New Engine Startup Tuning

69Rcode_Mach1 · Aug 22, 2005

:damnit: :damnit: :damnit: :damnit: :damnit: :damnit: :damnit:

Okay guys I am having a lot of trouble doing some of the most basic things right now. I am getting to the end of my rope. I don't know what is up but for some reason I can't time this thing for the life of me. She starts up and then I go to time her and if I take it any lower than 30 degrees she dies now I know there is something up because my car shouldn't even turn over if I have 40 degrees timing. I want to follow the plan but am stuck between a rock and a hard place. I wanted to time, adjust valves, and finally begin tweaking the carb. But I have decided to atleast get a good idle set and going before I adjust the valves I have a vacuum guage and will take that route. The problem is the thing runs pig rich with only 71 primary and 79 secondary jets. Now I was thinking about the power valve and that something may be keeping it open cause the jetting seems decent for my setup and elevation what do you guys think? I know it shouldn't be so rich when idleing with these jets if the rpms are increased it begins to run cleaner which is why I am thinking the powervalve is dumping gas in there and it doesn't need all that down low. Oh yeah the carb is a 750cfm speed demon with mechanical secondaries. I figure I will get the optimum jetting, power valve, and accelerator pump settings on this carb for when I get ready to slap on the mighty demon carb and then I will just swap it over. I know it is a lot but bear with me guys, I am getting ready to tie the rope around my neck because of this crap.

coolblue65 · Aug 22, 2005

are you sure you have the distributer in right? Sounds like it could be one tooth off.

thehueypilot · Aug 22, 2005

Is your vacuum advance plugged into the timed vacuum port or is it getting full vacuum at idle? It should have no vacuum at idle. If it is running really rich adjust A/F screws all the way in and back them out only 1/2 or one full turn to get the engine to idle better. Jet size has nothing to do with idle quality.

brianj5600 · Aug 23, 2005

Are you using the same damper? Pointer? Sounds like a 10 o'clock pointer and an 11 o'clock damper. Or vice versa.

69Rcode_Mach1 · Aug 23, 2005

I have got the vacuum advance plugged and I know all the details about the idle. The problem is that the needles can be turned all the way in and it will stay running so long as one of them has somee flow through. I know it shouldn't be like that which leads me to suspect the powervalve. Hmmmm. I am using the same pointer that was on the engine originally however I am using one of the summit oem dampers how can I tell which one is which and got any links so I can examine the two and determine what I got. I am leaning towards the pointer problem.

thehueypilot · Aug 23, 2005

If the engine keeps running after you screw the A/F mixture screws all the way in you are not running off the idle circuit. You can open the secondary throttle plates slightly to get more air which should increase the rpm allowing you reducing the primary idle screw to close the primary throttle plates which will reduce your rich mixture and bring your idle problem under control.

krash kendall · Aug 23, 2005

My edelbrock carb did the same thing. Carb wasn't down tight enough and was pulling air under the idle curcuit and grabbing fuel along the way as that section is open to the gasket. Don't know if that is your problem, but a quick spray of something flamable at the base of the carb should tell you. As far as timing - is your light hooked to the right lead?

BarnStang · Aug 23, 2005

You could consider validating the Summit damper. If that is a new part, then the decal or engraving could be wrong (unlikly) but you could prove it out just so you know. Pull the No. 1 plug and bring the crank around by hand so the pointer is at zero and both valves closed-is No. 1 cyl actually at TDC? If your idicating 30 degrees of timing and the car runs ok then tune it up. The damper has to be wrong. Or, yank it and compare it to your old one. Do they match up or is the new one off? It is unlikly the car would start with base timing set at 30 degrees BTDC. I "assume" the timing chain was installed "straight up"...

Edbert · Aug 23, 2005

Was the cam degreed during install?

brianj5600 · Aug 23, 2005

Mine has 3 sets of timing marks. If you bring #1 to tdc, regardless of the cam or valves, it should line up with one set of numbers. Pull #1 plug and turn it over by hand until the piston tops out. I used a wooden dowel to feel the piston stall at the top of the stroke since it was hard to see the piston through the plug hole. I painted the other 2 sets of marks black to cut down on confusion.

69Rcode_Mach1 · Aug 23, 2005

Yeah everything has been installed straight up and all specs taken down. Keep in mind I am running a 302 cam so I wired the dizzy for a 302 but I don't think that would make a difference. There is no way that this thing is running 30 degrees timing if it goes below that it dies my car wouldn't even fire if I did have that much timing.

Here is a link to the damper I am using: http://store.summitracing.com/defau...art=SUM-163289&autoview=sku&Ntk=KeywordSearch

Any more info on the different dampers and pointers. From the looks of things my timing pointer is at 2 o'clock looks like it needs to be moved to 1 o'clock to be accurate.

I am ordering a driveshaft tonight so hopefully in a week or so I can get her out on the road and do some hard pulls and start feeling and reading the plugs better.

Any other suggestions are appreciated this is helping me out a lot guys.

grego37 · Aug 24, 2005

which firing order are you using

Is the cams firing order the same as the order you have your wires on your cap
15426378?

69Rcode_Mach1 · Aug 24, 2005

yeah that is the firing order I am running. Which is the 302 firing order, it was broken in on a 302 so the firing order should be okay.

grego37 · Aug 24, 2005

Before you start replacing your balancer or moving your pointer and all that,

Remove the pass. side valve cover.
Rotate engine by hand or bump starter until the TDC line on the balancer is at the pointer.
at that point check and see if the both valves are closed on #1 cylinder (both rockers should be loose)
If the valves are not closed rotate one more turn on the balancer , and check again.
When they are closed, and the mark is at the pointer,
With a felt pen , find where your #1 wire is on your dist. cap and mark the body of the dist.at this location.
then pull your dist. cap.
The rotor should be pointing just before this mark for #1 plug wire.
If it's not, you must pull the dist. and re-install it so it is.
This isnt finding exact TDC, but will get you close, then do final timing setting with the timing light, then adjust your carb. air/fuel mixture screws at idle to highest rpm (or highest vacuum reading)

69Rcode_Mach1 · Aug 24, 2005

I will do that its a good idea. I won't be replacing that balancer, but if there is a different pointer I would like to get a hold of that it would greatly simplify things.

stangman16 · Aug 25, 2005

How can you tell if the pointer and dampner will work together?

krash kendall · Aug 25, 2005

stangman16 said:
How can you tell if the pointer and dampner will work together?

They will indicate 0* when the motor actually is at TDC.

New Engine Startup Tuning

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