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.