351W smog stuff

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Jul 6, 2006 | 12:24 PM

Kecky

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Mountain Pass

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From: N. Vancouver B.C.

351W smog stuff

I know this is a bit off topic but since I put it in my 56F100 I thought I could ask. The engine is a 79 with a 2bbl carb and has the smog stuff. Air pump, cross over pipe on back of engine from one head to the other connecting to the EGR valve and various vacuum lines. I want to get rid of the smog stuff. Can i just remove the air pump, remove this crossover pipe and block the holes in the back of the heads with a small plate or plug? I would basically like to simplify the setup as much as possible. The engine cam from a Gran Marquis that had power everything and so many of the vacuum lines ran stuff like the power trunk, heater controls etc.

ANy help would be appreciated.

Kevin

Jul 6, 2006 | 12:34 PM

Kecky

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Mountain Pass

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From: N. Vancouver B.C.

P.S. I did post this in the engine forum but didn't get much of a response. More worried about performance i guess.

Thanks.

Kevin

Jul 6, 2006 | 12:47 PM

mcdonaldm

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Joined: Jun 2004

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From: Edmonton, Alberta Canada

yes you can.
remove the crossover pipe and plug the holes (unless you want a exhaust leak).
not sure how it connects on the 351, but on my 460 you can get plugs (looks like frost plugs) that plug these holes or you can run an NPT tap and use a pipe plug to block them off.

as for the EGR, if memory serves me correct, it is bolted to a plate underneath the carb. i would remove the EGR valve and block it off with a plate and gasket as sometimes they will stick open and cause a nasty vacuum leak. or better yet, yank the carb and manifold off and put on a 4bl carb and manifold to wake up that motor a bit.

just make sure that any open ports are plugged properly as if not you will have vacuum leaks that will make the motor run like crap. on these engines there are a lot of hidden connection ports so look around a lot to make sure you have them all. Best would be to remove any unused vacuum tees and plug them off instead of using vacuum caps as they tend to deterioate (?) over time and cause a leak.

good luck
Mike

Jul 6, 2006 | 05:12 PM

bobbytnm

Roast em' if you got 'em

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From: Rio Rancho, NM

For the small plugs (expansion plugs) to block off the crossover pipe, go to your local engine builder. They generally keep a large stock of those small plugs in house. Its a nightmare trying to find the right size, they will probably be able to look it up or measure it for you.

I did the same thing on my 1972 Caddy 500ci, the AIR crossover pipe went from head to head in front of the engine (yuck) after talking with the machinists at the local engine building place he gave me a couple of the correct plugs. No problem.

Bobby

Jul 7, 2006 | 08:59 AM

Okiedokie

Fleet Mechanic

Joined: Sep 2002

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From: okla

Hey Kevin, I am fairly sure[it has been awhile] that I was able to screw a large bolt into those holes to block them off. I know it seems unlikely, but I believe I did. I sure don't remember tapping the holes, so I assume they were already threaded. I probably coated the bolts with copper coat gasket sealer. I gutted the smog pump and use it as an idler pulley for the serpentine belt. Worked fine so far. Look at the holes where the crossover connected. Joe

Jul 8, 2006 | 11:28 AM

Kecky

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Mountain Pass

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From: N. Vancouver B.C.

Thanks for the replies. I was hoping this was the case. Took another look at the EGR and it is built into the manifold not on a plate under the carb. It looks like, unless I plan on switching the manifold, I will have to keep it. That's not so much of an issue as I was more interested in getting rid of this cross over pipe at the back of the engine.

Thanks again guys.