Pinging Or Dieseling - Page 2 - 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> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #16 (permalink)  
Old 05-30-2010, 12:08 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 60
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
You're probably going to find that even w/o ANY vacuum advance, it will still ping if it has anything approaching 34 total- which you need to get the power that cam will make. Anything less will possibly help the detonation but will rob you of power.

Most of the "octane in a can" doesn't really add any significant amount of actual octane.

This is a classic case of a mismatched combo.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #17 (permalink)  
Old 05-30-2010, 07:05 PM
Registered User
 
Join Date: May 2010
Location: NJ
Posts: 70
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by 454C10
the root of the problem is you are running too much compression for that cam.

drop the cr to 9.5:1 or install a bigger cam. That much cr needs a cam around the size of a compcam 292H. But that cam would also require a 3000 stall and 4.11 gears.

aluminum head would help but may not be enough.

maybe a set of aluminum heads and a 280H compcam would do the trick.

bigger chambers would also do it. if you are using 64cc heads then a set of 72's should drop the cr to 9.6.
When I talked to Lunati's tech support they said 10.5 would be fine with that cam. The only thing I don't have yet that they recommend is 3.73's, I'm running 3.42's now. I'm going to go after advance limiter and if that doesn't take care of it all, then I'll have to mix in some race gas..
Reply With Quote Quick reply to this message
  #18 (permalink)  
Old 05-30-2010, 07:56 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 13,154
Wiki Edits: 326

Thanks: 793
Thanked 1,084 Times in 897 Posts
Quote:
Originally Posted by 454C10
the root of the problem is you are running too much compression for that cam.
I agree, no matter what Lunati told you on the phone. The timing events are 10.5/42.5/54.5/6.5
Plugging in the intake close (42.5) with the 10.5 SCR, 5.7 rod and 3.48" stroke into KB's DCR calculator, the result is 8.827:1 DCR. Way too high for pump gas in my opinion.

19nova69, way back on post #4, I asked you for information about this build. You never responded. I suspect you may not have set the squish on the motor when you were doing your trial assembly and subsequent machining and this is what is contributing most strongly to the detonation, although 8.827:1 DCR ain't gonna be too pump gas friendly either.

My best advice: Disassemble and start over.
Reply With Quote Quick reply to this message
  #19 (permalink)  
Old 05-30-2010, 08:07 PM
Registered User
 
Join Date: May 2010
Location: NJ
Posts: 70
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by techinspector1
I agree, no matter what Lunati told you on the phone. The timing events are 10.5/42.5/54.5/6.5
Plugging in the intake close (42.5) with the 10.5 SCR, 5.7 rod and 3.48" stroke into KB's DCR calculator, the result is 8.827:1 DCR. Way too high for pump gas in my opinion.

19nova69, way back on post #4, I asked you for information about this build. You never responded. I suspect you may not have set the squish on the motor when you were doing your trial assembly and subsequent machining and this is what is contributing most strongly to the detonation, although 8.827:1 DCR ain't gonna be too pump gas friendly either.

My best advice: Disassemble and start over.
I never did anything with the motor. This is the way I got the car. It had a dirt track race motor in it with dart 200 heads, a victor jr and some crazy cam that only made power above 3k. I'm trying to tone it down and make it somewhat streetable. I honestly have no idea what CR I have we just made a guess that its somewhere around 10 or 11:1 based on compression numbers compared to other cars with similar readings.. It's gotten a whole lot better in the last couple days after the cam and intake swap and playing with timing.
Reply With Quote Quick reply to this message
  #20 (permalink)  
Old 05-30-2010, 08:29 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 60
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by 19nova69
I never did anything with the motor. This is the way I got the car. It had a dirt track race motor in it with dart 200 heads, a victor jr and some crazy cam that only made power above 3k. I'm trying to tone it down and make it somewhat streetable. I honestly have no idea what CR I have we just made a guess that its somewhere around 10 or 11:1 based on compression numbers compared to other cars with similar readings.. It's gotten a whole lot better in the last couple days after the cam and intake swap and playing with timing.
If I understand you, you now don't know what the CR is at all- so it's safe to say it could be even higher than 10.5:1.

I don't know what of the advice you've received you've put into use, but the help from detonation will come from more octane, cooler intake air, slowing the advance curve (stiffer mechanical weight springs) and limiting the total timing to something the engine will tolerate (lower the total timing by where the distributor is set and by limiting/eliminating the vacuum advance.

You can richen the carb to help matters some, but there's a limit on this as well as the timing as to just how far you can go before you start to take away too much power from the engine, have problems w/running hot, etc..

Most any other improvement will come from changing hard parts in the engine, gearing will help some.

In my opinion, the thing to do would be to pull the heads off, measure things to know where you are and make your tuning decisions based on hard facts.

Like Cole says, JMO.
Reply With Quote Quick reply to this message
  #21 (permalink)  
Old 05-30-2010, 10:05 PM
automotive breath's Avatar
Registered User
 
Last photo:
Join Date: Mar 2006
Location: New Orleans
Posts: 891
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
You can get a good idea of what tune-up the engine will tolerate like this:

Set the air fuel mixture slightly rich (both idle and main circuits), keep water
temperature ~170 - 180 degrees no hotter.

Lock out the centrifugal advance, disconnect the vacuum advance and plug
the vacuum line. Set the ignition advance to 24 degrees and test the engine
with a light load for ping. The engine will be sluggish, if no ping - increase
ignition advance 2 degrees and retest. Continue to do this until you hear
slight ping, when you do retard the ignition 2 degrees and test under various
conditions including up hill acceleration.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

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:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

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
Pinging on 03 Chevy 5.3 Engine in Suburban bry21317 Engine 42 10-02-2011 08:35 PM
Dieseling rtyauch301 Engine 20 12-14-2009 07:36 PM
400ci Small Block pinging JustinBoxman Engine 5 05-19-2008 08:03 AM
pinging and no acceleration twisted91 Engine 19 11-13-2006 12:45 AM
Rich at idle but pinging on tip in? JoeS Engine 24 02-21-2006 09:02 AM


All times are GMT -6. The time now is 03:06 AM.


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.