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ekslut
21-02-2005, 05:17 PM
I have just got myself a B16A and coz I dont know how many km's it has done I am looking at rebuilding it now so I can get my engine reliable and I can trust it. When I rebuild it I want to do some mild power upgrades for now, and because of all the effort involved in changing pistons, I want to run some higher compression pistons now, so that in the future when I get some agressive cams (eg. Toda stage 2 or 3), my pistons will work perfectly with them.

So now my question is; On a stock or near stock setup, if I run high compression forged pistons (eg. 12:1) Will my engine cope with this or not? I plan on using a microtech to control it all.

McChook
21-02-2005, 05:51 PM
In short - ther eis such thing as too much compression, but 12:1 isn't a problem

Also - Toda Bs have the same low lobes as Toda Cs - Cs have the biggest VTEC lobe, so don't bother with Bs, its either As or Cs....

Take a few thou off the cylinder head when ya do the pistons, you'll get a bit more compression out of that. Cmopression is basically immediate horsepower.

Depending on how long you take, I'd get a Hondata S100 - for $350, they are the biggest bargain you'll get, and work just as well (if not better) than the mircotechs

The man to speak to BTW is Dyno Dave, and he lurks the forums, I am sure he'll see the thread shortly

ProECU
21-02-2005, 07:09 PM
you need to decide on cam selection prior to deciding on pistons & compression setups.

In a B16A, the swept volume is low, so to raise compression you need (this is a must) a large piston dome and low cylinder head cc volume.
As an example, 7.5cc piston dome & 41.7cc chamber with zero deck heaght clearance will net you 12.5-1 static CRatio.

Cam selection will govern valve relief depths and hence effect compression. Personally I disagree with McChook on the Cam issue. I'd stay away from C cams for that simple reason.

On the compression for a b16, the larger the dome needed to raise compression, the worse the flame propogation to the exhause valves. This also increases chances of pre-ignition. So you'll see, larger cams = larger dome for higher compression = not always a good thing.

Choose wisely, research properly before hand. Biggger isnt always better & JDM isnt always better.

Good luck

BLKCRX
21-02-2005, 07:23 PM
McChook hit it on the money... high comp 12.5 or 13:1 with a set of toda C's and it will be as good as you can get... piston design comes into the play also with regards to valve area and different manufactures have different valve seat area's... which is why some pistons are better than others…but you can also cheat and change the shape of your valves ;)



Iv tuned many toda a's b's and c's on b16 b18 and b20's and the c's love compression. Remember boost on an engine is like increasing the compression ;)

boost = power

compression = power


Its all about how its harnessed, designed and tuned.

PS remember how the engine built, tolerances and clearances and ring gap, along with many other factors can also make all the difference between a good and dud engine.


Regards James

tinkerbell
21-02-2005, 07:27 PM
if going B16A try to use a bigger bore (84mm) to improve the flame front problems of such small combustion chambers...

yeah, i agree with ProECU - B16A is not a good candidate for high compression work, B18C is good, but B20VTEC is better, if you are going to go to the trouble of building the bottom end, start with the biggest displacement you can ;)

BTW - "reliable" and "high compression" usually dont go hand in hand with "I have just got myself a B16A"

ProECU
21-02-2005, 07:49 PM
boost = power
compression = power
Regards James


James, its not boost that makes power dude.

Why do u think turbos make less gains as psi increases? Think about that one and post back.

In any event, I wouldnt go much past 13-1 CR on our street fuel for daily use.

BLKCRX
21-02-2005, 08:00 PM
Boost does make power ;) its compressed air, but like everything there are rules regulations, limitations and efficiency. But this isn’t a boosted questioned.



Back to NA

13:1 (Ish!!!!!!! ) is great fun on the street for a built NA car, but good fuel and a careful driver who doesn’t go around trashing his car on the street is a must also.



Regards James

ekslut
21-02-2005, 08:29 PM
hmmm...many things to think about. By the way I forgot to mention, this car is mainly going to be used on track (sprints and the such). It will not be a street car and about all the street use it will see is the trip to PI, Winton, or Sandown.

But from the sounds of things running some higher comp pistons with near standard internals should be fine, if I choose to do that. But when I do upgrade Toda C's are the cams to use?

