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View Full Version : Is 14:1 CR too high for 98RON



pornstar
23-05-2004, 06:54 PM
need advice, ive run 13 to 1 pon 98 before and thast been ok, has anyone done 14 to 1? Wanna lift it to the maximum possible!

DynoDave
23-05-2004, 07:18 PM
Yes I was using that much comp in our Hyundia super tourer when we where racing it, it took us a very long time on the dyno tuning it and we wasted 3 race meetings with blown head gaskets but once ACL made us some special head gaskets the engine was perfect and we raced it like that for 14 meetings and it is still sweet as.The only fuel that I found to handle that much comp was Mobil's 8000 Premium with all the others you could not use enough ignition advance to make power.
Regards Dyno Dave

pornstar
23-05-2004, 07:25 PM
DynoDave, what sort of porting flow did the head have? the head that we want to use is flowing a little too much, and we are thinking of using restrictor plates to increase lower rpm torque.

The cams are going to make poewr to 13k rpms, so they claim. We need a high enough CR to maintain power, or else the falling VE from the high rpm will see us platue or lose power. Thats why we want high as possible. Any higher than 14:1 possible?

This is on a b18c type R motor, NA.

mugsee
23-05-2004, 08:50 PM
omg... b18c revving to 13k? what type of cams? titanium spec z?

wanna run? ;)

McChook
23-05-2004, 09:02 PM
omg... b18c revving to 13k? what type of cams? titanium spec z?
;)

Screw the cams, what about the valves and valve springs???
With the inertia loading at 13,000rpm, the valve collets will be the next Mars explorer...

DynoDave
23-05-2004, 09:27 PM
That is too many Revs for me 10,000-10,500rpm are the most I have ever had to use in a Honda engine or would like to.
Regards Dyno Dave

pornstar
23-05-2004, 09:58 PM
Thanks captian obvious aka McChook. Ill just go and do everything else except valves and valve springs. :P

Dynodave, its what the manufacturer claims but if i gave u the specs, Id find them hard to believe that even at 13k the power doesnt fall off. At this stage the flow bench is being used to port the head, and custom extractors are being match ported to fit too.

Mugsee: Everything has been taken apart for this rebuilt motor, but we are struggling with piston specs. We are thinking 14:1 right now, but we mgiht even try pushing 15:1 in connjunction with running octane booster to the 98. up to the owner if he does this or not.

Its being bored out to 2 litres (a little bit under), the quad throttles are being abit of a pain, but restrictor plates are being used, not sure how thats going to work, im not the builder so i dont know. As for what it will actually rev, its more likely to rev only to 12k rpms if u take into account all other factors in the head.

peace.

VTEC16
23-05-2004, 10:01 PM
That sounds like one beast of an engine! make sure you tell us how it turns out!

McChook
23-05-2004, 10:04 PM
Thanks captian obvious aka McChook. Ill just go and do everything else except valves and valve springs. :P


I think you took that the wrong way
I wanna know what you're using in the head - We're with DynoDave, we keep it under 10,000rpm (200fwhp BTW).

I wanna know what you got in there - springs and valves, what the hell you gonna use - because I don't know of any that will take that sort of punishment

pornstar
23-05-2004, 10:28 PM
OK sorry if i sounded like Im giving it to ya, i was just kidding hence the " :P " sign.

For a normal street car 10k rpms would really be good enough, but this motor is being built to take on PI and other circuits where the straights have been troubling past engines. previously, the long straight on PI had been creating problems for the owners previous motor and box because he would have to change to 5th gear just near the end of the straight, hence drop rpms, but jsut before he enters the first turn, this is not opitmum. Therefore to rectify the problem, the car owner wants the revs to go to 13k rpms, and hence keep him in the top of 4th without having to do 2 gear changes, this is one of the main reasons why he wants to be able to rev to 13k rpms.

He might not actually make power up past 11.5k rpms, but at worse he will keep the power platued there and thus not lose any power, and only maintain rpms so he doesnt have to change.

As for what is being used. Its actually all being custom built right here in exotic melbourne, dont ask me anymore on who it is as i cant name him right now. The valves and springs are titanium items, and they are being custom made for this setup, but depending on how a group buy response goes, it may be made to a limited number ie 20 sets.

Ill pass on the interest to the owner of the car, and leave it to him to answer any more info he he pleases. Otherwise if there are more general things that i cna answer go ahead and ask, ill do my best to answer. For those more mechanically inclined, the builder has hinted at the need to remove rocker arm designs, and go to bucket and shims. its not definate, at this stage this is all being worked out, but there are some aprts already being used as testing trials on the car. And for those who hve even more mechanical knowledge, then u will also realise which the car has to run a bonnt scoop/vent.

