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 Post subject: 440 compression
PostPosted: Tue Apr 02, 2013 5:25 pm 
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Joined: Wed Dec 26, 2012 5:10 pm
Posts: 10
Help, I have a 1967 440 that has 10.25:1 compression. The heads have not been milled and the block has not been decked. I am tired of using cam2 to just drive around and I am tired of the pinging. Timing has been set at 12 deg. btc. What can I do to lower compression to 9.25. Do not have alot of $ to spend. Thanks


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 Post subject: Re: 440 compression
PostPosted: Tue Apr 02, 2013 5:32 pm 
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Joined: Sun Nov 01, 2009 7:49 pm
Posts: 890
Location: Upton, Massachusetts
What size head gaskets are you running? Thicker head gasket=lower compression ratio

What is you total ignition timing? All in at what RPM?

You can try heavier springs on your mechanical advance in your distributor

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Shawn Matellian
1969 Dodge Super Bee 440 Six Pack 12.48 at 109
1969 Dodge Dart Swinger 500'' Indy 9.75 at 139
1968 Plymouth GTX J code 426 Hemi 4 speed
1964 Dodge Polara 500 Golden Anniversary 383
1963 Dodge Polara 426 Ramcharger Stage II 10.94 at 126


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 Post subject: Re: 440 compression
PostPosted: Tue Apr 02, 2013 6:18 pm 
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Joined: Fri Jul 25, 2008 12:26 am
Posts: 7469
Location: Bristol CT
10.25 is not very much compresion. Check your distributor make sure you don't have to much timing advance. What is your total timing when the distibutor is done fully advancing? Dial back the distributor.

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66 Belvedere I HP2 Hemi Auto 11.13 @ 124MPH 1.68 60' S/A

70 RoadRunner 440+6 Auto 11.05 @ 125MPH 1.67 60' S/A

70 AAR Cuda 340+6BBL 4 Spd. 11.58 @ 121MPH 1.76 60' S/A

72 Demon GSS 340 S/A 11.76 @ 118MPH 1.89 60' S/A


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 Post subject: Re: 440 compression
PostPosted: Tue Apr 02, 2013 6:49 pm 
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Joined: Fri Jul 25, 2008 6:12 pm
Posts: 2617
Location: North Salem NY
Also check that your not too lean, or have a hot spot, such as a burr or burnt valve!
Detonation no good!

Also Run the coolest plugs you can get

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 Post subject: Re: 440 compression
PostPosted: Tue Apr 02, 2013 6:54 pm 
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Joined: Mon Nov 02, 2009 8:28 pm
Posts: 1552
:agree Mopar distributors have a reputation of a ton of vacuum advance. A company called 4 seconds flat sells distributors with custom curve and phasing for about $180 for your combination. No personal experience,but have only heard good things about them. :pop

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 Post subject: Re: 440 compression
PostPosted: Tue Apr 02, 2013 7:04 pm 
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Joined: Sun Nov 01, 2009 7:49 pm
Posts: 890
Location: Upton, Massachusetts
Moparts website has some good information on the subject

http://Www.moparts.com

Once on the website, do the Google Custom Search :aok
Detonation 440 Mopar

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Shawn Matellian
1969 Dodge Super Bee 440 Six Pack 12.48 at 109
1969 Dodge Dart Swinger 500'' Indy 9.75 at 139
1968 Plymouth GTX J code 426 Hemi 4 speed
1964 Dodge Polara 500 Golden Anniversary 383
1963 Dodge Polara 426 Ramcharger Stage II 10.94 at 126


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 Post subject: Re: 440 compression
PostPosted: Tue Apr 02, 2013 9:00 pm 
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Joined: Thu Sep 04, 2008 3:57 pm
Posts: 849
I would be happy to swap my 83cc heads for your 73.5cc heads. It should get your compression down to 8.5 -1 and it will probably run OK on cow pee. But I don't think you have to. Just disconnect your vacuum advance and reduce your initial advance to zero or less if neccessary and see if the pinging goes away.

Then you will just have to work the advance back up as far as you can. As I think Shawn said it could be too lean. Try richening the jetting if the first suggestion doesn't work by itself.


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 Post subject: Re: 440 compression
PostPosted: Tue Apr 02, 2013 9:08 pm 
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Joined: Mon Oct 26, 2009 10:20 pm
Posts: 297
Location: Peabody, MA
Are you sure that your CR is actually 10.25:1? I run a 440 with about the same compression on 93 octane on the street with around 32-34 deg total advance and rarely have pinging except when the weather is really hot. I know first hand that my compression is just over 10:1 because I measured the combustion chamber volume, cylinder volume and compressed gasket volume and did the math. Good luck! :aok

Kevin

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'70 Challenger - Vanishing Point - 440 Six Pack, 4-speed 11.431 @ 124.58 mph


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 Post subject: Re: 440 compression
PostPosted: Tue Apr 02, 2013 10:04 pm 
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Joined: Fri Jul 25, 2008 6:12 pm
Posts: 2617
Location: North Salem NY
Or, Retard your cam!