I would like to stay 1600cc's so when I go to track I can stay in the under 1600cc class, so increasing to 1800 or B20VTEC is out of the question.

Im mainly at the moment trying to get the engine in good condition so I can trust it and it be reliable. But I dont like doing things twice. So thats why I want to try and get the bottom end sorted now while I am rebuilding it, and when I have a bit more cash in about 6 - 12 months, then get the good cams/cam gear/valve springs/retainers.

I am just trying to work out which pistons I should use. Like what compression, size, and brand. Just trying to learn as much as possible so I can make the best decision that I can.

PhatSol
21-02-2005, 11:14 PM
...and a careful driver who doesn’t go around trashing his car on the street is a must also.

Just curious, what is the diffrence between hard street use and hard track use? I thought the track work would be tougher on the car than any street driving?

pgclee
22-02-2005, 02:59 AM
street use - Do not always trash your car

Track use - Always Hit's the rev limits...

haha...!

13.1:1 compression is too high to any street car...High compression doesn't mean that your car will be freakin fast as well...The Figure is impressive, but it's all up to the Final tuning...i use to have 13.1:1 compression and droped to 12.5:1 compression...at least it sound MORE LIKE a normal car....muahahaha...

tinkerbell
22-02-2005, 09:19 AM
But from the sounds of things running some higher comp pistons with near standard internals should be fine, if I choose to do that. But when I do upgrade Toda C's are the cams to use?


i am sorry, i dont understand what this means?!?

if you change the pistons you are changing the internals.

the pistons ARE part of the internals.

BLKCRX
22-02-2005, 09:26 AM
If you wanta stay 1600cc, stick with the 81mm bore or 81.5 ( after u hone the block for new pistons )
Chuck in a set of eagle rods.... not the worlds greatest rod's but they will hold 9500rpm and rev all day if installed correctly...and there better than stock. Use correct sized bearings and a good machine shop who builds Honda engines and you should be sweet.

See if the rules and regulations tell you which fuel you can use.. I know all the GTP car's that I tune that race on TV in the Pro Car series last year all had to use BP ultimate fuel.... but also in the GTP your not allowed 2 hardly modify anything...apart from ECU/Intake/Exhaust but if your allowed 2 use lets say ELF-LMS or Sunoco supreme fuel then look for 13.5+ comp ratio.

Springs and Retainers = Toda
Cam Gears = Toda
Cams = Toda

Talk to Adrian from Advan in Sydney/Silverwater for all your Toda equipment, he might be a little more expensive than importing your self, but you get local support and help support the local Australia industry !!

Should be a nice fast rev’ing engine, might also pay to play with fhy wheel combo’s and harmonic balancer to help the engine rev, along with a nice intake setup / exhaust setup.

Long live the b16 engine ;) I love my 400kw+ b16 engine ;)


Regards James

tinkerbell
22-02-2005, 09:27 AM
Just curious, what is the diffrence between hard street use and hard track use? I thought the track work would be tougher on the car than any street driving?

teh difference wetween what Jmaes is talkinga bout (street thrashing) and track is one wortd:

control

on the circut, you are constrained by the length of straight between you and the next corner, and you know exactly where your braking point is (or you SHOULD) and you will accellerate to that point then brake.

the car is not being randomly revved to suit the whims of the 'thrasher'

imo - that can be much harder on a highly tuned engine than controled circut work where the engien gets to a temperature and stays there untill it is time to come off...

blah blah blah.

---

anyways - EK slut- if it truely is going to be a circut car, you need to learn how to drive the car before wasting money on your engine.

you need R compound tyres and hard suspension first.

a racing seat and 5pt harness next...

some swaybars and chassis stiffening...

THEN if you have reached your limits and are going as fast as the engine will go, THEN you start wasting money on the engine....

ekslut
22-02-2005, 09:49 AM
Tinkerbell: I have already been on track before and have practised my skills. I have done many driving courses too. I already know about suspension and tyres and have them all sorted. My previous EK4 was all susension, chassis work, tyres, and gearbox, no engine mods at all. Thats why I am asking about engine mods, becasue I have never bothered modifying my engine before. But it was becoming too hard to drive a track car in peak hour traffic. Hence why I am building one for track only and have another car for everyday use.

