How can I see if it is the correct advance can?

Thanks

 

You have to get the correct reading of engine vacuum then pull a vacuum on the can and see when it starts to move. It needs to be 2 inches higher of HG vacuum to be correct

 

I would be surprised if Mr. Sloot isn't in information overload by now.

 

I certainly am.

 

Until the OP gets the engine manifold vacuum over 9", I'd see little purpose in checking the facuum can 'cause you don't know what vacuum to expect when you fix what's wrong with it.

 

Mike I only asked to have him pull a vacumn on the can to make sure it's still good. Not to see if it's the correct one. Sounds to me his car was running fine then had a problem. So to me something failed

 

Okay so I switched hose to full manifold today and after that I tuned the carb, I turned the Idle mixture screws more fuel (And the vacuum can checked for vacuum and it holds vacuum)

So I have very good news and some weird news.
The very good news is that the car idles and drives great again the bog is gone.

The weird news is that the I put a T in between the vacuum advamce can and the full manifold vacuum. The result was a very very steady vacuum until I gave a lot of throttle then it would go down,
all sounding normal right. Only problem the steady vacuum was 6 hg???

Am I using this thing wrong or what?

But car runs as it did before

 

I understand.

 

I have to add that in first gear it still had it slightly comming from 1000 rpm to 2000 rpm

 

What are the units of measurement of your vacuum gauge? We here in the USA are used to seeing inches of mercury, abbreviated "in-Hg". Is your unit on that gauge some sort of metric like kilometers of quiche, or something else? I cannot find any conversion whether it be Torr, mm-hg, pascal, atm or anything else that will correlate the value "6", with what you should be reading if your engine had a "300 horsepower" cam.

Ah, take a picture of the vacuum gauge. You Teed the gauge in to the line going to the vacuum advance can. Is that right? If so then that's good. Six inches vacuum is awfully low..............the engine should be on the verge of stalling at that level..................and that's with a long duration cam. I don't think a 300 horsepower cam will run at all with a vacuum reading anything less than maybe 13-14 in-hg.

Borrow or buy another gauge. It makes no sense, whatsoever. Your gauge might be wrong. If not then you have a big cam in this engine whether hydraulic or mechanical. You won't even bother checking whether its hydraulic or mechanical.

First we have to establish the TRUE, actual vacuum and engine idle speed, then we can more or less guess as to what cam you have.

These three threads of yours have a lot of us scratching our heads.

I don't know about the others, but I have not seen proof or establishment of anything and getting information and cooperation from you is like pulling teeth.

I recommended long ago that we have to determine what cam is in that engine before going any further. But, even BEFORE THAT, WE HAVE TO KNOW WHETHER YOUR VACUUM GAUGE IS FAULTY OR NOT.

 

Uh. Hope it's not a metric vacuum gauge.

I've never owned a classic car with less than 12. And yes vacuum will drop when you blip the throtlle cuz the carb plates are opening to the atmosphere.

 

First of all thanks to everybody,

I have been thinking and I would like to explain how I think things worked out, first forget about the vacuum reading.

I got the car it ran fine but it was at the end of the summer really cold outside and we only drove the car for 5 minutes, the car seemed to be running just fine but it might have been that during that first drive the choke did not fully turn off.

When I drove the car this summer the first time for a longer period the problem occured, it might be that it was just the first time the choke fully turned off and it just ran to lean.

I got some bangs in the intake which point to leanliness, but I as a rookie didn't want to mess with the carb so I turned to the forum.
And I got the idea the car maybe ran to rich or other problems were going on.
So I tried to tune the carb a little and checked some things you aksed, but not much changed to the car other than some new spark plugs which didn't solve the problem.

So I started to run the vacuum test which gave weird results and I started think of very obscure problems which didn't lead me anywhere.

So yesterday we came to the conclusion that the advance hose was wrong and I swapped that today and for the first time I properly adjusted the carb today to get the highest idle with the mixture screws and it runs good now.
So effectively the only thing changed now is: hose swap and mixture more rich.

As for the vacuum reading I cannot explain it, I do know my meter is in IN HG and I bought it new a week ago so I expect it works. (Allthough it was a cheap one)

 

30-30 cam in a 302 will give lowest idle vacuum of any GM engine. About 8 in-hg @ 900 RPM.

With 30-30 in my 327 was about 8 in-hg @ 800-850 (when lashed @ .030/.030); about 7 when lashed tighter. WOULD NOT IDLE BELOW ABOUT 800 AND WOULD STALL WHEN IDLE VACUUM DROPPED BELOW ABOUT 6.

Cam now in my 327 gives 8 in-hg @ 950.

Yes idle drops momentarily when you open throttle with no load but recovers quickly as revs climb.

 

If that is indeed true, then you have a damned BIG cam in that engine. Hydraulic or otherwise. I have to take your word in that since you don't want to check it to find out fer sure.

I'd try another one just to make sure. Get a better one this time.

 

What I can do, (because I also think it's a very special reading)
I can go down a shop I know ask their vacuum gauge and I will do a measuring with theirs straigt from the intake plug. And I wil show you the results.

 

That's interesting because that engine didn't have a damned big cam in it when he parked it in the fall, and it ran great.

 

Why couldn't it have it's the first c2 I drove in, I only drove in it for 5 minutes and to be honest I was expecting a calm car since it's 50 years old and has the smallest engine, I know from that 5 minute drive it was way and way more powerful than I expected, and it idled at 1200 at time which kind of indicates it was probably still on choke

 

I think it's time to get off the big cam kick and quit confusing things. He's already said he knows what solids lifters sound like. I think he's said it idles smooth and you're right Critter, it didn't get a big cam by itself while nobody was looking.

 

But what do you guys think of the low vacuum, the car drives okay now so should I worry about it?

 

Oh btw someone asked if I could post a pic from looking into the carb, I don't know if it is still needed but here is a pic from the carb while running 800 rpm at idle