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Discussion Starter #1
I looked guys, everywhere, and cannot find a description of the procedure for adjusting the timing on my 4.2L. Any description at all merely says“Use a timing light and aim it at the harmonic balancer”.DUH, I get that, I can do that all day, but WHAT lines do I line up with thefixed (plate? marker?) part on my engine? Looking at my harmonic balancer, Isee scribe marks and a Yellow painted line which I assume is TDC.
I also cannot find the BTDC ignition setting that I need to achieveusing the light, and I also assume I’ll need to interpret the scribe marks toget to the necessary BTDC timing.
Is this posted somewhere that I haven’t found?
 

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1970-1995 Range Rover Classic
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Hi - Idle Speed - 665-735 rev/min
Ignition timing at 800 rev/min MAX
Dynamic ignition timing 6 degrees BTDC, though if your engine is tired, you can likely see added performance advancing it a bit. Mine is around 15 or 16 degrees BTDC and runs very well.

You should be able to see the pointer when looking down from the driver side. As far as TDC mark on the balancer there is usually a "notch" all my other marks were worn off. (if the engine is tired, they also may not be accurate) Get yourself a dial indicator timing light, take a shiney felt pen to mark the notch so you can see it, and go by ear. Start by getting it 6 BTDC and go from there.
 

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also - do you have RAVE? if not - you need it. Its in the sticky above on the main forum page.
 

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Discussion Starter #4
Thanks for the timing data, that's exactly what I was looking for. 16-deg BTDC seems kinda sporty!

The RAVE link is blocked to me at work, and as I recall, from home the link was not active. I will check again.
 

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Thanks for the timing data, that's exactly what I was looking for. 16-deg BTDC seems kinda sporty!
Hahaha yea. might have been 12.... cant remember to be honest. Too many projects since i messed with that. The timing chain is old on my RRC, and when i break down and do the HG, ill replace the front cover and re- set it.
 

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Should be around 12, but yes original documentation states 6 which is a little conservative. At 14-16 I get a light pinging accelerating hard with a hot engine so that is probably as far as you want to go really with 12 being safe..
 

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Discussion Starter #7
I took a hint and looked under the hood at the factory specs on the factory label....8 deg BTDC.

But after I got it running last night and put the timing light on it, I realized that theONLY mark visible on my spinning harmonic balancer was the painted-on yellowstripe, which was showing to the right of the sheet-metal pointer as I waslooking down. I assume that meant my timing was at a setting BTDC, notafter-TDC. Whether it was 8 deg, I have no clue.
Idle seemed kinda low, so I advanced the dizzy just a tweakand buttoned it up. It idles and drives GREAT now, but I again have no ideawhat the setting is. I marked the dizzy with respect to the W-pump before Itook it off, and it’s advanced slightly from that now.
There’s a perfect hill on my way to work that’s steep, and Ican hit it at 65 mph. I hit it, then floored the pedal hoping to hear somepinging. No pinging at all.
Since I have no visible marks on the harmonic balancer,could I/should I go old-school and keep advancing it until I DO hear slightpinging on my test hill, then back down just ‘till I don’t?
 

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By ear should be good enough. There also should be a "notch" in the balancer giving you TDC... I had to crawl around it, bumping it a few times till i found it.....
 

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The balance can move throwing the TDC mark off, so measuring timing is not 100% guaranteed unless you go through the trouble to check the marking (mine was 1 deg off btw).

If you tune it by ear, the car runs fine, does not use too much fuel or runs hot (too late timing) or pings (too early) you should be just fine. It is not all that accurate and precise as some people like to think.

However, it is not unusual for the distributor to be stuck, so for piece of mind, whip off the dizzy cap and check the rotor moves against the weight springs and the vacuum advance moves the base plate if you suck on the advance gizmo with a piece of hose.
 

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THAT'S a LAUGH! How could I tell if I was using too much fuel?!
after a while of tuning vehicles the old school way, you sort of develop a sense for the drive and feel of a well tuned engine in, sounds, smell, performance, temp, power etc. even on fuel injected and computer managed engines where there is little to no room for adjustments.
 

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timing_marks_94_classic.jpg
Hi @Classicpain, going back to your first post, here is a pic of the factory timing marks on the harmonic balancer (this is '94 but I've done timing on '93 and it is same). Not real precise, per RAVE it is marked at 6 degrees BTDC for initial startup (like after rebuild or if distributor is switched like mine). Then time to 8-9ISH degrees BTDC. Line marks with perpendicular "pointer" on top. I find pics really helpful.
 

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Discussion Starter #13
View attachment 265958
here is a pic of the factory timing marks on the harmonic balancer (this is '94 but I've done timing on '93 and it is same)
Pics ARE the best, thanks! Your photo looks like it was taken from underneath, I need to do that and see if I an cleanoff the balancer to see my marks. I can only see a pale yellow stripe, similar to what looks like a white stripein your photo.
Can you tell me what the words are on both sides of the TDCline? And what do the ½ numbers refer to?
 
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