By the way by stock internals I meant stock cams/cam gear/vavle springs/retainers

BLKCRX: Thanks for the info. You have been very helpful throughout this discussion. So you think rods should be upgraded?

tinkerbell
22-02-2005, 09:51 AM
no - high compression pistons will not work with 'stock internals'.

an engine is a system, not just a sum of its parts.

what are your best times on the tracks?

ekslut
22-02-2005, 10:33 AM
Thats why I am asking. I have no idea at all about the engine. And I know its not just a sum of parts, especially hondas need to be put together well and have the right parts choosen for them, or else it wont work. Thats why I am here asking for advice on what I should do, trying to learn.

And I am not saying I am a great driver. I still have much to learn, and am only new to it all. But I am trying to learn all I can, hence why I am doing driver training courses. My best time at PI is 2:03 with a stock engined EK4 with HKS coilovers, some chassis bars and worn yokohama semi-slicks.

tinkerbell
22-02-2005, 10:50 AM
2.03 @ PI is excellent!

OK, here is my suggestion:

get JDM CTR parts, pistons (81.25mm), cams, springs, retainers and intake

get the block stripped, check for damage, have the bores honed to suit the pistons, get the crank checked, get new bearings, have the bottom end assembled and the reciprocating assembly balanced.

put the head together with a little tidy up and take 20 to 40 thou of the head surface, make sure you get the piston to valve clerance checked BEFORE you do this AND make sure it is done with the VTEC mechanisms engaged.

this should leave you with a blueprinted engine (ie to factory specs) - with about 11:1 CR (depending on the head shave)

then add a light weight (~4kg) flywheel, with heavey duty single plate organic clutch, a good set of 4-1 headers and 2.5in cat and exhaust.

leave your ecu stock, get a *known* good chip'd ECU and maybe use a VAFC if you are not happy with how the engine performs on the dyno

or use Hondata (definitly use Hondata over Microtec!)

THEN if you can out-drive this engine, then it is time for spendign the big bucks

a good high compression 'system' = about $8000-$12000

compared to about $4000 for the above...

BTW - is is simply ONE suggestion, it is certainly not the ONLY solution, but i think it is quite appropriate for what you want to achive (ie you wnat the car on the track more than it is at the workshop or tuners ;))

ekslut
22-02-2005, 10:53 AM
And Tinkerbell, if you read the posts I'm not doing this so I can have heaps of power. Its that I dont trust my engine. I dont know its history. Thats why I want to mildly rebuild it now and later when I do have experience I will go with the bigger mods. But I dont have the money to go around buying sets of pistons all the time. Hence why I want to get some good pistons now, and run it with a set of CTR cams/cam gear/valve springs/retainers I have at home. And later when I have some more money/experience all I need to do is get some Toda stuff for the cams/cam gear/valve springs/retainers and from what BLKCRX said some eagle rods, which is much cheaper to install than opening the bottom end again to do pistons again.

Hence this is why I am asking can I run some higher comp pistons with near standard internals (obviously not standard pistons). And what I should look out for when choosing a set of pistons (comp ratio, size, etc..)

ekslut
22-02-2005, 10:56 AM
your other post poped up when I was typing out my other one. Thank you for the reply and advice Tinkerbell. That was exactly the type of advice I was after.


But 1 question, is it worth getting CTR pistons, when for not much more you can get some american or whatever forged one?

tinkerbell
22-02-2005, 11:06 AM
And Tinkerbell, if you read the posts I'm not doing this so I can have heaps of power. Its that I dont trust my engine. I dont know its history. Thats why I want to mildly rebuild it now and later when I do have experience I will go with the bigger mods. But I dont have the money to go around buying sets of pistons all the time. Hence why I want to get some good pistons now, and run it with a set of CTR cams/cam gear/valve springs/retainers I have at home. And later when I have some more money/experience all I need to do is get some Toda stuff for the cams/cam gear/valve springs/retainers and from what BLKCRX said some eagle rods, which is much cheaper to install than opening the bottom end again to do pistons again.

Hence this is why I am asking can I run some higher comp pistons with near standard internals (obviously not standard pistons). And what I should look out for when choosing a set of pistons (comp ratio, size, etc..)

