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. 
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| 440 compression http://www.supercarraces.com/phpBB3/viewtopic.php?f=5&t=1220 |
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| Author: | 69 roadrunner [ Tue Apr 02, 2013 5:25 pm ] |
| Post subject: | 440 compression |
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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| Author: | Shawn [ Tue Apr 02, 2013 5:32 pm ] |
| Post subject: | Re: 440 compression |
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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| Author: | RalphsRapidTransit [ Tue Apr 02, 2013 6:18 pm ] |
| Post subject: | Re: 440 compression |
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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| Author: | Ted Daros [ Tue Apr 02, 2013 6:49 pm ] |
| Post subject: | Re: 440 compression |
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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| Author: | furrystump [ Tue Apr 02, 2013 6:54 pm ] |
| Post subject: | Re: 440 compression |
| 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.
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| Author: | Shawn [ Tue Apr 02, 2013 7:04 pm ] |
| Post subject: | Re: 440 compression |
Moparts website has some good information on the subject http://Www.moparts.com Once on the website, do the Google Custom Search  Detonation 440 Mopar |
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| Author: | old fart racing [ Tue Apr 02, 2013 9:00 pm ] |
| Post subject: | Re: 440 compression |
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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| Author: | Kowalski [ Tue Apr 02, 2013 9:08 pm ] |
| Post subject: | Re: 440 compression |
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! Kevin |
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| Author: | Ted Daros [ Tue Apr 02, 2013 10:04 pm ] |
| Post subject: | Re: 440 compression |
Or, Retard your cam! Doing the hard stuff first is more fun! 
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| Author: | gtxjimmy [ Tue Apr 02, 2013 10:05 pm ] |
| Post subject: | Re: 440 compression |
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  Timing comes in a little later which is fine on the street.
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| Author: | a67gtx [ Wed Apr 03, 2013 5:55 pm ] |
| Post subject: | Re: 440 compression |
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. Run tighter springs.. you may have to recurve the dist.??? |
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| Author: | 69 roadrunner [ Wed Apr 03, 2013 8:45 pm ] |
| Post subject: | Re: 440 compression |
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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| Author: | RalphsRapidTransit [ Wed Apr 03, 2013 9:30 pm ] |
| Post subject: | Re: 440 compression |
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. |
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| Author: | 69 roadrunner [ Wed Apr 03, 2013 9:46 pm ] |
| Post subject: | Re: 440 compression |
Thankyou again. Who is Billy Atwood and how do I contact him? |
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| Author: | 1972LS5Chevelle [ Wed Apr 03, 2013 9:50 pm ] |
| Post subject: | Re: 440 compression |
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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