Doing the hard stuff first is more fun! :mrgreen:

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69 Nova SS 396 L89
10.481
1.61 60’
132.34 mph


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 Post subject: Re: 440 compression
PostPosted: Tue Apr 02, 2013 10:05 pm 
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Joined: Tue Oct 27, 2009 12:00 am
Posts: 342
Location: Chicopee MA
I've had the same issues that you are having. With the vacuum advance I was hitting 54 degrees and it was advancing to fast as well. I had Billy Atwood recurve the distributer (after trying a few other things) and it worked miracles. With an initial of 10-12 degrees and total in the 28-30 (mechanical timing) range my problems were solved with pump 93. No more pinging and sluggish bogging performance. My motor has 11.5.1 compression :bang Timing comes in a little later which is fine on the street.


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 Post subject: Re: 440 compression
PostPosted: Wed Apr 03, 2013 5:55 pm 
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Joined: Sat Nov 29, 2008 9:46 pm
Posts: 32
furrystump wrote:
:agree Mopar distributors have a reputation of a ton of vacuum advance. A company called 4 seconds flat sells distributors with custom curve and phasing for about $180 for your combination. No personal experience,but have only heard good things about them. :pop

Run tighter springs.. you may have to recurve the dist.???

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1968 Dodge (J code) HEMI 4Speed, Super Bee.


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 Post subject: Re: 440 compression
PostPosted: Wed Apr 03, 2013 8:45 pm 
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Joined: Wed Dec 26, 2012 5:10 pm
Posts: 10
Thankyou for all the replies. I used stock mopar head gaskets,and a mallory unilite distributor. I use Champion RJ12-y PLugs, gapped at .040 with a Jacobs Mileage Master ignition. I think the total advance is 28-30,but not sure. The Holley carb was rebuilt to stock 440 specs. How about low compression 440 heads? To some this may be sacriledge, but I'm not too interested in going super fast anymore;just having fun and keeping the local law enforcement personnel away from me.


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 Post subject: Re: 440 compression
PostPosted: Wed Apr 03, 2013 9:30 pm 
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Joined: Fri Jul 25, 2008 12:26 am
Posts: 7469
Location: Bristol CT
69 roadrunner wrote:
Thankyou for all the replies. I used stock mopar head gaskets,and a mallory unilite distributor. I use Champion RJ12-y PLugs, gapped at .040 with a Jacobs Mileage Master ignition. I think the total advance is 28-30,but not sure. The Holley carb was rebuilt to stock 440 specs. How about low compression 440 heads? To some this may be sacriledge, but I'm not too interested in going super fast anymore;just having fun and keeping the local law enforcement personnel away from me.


I would bet it has nothing to do with Compresion. Your in CT give Billy Atwood a call and let him take a look at it. I'm sure it will be cheeper than throwing parts at it and finding out in the end it was a simple fix.

_________________
SUPERCAR LEGAL

66 Belvedere I HP2 Hemi Auto 11.13 @ 124MPH 1.68 60' S/A

70 RoadRunner 440+6 Auto 11.05 @ 125MPH 1.67 60' S/A

70 AAR Cuda 340+6BBL 4 Spd. 11.58 @ 121MPH 1.76 60' S/A

72 Demon GSS 340 S/A 11.76 @ 118MPH 1.89 60' S/A


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 Post subject: Re: 440 compression
PostPosted: Wed Apr 03, 2013 9:46 pm 
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Joined: Wed Dec 26, 2012 5:10 pm
Posts: 10
Thankyou again. Who is Billy Atwood and how do I contact him?


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 Post subject: Re: 440 compression
PostPosted: Wed Apr 03, 2013 9:50 pm 
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Joined: Sun Dec 26, 2010 11:42 am
Posts: 564
Location: Florida
69 roadrunner wrote:
Thankyou again. Who is Billy Atwood and how do I contact him?


Click the banner at the top of the page - Auto Service of Old Saybrook. If you don't see it, refresh the page until you do.

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1972 Chevelle SS 454 4 speed
1969 Malibu 2dr hardtop L48/4 speed -> 427 L72
1968 Malibu 2dr hardtop restomod
1972 Monte Carlo

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