'79 302 timing |
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79CC
Newbie Joined: February-24-2016 Location: SW Missouri Status: Offline Points: 13 |
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Posted: September-14-2016 at 2:57pm |
Hello all,
I have never checked the timing on my boat and would like to. Best I can tell the timing is supposed to be set at 6° BTDC. Problem I see is the balancer only has markings to 3° BTDC. Can anyone give me an explanation for this. I'm pretty sure its the stock balancer. Checking the timing it appears to be about 5°, more or less (its off the scale). what have others done to time the engine with this issue? thanks in advance. |
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'79 Ski Tique
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Dreaming
Platinum Member Joined: May-21-2010 Location: Tacoma, WA Status: Offline Points: 1870 |
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You need a timing light with an advance feature. The old school way would suggest that you can find the timing marks by measuring and marking the harmonic balancer, but I think you'd spend a lot of time and energy doing that. The newer timing lights digitally set the advance and flash so that you set your timing to 0° mark with the electronics doing the work. Its a super easy process and seems to take a lot of the guess work out of things from my experience. A good timing light with the advance feature is about $100, and can be found on amazon or locally if you need it right away. you might be able to borrow one or check one out from a local Auto parts if they have one on their tool rental list.
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MrMcD
Grand Poobah Joined: January-28-2014 Location: Folsom, CA Status: Offline Points: 3750 |
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Any chance you are looking at the timing on the wrong side of zero, ATDC rather than BTDC. The marks should go out to at least 12 degrees. BTDC.
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Duane in Indy
Platinum Member Joined: October-26-2015 Location: Indiana Status: Offline Points: 1578 |
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Assuming that your damper is 6.5" in diameter, then you could figure on 8 degrees being about 7 / 16" from TDC. If you go for 32 degrees for maximum timing at 3000+ RPM then use a mark 1 13 / 16" from TDC.
Initial timing of 6 or 8 degrees is not as critical as your maximum advance. You can be off on initial timing and not hurt your engine, but don't exceed 32 degrees maximum timing or you can start hurting parts. Some even go for 10 degrees initial but remember what you do to initial advance will effect your maximum advance. Yes, a light with digital timing is nice but you can still get by fine with your light. Summit and Jegs both sell timing tape to add to your damper. |
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Keep it as original as YOU want it
1978 Mustang (modified) |
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GottaSki
Grand Poobah Joined: April-21-2005 Location: NE CT Status: Offline Points: 3363 |
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However What works on a 351 is not gospel for a 302.
Due to the short stroke, the 302 likes about 2 degrees more advance than the 351 for final. And can run 36-38 all in all day. I feel 34-36 max for a std compression 302 is still a safe cap, and suspect 32 may leave performance on the table. |
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"There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing."
River Rat to Mole |
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79CC
Newbie Joined: February-24-2016 Location: SW Missouri Status: Offline Points: 13 |
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yep, BTDC only goes to 3°. Oddly the ATDS side goes to 6°.
Thanks for all the comments and suggestions. I'm going to verify TDC and get some timing tape. Cheers |
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'79 Ski Tique
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21186 |
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Timing tape works, dial timing light is better. Remember to install the tape backwards as you have a RH engine. Don't assume the balancer is correct, I've seen them both right and wrong.
Listen to Gottaski on the final timing numbers. 10-12 initial is ideal, don't set it to 6 unless you want a lazy holeshot or a stumble. Depending on how much advance your distributor has, you may need to compromise between optimal initial and final settings. |
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wolfman
Newbie Joined: August-11-2015 Location: whitehall, mi Status: Offline Points: 34 |
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When I first got my 78 Tique running this cost me a couple weeks of frustration and head scratching. Turned out it had a normal rotation balancer and tdc was off by about 45 degrees. That's when I stopped taking anything on the boat at face value. Since then everything is easier.
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21186 |
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TDC is in the same spot regardless of engine rotation- it is not offset by 45deg.
