Red top 3B Fueling and EGT

[brownbear]

700 on long hill is not unheard of. But if you are seeing 500 that might be more normal on a N/A 3B. I put an EGT gauge in my cruiser before i turbo'd like 20 years ago and was shocked how low my fuel was turned down. When I bumped it up it got hotter, but had more power. I tried too much and then it was hitting like 1300F. SO I dialled it back. I cannot stress enough how much a turbo makes a 3B a normal engine. They are very slow and chuggy without it. I think it's awesome you put a 3B in Land Rover.

 

[KIWIALEX]

Retarded injection timing will give you really high EGT. Along with poor starting and low power.

Just thought I give a reply.

After reading this I fiddled with the fuel pump and it now drives and starts better. EGTs are better now and the engine stays at a good temp at idle and open rd

 

[stevebradford]

Edit: I missed where you said it was naturally aspirated and assumed with those temps you were turbo’d.

The 3B is a high compression motor with 20:1 compression ratio adding a turbo with 10 psi boost further increases that ratio to 23:1 or more. As we know diesel motors run by compressing fuel till it explodes and under boost that extra compression advances the fuel explosion timing by a couple degrees.

Having the timing slightly retarded is highly recommend when adding a turbo.

Higher egts should not be a thing from having the timing correctly retarded when turbo’d. At idle you are not burning enough fuel to have high egts. Under load the boost will inadvertently advance the timing with compression being higher. So if you have the timing retarded by 2 degrees or so, this will actually set your timing back to center under load when your creating higher egts.

 

[stevebradford]

I noticed that my EGTs felt pretty high. I was hardly able to accelerate (At full throttle) past 70km/h without the egts reaching well over 600 even into 700 degrees Celsius and that was on flat ground. And my 3B is in the Landrover series 3 which as far as I’m aware is pretty light compared to the 40 and 60 series etc.

It does reach and cruise at around 90km/h gradually without setting the gauge alarm off and I’m aware it’s not a race car but the egt just seems a little to high to soon. I’m thinking the fuel screw may need to be turned down as it may be over fueling as it does puff out a little black smoke when reved

Just wondering if anyone else had any insight to this?

Note: the EGT sensor is right on the manifold

Since you are are N/A and experiencing such high egts as 3B’s running a turbo I would assume you are correct that it is over fuelling. Also wise to set it to the factory timing marks on the injection pump.

Dialing in the the max fuel adjustment here is super easy to play with. I suggest reducing that by 1/2 turn increments just until you see that puff of black smoke when revved not under load stop and hopefully see a reduction in egt’s.

 

[Dougal]

Edit: I missed where you said it was naturally aspirated and assumed with those temps you were turbo’d.

The 3B is a high compression motor with 20:1 compression ratio adding a turbo with 10 psi boost further increases that ratio to 23:1 or more. As we know diesel motors run by compressing fuel till it explodes and under boost that extra compression advances the fuel explosion timing by a couple degrees.

Having the timing slightly retarded is highly recommend when adding a turbo.

Higher egts should not be a thing from having the timing correctly retarded when turbo’d. At idle you are not burning enough fuel to have high egts. Under load the boost will inadvertently advance the timing with compression being higher. So if you have the timing retarded by 2 degrees or so, this will actually set your timing back to center under load when your creating higher egts.

Keep in mind when you inject more fuel with a mechanical pump it takes longer (crank degrees) to inject which effectively retards the timing. This is the major reason people advance timing when injecting more fuel. But advancing the timing does increase mechanical stress on everything. I suggest keeping the stock timing when you turbocharge and add fuel as it naturally retards with the extra fuelling under higher load.

The effect on exhaust temperatures and energy (pulse strength) can be easily noticed in spoolup on a turbo motor. Retarded timing drives the turbine harder.

 

[Bluebj42]

I can’t imagine the small amount more fuel injected into a tractor motor will affect the timing as much as advancing the timing

 

[Dougal]

I can’t imagine the small amount more fuel injected into a tractor motor will affect the timing as much as advancing the timing

There isn't anyone here saying it will. Fuel quantity injected is dynamic and always changing, advancing/retarding timing moves everything.

