kelowg Posted September 27, 2014 Report Share Posted September 27, 2014 Wondering what u guys thoughts r on what c/r this might be. Pings at anything more than 3-5 degrees adv with 91 oct. Adding head gasket spacer help with this? Bore size: 87.75mm (Z22E bored out .75mm) Stroke: 86mm (L20b crank) Headgasket bore: 88mm (that's a guess; I just figure it's gonna be 1mm over the stock bore) Combustion chamber volume: 45cc (A87 open chambered head) Piston dish volume: -9.32cc (stock Z22e pistons, but they are shaved down a bit, so this might be a little less) Deck clearance: .2mm over deck (shaved down from .4mm) Shadbolt cam m445 Electronic distributor. Weber 32/36 Quote Link to comment
datzenmike Posted September 27, 2014 Report Share Posted September 27, 2014 Wondering what u guys thoughts r on what c/r this might be. Pings at anything more than 3-5 degrees adv with 91 oct. Adding head gasket spacer help with this? Bore size: 87.75mm (Z22E bored out .75mm) Stroke: 86mm (L20b crank) Headgasket bore: 88mm (that's a guess; I just figure it's gonna be 1mm over the stock bore) Combustion chamber volume: 45cc (A87 open chambered head) Piston dish volume: -9.32cc (stock Z22e pistons, but they are shaved down a bit, so this might be a little less) Deck clearance: .2mm over deck (shaved down from .4mm) Shadbolt cam m445 Electronic distributor. Weber 32/36 You don't mention but likely have the 152.5mm Z20E rods and the late Z22 pistons that are 32.1mm tall. crank.......... 43 mm piston......... 32.1mm rod........... 152.5mm total.......... 227.6mm The L20B block height is 227.45mm, so those pistons are well under the 0.3mm recommended max. deck height and do not need shaving. Unless the block was decked, that is. Also the late Z22E piston dish is unknown to me. Did you cc them or is this just assuming the early and late Z22E pistons are the same? (I have no idea) From the info submitted using a 1.2mm crushed gasket thickness, the 9.32 (assumed) dish and a zero deck height (also assumed) I get only 9.421 compression. Pinging is basically the heat of compression setting off the fuel air mixture before the spark timing does. It can also be caused by any other heat source such as the wrong heat range spark plug, glowing carbon deposits a sharp edge in the combustion chamber and running too lean a mixture. Keep in mind the compression may be higher than calculated from incorrect info submitted. Higher compression will always need less ignition advance because the burn time is shorter. Three to five degrees may be where the engine needs and wants to run. Quote Link to comment
Laecaon Posted September 27, 2014 Report Share Posted September 27, 2014 With an Open chamber you are right at the Ping spot on CR. A Closed chamber would probably ping less. Im at 9.35 with flat tops and an open chamber and ping if Im not running good quality gas. Quote Link to comment
flatcat19 Posted September 27, 2014 Report Share Posted September 27, 2014 What is a head gasket spacer? Quote Link to comment
kelowg Posted September 27, 2014 Author Report Share Posted September 27, 2014 2 heat ranges cooler,but this z22e block not l20. this motor came to me running. Runs good but with more advanve it pulls bit better. Just seems like is not at its full protential. Quote Link to comment
kelowg Posted September 27, 2014 Author Report Share Posted September 27, 2014 Spacer, as in solid copper gasket plus standard gasket(thicker overall) Quote Link to comment
flatcat19 Posted September 27, 2014 Report Share Posted September 27, 2014 Why not 1 really thick copper gasket? Quote Link to comment
datzenmike Posted September 27, 2014 Report Share Posted September 27, 2014 L20B and Z22 blocks are essentially identical, only the cylinder walls are different to allow a wider bore. 2 heat ranges cooler,but this z22e block not l20. this motor came to me running. Runs good but with more advanve it pulls bit better. Just seems like is not at its full protential. Perhaps needs richer mixture at WOT? Quote Link to comment
kelowg Posted September 27, 2014 Author Report Share Posted September 27, 2014 13-13.3 a/f at wot. Diesels really bad with idle cut off, unless half and half tank 91/100 octane Quote Link to comment
datzenmike Posted September 28, 2014 Report Share Posted September 28, 2014 I think 12 would be better for full throttle. The extra gas cools the intake air and the hot combustion chamber by evaporation. It's like adding octane. If you can adjust it to low 12s but keep the 14 or so part throttle cruise the mileage won't suffer. Quote Link to comment
Z-train Posted September 28, 2014 Report Share Posted September 28, 2014 No mention of head casting number & height. Quote Link to comment
kelowg Posted September 28, 2014 Author Report Share Posted September 28, 2014 A87 open. I think its likely sharp edges in comb chamber. Havent torn in to it. Goin to try 1 gal of 100octane every half tank fill up, same price as oct boost but might actually improve it a bit Quote Link to comment
flatcat19 Posted September 28, 2014 Report Share Posted September 28, 2014 Is the cam timing correct? Quote Link to comment
kelowg Posted September 28, 2014 Author Report Share Posted September 28, 2014 Yep, just redid it. Notch at right edge of cam plate dash mark. Tried all 3 positions,made no difference Quote Link to comment
datzenmike Posted September 28, 2014 Report Share Posted September 28, 2014 Well you can increase the octane to tame it but like I said earlier 13 to one isn't rich enough. Quote Link to comment
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