speeder Posted August 6, 2007 Share Posted August 6, 2007 Ive just built a nice Crank trigger'ed LT1 damper and, looking to install it, find that I should have made some reference marks before removal. There are no timing marks on this motor. And it gets worse-It has a keyless damper hub and from the looks of the balancing holes on the damper, It's important for balancing that it be installed at the correct index. It looks as if the angle is wrong to stick something in a spark plug hole and feel for TDC as the engine is rotated. Barring any suggestions for a simpler method, (and they would be welcomed) Here's what I plan to do: I know that this damper is installed with its pointed spoke at exactly 12:00 at #1 TDC. The crank snout has a keyway in it, although not used, it is in line with the timing sprocket's keyway. On the back of the damper there is a mark where the timing sprocket's keyway meets the rear of the damper. You can see the little square mark at about 10:00 in the pic above. I plan to make a jig to accurately measure the angle between the pointed spoke's center and the key mark's center. I will install a degree wheel zero'ed vertically, then make sure the engine is on #1 compresion stroke and rotate the crank until the keyway matches the measured angle from vertical. Now if the damper is installed with the pointed spoke vertical it should be correct. What fun it will be to get this alignment correct! Like I said, I hope someone has a better idea - And you can believe that there will be timing pointers made as soon as this situation is fixed. Quote Link to comment Share on other sites More sharing options...
dustin280zx Posted August 7, 2007 Share Posted August 7, 2007 you could pull #1 plug and check piston. i always do that after the motor is together just to triple check everything is right and in line. Quote Link to comment Share on other sites More sharing options...
speeder Posted August 7, 2007 Author Share Posted August 7, 2007 you could pull #1 plug and check piston. I tried that but couldn't get a good angle through the plug hole to feel the piston - used a long thin woooden q-tip stick. Maybe that would work with the header off? Quote Link to comment Share on other sites More sharing options...
bodie Posted August 7, 2007 Share Posted August 7, 2007 you could alway pull the left valve cover and watch the springs, it will get you in the general area. +- 10 Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted August 7, 2007 Share Posted August 7, 2007 Pull the valve cover, pull the #1 plug, put a finger over the plug hole and rotate the engine until you feel compression on your finger and both valves are closed. Will not tell you #1 TDC spot-on but will get you close and assured you have #1. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted August 8, 2007 Share Posted August 8, 2007 SUM-900189 http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2D900189&N=700+318773+115&autoview=sku http://store.summitracing.com/egnsearch.asp?N=115+400304 (1) buy the piston stop and timing tape (2) remove all spark plugs and disconnect the battery if you have not done so yet (3) screw the piston stop into cylinder # 1 and adjust the depth so the piston in the cylinder can be placed almost to the top of its stroke before it touches the piston stop (4) rotate the engine by hand untill the piston touches the stop, use a fine tip scribe and some machinist blue on the crank snout and mark the 12 oclock point on the crank snout, now rotate the engine in the reverse dirrection and do the same thing again, the marks will be apart about 1/2"-1/4" exactly centered between the marks is TOP DEAD CENTER FOR CYLINDER #1 mark that on the crank, snout , move that so the true TDC mark is at 12 o-clock,now mark it on the damper so that the timing tab indicator on the engines timing cover or where ever it is on your engine shows that TDC on the damper and TDC on the timing tab MATCH, once thats done seat and lock the damper in place without moving the relative relationship between them,(if your sure the arrow points at 12 oclock put it there but be darn sure the true TDC and indicator on the engine and dampers outer surface agree with reality)) once the dampers on, clean with acetone and install the correct timing tape for the damper dia. and get a prick punch and make a mark on the crank snouts front edge and damper inner edge,contact point, so the punch hits the junction between the two, and then