foster461 Posted March 28, 2013 Report Share Posted March 28, 2013 My engine is mosly re-assembled with the cam timing done and the head installed, oil pump and dizzy installed. It all looks good. Before I button it all up I'm double checking everything and one thing I notice is that the hole in the pulley is quite a bit off where actual TDC is. In the picture below the black dot on the tape is where the hole in the pulley is, the black line is where TDC is relative to the pointer on the front cover. Have I misunderstood what that hole is indicating or is this discrepancy normal for these engines or did I do something wrong ? Quote Link to post Share on other sites
BlueTR3A-5EKT Posted March 28, 2013 Report Share Posted March 28, 2013 Repro or genuine pulley? Genuine pulley the hole is TDC when aligned with the pointer. Quite possible the Chinese got the hole in the wrong place........... Quote Link to post Share on other sites
foster461 Posted March 28, 2013 Author Report Share Posted March 28, 2013 Repro or genuine pulley? Genuine pulley the hole is TDC when aligned with the pointer. Quite possible the Chinese got the hole in the wrong place........... As far as I know it is the original pulley. It had the same barnacles on it as the rest of the engine. Unfortunately I didnt think to check TDC calibration before I pulled it apart. I did have the pulley apart for cleaning and painting but I dont recall any wiggle room in the bolts. I only have the front cover resting on the dowels. Perhaps I should snug that down with some bolts and check again in case the front cover is not sitting square on the front plate. Stan Quote Link to post Share on other sites
RogerH Posted March 28, 2013 Report Share Posted March 28, 2013 Hi Stan, the front pulley is usually a good fit on the front end and the hole in the flange would normally be acurate. Are you sure the crank/pistons are at TDC. There can be quite a large radial movement of the crank for a very small piston movement. Roger Quote Link to post Share on other sites
Guest ntc Posted March 28, 2013 Report Share Posted March 28, 2013 Stan You should have found true TDC before fitting the head,and marked it as they can be out Quote Link to post Share on other sites
Mike Kitchener Posted March 28, 2013 Report Share Posted March 28, 2013 Stan, Posted 02 February 2013 - 06:35 PM Berry wrote: The easiest way to find TDC is bring #1 piston to near the top of its stroke, screw a bolt of the same size as the spark plug (14mmX1.25mm) into the spark plug hole until it contacts the piston and scribe a mark on the damper. Then carefully turn the crankshaft counter clockwise until the bolt contacts the piston and scribe a mark on the damper. True TDC will be half way between the marks. Cheers, Mike. Quote Link to post Share on other sites
foster461 Posted March 28, 2013 Author Report Share Posted March 28, 2013 I establised TDC for number 1 before fitting the head using a dial guage. After the head was fitted I rechecked TDC with a piston stop. The black line on my tape is #1 piston at TDC, I'm pretty confident about that. If having that hole offest by this amount is unusual I need to track down the cause. Stan Quote Link to post Share on other sites
AlanT Posted March 28, 2013 Report Share Posted March 28, 2013 The pointer on my 4A timing cover is brazed on. No idea if this is right or not. Is yours brazed on? Al. Quote Link to post Share on other sites
foster461 Posted March 28, 2013 Author Report Share Posted March 28, 2013 The pointer on my 4A timing cover is brazed on. No idea if this is right or not. Is yours brazed on? Al. Al, it looks like my pointer is spot welded to the timing cover. Perhaps someone relocated yours because it didnt line up with the hole Stan Quote Link to post Share on other sites
LGFromage Posted March 28, 2013 Report Share Posted March 28, 2013 I establised TDC for number 1 before fitting the head using a dial guage. After the head was fitted I rechecked TDC with a piston stop. The black line on my tape is #1 piston at TDC, I'm pretty confident about that. If having that hole offest by this amount is unusual I need to track down the cause. Stan The dial gauge gave the correct TDC and it is the pointer that is out. Just think the timing cover is a piece of pressed metal with a pointer welded approximately in place. You are lucky as you took the trouble to identify where TDC should be on your pulley. I forgot. Tim Quote Link to post Share on other sites
foster461 Posted March 28, 2013 Author Report Share Posted March 28, 2013 The dial gauge gave the correct TDC and it is the pointer that is out. Just think the timing cover is a piece of pressed metal with a pointer welded approximately in place. You are lucky as you took the trouble to identify where TDC should be on your pulley. I forgot. Tim Tim, that makes perfect sense. I bet they mass produced these and tweaked them when they built the engine. I had a spare timing cover so I just cleaned it up and tried it. The pointer on this spare cover was just a gnats off the center of the hole so I gave it a gentle tap with a hammer. Now the pointer and the hole are aligned while #1 is at TDC !. Thanks a bunch, now on to double checking the valve timing. Stan Quote Link to post Share on other sites
AlanT Posted March 28, 2013 Report Share Posted March 28, 2013 I think thats the point I was getting to. Either mine fell off or was broken off when someone found it was in the wrong position. We tend to forget that production in the 60's was nothing like as accurate as it is now. Al. Quote Link to post Share on other sites
foster461 Posted March 28, 2013 Author Report Share Posted March 28, 2013 I think thats the point I was getting to. Either mine fell off or was broken off when someone found it was in the wrong position. We tend to forget that production in the 60's was nothing like as accurate as it is now. Al. Indeed Al. I think the manual describes setting the timing as use the calibrated components to get the engine running and then tune it by ear. Anyway I'm all relaxed now about the hole and the pointer and appreciate the interest and discussion as always. Stan Quote Link to post Share on other sites
AlanT Posted March 29, 2013 Report Share Posted March 29, 2013 We could all think of ways you could have put this together and been miles out, but not just a few degrees. I did a bit of trig to decide that the pointer had to be out. Then I remembered the braze that appeared when I stripped mine. Al. Quote Link to post Share on other sites
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