the mopars in Australia are so cool
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| Timing Question https://slantsix.org/forum/viewtopic.php?t=47798 |
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| Author: | wayfarer [ Wed Feb 01, 2012 9:25 pm ] |
| Post subject: | Timing Question |
Howdy all! I'm a new Australian member with a question for all the slant gurus about timing. I have had some work done on the old girl and can't seem to find the best timing, heating and running on are my issues! Ill list what has been done and let me know what you reccomend! 225cui slant six 40 thou overbore pacer cam heads for unleaded fuel 350 holley carb 3-2-1 extractors electronic ignition Oh, and its in a '66 VC Wayfarer utility, i tried to add pics, but i need to host first.... Please advise!! |
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| Author: | terrylittlejohn [ Thu Feb 02, 2012 4:38 am ] |
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hi down there,i am not sure of some of the terms you used (3-2-1 extractors )('66 VC Wayfarer utility) must be like newfenize, what is the compression of the engine? what timing are you running now? also what octane fuel do you have? with a 10.5/1 motor i ran 32degs total with 91 octane and booster.with 11.5/1 i ran 25degs with 50/50 mix of av gas and 91 supreme gas. base timing was 12degs to 17degs range. are you over heating at highway speed or just cruising?your run-on problem might be if the throttle setting is to much to compensate for not enough initial timing. |
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| Author: | wjajr [ Thu Feb 02, 2012 5:10 am ] |
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3-2-1 extractors = Headers such as a pair of Clifford to “Y†pipe out the back with single exhaust. Valliant Charger Ute. --- [url=http://www.shannons.com.au/auctions/lot/E3T7AF3E9C1FJA1C]Look here[/url]. |
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| Author: | terrylittlejohn [ Thu Feb 02, 2012 6:06 am ] |
| Post subject: | |
the mopars in Australia are so cool
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| Author: | wayfarer [ Thu Feb 02, 2012 12:57 pm ] |
| Post subject: | |
 32 degrees!!im not sure of the compression right now  currently five degrees advanced and running on between 91 and 95 octane unleaded. the heat is during city driving (mostly at lights) however it heats up quickly!It's funny you say Aussie Mopars are cool! In Australia, if you want a tough pentastar, you import one from the states!! |
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| Author: | Reed [ Thu Feb 02, 2012 1:18 pm ] |
| Post subject: | |
Stock slant six initial (base) timing specs varied from 5 ATDC to 16 BTDC depending on the emissions package, ignition system, and camshaft installed. To determining your ideal base timing with an aftermarket cam is not as simple as you would think. Slants generally "like" 32 degrees total mechanical advance with 8-12 degrees base advance and about 54 degrees total advance. The exact number of degrees BTDC you will set the timing depends on several variables- your cam profile and the amount of degrees of centrifugal and vacuum advance your distributor provides. To get in the ballpark, you should pull the distributor and see the number that is stamped on the governor. A 9R governor provides 18 degrees of crankshaft timing advance, an 11R provides 22 degrees, etc... To get a rough idea of your base timing, you take the number stamped on the governor and multiply it by two, then subtract that number from 32. So, for a governor stamped 9, your base timing would be about 14 BTDC: (32-[9*2])= 14. You can advance or retard your base timing as needed to deal with different cam profiles. While that number is the rough estimated base timing, the vacuum advance also comes into play. You need to see how many degrees the vacuum advance provides. Different vacuum advance cans provide different amounts of advance (and also apply that advance at different vacuum levels). While you have the distributor out, check if there is a number stamped on the vacuum pod arm. You will also have to multiply this number by 2 to get the number of crankshaft degrees the vacuum pod advances the timing. You want to have total spark advance of around 54 degrees. That means about 32 degrees of mechanical advance and 22 degrees of vacuum advance. You need to make sure that your base timing will not make the total spark advance get too far beyond 54 degrees when the vacuum and centrifugal advance systems are "all in." There are numerous discussions on this board about "recurving" your distributor. Those threads have input from people much more knowledgeable than I, and give you all the info you need to determine your optimal base timing. I highly recommend searching for them and reading them. |
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| Author: | wjajr [ Fri Feb 03, 2012 6:35 am ] |
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Well put Reed. |
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| Author: | chucksrodgarage [ Sat Feb 04, 2012 7:27 pm ] |
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reed, great post |
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| Author: | wayfarer [ Sun Feb 05, 2012 7:48 pm ] |
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thanks for the advice, it was a good read. I now have another problem that has arisen, the perfect timing was about 12 deg advanced. This made the ole' girl purr like a kitten , aswell as have quite a bit of poke! I took her for a good long run of 2hours including a range climb and noticed the power had decreased. I put the timing light back on and found her to be at 0 deg!! I adjusted it again and found the timing slipped again..... this electronic distributor is coming out 
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| Author: | Reed [ Sun Feb 05, 2012 8:12 pm ] |
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Before you pull the electronic ignition, I would check that both adjustment bolts on the distributor hold down bracket are good and tight. There is the bolt in the block and the bolt on the bottom of the distributor. I would also make sure that the outer ring on the vibration dampener (the part that has the timing mark) has not slipped in relation to the center ring that slide on the crank. I once had a dampener that had slipped 13 degrees. |
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| Author: | wayfarer [ Sun Feb 05, 2012 9:13 pm ] |
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thank you for your suggestions once again reed. the harmonic balancer is brand new and the engine is less than 700miles after a complete rebuild. i did check that TDC was in line with number 1 on the compression stroke. all was good there, so i think its dizzy swap time! i have the origional points style ditsributor here so its no big deal.. |
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| Author: | Reed [ Sun Feb 05, 2012 9:25 pm ] |
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Nothing internal to the electronic ignition distributor will make the timing change. There is something somewhere else that is causing the timing to slip. Points ignition is a huge step backwards in terms of performance, economy, and reliability from any form of electronic ignition. If you do reinstall the points system, at least upgrade to a Pertronix electronic ignition. |
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