[Shockwave78]

Originally Posted by PunchT37

Or, if no degree wheel, if I were to pull the cover again, I would use the 4 degree advance symbols and go from there. If you have a multiple key crank gear.

Have you had the same issue? Just want to make sure, I am coming around to that idea as well.

[PunchT37]

Originally Posted by Shockwave78

Have you had the same issue? Just want to make sure, I am coming around to that idea as well.

I have run that same cam in a stock W72 400. It ran well, so the cam is not "too big".

It has been more than a few years since I installed that cam. It was not my car. But, it did have adjustable rockers and a 3 keyway chain. I did not use a degree wheel so, if I were to guess my own work, I most likely used the 4 degree advance setting.

This was a `79 Trans AM, SE, WS6 car.

[Shockwave78]

Originally Posted by Stan Weiss

The amount of piston movement around TDC is very small. You could be off 10 or so degrees and not see it checking that way.

Do you know the diameter of you dampener? If not can you measure the dampener's circumference? I could than make you a pdf of a timing tape.

Stan

I am not able to measure it right now, but it is the stock balancer and from some quick research I came up with 6.8 inches

[Stan Weiss]

Originally Posted by Shockwave78

I am not able to measure it right now, but it is the stock balancer and from some quick research I came up with 6.8 inches

See how this works.

Stan

[Gach]

If I were you I’d definitely invest in a degree wheel, you can make a piston stop out of a spark plug. Its really important to know where cam is, if it on 109, or completely off like 112-113 which is really retarded. That way you can also fine true top dead center.

[Stan Weiss]

Originally Posted by Shockwave78

Idle speed is set to 750 and I am seeing about 15" of mercury. With the stock cam, the vacuum was 18-19", I was expecting a drop with the new cam, but I wasn't sure how much it should be.

Originally Posted by Shockwave78

Out of all those, it is closest to late valve and late ignition timing. I am not sure which because I do not know what the vacuum should be with that cam. At idle the Vacuum I saw was 10" +/- .5". I disassembled the carb and the float was bent in the wrong way, so as the fuel level dropped, the needle never opened. With constant fuel pressure, I'm sure the needle was never seating. Everything else looked good so I reset the float and will be putting the carb back on today, if that doesn't fix the issue I will probably end up pulling the cam and reinstalling the stock one.

I am working on a couple of different things and so I don't catch this until now. Which one is correct? After your first post I did a rough calculation and came up with your engine, cam and 8.0:1 CR should show about 14.7" at idle.

Stan

[slowbird]

Originally Posted by Gach

If I were you I’d definitely invest in a degree wheel, you can make a piston stop out of a spark plug. Its really important to know where cam is, if it on 109, or completely off like 112-113 which is really retarded. That way you can also fine true top dead center.

Really??? 112-113 is really retarded? No it isn't 112 is starting up! Yes it would probably run better at 109 but that 3-4 degrees is not causing these issues.

[Stan Weiss]

Originally Posted by slowbird

Really??? 112-113 is really retarded? No it isn't 112 is starting up! Yes it would probably run better at 109 but that 3-4 degrees is NOT causing these issues.

Brian,
I fixed it for you.

Stan

[slowbird]

Originally Posted by Stan Weiss

Brian,
I fixed it for you.

Stan

Thanks Stan

[Gach]

I was just wondering how long it was gonna take..Let me help you out, the whole purpose of checking a cam and making sure its in correctly. I installed one dot to dot. It was supposed to be in at 108. Turns out it was in at 114. I just used the 112-113 as and example. My whole point was that it could be retarded. Whole point is to help the guy out. But I guess you just didn’t get it. But that’s OK we know it’s harder for some people.

[Gach]

I should say come to fine out that cam was ground on 114 not a 108.

[Gach]

Little more help for you, maybe it’ll sink in. If it’s on a 109, once that chain stretches it will end up at 111-112 which is exactly what they want. But if it checked and turns out it’s 114 then chain stretches 2-3 degrees then guess what thats 117. I’m not saying that’s what it is but having experienced it.. its possibility.

[Gach]

Obviously he has other issues going on, sounds like the Carburetor is one of them, plus valve adjustment was off. Poor guy is trying to narrow it down.

[slowbird]

Originally Posted by Shockwave78

Out of all those, it is closest to late valve and late ignition timing. I am not sure which because I do not know what the vacuum should be with that cam. At idle the Vacuum I saw was 10" +/- .5". I disassembled the carb and the float was bent in the wrong way, so as the fuel level dropped, the needle never opened. With constant fuel pressure, I'm sure the needle was never seating. Everything else looked good so I reset the float and will be putting the carb back on today, if that doesn't fix the issue I will probably end up pulling the cam and reinstalling the stock one.

I thought you had said in a previous post (post 18 on 1st page) vacuum was 15 at idle with current cam (18 with stock)? Now it's 10?
Any chance you can post pics of spark plugs? I would be looking into carb and ign timing.

[slowbird]

Originally Posted by Gach

Little more help for you, maybe it’ll sink in. If it’s on a 109, once that chain stretches it will end up at 111-112 which is exactly what they want. But if it checked and turns out it’s 114 then chain stretches 2-3 degrees then guess what thats 117. I’m not saying that’s what it is but having experienced it.. its possibility.

He just got it running, I don't think we need to bring chain stretching at this point.

[PAUL K]

GTOGEORGE didn't degree in his cam sometimes and he ran sevens! If the cam timing isn't off a tooth or more you are splitting hairs and that's not the issue.

I know one guy who's cam timing was off 30° and he still ran bottom 8's.


Carry on

[slowbird]

Originally Posted by PAUL K

GTOGEORGE didn't degree in his cam sometimes and he ran sevens! If the cam timing isn't off a tooth or more you are splitting hairs and that's not the issue.

I know one guy who's cam timing was off 30° and he still ran bottom 8's.


Carry on

The cranking compression shows it isn't way off, but people seem to have tunnel vision on that.

[Gach]

Pual I can’t believe your even saying that. I’m not going to get into it, its a waste if time, but a cam ground on a 114 changes the overlap, then compression comes into play.. so a cam on 114 with only 8.1 compression, is going to be a nightmare. especially if it has a ton of overlap. WOW! I’m not saying that is the issue obviously he’s had other issues. But if it is ground wrong it could be compounding the other issues. I mean let’s try to help the guy out instead of arguing over who is the cam genius

[Gach]

Originally Posted by slowbird

The cranking compression shows it isn't way off, but people seem to have tunnel vision on that.

Dude the True cranking compression, wasn’t discovered until the other day. Which kind of Throws off the whole scenario. As more and more comes to light it changes The whole scenario. Carburetor issues valve judgment issues.

[slowbird]

Originally Posted by Gach

Dude the True cranking compression, wasn’t discovered until the other day. Which kind of Throws off the whole scenario. As more and more comes to light it changes The whole scenario. Carburetor issues valve judgment issues.

Dude in his 1st post he states it was 150psi.