ATDC and BTDC are obviously backwards between a RH and LH balancer, but the 0deg mark is still correct. |
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wolfman
Newbie Joined: August-11-2015 Location: whitehall, mi Status: Offline Points: 34 |
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Well, I'm not really sure how these attach on this engine but what I mean is the factory etched TDC mark was off by about 45 degrees from true TDC. Not having timed many engines, it took me awhile to figure out it was even backwards, with the flashing lights and all. I figure Commander, the marinizer(whoever this company is I can find nothing about them) just used a pile of parts from a box labeled balancers and put in on crooked so I would know not to use the timing marks, Or, it could just be some back yard hack and I should be thanking my lucky stars this engine is holding together as I'm doing 40 off the side on my bare feet spraying my family. Yes I got up on the boom the other night first time and feeling good!
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 11113 |
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Sounds like you got yourself a regular mongrel there.
Ford did put their timing marks on the engine in different places depending on water pump outlet position which then necessitated different markings on the balancer too. Seems like you got a mixed bag of parts on it when you bought it. So yes TDC is the same but the markings can be all out of whack if parts are mixed together. The typical PCM 302/351 has the timing pointer at about the 1 o'clock position, whether it'a normal or reverse rotation. I think Commander had the marks the same as PCM. A lot of Ford auto 302 engines have the pointer at about the 11 o'clock position due to water pump outlet changes which block the access to the original location. Might be a little tough to visualize without having the parts in front of you or having been bit by this in the past. It's happened to me before and you either get the right match of parts or remark the damper to correct things |
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wolfman
Newbie Joined: August-11-2015 Location: whitehall, mi Status: Offline Points: 34 |
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I ended up manually marking true TDC and use a dial back timing light and set it at 11 degrees and all is well now, it really rips. Speaking of, who has the 79 Tique on youtube that does 56.4 mph? What engine are they running? It doesn't say on the video. I might like to upgrade to a 351 someday.
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1978 Ski Tique 302
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Duane in Indy
Platinum Member Joined: October-26-2015 Location: Indiana Status: Offline Points: 1578 |
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Just curious, how did you locate true TDC??
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Keep it as original as YOU want it
1978 Mustang (modified) |
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wolfman
Newbie Joined: August-11-2015 Location: whitehall, mi Status: Offline Points: 34 |
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Took out the #1 plug and stuck a wood dowel in, turned crank by hand until dowel is at highest point. Mark location of timing pointer on balancer with white paint. I cant remember how I made sure it was on the compression stroke but I think It was at the same location on the compression stroke and exhaust stroke.
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1978 Ski Tique 302
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Duane in Indy
Platinum Member Joined: October-26-2015 Location: Indiana Status: Offline Points: 1578 |
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That will work. TDC is same on all strokes, does not matter about compression. Great news. BTW what is total advance set at?
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Keep it as original as YOU want it
1978 Mustang (modified) |
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wolfman
Newbie Joined: August-11-2015 Location: whitehall, mi Status: Offline Points: 34 |
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I have not checked that yet. Thanks for reminding me. One of my springs is really rusty, Hoping to make it to the off season and replace it and get that total advance set right.
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1978 Ski Tique 302
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21186 |
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Sounds like you got it figured. Ken, I didn't realize Ford used different reference points for the timing marks- I see how that could be disasterous if the marks and reference point are out of synch.
That is my former '78 Tique on YouTube, my uncle Todd built the new motor. |
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 11113 |
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[QUOTE=TRBenj] Sounds like you got it figured. Ken, /QUOTE]
Let's just say I learned it the hard way on a land based engine and it wasn't a lot of fun at the time. |
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MrMcD
Grand Poobah Joined: January-28-2014 Location: Folsom, CA Status: Offline Points: 3750 |
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It is possible for the harmonic balancer to slip and rotate away from original set up if the rubber is shot. One more possibility to consider. Rebuilt or new balancers are available.
There are also Piston stops available to determine TDC in an engine, they screw into the spark plug on number one. Finding TDC can be done on every rotation, it does not matter if the piston is on compression or exhaust stroke, you only need to know when it is at Top Dead Center. You rotate carefully until the piston lightly touches the stop. Mark your location at this point, now reverse and rotate again till the piston hits the stop and mark it again. Your TDC is the exact center between the two marks. Usually your two stop marks will be about an inch apart depending on how deep the stop is in your engine. Rotate only by hand and go slowly or your stop can damage a good piston. This method is accurate and a little better than the dowel method but takes a little longer. |
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