LOL! i kinda realised this :thumbsup:

see my post above for suggesstions :)

problem is that one size can never fit all, getting 12.5;1's now to match Toda B's later on is going to create a lot of compromise for you...

it will be your choice to accept this.

BTW - you have to open the bottom end up to install rods, so these *should* be installed at the same tiem as the pistons...

so you have to make the decision NOW.

"do i build it full-on now or do i build it reliable now..."

my opinion is that you shoudl match all the components as best as possible to get teh reliable and acceptable result.

hence the 'stock' CTR route, as this matches the cam duration and lift to the high 10 CR of the pistons.

but i think you need to do some more reading, so i will suggest a site that i hardly ever do on ozhonda which is http://www.team-integra.net/sections/articles/listArticles.asp?Show=1

you need to register, but there is lots of theory on there as well as practical testing and evaluations of engines as 'systems'

very good site if you are willing to read lots ;)

ekslut
22-02-2005, 11:12 AM
Thank you very much Tinkerbell. Forgot about the rods, and that they belong to the bottom end. I realise that for the moment it will be a compromise, and not the ideal setup, but as long as it only has a effect on power (ie. I dont get as much as I could) and doesn't stuff up anything in the engine, then I am willing to make that compromise.

But it seems like I have a lot of reading and thinking to do before I make any decitions though.

McChook
23-02-2005, 07:27 AM
I should also add

You might like to look at a set of closer set of gear ratios. For this, I recomend ATS (Active Traction Servoces).. Should not only increase accelleration, but keep it on the power band

ekslut
23-02-2005, 07:36 AM
yeah, dont worry about gearbox and suspension. I already know about them and have them sorted. I have played around with them before on my previous car, so have learnt a bit about them. Its only really the engine, that I dont know much about. Thanks anyways though :D

McChook
23-02-2005, 07:37 AM
yeah, dont worry about gearbox and suspension. I already know about them and have them sorted. I have played around with them before on my previous car, so have learnt a bit about them. Its only really the engine, that I dont know much about. Thanks anyways though :D
Satisfy my curiosity then - whatchya do about the box then??

ekslut
23-02-2005, 07:52 AM
So far I have a CTR gearbox with Exedy 3 puck clutch, ACT flywheel, and KAAZ LSD. Also have a hasport shift linkage, with spoon shift linkage bushings. Im on the market from some Spoon gears too (too damn expencive though). I used to have KAAZ 3-5th gear in the EK4, but they were too close together for track.

z3lda
23-02-2005, 01:42 PM
where abouts are u gettin ur b16 reco. in melb? looking to rebuild mine too

ekslut
23-02-2005, 02:00 PM
I get my mechanic to do it all. Besides myself, he is the only one to have worked on my EK4. He did my last gearbox perfect, and I am very happy with him. Not bad priced too.

Lay Automotive
5 Kempson Crt
Keysborough

Ph: 9701 8082

z3lda
23-02-2005, 02:08 PM
hrms

how much would he charge for a normal rebuild ?

tinkerbell
23-02-2005, 09:26 PM
Im on the market from some Spoon gears too (too damn expencive though).

SP0017 is selling a used 'non-Type R' set for 1700 :thumbsup:

ekslut
24-02-2005, 08:04 AM
I can't remember how much for a rebuild. I have always supplied all the parts so I have just been charged for labour and gets the little bits I have forgotten.

Tink, yeah, I know about them. I was talking to him the other day about it. But they dont fit my gearbox. They are for a B16, mine is a CTR. But its a excellent price though. I have been looking and they are over $3000 new

pgclee
25-02-2005, 12:06 AM
Sort out a thing at a time then u will see the big picture mate...

but just to remind you, if you wanna TOUCH the Block, i advice you to resleves + piston and rods togather in it...plus Re-design your Crank...save hips of money and time...

tinkerbell
25-02-2005, 10:02 AM
Sort out a thing at a time then u will see the big picture mate...

but just to remind you, if you wanna TOUCH the Block, i advice you to resleves + piston and rods togather in it...plus Re-design your Crank...save hips of money and time...

such invaluable advice :wave:

ekslut
25-02-2005, 10:47 AM
yeah, I know. Its too hard to do it in 2 stages. I think Ill just do it all at once and be done with it. Just means I will wait longer and save up some more money and do it right the first time.

hondar
26-02-2005, 02:58 AM
I have just got myself a B16A and coz I dont know how many km's it has done I am looking at rebuilding it now so I can get my engine reliable and I can trust it. When I rebuild it I want to do some mild power upgrades for now, and because of all the effort involved in changing pistons, I want to run some higher compression pistons now, so that in the future when I get some agressive cams (eg. Toda stage 2 or 3), my pistons will work perfectly with them.

