66 Coupe Progress Thread
- Thread starter DTCRAWLEY
- Start date
I allow images, tune files, pdf files, and a host of others but [not] do video files.
The files themselves are not the issue. Serving/Streaming those files over the internet is something we're not setup to do.
Youtube is setup to serve video files. Host it there and post the link here. Some people even upload to their Bookface account and post link from there. Whatever works best for you.
The files themselves are not the issue. Serving/Streaming those files over the internet is something we're not setup to do.
Youtube is setup to serve video files. Host it there and post the link here. Some people even upload to their Bookface account and post link from there. Whatever works best for you.
Mcmahst
5 Year Member
Any chance that you could contact the PO and ask him why he put a vacuum pump on the car? I’m just wondering if he installed the engine and then realized he had such low vacuum that he wasn’t getting the break performance that he wanted or expected and he added the pump instead of chasing down the vacuum problem. I think that vacuum is too low at idle. The throttling and changes in vacuum look completely normal with the exception of the vacuum at idle. Just a set of hunches, but first and likely a vacuum leak in the base gasket of the carb, a hidden hole in a vacuum hose, and intake manifold gasket. Next potential problems, and this goes back to to my first question. Intake valves with too much preload, causing a very slight leak.
Did you verify initial timing and total all-in timing? Good luck.
Did you verify initial timing and total all-in timing? Good luck.
Don't look at the vacuum reading alone, the needle action shows an issue, the needle should be steady at idle unless you have a cam with a lot of overlap,
first adjust the timing to get the highest vacuum reading, you will likely have to adjust the idle too, make your timing adjustments with the vacuum advance disconnected and plugged.
can you get a steady vacuum needle by doing this?
first adjust the timing to get the highest vacuum reading, you will likely have to adjust the idle too, make your timing adjustments with the vacuum advance disconnected and plugged.
can you get a steady vacuum needle by doing this?
Mcmahst
5 Year Member
well I know there is a slight cam so i think the vac is what it is. Have not been able to locate a vac leak around the manifold using the carb cleaner spray. Still messing with float level. Seems at higher steady revs it may be starving for fuel. Could be the mixture screws as well.
Mcmahst
5 Year Member
From your first post, I suspected the problem might be cam timing. You said you have consistent 135-140psi in the compression test. That sounds low to me, especially for a new engine. 165/175 would be my expectations. So, if it is a new engine, and you have low vacuum at idle, and low compression, cam timing would be the first place I would verify. A performance cam usually creates low idle vacuum due to the overlap. But you don’t usually see these cams on engines with low compression, like 8:1 or something around that. If you’ve run out of likely causes, then cam timing becomes more likely; at least likely enough to run it to ground. Good luck.
I'm gonna jump back in this week. Timing is set to 12 deg advanced to 33deg.at throttle. dont know the rpms as no tach,auto trans. I will check everything....timing again, fuel pressure (going to install a regulator setup), bowl float levels, mixture screws, etc. Will remove and clean plugs first and work through everything. The one thing I'm not sure about is that the carb is black from running so rich for so long. Best way to clean it?? Thanks for any input you may have.
Also I want to reroute the gas line to the rear of the motor (Firewall area or brackets on motor or valve cover bolts) as i am going to clean up the front topside of the motor. Should I make metal lines to mount on the "Body" (or motor) and then rubber gas line from the mechanical fuel pump to said line and then rubber lines from said line to carb filter/regulator setup?
Also I want to reroute the gas line to the rear of the motor (Firewall area or brackets on motor or valve cover bolts) as i am going to clean up the front topside of the motor. Should I make metal lines to mount on the "Body" (or motor) and then rubber gas line from the mechanical fuel pump to said line and then rubber lines from said line to carb filter/regulator setup?
You can run a rubber line from FP to the frame rail/fender apron area to a hard line mounted with those nice isolated line clamps, with a bend at the firewall, then a rubber line from the firewall to the carb
