can anyone tell me if go 13.1 Compression fully build motor,, daily driver is too much with 93 pump gas?????

 

It can be tuned, however you will have to de-tune it so much that it will be pointless to have that much compression.

You should consider usable compression such as 11.8:1-12.0:1

 

pointless unless you track it on the weekends and can put some better fuel in it from time to time.

 

ive seen people run 13 cr on dd but i wouldnt. im running 12.5 cr all day on a dd for a good 2 years now on 93 octane with absolutly no issues. just have a good tune.

 

your biggest worry will be taking out soo much timing that negates any potential power the engine could make.

Acceleration points under WOT will be your biggest enemies and street tuning will be your biggest friend.

 

thanks a lot guys........

 

I will be glad to fix it when it FACKS up. Call me.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote">I will be glad to fix it when it FACKS up. Call me.</TD></TR></TABLE>


My buddy ran CTR's in his GSR, stock ecu, 91 octane, and then wondered why his pistons disinetegrated

 

I'm going to disagree with the general consensus based on my recent experience: https://honda-tech.com/zerothread/2371314

If you run a cam with a little bump to the non-VTEC profile, which mutes the volatility of high CR low rpm driving, it's even more tractable. If you do not, you may find you have very good results by fudging distributor orientation to allow more retard in the low rpm high load range. It worked for me.

I tune a 13.3:1 CR LS in two weeks, 39cc chamber, 33mm Prelude intakes aka poor man's P8R, should be interesting.

 

Also, the C-speed compression calc says Blundar's new beater B20/VTEC is 13.7:1 CR. It's pushing 200 whp on ITR cams, made more than a Pro1 equipped car he tuned the same day.

I suspect there are a lot of assumptions about the nature of octane that aren't entirely true.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Joseph Davis &raquo;</TD></TR><TR><TD CLASS="quote">Also, the C-speed compression calc says Blundar's new beater B20/VTEC is 13.7:1 CR. It's pushing 200 whp on ITR cams, made more than a Pro1 equipped car he tuned the same day.

I suspect there are a lot of assumptions about the nature of octane that aren't entirely true.</TD></TR></TABLE> Like what? Specific gravity, BTU's, burn rate? Just run it rich, retard the timing, and hope for the best? So, 200 WHP is good on a 13.7-1 B20/VTEC? Must be a new record.

 

sorry buddy, but blundar's B20/VTEC is 12.5:1
13.7:1...thats just rediculous AND not true.

ask him...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote"> Like what? Specific gravity, BTU's, burn rate? Just run it rich, retard the timing, and hope for the best? So, 200 WHP is good on a 13.7-1 B20/VTEC? Must be a new record.</TD></TR></TABLE>

You're the only person in this thread's opinion I give two [freak]s about. Instead of baiting me, spit me your $0.02 and why you think that way. I assure you I'm listening, and my ears are perked all the way up.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C1NMotion &raquo;</TD></TR><TR><TD CLASS="quote">sorry buddy, but blundar's B20/VTEC is 12.5:1
13.7:1...thats just rediculous AND not true.

ask him...</TD></TR></TABLE>

I did before I made that post. We call each other 1-4 times per week to exchange advice, have for years. Who are you again?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">me: What was the CR on your B20/VTEC?
Dave: I don't know
me: Estimated?
Dave: 11.9:1 with stock piston - head
0.040" off head
0.005" off block
pistons 0.007 in hole
4:41 AM C speed says 13.72:1
</TD></TR></TABLE>

 

I run a 13.5-1 with pro 2s lsvtec on pump and make 230whp all day. o and its king motor sports bulit and tuned.

 

Good for you, you have beat the odds. But from a logical stand point the last 12.8-1 King motor i checked was 11.4-1. Guess i need a new calculator. The other stupid question is why, are you just that dumb? Why run a compression your fuel cannot handle without retarding the timing so your peak cyl. pressure is 10 degrees from the optimum point. DOH. If you are actually going to build a race motor to take advantage of the octane available, good on you, to say I have a 13-1 street motor for braging rights make you a DORK.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote">Good for you, you have beat the odds. But from a logical stand point the last 12.8-1 King motor i checked was 11.4-1. Guess i need a new calculator. The other stupid question is why, are you just that dumb? Why run a compression your fuel cannot handle without retarding the timing so your peak cyl. pressure is 10 degrees from the optimum point. DOH. If you are actually going to build a race motor to take advantage of the octane available, good on you, to say I have a 13-1 street motor for braging rights make you a DORK. </TD></TR></TABLE>

lol

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote">To say I have a 13-1 street motor for braging rights make you a DORK. </TD></TR></TABLE>

Are you new to Honda-tech or something? If you dont run 13:1 compression in your street car on pump gas you ain't NOBODY

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by unusual71 &raquo;</TD></TR><TR><TD CLASS="quote">

Are you new to Honda-tech or something? If you dont run 13:1 compression in your street car on pump gas you ain't NOBODY </TD></TR></TABLE>

Lol.

