I'm very confused....the other side doesn't have an EGR valve, so how are you comparing the two?

 

He means intake and exhaust side of valve, not other side of the intake.

Exhaust Gas Recirculation, aka EGR, means reburning a portion of cylinder exhaust to cut down on tail pipe emissions. Injection point is jets in the floor of the intake, extraction point is one exhaust valve on each head. Dual function of this passage between heads in to heat the intake for improved atomization of fuel. Fun part is that the passage collects particles from the exhaust and eventually plugs up resulting divorced choke fail, running rich and in extreme cases radiator boil over before engine gets to operating temp. If you know how to look for it, ya can spot it with ice water.

Intake gasket leaks are a thing on small blocks so it will suck oil out of the lifter valley. Exactly the same way you'll get a small pool of oil on the intake next to a bolt, more so with aluminum intakes..

 

This is the driver side hole I'm talking about in the head. Not the Intake. I just need to know if that's supposed to be there or not. I assume it is because if the head had a hole that size I doubt I could get it to run. You can see where the egr ports are on the intake next to it. Sorry for the confusion. It was a 2 or 3 question post.

 

Supposed to be, blind hole, best guess is for cooling, big block heads are the same way.

 

He means intake and exhaust side of valve, not other side of the intake.

Exhaust Gas Recirculation, aka EGR, means reburning a portion of cylinder exhaust to cut down on tail pipe emissions. Injection point is jets in the floor of the intake, extraction point is one exhaust valve on each head. Dual function of this passage between heads in to heat the intake for improved atomization of fuel. Fun part is that the passage collects particles from the exhaust and eventually plugs up resulting divorced choke fail, running rich and in extreme cases radiator boil over before engine gets to operating temp. If you know how to look for it, ya can spot it with ice water.

Intake gasket leaks are a thing on small blocks so it will suck oil out of the lifter valley. Exactly the same way you'll get a small pool of oil on the intake next to a bolt, more so with aluminum intakes..

So I have a piece of 1/4 inch aluminum plate that I can make the size of the mating surfaces of vacuum pod. If I gasket both sides of it, will it fully blow the exhaust from getting into intake? I'm having pretty good heat soak problems in the summer. Intake will be hot enough that you can't touch it. And it's causing fuel to boil out of bowls. And hard starting when hot.

Supposed to be, blind hole, best guess is for cooling, big block heads are the same way.

View attachment 645223

Okay thanks for clearing that up.

 

Yes, those "holes" are for cooling the EGR ports in the head. Just vacuum gunk out of there. Sucking up the oil from around there is normal hence why it's covered in burnt oil all around there. New gaskets will fix all the leaks. You shouldn't be able to touch your intake even if it's running properly. If your engine idle is low and the rad is clean and your thermostat is the correct temperature and it works properly and your water pump works properly and you STILL suffer heat soak, then you might have a scale problem.

 

Thanks buddy. I'm afraid to even try doing that hefty monster of an intake with new gaskets. I have pretty severe back problems so trying to lift a 70 pound iron intake off engine while in engine bay will be extremely hard to pull off without using a cherry picker. Makes sense it's leaking though. Most of the leak dripping off engine is back behind intake somewhere. I originally thought it was rear main seal, so I replaced it when I dropped oil pan to put in new oil pump. Turns out it's not that. Valve cover gaskets were also replaced at the same time. I guess the rear china wall gasket gave out.

 

The intake is supposed to be too hot to touch. In fact, that's how you prove the cross over is blocked without a wrench - choke well cool enough to touch without dipping you hand in ice water first. Dip it anyway in case it isn't. Lean burn engines don't run EGR so they ship with a block off plate where it should be. While you're at it, pull the jet out of the intake floor and replace it with a bolt.

 

I'm gonna need you to elaborate lol. So the cross over being blocked because of the vacuum valve or because it's built up inside with carbon.

The second part is what I couldnt understand. Choke well? And I gotta dip it in ice water? I did see the big deal inside the intake. I'm assuming that's where the exhaust gasses get recycled into the intake for emissions? Does it just spin out?

I don't believe my engine is lean burn if that's what you're referring to. I do know it had a dual pickup distributor. But I had issues getting the engine to start reliably. So i changed it out to a normal single pick up style.

 

There's a passage in the intake that goes from the center of one head to the other. The EGR Ts off that passage and feeds another that leads to the intake plenum.

The crossover passage also provides heat for the factory choke setup. It's common for the passage to get plugged with oily goo and cause improper choke and EGR operation. The well around the choke should be hot during operation, Rick described the test.