McChook
23-05-2004, 11:37 PM
Again, without giving it to you - wouldn't a close ratio gearbox or a change in the final drive be a safer, easier and cheaper solution. 13K revs will destory the engine in no time, and the valves and springs, being titanium, will have to be replaced often. Rebuilds will be frequent and expensive. Unless your running a BTCC Super Tourer, this sort of extreme work is unjustified IMO

We run our engines at PI, and sure, we lack the HP numbers in a straight line, but not much else in the class can keep up with the same displacement...

I guess it is a race car, so what class is the car running in??

DynoDave
24-05-2004, 12:03 AM
What lap times was this car doing around PI as we have raced down there and I would be keen to find out what times this car has done.
Regards Dyno Dave

VTEC16
24-05-2004, 01:45 AM
wouldn't a close ratio gearbox or a change in the final drive be a safer, easier and cheaper solution

OMG YES!

Thats the first thing i thought of......sounds like your going into too much trouble for nothing.

pornstar
24-05-2004, 07:12 AM
Ill ask the owner of previous best times. Its a street car, its not a race car and its not a tourer or even GT production etc etc.

Yes the box was one thing that we thought of, but by changing the gearing and such, it compromises other parts of the car like dropping in and out of high rpm and VTEC etc. Belive me, all other avenues have been explored, well the builder thinks so, hence going to this trouble.

If you guys hae so much knowledge, as dynodave has offered, perhaps you can pm me or even reply here what else u might do.

pornstar
24-05-2004, 07:13 AM
Ill ask the owner of previous best times. Its a street car, its not a race car and its not a tourer or even GT production etc etc.

Yes the box was one thing that we thought of, but by changing the gearing and such, it compromises other parts of the car like dropping in and out of high rpm and VTEC etc. Belive me, all other avenues have been explored, well the builder thinks so, hence going to this trouble.

If you guys hae so much knowledge, as dynodave has offered, perhaps you can pm me or even reply here what else u might do.

TODA AU
24-05-2004, 10:21 AM
13k - 2.0L B18C :D
Cool...
Turn it up... Bring the noise... :D :P

VTEC16
24-05-2004, 10:25 AM
Yes the box was one thing that we thought of, but by changing the gearing and such, it compromises other parts of the car like dropping in and out of high rpm and VTEC etc.

Make the gear ratios shorter - that way he will accelerate faster and wont have the problem of changing to 5th as he gets to the corner....he will do it earlier.

No problems with droppig out of VTEC either!

pornstar
24-05-2004, 10:34 AM
and then what? have 8 gears so he can hit a top speed of 220kmph? u do realise that dropping gear ratios is good, thats fine and dandy, but then u sacrifice top speed and other things.

VTEC16
24-05-2004, 01:47 PM
5th gear is usually a a cruising gear anyway- it doesnt match the rest for acceleration.

I think the solution requires a compromise between gear ratios and increased engine speeds.....you dont need to go to extremes with either.

pornstar
24-05-2004, 03:00 PM
well ill mkae sure i get u to setup the next car for a circuit race. Cos if i dont need to be going to extremes then this guy with 20 years of GT experience and all of their racing experience and knowledge means nothing, if u can do it wihtout making this guy do what they hvae made him done.

Is there a contact number we can contact you on so we can get this sort of work done?

mugsee
24-05-2004, 03:24 PM
Hey Andy,

If the guy doesn't mind, pm me details on when you guys plan to dyno/tune this monster. I'd absolutely love to see this beast in action! It sounds craz-zeee!

pornstar
24-05-2004, 03:29 PM
lozl yep, well he wont mind, but i dunno if the dyno tuner will allow it, cos he is doing a sponsor deal with it. but eh, cant hurt to ask. if its ok, ill get the ozhoinda boyz down there for a day haha

VTEC16
24-05-2004, 03:31 PM
no need to get narky man - im just suggesting things. Why dont you tell me why im wrong....im here to learn.

mugsee
24-05-2004, 03:32 PM
sweet... :D i'll bring my tissues for when the ears start to bleed ;)

ts0nda
24-05-2004, 04:58 PM
if its ok, ill get the ozhoinda boyz down there for a day haha

now now we dont want to embarras them do we lol :P

ts0nda
24-05-2004, 05:00 PM
oh is this thing gonna be at phillip island weekend that is posted in the events section? cause i would love to see somethiig like this in action

McChook
24-05-2004, 06:27 PM
In all honesty, you have access to a lot of resources on this forum - Visitors here include 2 of the better Honda engine builders and race car engineers.

