fully understanding DCR - Page 3 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum

Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Hotrodding Basics
User Name
lost password?   |   register now

Closed Thread
LinkBack Thread Tools
  #31 (permalink)  
Old 01-17-2013, 07:54 AM
F-BIRD'88's Avatar
Yada Yada Yada
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,211
Wiki Edits: 0

Thanks: 5
Thanked 389 Times in 383 Posts
I don't think any of us are willing to risk good money on a "what-if" of this kind. This was originally a question posed by Vinnie and I chimed in to put my 2 cents worth in. I've never tried the combination and never will. Advancements in the sport are not made by those who sit back and are comfortable with the status quo, they are made by those who buck the system and try different things. Again, like I said though, I'm not foolish enough to try this, it was just an exercise in fantasy land.

Tech: This is exactly what I am getting at. You are promoting something you have never tried in any fashion to see if it is even remotely practical. Yet you are promoting this and yourself as if you are an authority.

You are not an authority on this and now admit that you would never even think about trying it.

I have built and run high compression ratio engines (been to the dark side) and even stepped over the edge.

Your over simplified incorrect DCR theory and calculations based on incorrect real valve timing

Totally ignores other factors like the HEAT OF COMPRESSION. Look up your gas laws.
The real in cylinder presssure and temperature in the rngine as it is reunning at speed.
The ever increasing number of fireing cycles per sec as the rpm rises. MORE HEAT with less TIME TO REMOVE THE HEAT @ WOT. AS RPM RISES. ALl thisand more effects the octane requirement-compression ratio.

High compression ratio engiens that actually run and make power @WOT need a higher octane fuel.
On the street once you get beyond about 10.5:1 things get real dice. on even good premimum 92 octane gas.
EVen worse if/when the fuel octane is not so good.
Even worse if hwne the tune os not 100% correct in all cylinders. Even worse on a hot day or after running for extended time on the hyway, then suddendy ge4t on the throttle from a stop. when things are hot.
You learn this actual real world experience. many people have had to learn the hard way thru $$engine failure$$$, th real practical limits of pump gas fuel and compression ratio, reguardless of the cam timing.

Stop trying to mis repressent yourself as a authority on this and stop representling this as a absolute.

Don;t you think that if this workedwe whould have figured out a long time ago and ther would be no higher octane fuel
Or all engines would just be over cammed to get them to run on pump gas ????????
Start ny checking your history. All the research on all ths HAS BEEN DONE..
All the modern combustion shapes ( fastburn, cloverleaf),,, etc etc ARE NOT NEW.
They are old designs that were done a long time ago.

The best most effective way to avoid detonation is to back off the spark advance.
And that is exactly what modern computer controled engines do to avoid damage when ever
you rug the gas petal and operating conditons are NOT optimum.

Stop promoting this recklessly, when you freely admit you never intend to try it....etc...

Like I said Build your first high performance engine and get back to us.....

Quick reply to this message
Sponsored Links
  #32 (permalink)  
Old 01-17-2013, 07:58 AM
F-BIRD'88's Avatar
Yada Yada Yada
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,211
Wiki Edits: 0

Thanks: 5
Thanked 389 Times in 383 Posts
Originally Posted by steeny View Post
I know I said I would not say anymore on this subject but I can't contain myself.

To the guy's that say it is ok to run "pump" gas ( of any grade) on an engine with 13-1 and compensate with a large duration, high overlap cam is good to go then why would one use a better composition of gasoline to run this same engine at the track. If there is no need then why do it.....cause it smells good?

To the guy's that were like me back in the early 70's building hot rods and high compression engines (even over what you could get already from the factory) to cruise the blvd and race out on the lonely road we definitely understood (even before we were off to college for higher learning) the need. Sunoco 260 was our friend!!

To the stubborn crew that does not want to listen to experience?......go ahead and try your combo on the street with the quality of gas these days. Let us all know of your real world experience learned. Bet I know the answer if your feedback is honest!!

To the guy's that do it successfully.....kudo's for the knowledge and understanding that there is more to it than just huge domes, small chambers and wild camshafts!!!!
Steeny:; Excellent post...... A bit of cold hard reality.... Thanks...
Quick reply to this message
  #33 (permalink)  
Old 01-17-2013, 12:12 PM
OneMoreTime's Avatar
Hotrodders.com moderator
Last wiki edit: Health and safety in the shop or garage
Last journal entry: Yard Dog pic
Last photo:
Join Date: Jul 2004
Location: Washington State
Age: 70
Posts: 7,474
Wiki Edits: 3

Thanks: 68
Thanked 167 Times in 156 Posts
There is or was an ignore user feature under my profile where you can select that..

I have tried most all of it and now do what is known to work..
Quick reply to this message
  #34 (permalink)  
Old 01-17-2013, 12:22 PM
F-BIRD'88's Avatar
Yada Yada Yada
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,211
Wiki Edits: 0

Thanks: 5
Thanked 389 Times in 383 Posts
Post reported and complaint lodged..
This is clearly going beyond the rules of the forum and its technical advice intent.
Quick reply to this message
  #35 (permalink)  
Old 01-17-2013, 12:32 PM
dinger's Avatar
Hotrodders.com Moderator
Last wiki edit: Health and safety in the shop or garage
Last journal entry: 36 Ford painting
Last photo:
Join Date: Jan 2002
Location: Visalia, Ca.
Age: 62
Posts: 2,711
Wiki Edits: 1

Thanks: 106
Thanked 115 Times in 80 Posts
Fbird, Tech, you guys know the rules of this forum. Your 5th grade name calling and jabs are done as of NOW! anymore, there will be suspensions handed out.
"When I was younger, I could remember anything, whether it had happened or not." - Mark Twain
Quick reply to this message
Closed Thread

Recent Hotrodding Basics posts with photos

Quick Reply

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
DCR calculator conflict - by ALOT! 64nailhead Engine 16 01-11-2013 05:27 PM
chevy 454 DCR question chvypwr Engine 2 12-06-2011 02:02 PM
? about DCR for my 350 sbc streetmaster42 Engine 7 03-13-2008 02:06 AM
Another DCR question. Hippie Engine 7 08-04-2005 02:00 PM

All times are GMT -6. The time now is 04:16 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.