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Hey guys have old blue(84 F250) here and I was looking into doing an EGR delete. I have the 460 with an edelbrock 1406 on it and I’m doing a rebuild of the carb and when I was taking it off realized there is a plate under the carb and it is what the EGR valve connects to. Is this something that I have to keep and modify to do a delete or is that one thing I can just trash and get another spacer and call it good? Pictures will be attached. Manifold side Carb side And also what are the plates on the inside of the intake? And YES I know how dirty she is. Had her running for the first time since 05 this week
I dont know if anyone makes a delete plate?
Maybe someone else knows?
The problem is the ear that is off the side of the plate has to be covered and with that said the gasket also needs to be in that area.
Use a high heat gasket between the intake & plate and I think I would also use a thick gasket between plate & carb to keep carb cool as you can, and leave the plate just dont hook up the hose to the valve.
Make sure you plug the hose so you dont have a vacuum leak.
Dave ----
The carb was sitting on a double gasket. But have you ever seen that bottom gasket for the intake to EGR spacer. I have no clue what to even try and search for it.
You can delete that adapter but you have to block that port in the intake or you will have hot exhaust gases blasting up under/besides the carb... which would likely end badly. It looks like they have combined the carb heat riser and EGR functions into one piece with this setup so it wouldn't be a terrible idea to keep the spacer and just remove the the EGR valve and put a small blockoff plate there.
Do you have emissions testing in your area? If so, don't just remove the EGR valve and replace it with a block-off plate. You'd quickly fail a visual inspection.
On my '84 351W, I blocked off the exhaust crossover passage in the intake manifold. I used manifold gaskets that did not have openings for the crossover passage. I wasn't joining the "Get rid of all that pollution crap" club. I was doing this due to excess heat affecting fuel in the carb.
With this passage blocked off, no exhaust gas is available for the EGR system. The valve is just going along for the ride now. In a belt and suspenders approach, I fabricated a metal block-off plate to fit between the valve and spacer. I put a gasket against the spacer. Other than the slight extra thickness of this plate, everything still looks totally stock.
Be sure to disconnect and plug the vacuum line to the valve, in case the valve ever springs a leak.
You could add the block-off plate by itself if you don't want to bother blocking off the exhaust crossover passage. But if you ever do experience heat issues with the fuel in the carb, making this mod will be a huge help.
Some people use JB Weld to plug the exhaust hole. As long as you seal around the 4 holes (shown in red below) you should be fine. I would buy a spacer close to the same height as the old EGR spacer to make the carb studs and the original carb height work out.
You can delete that adapter but you have to block that port in the intake or you will have hot exhaust gases blasting up under/besides the carb... which would likely end badly. It looks like they have combined the carb heat riser and EGR functions into one piece with this setup so it wouldn't be a terrible idea to keep the spacer and just remove the the EGR valve and put a small blockoff plate there.
Okay I looked a little harder and was thinking the same exact things everyone is suggesting or did.
Even if the OP doesn't have emissions testing where he is at, how is it going to effect the drivability of his truck by deleting the EGR? Would the distributor curve have to be changed as well?
Just brainstorming.
Do you have emissions testing in your area? If so, don't just remove the EGR valve and replace it with a block-off plate. You'd quickly fail a visual inspection.
Originally Posted by Franklin2
Some people use JB Weld to plug the exhaust hole. As long as you seal around the 4 holes (shown in red below) you should be fine. I would buy a spacer close to the same height as the old EGR spacer to make the carb studs and the original carb height work out.
Fortunately Texas has this truck exempt and we don’t do emissions test anyways. 👌🏼
I was looking at the spacer that edelbrock makes but it won’t cover the hole for the exhaust gas, so I’m just gonna try and find the same gasket which I think i did for like 10$ and glob some JB weld down in there and just plug off vacuum lines. I haven’t noticed a lot of vaporizing but my carb is being rebuilt and cleaned right now. Also the nuts for the carb were barely hand tight 🤦🏼♂️
Even if the OP doesn't have emissions testing where he is at, how is it going to effect the drivability of his truck by deleting the EGR? Would the distributor curve have to be changed as well?
From my limited experience with a 351W, the side effects are very minor. I noticed a slight bit of pinging at part throttle settings.
There's no EGR flow at idle or full throttle, so no difference there. With part throttle, I could adjust the gas pedal just a smidge in either direction and all was good. I suppose you could retard the base timing, or tweak the distributor curve, but I didn't make any changes as the pinging was so slight.
EGR is one of those systems that gets an undeserved bad name. Its primary purpose is to reduce NOx formation, but it also allows increased timing advance and reduces cylinder temperatures under certain conditions. I had to block off the exhaust crossover passage to reduce heat reaching the carb, but was hesitant to do so because this would also kill the EGR system. I investigated some alternate path to feed the EGR valve but couldn't come up with a workable answer.
Oh yes, the EGR deserves any bad name anyone wants to give it. Putting exhaust gas back into the intake of the engine is not good in simple terms. Once you do that, then the rest of the engine is tuned for it, and that is what causes the problems. It's main reason for being is as was said, emissions. Does it reduce combustion temps and thus reduce pinging? Yes. But this is more a product of the design of the engine and combustion chamber along with the tune of the engine such as jetting and ignition timing.
Engines ran fine since the early 1900's to around 1970ish without EGR systems.