IF you wanna get right into it, send the details (with lap times, car (civic/teg etc), to me and I shall forward them - Any "expert" who is answering the question with 13,000rpm is a few fries short of a happy meal.

mugsee
24-05-2004, 07:00 PM
tinkerbell might be able to offer some insight into this. if your after info, he's always got something to say ;)

wynode
24-05-2004, 08:26 PM
Whatever happens post back here cause we are all happy to learn.

Gluck!

pornstar
24-05-2004, 10:18 PM
yep Dynodave has answered many questions so far, and his help has been inmeasureable.

Im not getting narky, but this post is quite a serious post, but ppl are talking like these guys are idiots that would not do the first simple things that would not cost above 20k.

Ill clarify that, Im not taking it personal from anyone, and tho i sumtimes seem it, im not going personal on anyone either, except u can understand my frustration when i get 10 pm's about absolutely crap that doesnt even reflect on the problem.

McChook, theres pros and cons to every setup, im sure u would know that as u seem to be quite a smart guy. At the same time then, u should also realise that there is no 1 best solution for every problem. Hvaing 13k of maximum rpms is going to allow the driver to change the driving condition to suit each track to a certain degree. As for forwarding u info and stuff, if u read the post carefully, alot of this has to be done in PRIVATE and confidential, thus i cannot just forward info like that. If these so called "expert" visitors could help, why dont they just post here or PM me like Dynodave has done? theres an answer for that that i hope i dont have to say, ur smart enough work it out.

Now the owner of the car does not mind if we are there for the dyno, BUT the dyno operator has not given an ok as we have not put a question to him.

And again, thanks for all the PMS from ppl who actually looked at the question for what i asked, and didnt friggin pick on the nitty gritty of the setup.

Tsonda, no way it will be ready in time, the head that is being ported on the flow bench took more than 4 weeks to do because of the ever changing stroke length, and rotational mass on the head. Currently looking at removing the head rocker design and going toa 1to1 shim and bucket. Any inputs?

After all that I have said, yes its good to be reminded of the simple things cos sometimes they can be overlooked, but when its done in a manner that seems to be ridiculing a setup, u can understand the frustration one would feel.

PEace all.

VTEC16
24-05-2004, 10:34 PM
thanks for that and good luck!

crx_16x
24-05-2004, 10:55 PM
Pornstar,

To get 2000 cc have you kept the stroke of the engine standard and resleeved the engine to run an 85mm bore?

Or are you using a different stroke and a slightly more conservative bore?

Am very interested in how this turns out.

Good Luck.

James.

McChook
24-05-2004, 11:05 PM
McChook, theres pros and cons to every setup, im sure u would know that as u seem to be quite a smart guy. At the same time then, u should also realise that there is no 1 best solution for every problem. Hvaing 13k of maximum rpms is going to allow the driver to change the driving condition to suit each track to a certain degree. As for forwarding u info and stuff, if u read the post carefully, alot of this has to be done in PRIVATE and confidential, thus i cannot just forward info like that. If these so called "expert" visitors could help, why dont they just post here or PM me like Dynodave has done? theres an answer for that that i hope i dont have to say, ur smart enough work it out.

To be honest - The best people don't post here as they get bombarded with emails from people who can;t do their own research, or have no clue whatsoever. The amount of rediculous and just plain dumb questions myself and my father recieve on SkylinesAustralia is obscene, and takes a lot of time to answer too - and there is the answer to your question.

Work it out - experts charge a lot of money for their time.
The time they spent replying to messages and emails is free to the quaestion asker, but costs the writer time. That time is valuable money which will never be recovered. A lot of the time, the same question is asked over and over, as is so frequent on this forum in particular. Thats why, when a rather different post like this comes up, it sparks a little bit of extra attention, and I assure you, a lot of interesting peope have looked at this thread with interest.

In the end, leaving this one to DynoDave was easy - he answered first, no need to jump in on his answer. Dave knows his shit, there's no need for myself or anyone else to take it further in PMs.

The secrets to building an engine aren't always secrets.

And also, in reply to the question - I'd be running one of the ELF mixtures (not LMS or TurboMAX). May as well, since the budget is high, use the best petrol you can and make more horsepower

ts0nda
24-05-2004, 11:25 PM
pornstar: hehe nah i honestly wouldnt have a clue about the real technical side of engines, hence i havent really questioned any of your comments i just read and try to learn. im positive you know what your doing, respect! ;)

pornstar
25-05-2004, 12:51 AM
thats the nail right there McChook. Your only problem is that my post isnt a statement of "golly look at this mad setup", its a question looking for an answer. I dont really care whos interested and whos not etc. I just wanna find answers to the qn asked.