Those open areas in the center of both heads are normal and used to keep hot exhaust from cooking the valve cover gaskets.

The goo you found is normal buildup of yucky stuff in the exhaust.

 

What he said and yeah threaded. When everything is working right, the choke well area of the intake should be about the same temp as the exhaust manifold head pipe and ya know, don't grab that bare handed. The other tell tale sign of a blockage is tail pipe temp low enough to hold your hand in front of the exit.

If the original distributor had (2) electrical connections and (0) advance cans, that's a lean burn distributor. Only mentioned ELB to say some motors rolled off the line with a block off plate installed. This morning I'm wondering if ELB was ever an option for trucks and I wanna so no but with used cars anything is possible. Other way to spot a lean burn motor is (2) sets of timing marks and not uncommon for the average brand x guy to use the wrong set.

Base mechanical is the same old, same old - 10-0-10 scale on timing cover, full width groove in the balancer. The other is what looks like a small pen holder / sight hole about 16 degrees away and I want to say on the after TDC side. Google was on the ball this morning:

 

What he said and yeah threaded. When everything is working right, the choke well area of the intake should be about the same temp as the exhaust manifold head pipe and ya know, don't grab that bare handed. The other tell tale sign of a blockage is tail pipe temp low enough to hold your hand in front of the exit.

If the original distributor had (2) electrical connections and (0) advance cans, that's a lean burn distributor. Only mentioned ELB to say some motors rolled off the line with a block off plate installed. This morning I'm wondering if ELB was ever an option for trucks and I wanna so no but with used cars anything is possible. Other way to spot a lean burn motor is (2) sets of timing marks and not uncommon for the average brand x guy to use the wrong set.

Base mechanical is the same old, same old - 10-0-10 scale on timing cover, full width groove in the balancer. The other is what looks like a small pen holder / sight hole about 16 degrees away and I want to say on the after TDC side. Google was on the ball this morning:
View attachment 645230

Thanks for info. I do know timing plate is the normal +10-10. But yeah I had that dual point distributor with no vacuum canister. The whole ignition system had a mind of its own of when it wanted to work. So it's all been bypassed and unhooked with HEI replacement.

I'll try and spin that deal out of the intake plenum today so I can find a bolt for it when I go to parts store to pick up choke cable. As for as the egr actuator goes, like I said I got a 1/4 piece of aluminum that I can shape to size to cover both holes like a block off plate even have a new gasket for it as well. That should also keep it out of my plenum as well right? And factory choke stuff isn't in use anyway. Also would rather not even have cross over at all. I know it will cause engine not to run as well when it's cold but Missouri summers get over 100°f so having a hot intake isnt gonna run real good anyway.

 

I hear that. Pulled the intake off my Red about a month ago to swap it and I swear a lot heavier than when I installed 10 years ago.

 

Probably. I don't use gaskets along the china walls, I use Right Stuff sealant and build a nice bead and then put the intake on.

 

Probably. I don't use gaskets along the china walls, I use Right Stuff sealant and build a nice bead and then put the intake on. View attachment 645231

Yeah I was always brought up to ditch China wall gaskets and rtv them with a 1/4 bead, let it sit up 10or 15 minutes then squarely replace the intake so it squeezes down the rtv evenly. It's such a pain to get the intake off to begin with that Ive never even tried the china wall gaskets. Just always listened to my grandpa lol. I don't think I'm gonna replace the gaskets for intake. I know it's prime time to do it now with carb off. But I don't wanna change snapping one of them old bolts in it. Same reason why I never ripped manifold off to pull out all the air nonsense and that butterfly valve on passenger side. If I already had it out on a stand, sure I'd do it. But when it's up in a 4x4 truck with the front clip on, it's just too much for me to mess with anymore. Gonna be probably removing front clip to do body work before paint and I'll have a buddy then. Just have to see if I get a wild hair to do it or not. I'm not going through too much oil right now. Got a few drops coming off the back engine once I park. Better than it used to be. Had tranny fluid leaking out the transfer case for a while and both from axle seals were gone so I had just a pick grease spot from parking truck in the driveway for 9 months lol. Got all that other stuff fixed though. I don't ever wanna pull the diff out again after that lol

 

In my experience, Lean Burn was on the lowest of all powertrains in trucks. Out of the dozen plus I've had my hands on, 2 were/6 half tons and 1 was 85 318 Ramcharger.

Look for the putrr behind the battery.