So now my question is; On a stock or near stock setup, if I run high compression forged pistons (eg. 12:1) Will my engine cope with this or not? I plan on using a microtech to control it all.

mate,

a few things to consider.

1. get the right compression to fit the specific cams, not the other way round.
2. the highest compression is not always better. there is a way to calculate compression in 2 forms (both static and dynamic) to determine what sort compression is needed for your cams choice.
3. dont forget the fuel factor as well. 12:1 is very high, can our fuel handle that sort of compression and you got to tune it as well which cost money as well.
4. if i were you, i will plan what sort of set-up (or goal in mind) i have for my car and work from there.

my 2 cents :D

Non Vtec
26-02-2005, 08:13 PM
just out of curiousity why wouldnt you go to a B18C? as far as circuit racing goes unless there is a huge weigh advantage from staying as a 1600cc you'll never look back. I've seen almost Stock B18C's run better times around tracks than Built B16A and B16B's its more about the torque.
You'd get more than enough selling the CTR set-up to buy a stock block with CTR pistons makes 11.8:1 CR. port the head with a Stage 2 crane cam and you'll see 150-170wkw on pump gas. through in some Flat bottom 1mm oversized vavles and you'll see 175wkw and its still a good daily driver to..

pgclee
27-02-2005, 01:07 AM
I thought to B18c should have more torque than a B16???

I'm lost now...aren't B16's suppose to have more pull (higher Rev's) than B18c????

I wish that a simple CTR piston + stage 2 cams with oversized Valves can make it to 175wkw man...cause i've never seen one yet...it is impressive if you can tell us how you do that...mind sharing?...hips of Honda lovers would like to know...including me..

May be the reason he don't wanna get the B18's it's because he dowan to jump towards another class on race track?...am i rite Eksluts...hehehe...

ekslut
27-02-2005, 09:11 AM
Yes pgclee, you are right. As I have mentioned I want to stay in the 1600cc and under class. The next class up is under 2000cc, so if I was going to go up, I would build a B20VTEC, not get a B18.

I have decided now to spend a lot more time researching and get pistons later when I do everything else. That way I do it right the first time, and there is less stuffing around.

But in theory, to answer my original question, because I can't see anywhere if it has actually been answered. Although it may not be the best way of doing it, can you use some oversized forged 12.5:1+ pistons in a stock engine. Will it have any harmful effects to the engine?

TODA AU
27-02-2005, 09:14 AM
I can't remember how much for a rebuild. I have always supplied all the parts so I have just been charged for labour and gets the little bits I have forgotten.

Tink, yeah, I know about them. I was talking to him the other day about it. But they dont fit my gearbox. They are for a B16, mine is a CTR. But its a excellent price though. I have been looking and they are over $3000 new

I have TODA 1st & 2nd cross gear kit in stock for your CTR box.
2.929 1st gear / 2.056 2nd gear.
No need to change the other gears as 3rd, 4th & 5th are already ideal.
Pm or email me if you're interested.

TODA AU
27-02-2005, 09:25 AM
....my question is; On a stock or near stock setup, if I run high compression forged pistons (eg. 12:1) Will my engine cope with this or not? I plan on using a microtech to control it all.

With good tuning... No problem.
You'll return more power & torque with improve fuel ecconomy.
The high compression would be harmful without programable ecu.
Also, you'd be stuck with the fuel you tuned it on...

For what it's worth, use the best pistons you can afford, as you get what you pay for.
Further, do not let some moron put it together who thinks he knows better than the piston manufacturer when it comes to clearences.
You'll have to either modify your std rods by bushing the small ends. (Approx $200 to mod the set)
Or use aftermarket con rods.

pgclee
27-02-2005, 03:26 PM
But one thing TODA AU, Some people in my Country said that Using a STD Conrods (CTR or ITR) + bits of modification to it, it can stand up to 10,500RPM withoout any worries...is that true? What caused the Con's to Snap anyway?