As for skylines australia, dont even bring them into this forum, those guys are macho 2000 kw machines running 60psi boost stock. Their ignorance is a whole new meaning to the word.

Anyway, I guess by ur statement, u dont think power can be made past 10k?

crx_16x, ur right, by shortening the stroke it does loewr the CC capacity, but on NA setups, the sleeves can be overbored that far that it almost goes to 2 litres. Again, we have not measured it, nor do we know how much the stroke has changed by, its still being tested and being worked out. And u will note that i specifically said, its CLOSE to 2 litres, but didnt say that it was 2 litres :)

tinkerbell
25-05-2004, 12:55 PM
Therefore to rectify the problem, the car owner wants the revs to go to 13k rpms, and hence keep him in the top of 4th without having to do 2 gear changes, this is one of the main reasons why he wants to be able to rev to 13k rpms.
.

i have only read page 1,

if this is the MAJOR reason for 13krpm,

maybe it will be cheaper to custom build a gearbox than rev to 13k @ 14:1cr? in the long run...

i have heard of them in the US...

i think Dave might have a contact?

just a lateral thought :)

tinkerbell
25-05-2004, 01:03 PM
and then what? have 8 gears so he can hit a top speed of 220kmph? u do realise that dropping gear ratios is good, thats fine and dandy, but then u sacrifice top speed and other things.

oh - shoulda read page 2!!!

still, the argument fails on reliability grounds...

it will still be cheaper to get a custom 6 speed dog box built in the states than have to engines popping appart at 10krpms

this is simple logic.

if the guy wants to rev to 13'000 rpm then good for him, but there are better ways to solve his 'problem' besides BLATANTLY reducing engine reliabilty...

my 2c...

tinkerbell
25-05-2004, 01:34 PM
certainly will save shift time if he goes with one of these: http://www.xtrac.com/Product%20Specifications.htm#7

DynoDave
25-05-2004, 02:11 PM
Both Modena and PPG make dog engagement gearboxs for Honda B series Hydro gearbox's here in Australia.
Regards Dyno Dave

u mad?
10-02-2016, 04:26 PM
15:1 on 98 yeah no problems, will run sweet as

Daveho1
10-02-2016, 07:33 PM
have you tried it, nah? So fuk up.

Nah for real though how good is the variety in technical all motor, 15:1 compression talks and can't find engine number

RenzokukenJ
11-02-2016, 02:07 AM
Fuk u dave

Daveho1
11-02-2016, 04:07 AM
Hay hay Nh fuk u.

RenzokukenJ
11-02-2016, 03:53 PM
lol nh. fuk u

Daveho1
12-02-2016, 02:28 PM
I see where u coming from but fuk u

silver_screen
19-02-2016, 09:51 PM
*shakes head*

Daveho1
20-02-2016, 05:35 AM
Oi! You can fuk up too m8!



How good is ozhonda!

connorling
25-02-2016, 11:13 AM
fuk up

cbauto
25-02-2016, 03:14 PM
Lol, no one knows the history of username pornstar

RenzokukenJ
25-02-2016, 04:05 PM
Fuk up bot

u mad?
26-02-2016, 09:09 PM
Lol, no one knows the history of username pornstar

well are you going to tell us?

cbauto
26-02-2016, 09:32 PM
well are you going to tell us?
Byp v1 half as bad. Das it

u mad?
26-02-2016, 10:34 PM
Byp v1 half as bad. Das it

what, more deets m80

Daveho1
27-02-2016, 05:32 AM
fuk up
Sorry for delay in reply
Dear connorling, your profile and evidenced by your post tells me alot about what type of feral you are..... all class 'hay'!!!! ps. not your m8....

also fuk up

Daveho1
27-02-2016, 05:36 AM
Byp v1 half as bad. Das it

Fuk up
BYP is ozhonda primum supply of harnesses and gearboxes that don't have a third gear.

Inb4CeastAndDesistForBenjamin

SHOGUNOVDDRK
27-02-2016, 06:02 AM
Inb4CeastAndDesistForWynode

There I fixed it.

Daveho1
27-02-2016, 06:06 AM
Maybe they took wyn? BYP stole the mod, hopefully their restraints are as good as their products

broken-wheel
03-03-2016, 10:07 PM
Few things: piston speed at 13.000 rpm is impossible with the b18 stroke both mechanically and due to impossibility of getting air to flow that much at the b18 stoke/bore ratio.

No springs will be available to control the lift required
. The ITR springs are flattened to get the extra lift.

Compression ratio is fine as the cam overlap will bring it down to 12.5:1

Past 10.500 rpm reliably out of a b18 will cost $30k