 

Here's my home made block off plate I just made out on the shop. That quarter inch aluminum don't play around. I really thought my bench grinder would have shaped it fairly fast compared to steel. Made my rough cuts with angle grinder. Then had to go back and make even closer cuts because it was gonna take 3 fiscal days to get it ground down to the dimensions I wanted. It's a little bigger than the original. Havent put it on intake yet but I didn't want to go to far a waste that nice piece of aluminum

 

You need a special grinding wheel for aluminum otherwise it's cakes up on the wheel and does nothing.

 

I found that out lol. Now I gotta figure out how to get the aluminum out of the stone wheel. I just powered though it but boy did that aluminum get warm

 

I used to have a helper for climbing under the hood.

 

There are no words

 

Well I could not find a bolt or plug to fit that big EGR injector in intake floor. Went to a hardware store that sells all kinds. The closest I could get was a 3/4 pipe fitting. But the threads are just slighting pitched different so the plug won't even start into the hole. So I'm making a plug out of the injector and welding a bolt to it to plug the passage through the injector. I'm sure someone on here knows the exact measurement for the bolt I need but I can't get it in town so I'll just make my own plug

 

5/8-11 and the hard part is finding 1" full thread on the shelf. Drill out the jet, tap if for something smaller to thread inside. Skip the tap and use a wood screw. Fill the jet w/ RTV should work, was gonna do the set on the bench w/ Marine-Tex, now thinking about a spot of mig.

 

Yeah it only took my like 10 minutes to cobble this together. I cannot remember now what size the bolt was. I just grabbed one that was a tight fit in the passage way of the jet. Just free hand cut everything with an angle grinder and cleaned it up on the bench grinder. Put a chamfer the bolt and the the inside of port in hopes weld will penetrate better. My 110 fluxcore probably could weld it maybe with a little pre heat from torch but I'm taking it to my machinist buddy tomorrow. His multiple welding set ups go from welding exhaust to welding buckets for bull dozers

 

If he's already blocked the valve, he shouldn't have to fool with the plenum ports.

 

I'm just doing it purely out of spite at this point. Lol. Plus this plug will have a lower profile inside intake.

 

Well it ain't the prettiest looking plug. But the welds are air tight. Gonna just put the jaws of life on it to tighten it in

 

Intake heating, egr valve and egr jets are 3 different things.

The exhaust crossover for intake heating will always be there. 72ish and back, no such thing as EGR. 73ish and a few years, egr jets between the crossover and the intake below the carb. 75/up adds the valve which adds hot start delay and on demand switching. Thing is the valve only switches one side of the feed and it's not like there are 2 different exhaust passages through the intake.

 

Thing is the valve only switches one side of the feed and it's not like there are 2 different exhaust passages through the intake.

You were doing good until this sentence. The EGR valve switches ALL exhaust gases being recirculated. There IS a separate port from the valve to the intake carb jets. The EGR valve gets the gases from the crossover passage, and opens it to the carb/ intake jets.

Closing off one side would just stop the exhaust from going through the crossover, but not from being sucked into the intake by the engines vacuum.

You are correct, prior to the EGR valve there was just EGR, controlled by the port size below the carb. Between the intake port, and the crossover. Many look and do not see an EGR vlave, and think they do not have EGR system.

 

1st up is the most easily found at swap meets a couple decades ago. '70 340 Holley. Exhaust crossover, no EGR valve or jets.

2nd is my fave, not a tough score, '72 340 TQ. Crossover, no EGR valve, the jets are in the parts washer, one each side.

I think this one is an '81 318 TQ. EGR valve and only 1 jet installed, other one big enough to be not a restriction.

Should be splash plate to avoid scalding the oil, shows the 1 and half passages.

EGR valve removed, clearly separate passages for EGR, crossover.

Because poking around stock. 75-77 440. Both of the ones have only have one jet installed.

This one used to be 77 lean burn 440, has the factory block off plate. Will have to loop back to see about floor jets later.

 

Great post Rick.

 

God, unvalved EGR must have been a tuning nightmare. Can't believe engineers signed off on that.

Nevermind, I've seen enough stupid engineering to believe it.

 

It had less flow then the valved EGR, so not really noticed.

A properly working EGR valve can give you a few more MPG's, but that needs those vacuum valves on the intake to be working right, which most do not any more. You do not want EGR at idle, or full throttle.

 

Exactly my point, no flow under certain conditions, lots under others.

It's generally a pretty simple system and has no bad side effects if working correctly. Plus there are some benefits. Just need to understand it.