Dead cylinder

[Tom I.]

1962 327 engine. Problem started when turning off engine in driveway. Engine ran on or ran backwards then made a hissing sound. Tried to start engine without results. Inspection results provided loose PCV return hose on back of engine not connected. Reconnected hose result: engine did not start. Further inspection revealed Pertronix ring below rotor had one of the two nuts loose allowing ring to hang down a little. Secured nut, Engine would still not fire. At this point Pertronix unit is suspect. Replaced Distributor with one that has points. Still does not start.

Compression test on each cylinder indicated 190+ psi. Good spark present.
After checking and correcting timing engine started but has a miss. After some observation it was determined that #2 cylinder was not firing as determined by cold exhaust manifold. #2 plug was removed and grounded. Good spark was present. #4 and #2 wires and plugs were swapped. #2 still dead.

Removed intake manifold . Found intake gasket at #2 intake entry not same as other entry points. Noot appearing to seal same as other cylinders. Used straight edge on surface of intake manifold. did not find any other abnormal things. Installed intake with new gaskets. Plan on running leak down test. Waiting for leak down tester to arrive.
Any comments and all help invited. Tom Isenberg

[Anthony L.]

Re: Dead cylinder

Bent valve.

pull valve cover and confirm that valves are operational

[David H.]

Re: Dead cylinder

Tom

When you pulled spark plugs for your compression test, what was their condition?

Dave

[Tom I.]

Re: Dead cylinder

All spark plugs looked similar. #2 did not stand out. I ran many other tests. Removed valve cover, turned engine over. All valve lifters in head were even in rest position and lift height. Rocker motion same for all cylinders. Replaced all plugs and wire set along with distributor cap rotor and distributor. With #2 plug removed and grounded to head, turned engine over, had good spark on plug.

Hope leak down test will reveal some clues!
Tom I.

[David H.]

Re: Dead cylinder

Tom

Have you checked inside of cylinder with a borescope? Chance of significant carbon deposits?

Your first post: was engine at temperature, cold, or overheated at shutdown?

Had this dieseling at shutoff occurred before or was this a first time?

Dave

[Duke W.]

Re: Dead cylinder

Are the plug wires indexed on the cap IAW GM service documents? There were four "327" engines in '62. Which one does your '62 have and what other modification does it have besides what you mentioned. Also, is it a single point distributor with a Vacuum Advance Control or a dual point with no VAC?

Post the photo of the distributor as installed on the engine, and point our #1 plug wire.

Duke

[Tom I.]

Re: Dead cylinder

Currently engine is 327in 40 over, flat top pistons. 461 heads, 3269s carb, 3795397 intake manifold 379901 and 02 exhaust manifolds.1110984 distributor with pertronix conversion kit and B26 vac advance. Distributor was replaced with 1110984 with points 901 coil and no vacuum advance
(locked adv). Engine was rebuilt 1n 2011 with hydraulic comp cam. Engine backfired a couple times then I replaced the pertronix modified advance distributor with points version. Will be running Leak down test probably tomorrow. Do not have picture of installed distributor but the number 1 and 2 cap outputs lined up across from each other horizontal to the back of hood. which I find allows adjustment room for vac-adv.
Tom I

[Tom I.]

Re: Dead cylinder

I'm back. On my last entry I did not clarify that the engine components are for a 1962 327 340hp version except the heads for a 64-65 version.
I ran a leak down test on the engine and the results were as follows,'#1= 6%, #2 the "dead cylinder" =4%, #3 =4%, #4= 6%, #5=4%, #6 =6%,
#7 =4%, #8 =6%. With the dead cylinder leaking only 4% and spark plug on #2 firing a good spark when externally grounded it appears lack of fuel into the #2 cylinder is the reason for not firing. As a result I will be taking another hard look as the 3269s carburetor even though that does not make much sense.
All input is invited. Tom I.

[David H.]

Re: Dead cylinder

Tom

Have you removed passenger side valve cover and inspected valves on #2. No lifter stud(s) pulled? Valve operation (cycling) appears correct - no flat camshaft?

Dave

[Tom I.]

Re: Dead cylinder

David. The heads have screw in studs and lifter valve guides. With valve cover removed I observed lifter operation. #2 lifter movement was same as other valves in head.
Tom I.

[Domenic T.]

Re: Dead cylinder

Tom,
Long ago I had a similar problem. Just a shot in the dark, but feel around the valve spring for a sharp spot where it may be broken.

Dom

[Tom I.]

Re: Dead cylinder

Dom, thank you for the suggestion. Here is an update on where this project is going. After completing Leak Down tests and not finding any new tips on what to try next, I installed the plugs and started the engine. The valves were making more noise and the engine appeared to be missing more. After reviewing all the simptions, the main ones being; When the engine first stopped and appeared to run on or run backward then a loud hissing sound, I observed the pertronix pick ring hanging down a little and the pcv hose on the rear of the engine was disconnected by about one half inch, I suspected some pressure occurred within the engine causing the hissing sound. I am removing the heads looking for bent valves as suggested. It will be next week end before I can get the heads off so if I do not respond again before removing the head its because I do nor have anything further to report. Thank you for all the suggestions so far. Tom I.

[Anthony L.]

[Tom I.]

Re: Dead cylinder

Anthony, can you clarify what you mean by "dry cylinder pressure" carb open or closed? number of cycles etc.
Asking just to be sure test is proper. Will get back to you. Tom I.

[Anthony L.]

Re: Dead cylinder

Sorry Tom,
had to go to work. Prop the blades open on carb with long screwdriver, remove plugs, remove coil wire, then compression test cylinders with five to ten revs. You can tell from the gauge when it’s done. My gauge has a reset button so it will hold the highest rating.

I suspect you dont have compression on 2. You checked spark per your initial post, so there is not much left to keep the cylinder from firing other than no compression

stop taking it apart until you have diagnosed the problem, you are introducing more isssues to the puzzle