spaghetti dinner under the hood

cesully · 05-08-03, 03:01 PM

Hey Folks,
Could any of you late 70's owners shoot a few pics of where the vacuum hoses connect to. I removed my card for cleaning and after I put it back I ended up with 4/5 hoses I.m not sure where they connect to. I have a '78 Siver Anni and the hoses I'm talking about are coming from the EGR valve ( on the RH side of the motor), the hoses from the air cleaner and the 3 hoses from the fitting on the front of the intake manifold.

pics and or text description would be appreciated,

thanks a lot,

Craig

cesully · 05-08-03, 03:09 PM

Sorry for the mis-spell, I meant to say carb as in carburator.

thanks much-

rpounds · 05-09-03, 10:10 PM

I have a '75 and I would be glad to take some shots if you think it would help. However, if you go to www.docrebuild.com and look at the catalogue under vacuum hoses or emissions equipment, there will probably be a very good picture of the hose, routing and connections. That's where I found the info to put mine together correctly. Let me know if you want pics of mine and I will get some for you.

Ron

page62 · 05-09-03, 10:29 PM

Now is a good time to remove that smog stuff (only for test purposes, naturally)...

Stallion · 05-10-03, 12:15 AM

Quote:

Originally posted by page62
Now is a good time to remove that smog stuff (only for test purposes, naturally)...

Why? Wouldn't he not pass emissions then?

78SilvAnniv · 05-10-03, 01:38 AM

...don't require emissions testing. Thank goodness my county doesn't!

Heidi

Stallion · 05-10-03, 09:39 AM

Quote:

Originally posted by 78SilvAnniv
...don't require emissions testing. Thank goodness my county doesn't!
Heidi

Mine does.

cesully · 05-10-03, 11:30 PM

Thanks, Ron for the info- I'll follow up with that web site.

Heidi/Stallion/page62

I recently bough this car (approx. a month agao) and it already had the smog pump and associated brackets, plumbing and other hardware removed- wasn't real happy about it. Previous owner thought '78 didn't come with it- I told him that was incorrect. However, my county; Cobb exemps cars older than 1979 for state inspections- you might not have to have your '78 inspected this year either Heidi since you live in the Atlanta area.

Regards!

78SilvAnniv · 05-11-03, 12:58 AM

...and haven't had to be inspected yet.

We're not in a smogging county (too far from Atlanta?) and I think that by the time this county becomes a smogging county, my 78 will be old enough to be exempt.
All of my smog equipment is removed and in a box. Don't need to use it, but I want it to stay with the 78.
H

rpounds · 05-11-03, 01:16 AM

I often see posts here about people ripping the smog equipment off of their cars thinking that they are going to get some kind of huge neck snapping power gains. All I can say to that is (please excuse my frankness) hogwash. What robbed the power out of these cars was not the smog pump nor the EGR. And with modern straight through design cats, not even the cat is the culprit. These mid seventies cars were robbed of their power by the lowered compression ratio, anemic cams and lean fuel/air mixture. When you rip all of the 'smog equipment' off the engine, all you are doing is increasing pollution and violating federal law.

An engine can be made to run clean and strong if you know what you are doing (therein lies the key). There is no reason to make a gross polluter out of one of these classic beauties in order to get a little 'seat of the pants' thrill out of them.

78SilvAnniv · 05-11-03, 11:12 AM

Quote:

Originally posted by rpounds
An engine can be made to run clean and strong if you know what you are doing (therein lies the key).

Is there a way to do this without tearing into the engine?
My smog pump was removed when it froze up and I had to cut the belt to get home, I've just never replaced it.
Heidi

rpounds · 05-11-03, 01:00 PM

Heidi,

In a word, no not really. In order to get these things moving, the bare minimum that needs to be done is raise the compression and replace the cam with something that will allow it to breathe. Some exhaust work needs to be done (I'm not talking about taking the Cat off and throwing it away), some carb tuning and especially timing.

But my point was this. I often hear people bemoaning the presence of a smog pump and egr and pointing to them as the reason why these things are such sleds in stock form. And that simply is not the case. The air injector pump for instance, probably doesn't rob more than 3-5 HP, if even that much. Beyond that, all it does is inject air into the exhaust stream in order to help complete the combustion of unburned gases. On later cars ('75 and up) the Cat serves the same purpose - to complete the combustion of unburned fuel suspended in the exhaust gases. A quick note about Cats. The older designs that were OE on our 70's models were pretty restrictive. The new straight through designs are nearly transparent as far as restriction is concerned.

Now for the EGR. The EGR does nothing during hard acceleration. The EGR opens in order to introduce exhaust gases (Thus the name Exhaust Gas Recirculation valve) back into the intake manifold. A properly working EGR system only opens during high vacuum conditions.

Scrapping these parts in order to gain power is not really productive. It certainly does make working in the engine compartment a lot easier!!

But in reality, it's not going to do much for the seat of the pants feeling you get when you step on the loud pedal.

Just my .02

78SilvAnniv · 05-11-03, 07:15 PM

...and I am taking it to heart, but this goes against everything I was ever told about smog stuff!
I think this way of thinking will be a long time in coming around, not just for me, but for many people who have been led astray about smog equipment.

Is there a way to tell what kind of cam is in your engine without tearing it down to actually see? I have a GM crate engine in my 78, and all I know about it is that it is a 4 bolt main. How would I find out about its' compression and the cam, heads and so on?
Would the engine numbers tell me?..and how hard is it to do a compression test and is it accurate?
H

Stallion · 05-11-03, 10:08 PM

Quote:

Originally posted by cesully
Thanks, Ron for the info- I'll follow up with that web site.

Heidi/Stallion/page62

I recently bough this car (approx. a month agao) and it already had the smog pump and associated brackets, plumbing and other hardware removed- wasn't real happy about it. Previous owner thought '78 didn't come with it- I told him that was incorrect. However, my county; Cobb exemps cars older than 1979 for state inspections- you might not have to have your '78 inspected this year either Heidi since you live in the Atlanta area.

Regards!

What engine do you have? Because if it's an L48 then it doesn't have the A.I.R. pump. It just comes like that. But I don't know about the other smog "accessories".

rpounds · 05-11-03, 11:42 PM

Heidi,

Somebody may chip in here and give you some advice as to how to determine cam specs without tearing down the engine. However I'm not sure just how accurate that would be. Lift is easy enough to determine, but duration and lobe centers are probably another story.

You can get a decent idea of dynamic compression ratio with a compression gauge. However, static compression ratio is a completely different story and is dependent upon cam overlap.

To check these things out, you would be best off to contact the manufacturer of your crate engine. They should be able to tell you how the engine was built.

I know this goes against the grain with a lot of people's conceptions concerning smog equipment. I live in California, the LA area to be exact and have the most strict emissions testing in the country. I've been building engines since I was 15 years old in '72. These mid 70's vettes can be made so absolutely SCREAM . . . and still retain the ability to pass inspection.

Ron