SP0017
28-02-2005, 03:03 AM
trev, IF you are concentrating on PI then don't bother with 1 and 2 gears. you only use 2nd gear twice at PI at Honda and then after lukey heights. 3rd and 4th are more impt. Only at winton will you be using the lower gears. If you were not getting a whole set that is... i would get the 3rd and 4th and probably 5th

TODA AU
28-02-2005, 05:00 AM
But one thing TODA AU, Some people in my Country said that Using a STD Conrods (CTR or ITR) + bits of modification to it, it can stand up to 10,500RPM withoout any worries...is that true? What caused the Con's to Snap anyway?

I mentioned bushing the small end in my previous post.
This is the modification they are talking about.
Sustained 10,500rpm with std rods is fool hardy at best.
Personally, we never go past 9400rpm with modified std rods.
Shot penning & arp rods bolts can extend this a little further.
The cost of changing the bolts & peening mkes it prohibative,
These days, with the cost of aftermarket rods being what it is,
why wouldn't you include a set? (Example: Eagle rods)

Connecting rods snap for a variety of reasons.
Rod bolts stretch through excessive rpm, causing bearings to spin.
Oil surge causes the bearings to fail.
Detonation can cause rods to bend / break.
Snaping rods is generally a piston failure or that of the guy building the engine.
Snapped con rods are to be expected when your engine builder uses 2nd hand circlips to retain the gudgeon pin.
Other reasons for snaping rods are stress raiser from poor balancing.
(Surface finish not restored through peening),
damage through miss handleing before inclusion in the engine.

pgclee
03-03-2005, 01:00 PM
Thanx TodaAU....
But from what you've said, i think people in my country are either Good or bloody crazy in Modifying Vtec...hahaha...

tinkerbell
03-03-2005, 01:02 PM
your country = ?

SP0017
03-03-2005, 08:04 PM
anyways this was a pretty good thread.

but like was said trev, better to think abt exactly what you want next time and then start from the bottom in your build. Don't think there is any harm in getting the best (you can afford) in terms of pistons and rods now. pay a little more for parts now, save on labour (repeated) later. when we meet again i'll tell you my story.

Tink/Adrian,

would using say itr cams with high comp pistons cause dynamic compression to be too high? whats the ill effects of this? i have been told that with high comp i should use high lift cams becos the comp that really matters is dynamic and not static. Needless to say, i know nuts abt this

SP0017
03-03-2005, 08:11 PM
best if you can explain it in layman's terms hehe

TODA AU
03-03-2005, 09:25 PM
High comprssion is basiclly good in any case, so long as you have a programable ecu.
The trapping efficiency of the shorter cams at low rpm can cause timing issues but it's no real drama. The high comp allows the engine to "hang on" in the top end rather than roll over sooner.
Speaking generally, increasing the compression is a plus. Whatever the cam.
The gains are just more dramatic with bigger cams.

tinkerbell
03-03-2005, 10:23 PM
shaun - i think you (or whoever told you this) are perceiving the "bottling up" that would occur with short duration cams in a high static compression situation.

this *may* increase chances of detonation (due to higher cylinder pressures & therefore heat), but only if you are unable to tune for it,

and this 'bottling up' can also be minimised (or used to your advantage!) by the implementation of and dyno tuning for adjustable cam gears.

so i guess as adrian has said, increased compression will always be a benefit if you can control combustion :)

so ATEOTD - even though i advocate a more "system" based approach to engine building, it is probably more expensive in the long run (ie doing things twice), and a more compromised method of doing it once and adding to later may be just as suitable for ekslut :D

pgclee
05-03-2005, 02:23 AM
so assuming from all Pro's here, 12.5:1 compression on road, is a pretty normal thing...am i rite...

Hmmm...i wonder...hmmm...

TODA AU
06-03-2005, 05:46 AM
12.5 isn't common place, but it's certainly no problem so long as the combination is correct.
In that I mean it's tuned to run at this compression rather than with a std ECU.