drill a 1/8" deep 1/32" hole at the junction so youll always in the future have a mark to align it exactly correct with below is the normal way for a sbc with a damper thats already correcly marked and indexed and your just verifying tdc http://www.2quicknovas.com/happyTDC.html BTW old post on degreeing in a cam youll need a few basic tools and a good understanding of what your doing, but its certainly not all that difficult. I was asked where to get a CHEAP degree wheel heres one you can print out and save for engine builds on the engine stand (put curser on an click) http://savetheledges.org/test/AVS/images/tech/CrankDegreeWheel.png http://store.summitracing.com/partdetail.asp?autofilter=1&part=MOR%2D62191&N=700+303547+115&autoview=sku you could buy these from summit racing or similar parts from jegs http://www.summitracing.com/ http://www.jegs.com/webapp/wcs/stores/servlet/topcategory_10001_10002_-1 MOR-62191 $44 (wheel) MOR-61755 $47 (SBC) MOR-61756 $47.(BBC)crank sockets SUM-900188 $17 (piston stop, head off) SUM-900189 $6.95(piston stop, head on) TFS-90000 $94.95 (degree kit) youll also want two flat tappet solid lifters and two weak check springs instructions http://www.2quicknovas.com/happyTDC.html http://www.iskycams.com/camshaft.html http://www.thedirtforum.com/degree.htm http://www.ridgenet.net/~biesiade/camdegree.htm http://www.hotrodder.com/kwkride/degree.html http://www.cranecams.com/pdf/803.pdf Quote Link to comment Share on other sites More sharing options...
speeder Posted August 8, 2007 Author Share Posted August 8, 2007 I need to get the damper spot-on for an accurate ignition reference and also to get the balancing index correct. Looking at the damper balancing holes this appears to be an externally balanced engine. I already have it on #1's compression stroke, and am sure about the reference mark. Actually , I do have a piston stop and will use that. (Slaps forehead and says,"Doh!") Thanks Grumpy for setting me on the obvious path. Quote Link to comment Share on other sites More sharing options...
speeder Posted August 9, 2007 Author Share Posted August 9, 2007 Got 'er done. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted August 9, 2007 Share Posted August 9, 2007 congrats, any forward movement on a project helps Quote Link to comment Share on other sites More sharing options...
Danno74Z Posted August 9, 2007 Share Posted August 9, 2007 Speeder, Just curious, why are you going through all this work to put a degree damper on a LT1 engine? Are you no longer using the Optispark ignition? One would have to go through this exercise if they were putting in a new cam in the LT1. Danno74Z Quote Link to comment Share on other sites More sharing options...
speeder Posted August 9, 2007 Author Share Posted August 9, 2007 The Optispark/stock ECU is out, Megasquirt/crank trigger/Cadillac DIS coilpack is in. This LT1 (Not mine) is getting 65-pound injectors and a big turbo. Quote Link to comment Share on other sites More sharing options...
Danno74Z Posted August 9, 2007 Share Posted August 9, 2007 Cool - Thanks for the info. Danno74z Quote Link to comment Share on other sites More sharing options...
speeder Posted August 9, 2007 Author Share Posted August 9, 2007 See my edit above for the reason I had to go through this excercise. Just want to add: That degree wheel for printout that Grumpy gave the link for was very useful - My aluminum degree wheel is too big to fit on the engine in - car so I just scaled the online wheel to the right size and printed out, glued to poster board, and cut out. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted August 10, 2007 Share Posted August 10, 2007 free http://savetheledges.org/test/AVS/images/tech/CrankDegreeWheel.png small http://www.jegs.com/webapp/wcs/stores/servlet/product_10001_10002_24364_-1 large http://www.jegs.com/webapp/wcs/stores/servlet/product_10001_10002_39096_-1 Quote Link to comment Share on other sites More sharing options...
speeder Posted August 10, 2007 Author Share Posted August 10, 2007 Grumpy (Linkmeister), You the man! Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted August 10, 2007 Share Posted August 10, 2007 Za link meister! Quote Link to comment Share on other sites More sharing options...
speeder Posted August 10, 2007 Author Share Posted August 10, 2007 Za Linkenator! Za link meister! Quote Link to comment Share on other sites More sharing options...
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