Can I hear it run
Thread Starter
Racer
Joined: Aug 2019
Posts: 253
Likes: 24
From: Oklahoma
Can I hear it run
Given the fact that I have months of work ahead of me before my 79 project is road worthy I am hoping to work through one component at a time. Having reassembled and installed the engine and engine wiring I would like to know if it will run. I am not sure on where all the vacuum lines go but if someone could let me know what I need to hook up or plug just to do the initial start would be very helpful. Fresh gas,plugs,oil,filters and preoil are done. Only put in water in case of a problem with cooling. Thanks , I have a stock L82 with Q-jet
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
Hook up the PCV in the driver's side valve cover to the front port on the carb. Hook up your distributor vacuum advance to any manifold vacuum port (such as the port on the rear of the carb baseplate, coming out at an angle on the passenger side). Plug and cap all other ports on the carb and the intake manifold. Put power to the distributor and run it! 
Lars
Lars
Thread Starter
Racer
Joined: Aug 2019
Posts: 253
Likes: 24
From: Oklahoma
Got the holes sealed in the intake and am ready to set the timing. Is there anything I need to know on the vacuum lines to do this. I ask because I think the vacuum advance hose needs to be plugged to set timing. Thanks
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
Leave the hose on while you fire the engine up initially. Assuming this is a new engine with a new cam, as soon as the engine fires, get the rpm up to about 2500-ish, and rough-set the distributor by rotating it to obtain best quality running by feel and sound. Once done, and with rpm screw cranked in to hold the 2500 rpm idle, using your dial-back timing light set to 36, yank the vacuum hose off and give the engine some rev's past 3000 to observe the timing advance "pegging out." Rotate the distributor as needed to set that total timing, when pegged out, to 36. Snug down the distributor, re-attached the vacuum hose, and finish doing the cam break-in. Once you've done the 15-20 minute cam break-in, drop the idle down to normal idle speed, yank the hose off the vacuum advance, and check to see what your initial timing is. Make note - this will be your future idle timing spec. Re-attached the hose and finish fine-tuning the carb idle mixture and speed.
Lars
Lars
Thread Starter
Racer
Joined: Aug 2019
Posts: 253
Likes: 24
From: Oklahoma
So the PC valve and vac advance are the only thing hooked up? There are 2 large ports on the front of carb does it matter which to PC V? Last question is can I do cam break in with out setting overall timing?
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
There is only 1 large vacuum port on the front of any Q-Jet, and it's for the PCV.
Sure, you can break in the cam without the timing being set right, but why would you..? With the engine running, set the timing. Why would you not do that? With the engine running at 2500 rpm, I hold my beer in my right hand, the timing light in my left hand, and I can still flick the throttle with my beer bottle to check the total timing. What excuse could there be to not set the timing to spec when you have the engine running? Check and set the timing.
Lars
Sure, you can break in the cam without the timing being set right, but why would you..? With the engine running, set the timing. Why would you not do that? With the engine running at 2500 rpm, I hold my beer in my right hand, the timing light in my left hand, and I can still flick the throttle with my beer bottle to check the total timing. What excuse could there be to not set the timing to spec when you have the engine running? Check and set the timing.
Lars
Last edited by lars; Nov 3, 2019 at 11:43 PM.
Instructor
Joined: May 2011
Posts: 169
Likes: 2
From: petaluma california
Leave the hose on while you fire the engine up initially. Assuming this is a new engine with a new cam, as soon as the engine fires, get the rpm up to about 2500-ish, and rough-set the distributor by rotating it to obtain best quality running by feel and sound. Once done, and with rpm screw cranked in to hold the 2500 rpm idle, using your dial-back timing light set to 36, yank the vacuum hose off and give the engine some rev's past 3000 to observe the timing advance "pegging out." Rotate the distributor as needed to set that total timing, when pegged out, to 36. Snug down the distributor, re-attached the vacuum hose, and finish doing the cam break-in. Once you've done the 15-20 minute cam break-in, drop the idle down to normal idle speed, yank the hose off the vacuum advance, and check to see what your initial timing is. Make note - this will be your future idle timing spec. Re-attached the hose and finish fine-tuning the carb idle mixture and speed.
Lars
Lars
Hook up the PCV in the driver's side valve cover to the front port on the carb. Hook up your distributor vacuum advance to any manifold vacuum port (such as the port on the rear of the carb baseplate, coming out at an angle on the passenger side). Plug and cap all other ports on the carb and the intake manifold. Put power to the distributor and run it!
Lars
Lars
Right on Lars you are spot on!
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