Questions about adding egr valve

[dan2286]

I was just wondering what I would need to add the egr valve back on my engine? How important is it to match the correct valve to a certain engine? Is there any other adjustments that will need to be made after adding it, like carb or timing? Will that eliminate the option of using headers, or can they be made to work?

I have a stock '70 Olds 350, did they even use egr on that engine?

 

[megaladon6]

first thing is WHY? a '70 is too old to worry about emissions and EGR hurts power (not a huge amount but not always small) and is always a pain in the *ss. or is this going into a newer car?
you'd need the proper valve for the engine, the tubes to the exhaust/intake (unless the EGR goes straight into the intake) and the vac switch. i'm sure i'm missing a few parts.
you will need to adjust the carb and dist, but you can should be able to use headers.

 

[joe_padavano]

When functioning properly, EGR is only active at part throttle cruise, so it has NO effect on W.O.T. power. EGR was not required until the 1973 model year (72 on some Calif cars), so your 70 never had it. You need not only the correct valve, but also the control system (either vacuum and thermal valve or solenoid valve and computer). The pre-computer 70s cars that had EGR uses specific timed ports in the carb and associated thermal vacuum switches to properly time the EGR functioning.

 

[Bonnewagon]

A 70' did not come with EGR. 73' was the first year. The purpose of it is to lower the combustion temperature to not form oxides of nitrogen, or NoX on your inspection test receipt. It works by diluting the incoming gas/air mixture with inert gas(exhaust). A side result is that you can use lots more timing to try to make some power back. If your motor has it, it's not a big deal, but probably no one in the world has ever added it to a motor that didn't have it.

 

[dan2286]

I was hoping the motor maybe came with it, but I guess not. The only reason I considered adding it is because it does not use any power and may improve gas mileage. If I was able to add it and use the parts from the same year, I probably would do it. Since from what I know, egr is really engine specific, I will not even try. Probably to much money to even risk wasting.

 

[turbo78]

if you are after better fuel economy, then i suggest getting a simple LM-1 wideband and start tuning for it. very simple adjustments to timing and rich/lean conditions can dramatically change your economy 😀

 

[megaladon6]

EGR doesn't help MPG and it robs power, it does help lower NOx--that's it. all it does is recirc exhaust gasses in to the intake to lower the cylinder temps.

 

[dan2286]

EGR doesn't help MPG and it robs power, it does help lower NOx--that's it. all it does is recirc exhaust gasses in to the intake to lower the cylinder temps.

Can I ask how it ribs power when it is properly working?

 

[billyjack]

Can I ask how it ribs power when it is properly working?

It dilutes the intake air/fuel mixture with exhaust gas to lower combustion temperature. Higher combustion temperature equals more power. Original applications would prevent EGR at idle or during engine warmup since it would cause the engine to stall. EGR was also disabled at full throttle so that total power output of the engine was not reduced when full throttle was necessary.

Bill

 

[dan2286]

Can I ask how it ribs power when it is properly working?

It dilutes the intake air/fuel mixture with exhaust gas to lower combustion temperature. Higher combustion temperature equals more power. Original applications would prevent EGR at idle or during engine warmup since it would cause the engine to stall. EGR was also disabled at full throttle so that total power output of the engine was not reduced when full throttle was necessary.

Bill

That was pretty much how I thought it operated. So, yes it does rob power, but only when extra power is not even needed.