4BT timing, how much?

[Steve Graham]

I've advanced the timing to 1. 3mm (from 1. 0)and have seen the EGT's come down slightly (and performance go up) and was wondering how far I can safely take this?

Does the nonintercooled B's respond the same as my 6BTA?



thanks

Steve

 

[HoleshotHolset]

...here's some random thoughts on timing.

Since I don't know how mm of lift compares to ° of timing on the VE pumps... . it's hard to say.



If you can keep headgaskets in it at higher ° of timing and the amount of fuel you are pushing through it demands more timing... then more power to ya... crank her up.



It should respond to the timing just like a 6BT.



At some point increased timing will be counterproductive..... you will quickly notice when this happens.



Dyno tuning would be helpful, if you could do it.



Matt

 

[R.E. Miller]

Do not take the timing too far. If your lower your egt's, and it still sound good, go with it. Timing that is too far advanced causes detonation, which causes cracked pistons, which eliminates the whole beauty of the diesel engine, longevity. I would not go past 1. 7mm of lift.



Russell

 

[Steve Graham]

Understand about not wanting to go to far. I've ended up timeing at 1. 41mm. With all the injections lines off that was as far as the pump would rotate.



Steve

 

[R.E. Miller]

Just make sure that the little bugger doesn't sound like a full out tractor pull tractor at idle, you want it to sound smooth, not like four ballpeen hammers

Russell

 

[HoleshotHolset]

Russell: You described exactly how Deo's 1. 6L VW sounded after we put an insane fueling pump on it. Too bad it only ran down the street about 500' before it ate a headgasket. :-laf



Matt

 

[therabbittree]

i love that heehhehehehe soon soon again with teh metal head gasket heheh egiddy like a little girl ha

later

deo

 

[R.E. Miller]

Yikes!!

I would only watch Deo set the racks on one of his "D"etroit's with an armor suit and an escape pod with the sound of that lil' diesel torque and dork deal



Matt,

Isn't it real cool, at least to diesel junkies that finite differences in sound really engage the brain? For instance, how I was listening to hot farm tractors and noticed that some would idle around like happy little farm tractors with tiny puffs of smoke every now and again with "timing" noise that sounded quite sane in the world of normal tractor RPM, but when that same docile little tractor would chain up to the sled and the RPM's would enter whirlygig mode, the smoke and sound would be off the charts Likewise, some tractors were real turds to get started (me thinks low compression, yeehaw fuel: ok) lots of smoke that makes sense, white at low rpm, black when the throttle is blipped, but otherwise not black until the load is dropped on it. Point is... . forgot, love the male mind anyhow, diesel is cool, and have you seen the NEW cummins... . just for guys like you Matt. Huh, you have to know... . the QSK... . 78l he he he he 3500Hp all day, like 3750Hp standby, AND over 10,000ft/lbs at 1500Rpm Only weighs a tad over 23,000lbs BTW, can get it factory equipped with twin staged turbos, that takes the stock number of six up to 12

Later guys,

Russell

 

[HoleshotHolset]

Isn't it great knowing that there are more of us diesel geeks out there?



I'm diesel insane..... certifiable.



Matt

 

[Steve Graham]

The results,,

I ended up timing it @ 1. 4mm. It took me 3 days to get the air out of the system, bleeding about a half gallon of Diesel. Traced it to a air leak where the fuel line goes in to lift pump. What a pain! But I never once thought of "I wouldn't have this problem if it was a gasser"! Any way I think it runs smoother, and a little quiter. The EGT's don't hang at 400F as long for cool down and now I can turn up the fuel screw a notch more.

Steve