Timing Found shop in San Bernardino CA.

[J.P.]

If you want to read the book go back and look at my old posts, but I finally found a reliable shop to the set the timing on the Motorhome, so do you think 19 1/2 degrees BTDC is too much, apparently the mechanics that put the pump in when they installed the engine got it a tooth off, at this point I was only scheduled for setting the timing which is now at the bottom of the kidney slot at 15 BTDC, which just that much made a big difference, so I can't wait till we take it apart and put it together right, which will be in the next couple of weeks. I believe we will start around 3 to 6 degrees BTDC unless someone has a suggestion the rig is a 1985 Jayco 25 ' Motorhome 11,000 lbs with a 1994 7.3 IDI with ATS turbo the only other mod since the old posts is I removed the muffler from the exhaust, it seems to breath better, still has 20' of pipe to go thru so I only noticed a bit more noise, mainly under load and running downhill coasting it rumbles a little. The shop is Diesel Injection Service in San Bernardino and they have been there since 1959.

 

[OLDBULL8]

With the gears in the correct alignment for the IP, with a turbo 9.5* to 10* BTDC is about right, that depends on how old the injectors and IP are, but it's a good place to start.

 

[icanfixall]

Great find to start off with but try at least 8.5 or 9.5 degrees before top dead center. I feel you will be much better off at that timing. Its a terrible thing to learn some shop has your gear timing off by one tooth. Very sorry to hear about this. I think you should go back to the original shop that removed the pump, gear and cover and tell them what they did wrong. They need to know whats wrong with thier work so they can improve for the next customer. Be nice but be firm...

 

[J.P.]

Its way down in the Torrance ca area, and they are not really a diesel shop its a place where the previous owner took it to put this engine in originally. so for the most part I don't trust them any way. For you and oldbull we will set the timing with-in those parameters and see what happens checking temp etc. along the way, I am looking forward to power and mileage etc. Thanks

 

[J.P.]

OK went back to San Bernardino on Friday, Timing was off by 2 teeth, the stock setting is 3.5 for a 7.3 with Turbo, so that's where we started, it did not like that number, I felt it was better at 15 BTDC, so I turned it toward the Passenger side and went for a test run up a local grade, much better. I think it could go a little more but it is all the way in the kidney, maybe should have only moved it one tooth to get the higher degrees? I will try it and see what kind of mileage I get and go from there. No Smoke, EGTs max around 1050, turbo max 7/8 lbs. Hind sight being 20/20 I would suggest any other newbies like myself find out what their timing is if you don't know, could have saved me a whole bunch of headaches

 

[towcat]

part of the confusion is there is two completely different techniques in timing these motors. the first technique is the luminosity method. that method uses the 1deg to 3deg reference mark with a +/- of 2 deg variance. the second uses the piezo meathod, and that meathod uses the 8.5-9.5 deg reference with a +/- 2 deg variance. caution also needs to be used when using the piezo meathod, since some timing boxes needs a dial-in offset of 20deg reference in order to work.
now to really mess you up. the cetane value of the fuel you are running can have as much as 5 deg variance on your timing.

 

[J.P.]

Towcat ya messin with my Head its all good, I know that they used the pulse timing method, so if that helps ya, I figure it is running much better. I just hope the mileage gets better, I wont know till august when I go up toward Lone pine, do you have any Idea how much 1/3 to 1/2 a kidney slot is in relation to degrees?

 

[RLDSL]

Towcat ya messin with my Head its all good, I know that they used the pulse timing method, so if that helps ya, I figure it is running much better. I just hope the mileage gets better, I wont know till august when I go up toward Lone pine, do you have any Idea how much 1/3 to 1/2 a kidney slot is in relation to degrees?

If they were using the pulse method, 3.5 deg would have your engine wanting to run like total crap. Zero power and most likely flames out the exhaust under load . That is so far retarded it's not even funny, while 15 deg will have you munching glow plugs with your corn flakes and your engine trying to run backwards and forwards at the same time Just a hair over 9.5 will have you purring like a kitten.
Are you absoloutly certain of the timing method being used?

 

[J.P.]

Yes 99 percent but I will double check to be sure Thanks

 

[bbjordan]

Just for reference:

The IP gear has 106 teeth and rotates once for every two rotations of the
crankshaft (720 degrees). So 720/106 = 6.79245283. Each tooth is about 6.8 degrees

 

[Agnem]

Whoever is doing your timing is not someone I would trust. If they don't know the factory spec using the pulse method is 8.5 degrees before TDC with a 20 degree offset on the meter, then they are smoking something. I also find it hard to believe you were running at 20 degrees BTDC. With that much advance, your engine would have sounded like a Detroit 2 cycle, and ate glow plugs for breakfast.

 

[J.P.]

I will make a call tomorrow and make sure I am not blowing smoke I will let you know what I find out

 

[vegas39]

If you want to read the book go back and look at my old posts, but I finally found a reliable shop to the set the timing on the Motorhome, so do you think 19 1/2 degrees BTDC is too much, apparently the mechanics that put the pump in when they installed the engine got it a tooth off, at this point I was only scheduled for setting the timing which is now at the bottom of the kidney slot at 15 BTDC, which just that much made a big difference, so I can't wait till we take it apart and put it together right, which will be in the next couple of weeks. I believe we will start around 3 to 6 degrees BTDC unless someone has a suggestion the rig is a 1985 Jayco 25 ' Motorhome 11,000 lbs with a 1994 7.3 IDI with ATS turbo the only other mod since the old posts is I removed the muffler from the exhaust, it seems to breath better, still has 20' of pipe to go thru so I only noticed a bit more noise, mainly under load and running downhill coasting it rumbles a little. The shop is Diesel Injection Service in San Bernardino and they have been there since 1959.

I remember diesel injection service from when we lived in Victorville, good shop, our school district used them for years. Glad to see their still around.

 

[vegas39]

Whoever is doing your timing is not someone I would trust. If they don't know the factory spec using the pulse method is 8.5 degrees before TDC with a 20 degree offset on the meter, then they are smoking something. I also find it hard to believe you were running at 20 degrees BTDC. With that much advance, your engine would have sounded like a Detroit 2 cycle, and ate glow plugs for breakfast.

Im wondering if he made a typo and meant to say 9 1/2.

 

[J.P.]

OK OK I was wrong the timing method used is the Stanadyne Dynatrac Dynamic induction using a light or magnetic probe they use the probe yes still set at 3.5 which is book stock, and after I told them how it ran they suggested that I turn the fuel back up some and leave the timing at 3.5 and try it, see where the power and EGTs go and then adjust timing after that etc. so let me know what ya think now, didn't mean to get everybody riled up. They think max on the kidney slot at this point would be around 8 definitely no more that 10