 

Come on now Don, 13:1 WORKS JUST FINE as long as it is tuned properly with the right heat range plugs and chamber work. The timing doesn't need to be as retarded as you think, my bros 13.08:1 93 octane (reformulated 10% ethanol) wanted 24.5* WOT, But you already know this your just stuck in your old ways.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote">Good for you, you have beat the odds. But from a logical stand point the last 12.8-1 King motor i checked was 11.4-1. Guess i need a new calculator. The other stupid question is why, are you just that dumb? Why run a compression your fuel cannot handle without retarding the timing so your peak cyl. pressure is 10 degrees from the optimum point. DOH. If you are actually going to build a race motor to take advantage of the octane available, good on you, to say I have a 13-1 street motor for braging rights make you a DORK. </TD></TR></TABLE>

When comparing 87 octane vs 93 on my 12.5-12.8:1 SOHC, the only place I made more power without detonating was below 2000 rpms. I pretty much figured that was going to be the way it worked. Adding timing with 93, I gained less that two whp 6000-7000 rpms with audible pinging - no gains worth having. I didn't find any advantages from added octane despite cam, ignition changes? Kept the AFRs at a flat 13:1, should I have varied that?

In the case of my SOHC, it is a compromise engine meant for efficient yet fun daily driver duty. I've been making short trips between fill ups in an attempt to get a grasp on current mileage; the last jaunt was 57 miles of 75-80 mph highway cruise plus 35 miles of in-city driving netted me 41.1 mpg with the ECU still stuck in open loop; wideband-based lean burn and water injection have not been implemented. I'm not as aggressive a driver as some twenty-teen kid, but I do go 10 over the limit everywhere and I dislike being stuck behind slow pokes, so I'm not even driving for mpg like one of the hypermiler sites would tell me to. It's got a ZC/Si hybrid gearbox, it's not anything "meant" for mpg. From my perspective - I win.

Don, if there is some specific point you'd like to make I am all ears. I know you have a couple metric tons of knowledge rattling around between your ears that I do not, but all I'm hearing are sarcastic comments. Sorry to say but I'm better at ridiculing people than you are, I am a great vast well of negativity and insomnia, so you're going to have to come off of some tangible knowledge if you want to affect me in any manner.

Thanks.

 

lower my CR to 11.8 thanks a lot guys

 

I ran 13.7 with flat valves so It might put me on 13.9 or even 14.1 ran 93 octane all day long made 250whp but I spun a bearing racing other than that it was a great DD 25 mpg on the highway

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by k20coupe &raquo;</TD></TR><TR><TD CLASS="quote">I ran 13.7 with flat valves so It might put me on 13.9 or even 14.1 ran 93 octane all day long made 250whp but I spun a bearing racing other than that it was a great DD 25 mpg on the highway </TD></TR></TABLE> You do realize that detonation, even when you cannot hear it pounds out bearings, right? Opps, you just proved it. How can you "guess" on you compression ratio 13.7, or maybe, 13.9, or even 14.1 if you actually had a "RACE" motor? A kit is like $60.00 from summit, guess your motor was not worth the money. I would go 14.5 on your next one just so you can tell what happens with pre-ignition.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BearsEK-KMSU &raquo;</TD></TR><TR><TD CLASS="quote">Come on now Don, 13:1 WORKS JUST FINE as long as it is tuned properly with the right heat range plugs and chamber work. The timing doesn't need to be as retarded as you think, my bros 13.08:1 93 octane (reformulated 10% ethanol) wanted 24.5* WOT, But you already know this your just stuck in your old ways. </TD></TR></TABLE> Yup, I know the last thing you schooled me on, how 48mm Jenvey's could not match the output of your guy's "mailbox" plenum manifold on your big motor. How did that work out?

 

the pistons are 13.7 with a milled head and flat valves doesnt raise the cr a little more? also the motor lasted almost a whole year of DD and racing and what gave up where the pistons rings