer gasket and got 11.1 I am wondering should I go with the 11.1 or the 10.6? I have also thought about breaking out my USDM Si pistons and dropping them in.... Where should I go with this? How much difference in HP does compression make should I even be worried about this? Plus with my valvetrain I should be able to rev up to 10,000rpm should I run an 11 c/r when going that high?
</TD></TR></TABLE>
I believe if you want to go with a OEM bottom end CTR pistons get you somewhere near to 12:1 Compression, and if you want to take it to 10k which i doubt you'll make power that high, but regardless all you'll need is ARP rod bolts which have been proven to been able to make OEM parts rev up to 10k. Then a nice set of cams, like Toda Cs or JUN 3s you could make power at like 9k.

 

The AFC messes with your timing, so I wouldn't use it at all. Just tune your car well the first time and you won't need to make changes to your A/F. That's just one more thing you don't need. I have a turbo car and I don't make changes, so I doubt you will need to with an all motor car.

As far as what compression you will end up with I am not sure. I think there is a sticky at the top of this forum about ITR/CTR pistons though. Maybe try searching at well and I know there are a few compression calculators around.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beerbongskickass &raquo;</TD></TR><TR><TD CLASS="quote">The AFC messes with your timing, so I wouldn't use it at all. Just tune your car well the first time and you won't need to make changes to your A/F. That's just one more thing you don't need. I have a turbo car and I don't make changes, so I doubt you will need to with an all motor car.

As far as what compression you will end up with I am not sure. I think there is a sticky at the top of this forum about ITR/CTR pistons though. Maybe try searching at well and I know there are a few compression calculators around.</TD></TR></TABLE>
Not true, AFC = Air Fuel Controller. It will be close to 12.1 With Oversized OEM pistons you should be close to 12:1 I personally, if it was me i would bore and hone the block so it can accomidate .25 oversized CTR pistons and so you have a clean new hone for your new pistons, cause you never know you might have some scarring when you pull your pistons in your block now.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Soda Popinski &raquo;</TD></TR><TR><TD CLASS="quote">Not true, AFC = Air Fuel Controller.</TD></TR></TABLE>

Not true? It lowers the map voltage to adjust the fuel, so this will affect ignition timing as well. Check this thread out...

https://honda-tech.com/zerothread?id=841443

 

What if I just honed the block and went stock size? Would that lower/raise the compression and how much does that actually do to affect the performance? Would I need to be carefull when my block is bored? How much does boring cost? What about the head gasket then? Would I need to modify that as well?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beerbongskickass &raquo;</TD></TR><TR><TD CLASS="quote">

Not true? It lowers the map voltage to adjust the fuel, so this will affect ignition timing as well. Check this thread out...

https://honda-tech.com/zerothread?id=841443</TD></TR></TABLE>
Interesting.... Never knew that, its sad that with a unit like a VAFC they never incorporated a way of messing timing manually though.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2-logicl &raquo;</TD></TR><TR><TD CLASS="quote">What if I just honed the block and went stock size? Would that lower/raise the compression and how much does that actually do to affect the performance? Would I need to be carefull when my block is bored? How much does boring cost?</TD></TR></TABLE>
Cant give you a random Quote, but talk to your local Machine Shops, and talk to them, source out one that deals with honda bottom ends on average, and shop around for good pricing. Yea you'd be fine, but then again fi you pull the pistons and find some scarring on the walls it be better to hone .25 over and get .25oversized honda pistons, as they make it that way for people that **** up their bottom ends.

 

1st thing you need to do is read this!
https://honda-tech.com/zerothread?id=717928


You cant hone and just put oversized pistons in, it will need to be bored and honed,
if your bore is within spec you can just hone it. It sounds like u need to talk to a eng machinest and a tuner.

 

no I guess I am coming off wrong I meant hone it and put stock pistons in... I know the difference between boring and honing..... I was just asking will boring it make a higher compression or more Hp... Basically other than fixing scarring on the cylinder wall is there a benifit of going oversized? I am not asking so that I could be some ricer and do anything to gain HP I am just weighing my options as I want this **** done right the first time and have a respectable engine set up that will last.....

 

Boring 0.5mm over would make sure the cylinder walls are perfectly round, so I say go for it.

Here's a good article on engine building... http://forums.evans-tuning.com/viewtopic.php?t=326

 

I just gotta get the pistons....

 

What about LS rods and crank I have been hearing that they would be good in this set up any truth to that...., I greatly appreciate you all blessing me with your knowledge...

 

So with a set of CTR pistons OS I should be fine?

 

???