the saga continues......and one boneheaded (?) movei

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bizjetmech

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Re previous thread "Tired of looking at cam specs".

After reading some of the commentary, decided to keep the old cam, look at the cam installation. Spent a day and a half, couldn't figure out why my installation would never match the cam card......was all over the damn place, no matter how I installed the crank gear, or whether I "aligned the marks" or moved them one tooth of the cam sprocket in either direction.

Finally figured it out. I had my dial indicator directly on the LIFTER, not on the valve/retainer itself. Cam specs of intake opening/closing were @ .050 of VALVE lift.......put in a correction factor for the stock rocker ratio, and everything fell in nicely. I had the cam advanced too far, evidently.

Started it today. Better, but still screwed up. At least the M1 dual plane clears the hood. Same problem, but not as bad, needs a lot of initial ignition lead to even idle. When at "idle", carb has vacuum out of the timed vacuum port. Idle mixture screws don't seem to have much affect on the idle. Same deal with the timing.....it idles all day with "X" advance, but turn the distributor just 1/8" too far retarded......dies almost immediately, won't restart until distributor moved back to original position. Managed to get it a mile or so down the road and back in low gear.

I'm run out of time to sort out this pig. Anyone know of a good shop in the KC Metro that works this kind of problem, and won't tell me all day "....you should have bought a Chevy....."

And.......anyone using one of the new Barry Grant "Street Demons"? I'm thinking it sure looks a lot like an old Thermoquad...........
 
If you tried degreeing you cam, you go off the lifter!

You might take 8 minutes out and watch this video:

[ame="http://www.youtube.com/watch?v=S7ZzYaMVi00"]ProCharger, Turbo How to Degree Your Cam by Steve Morris - YouTube[/ame]
 
I'm not sure what you're talking about. I indicate off the lifter when degreeing. It's the most accurrate way and what most methods say to do. If the numbers were skewed you had a problem. Judging by the way it runs - you still have that problem.
 
The think the best advice I can give is don't get to frustrated. This may help. With the engine in the car and all the pistons in and the heads on it does make it harder to degree the cam in first remove all the spark plugs, rocker arms, push rods, lifters except the cylinder 1 intake lifter. clean the lifter bore out and just use WD40 to lube the lifter bore ( the lifter should slide up & down freely) Go to the Hughes Engine website or get a copy of the Comp Cams DVD this will give you a good under standing of the process on degreeing in the cam correctly and above all else take your time. Moving the cam gear one tooth will only change the timing of the opening & closing of the valves but the cam will still not be in the correct time.
 
bizjetmech said:
Started it today. Better, but still screwed up. At least the M1 dual plane clears the hood. Same problem, but not as bad, needs a lot of initial ignition lead to even idle. When at "idle", carb has vacuum out of the timed vacuum port. Idle mixture screws don't seem to have much affect on the idle. Same deal with the timing.....it idles all day with "X" advance, but turn the distributor just 1/8" too far retarded......dies almost immediately, won't restart until distributor moved back to original position. Managed to get it a mile or so down the road and back in low gear....
Click to expand...

Please expand on the comment that there is vaccum out of the timed vaccum port....do you mean the ported vacuum, the one above the throttle plate? (As opposed to the one below the throttle plate.) If this is the case, and the idle mixture screws do not have much effect, then you need to look very closely at the throtte plates and make sure they are realy closing properly. From the above 2 symptoms, it sounds like the throttle plates are still open to a fair degree at idle, and that would explain both symptoms. You are likely running off the intermediate, transition ports rather than the idle ports.

See if you can manually close the throttle plate by hand from where they want to rest. If not, check out the plates from the top looking down the throats if you can; the throttle plates would normally have almost no gap to the throat at idle, maybe 2-3 sheets of paper worth of gap. (Not knowing the particular carb at all, that is general info.)
 
The card for the cam I have shows you the degrees @.050 when the intake valve lifts OFF THE VALVE SEAT.

With a 1.5 to 1 rocker, .050 at the valve seat is .0334 AT THE LIFTER. It makes a difference.

When using the .0334 lift number while reading straight off the lifter, the open/close events as indicated on the cam card were dead nuts on.

And sorry......meant "ported vacuum". Project for today is to try to figure out a way to get this thing to idle with the primaries completely closed. The cam reinstall has knocked about 300 rpm off of the idle speed, if I can get the carb figured out, I think it's close. No sense in worrying about drivability yet, until I get the idle sorted out.
 
I use solid lifters and adjustable rockers set to zero lash and indicate off of the spring retainer to degree a cam. It most duplicates what the engine sees.
 
You have a copy of the cam card that you could post?

If it's this one it's tappet lift, not valve lift...
[ame]http://static.summitracing.com/global/images/instructions/lun-00043.pdf[/ame]

You need to quantify the settings you have. Saying it needs a lot of initial is worthless. Where was and is the cam installed centerline? If you said it needs 20* which you think is a lot, you'd at least give people an idea of where you are. I think 20* is probably going to be in the range to get the idle sorted out. If you think 12 is a lot of initial, you'd be way off base.

Good luck
 
bizjetmech said:
The card for the cam I have shows you the degrees @.050 when the intake valve lifts OFF THE VALVE SEAT..
Click to expand...

bizjetmech said:
Re previous thread "Tired of looking at cam specs".

..
Click to expand...

Look, if you are going to post something like this, AT LEAST post what exactly it is that you are referring to Nobody knows what this "previous thread" is or "what cam" you have that you are referring to. HTF is someone supposed to actually give you some actual meaningful advice, or do you just wanna hear yourself *****?
 
are your valves closing completely. what is the cranking pressure.
 
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