Hi all, Do I really need this EGR, or is there a block-off plate I can swap in instead? It's connected to my Edelbrock. Thanks!
Larry, I really want to know why. Why does that engine require an EGR valve to keep it from pinging. I guess what I’m saying is I don’t understand why some engines need them but other engines don’t have them. Does it have something to do with the timing on those engines? I do know what an EGR valve does. I believe it recirculates exhaust gas through the engine. I always thought that had to do with the emissions.
I know what it does... that's why I'm curious how and why I'd want to recirculate what essentially amounts to blow-by from the lifter valley. At least that's where it looks like 'gases' would be coming from. If I could find a better aftermarket aluminum intake manifold for this 350, I'd get rid of it totally.
Hey Joe, On your profile page it says you have a 72 Skylark. Is it the original engine? I live in Florida and when I was a kid my mom had a 72 Skylark 350. It definitely did not have an EGR valve. I’m just wondering why some engines have them and some engines don’t.
EGR introduces exhaust gas into the intake charge to lower the formation of Nitrogen Oxides. It does this by lowering combustion temperatures. Higher combustion temperatures and leaner fuel/air calibrations tend to increase the chance of ping/detonation. Disabling the EGR in an otherwise stock engine meant to run with it increases the chance for engine ping.
I see said the blind man. Thank you Larry! So… I’m guessing engines, 1972 and above, made for California had different heads and intake manifolds? I’m also guessing a leaner fuel mixture? As I said, my mom had a 1972 Skylark, with a 350 engine and two barrel carb. It ran on regular gas and I never heard it ping.
I know the heads have holes for the A.I.R. pump. Not sure if there were any differences for the EGR. The EGR was a different intake manifold, and the intake had the A.I.R. rails on both sides. You can see that in the intake manifold picture on the right in the page I posted above. EGR and A.I.R. were not fitted to all engines. Your Mom's 72 Skylark would not have had EGR or A.I.R.
If you are using the original carb, you are likely to be lean with the EGR disconnected/blocked off. If you can richen the carb up 2 jet sizes or have access to a non-EGR carb, you could likely do away with the EGR valve function.
Thanks guys. I appreciate it. Yes, the engine is all original...but it looks like it's been taken apart as far as emissions goes. It's originally a 4-barrel car and someone swapped the Q-Jet for an Edelbrock and kept the EGR. It's a CA built car. I'm not familiar at all with Buick engines so the top end is so foreign to me... I hate the intake and the distributor (HEI) placement. There's plates and doo-dads on the heads and intake I'm not familiar with. Sorry I didn't take pics, but I can look at the Assembly Manual and guess what they are. Now that I think about it... there's a bracket that's part of the Power Steering that is missing something. Am I correct that it was probably the A.I.R. pump? It looks like a cast aluminum setup with nothing mounted in it.
Let me rephrase that... I DO like that it's in the front. Talk about convenient. But it's been swapped to an HEI and the upper radiator hose is practically crushing it. I can re-phase the spark plug wires I suppose to turn it so the coil connection is facing more forward and get it out from under the hose. Or get a small body distributor. So yeah... the A.I.R. has been removed. I haven't had much time to get used to this Buick engine yet. Still working out what's what. I'm a Chevy guy. I'd hate to cave to my first instinct and throw a 6.0 LS in there. I would like to keep this car somewhat original... but my right foot might change things.
There may be a simple solution to your HEI issues. A lot of people put the upper radiator hose on incorrectly. It should come away from the distributor and then take a hard turn across the fan shroud to the upper radiator neck. It will work backwards and works better if you have no shroud and a mechanical fan but it is worse for the distributor. Granted, this is not an HEI but you can see that the hose takes the long way around the distributor. If you could share a pic, we'd be able to tell you for sure.
This is a screen grab from a video... It's tough to see but it's jammed super tight against the cap where the tach and Ign. plug in that I don't like it. I can't even unplug them if I want to because of it.
Hmm, it looks like it is mostly correct but you might want to try a later model hose, like off a 75 Buick 350 car as we know they had HEI and it wasn't that close. Rock Auto shows two different part numbers for those hoses. A 76 Century 350 shows an AC Delco 26073X while a 72 Skylark 350 is AC Delco 26028X. How's this look compared to yours? Maybe you can clock the hose at the radiator and the thermostat housing to move it a bit.
I re-clocked my distributor so that the wire connections an vac. cannister face the radiator and have plenty of room for the hose.
