bmarchuk Posted February 4, 2009 Share Posted February 4, 2009 Ive been trying to find info on this but cant seem to locate it, Is a 3mm overbore safe for a turbo'd l28 with a n42 block? Here is my setup I am toying around with doing. N42 block P90a Head (why? because i already have one) LD28 crank L24 Rods KA24 Pistons (hence the 3mm overbore) 2mm gasket to lower estimated compression to 8.9:1 Is this safe with boost? Should I use different pistons/rods? If so which ones, I was toying around with the idea of the LZ24 pistons but im not sure of which will be the best for my setup, and those are alot more dished than the KA24. Possibly better for my turbo application? I could also use a STD or 1mm gasket with those if im correct? Brining my ratio to 8.09:1 (STD) and 8.25:1 (felpro/1mm) Hard to find info on people stroking/boring a l28 turbo, ive found tons of info from people with N/A engines and their setups, someone help please! Edit: I also heard from a previous post by I believe TonyD that the stock rods should be ok for a -400hp setup, what about the pistons? Im shooting for -400hp high torque. If the stock LZ or KA pistons wont hold up to 350ish hp, should I be looking for forged? Edit again: I heard from a good source found here:http://www2.zhome.com:81/rnt/L28conversion/3031FAQ.html , that the LD28 crank can be swapped into a l28 block fairly easily, with minor work, but he says nothing about the timing etc, I dont want to have to mess with my timing at all, with my N42 block p90a head, and ld28 crank am I going to have any issues setting up the timing, or will that be standard for any l series engine? ThanksBryan Quote Link to comment Share on other sites More sharing options...
510six Posted February 4, 2009 Share Posted February 4, 2009 I personally wouldn`t go over 2mm overbore on a turbo motor, as it promotes to much cylinder wall flex.Unless you plan on running race gas, E85 or having the timing retarded to hell, 8.91 is a little steep for a turbo L series. IMO other than the 3mm overbore the setup, provided if it`s built and tuned correctly sounds pretty rock soild to 400+ hp.A friend of mine had a set of stock L24 9mm rods bushed for 22mm full floating pins and used stock VG30dett( good for 500rwh) pistons with good results on His 3 liter build. Quote Link to comment Share on other sites More sharing options...
blue72 Posted February 4, 2009 Share Posted February 4, 2009 There's no difference in setting the timing when using an LD28 crankshaft. The question of maximum overbore for a turbo application depends on the quality of the block you have. The best way to determine cylinder wall thickness is with sonic testing. There are one or two threads here where 1 fast z and Tony D weighed in on their acceptable minimums for wall thickness in turbo applications. Quote Link to comment Share on other sites More sharing options...
bmarchuk Posted February 4, 2009 Author Share Posted February 4, 2009 Do you know where those threads are, ive been looking, I even pm'd Tony. I guess ill have to wait until I fully dissassemble the engine I to find out if this is possible, though I wanted to search for my parts before doing so.. Quote Link to comment Share on other sites More sharing options...
blue72 Posted February 4, 2009 Share Posted February 4, 2009 http://forums.hybridz.org/showthread.php?t=139381 Here's another one that deals with liners as well: http://forums.hybridz.org/showthread.php?t=119675 Quote Link to comment Share on other sites More sharing options...
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