 

[frankenyota]

@KIWIALEX did you have the injectors overhauled?
I would be checking the spill timing as already mentioned then play with fuel adjustment. When l got my HJ47 it was very slow to accelerate and l checked the spill timing of the pump and found it was out. It ran heaps smoother and accelerated better, well as much as a 2H NA does like the swap you did

 

[KIWIALEX]

@KIWIALEX did you have the injectors overhauled?
I would be checking the spill timing as already mentioned then play with fuel adjustment. When l got my HJ47 it was very slow to accelerate and l checked the spill timing of the pump and found it was out. It ran heaps smoother and accelerated better, well as much as a 2H NA does like the swap you did

Yep Injectors and fuel pump were both refurbished before first start of the engine. Iv had a fiddle with the pump. I’ll keep tweeking it to see how I got. At this stage after winding in the fuel screw for less fuel when it starts after about a second or 2 it goes into a slightly rough idle but if I give it a small amount of throttle (same amount a choak would give at half pull) it’s fine then after about 10 seconds it idles perfectly.

Might just take it into a diesel specialist if I can’t sort it.

 

[frankenyota]

The idle will change when you adjust the fuel screw, the idle will increase when you add more fuel so maybe it's needs more idle as you back off the fuel?

 

[Dougal]

I just realised this engine was rebuilt. Any chance the pump drive gears were installed a tooth out? A tooth retarded would give you high egt and low power.

 

[frankenyota]

@Dougal would that be picked up when spill timing? I thought my 2h was out a tooth but it turned out that the adjustment holes were caked solid with dirt so couldn't get to the correct timing mark.

 

[Dougal]

@Dougal would that be picked up when spill timing? I thought my 2h was out a tooth but it turned out that the adjustment holes were caked solid with dirt so couldn't get to the correct timing mark.

Yes it would.

 

[KIWIALEX]

I just realised this engine was rebuilt. Any chance the pump drive gears were installed a tooth out? A tooth retarded would give you high egt and low power.

Ahh no I don’t believe so. I installed the fuel pump but I made sure to triple check the marks etc as I installed it.

Here’s a quick timeline.

Start if the thread: it had a rough starting and high EGTs

Since the start of the post first thing I believe was I loosened the fuel pump and angled the top towards the block (advancing I think) after I did that immediately the engine started a lot better. The EGTs were noticeably lower. They’d sit at about 200-300 D Celsius at about 50kmh

But after doing the first long distance drive on open road EGTs were at about 550 - 600 d Celsius traveling at about 90 kmh (56mph)

Did a little digging at it still seemed a little high noting that the landrover weighs about 200kg less that the bj42.

Next thing iv done was wind in the fuel screw half a turn. Result from that was it now again has a slightly rough start and the egt have more or less stayed the same for travelling around town

 

[frankenyota]

If you are trying to time the pump by moving it on the match marks you are only guessing. Spill timing the inline injector pump is the only accurate way to get timing correct.
This is the 3B spill timing

 

[KIWIALEX]

If you are trying to time the pump by moving it on the match marks you are only guessing. Spill timing the inline injector pump is the only accurate way to get timing correct.
This is the 3B spill timing
View attachment 4213500View attachment 4213501View attachment 4213502

Yeah I’ve looked at this before. I get what it’s saying but I’m not exactly sure what I’m looking for when doing it? I get the fuel will be pushed out of the injector port, but am I looking for it to be at the surface each time the crank does 1 revolution back to 14 deg BTDC

 

[frankenyota]

I didn't use the tube but the idea is when the fluid or point of injection/ spill starts it should be on the timing mark. I allowed a small build up of fuel on the fitting and slowly rotated the crank and watched the point of spill from the fitting. If out adjust pump to suit, l turned back the crank and rotated to the timing mark instead of a full crank rotation. Hope that makes sense.

 

[KIWIALEX]

I didn't use the tube but the idea is when the fluid or point of injection/ spill starts it should be on the timing mark. I allowed a small build up of fuel on the fitting and slowly rotated the crank and watched the point of spill from the fitting. If out adjust pump to suit, l turned back the crank and rotated to the timing mark instead of a full crank rotation. Hope that makes sense.

Ah yep that makes sense

I take it if the fuel spills late timing needs to be advanced and if it spills early it needs to be retarded

 

[frankenyota]

If it spills late it is already advanced, eg more timing