ezzzzzzz Posted October 19, 2006 Share Posted October 19, 2006 It's been talked about and posted some many damn times. I've read until I'm blue in the face. I want to build a stroker using the F54 block, P90A mechanical lifter head, LD28 crank and 240Z rods. These parts are sitting in my garage ready to go. I want to keep the stock L28 bore. I don't want to bore out to 3.1 or 3.2 displacement. My reasoning is longivity and durability for an eaton M62 supercharger application pushing only 5-8 psi. There are discussions of quench, detonation, etc. Everyone has an opinion but nothing comes across as concrete information. I cannot come to any viable decision through all the fodder. I'm inclined to think I'll just have a set of slugs cast by Arias or JE or someone else to suit the L28 bore and proper pin height. Should I do something special to the piston crowns such as dish, flycut, etc. or just run them flat? I'm looking for good flame front and minimal risk of detonation. Quote Link to comment Share on other sites More sharing options...
rags Posted October 19, 2006 Share Posted October 19, 2006 Mark, I'd go with a piston that comes up even to the deck and has a "D" shaped relief to bring compression down to where you want it. If you use a 33.3mm pin height and a 8.5cc relief, you will get somewhere close to an 8 to 1 comp ratio that has a good quench characteristics for detonation resistance. Oh btw, if you don't bore the cylinders your only going to get a 2.9 motor with the diesel crank. Joe Quote Link to comment Share on other sites More sharing options...
naviathan Posted October 19, 2006 Share Posted October 19, 2006 I've heard of people running a supercharger or turbo on an L31 stroker. If you go with the P90A on KA24 pistons and a 2mm head gasket you should have plenty of room for forced induction. You can have pistons shaved down the fluch with the block also, if you'r really concerned with it. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted October 19, 2006 Author Share Posted October 19, 2006 I meant to change the 3.0 to 2.9 but hit the post button too soon...dang. I do not want to overbore the block due to thinning of the cylinder walls and a "once use only" build. There is not enough performance difference to justify it in my mind. Thanks for the info. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted October 23, 2006 Author Share Posted October 23, 2006 What is the best source for custom pistons? I contacted racetep and they were quoting $795+ for six pistons...OUCH! I'm more accustomed to SB chevy prices than these! Quote Link to comment Share on other sites More sharing options...
greenmonster80 Posted October 23, 2006 Share Posted October 23, 2006 Bore it out to 88mm. You will be pleasantly surprised to see that Nissan blocks hold out much better than the SB chevy stuff your accustommed too. Also if you are able to, spend a little more money on rods. 240z rods are still short to take full advantage of te depth of a LD crank. I used 138mm rods also from a nissan motor to build my stroker. Quote Link to comment Share on other sites More sharing options...
73ZCAR Posted October 23, 2006 Share Posted October 23, 2006 GM80; What are those rods from? What is the compression height on those pistons? Is the pin in the bottom ring area? If not how close? Where did you get your pistons? Mike. Quote Link to comment Share on other sites More sharing options...
fentin_fury Posted October 23, 2006 Share Posted October 23, 2006 Diamond pistons has made me a few sets of forged pistons for the L28 with a P90 head and 240Z rods. My design was a bumb up - with valve releifs - to increase compression ratio - however they do have the abilitiy to machine and surface on these you wish. http://www.diamondracing.net/ They have the correct pin height, etc. If you contact them and they can't locate their L28 info - PM me and I will give you the run numbers. Q Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted October 23, 2006 Author Share Posted October 23, 2006 I have two perfectly good F54 blocks ready to go with the stock 86mm bore. To bore either out would be a waste of money for me. There are ideals in bore and stroke as well as head work but I'm not inclined to pursue perfection at the associated costs involved. This is only for a fair weather 240Z that will not see track torture or street racing. While we're here though please elaborate on your components. I'm sure many would like to know the viable details. There are so many posts that talk about custom or alternative OEM parts being used but the essential info is often missing. What rods did you use? Were they reworked to fit? What was the pin diameter? Were they pressed or floating? How about those pistons? What was the deck height? Compression? It seems that you'd only have <28mm of crown height to work. That doesn't weem like much space for rings in anything other than a race-only engine. Please elaborate. Quote Link to comment Share on other sites More sharing options...
fentin_fury Posted October 25, 2006 Share Posted October 25, 2006 I will get the sheet tonight and post the specs. FYI - I asked for and used a standard ring pack. q Quote Link to comment Share on other sites More sharing options...
greenmonster80 Posted October 28, 2006 Share Posted October 28, 2006 GM80; What are those rods from? What is the compression height on those pistons? Is the pin in the bottom ring area? If not how close? Where did you get your pistons? Mike. Mike rods came from a L14 motor. Pistons are from escort. not ford. Pin height I am not sure right now. Could find the page link and forward you if you are that inteested... Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted November 1, 2006 Author Share Posted November 1, 2006 Greenmonster, if you can locate that link I'd be interested. Thanks. Quote Link to comment Share on other sites More sharing options...
greenmonster80 Posted November 1, 2006 Share Posted November 1, 2006 Here is the link for the escort pistons I used. The combo I used it described in the 3rd piston option. L14 rods with LD crank for the NA motor. Pin height is 29.5 and uses the standard 21mm pin. http://www.escort-jp.com/ I do not remember off hand what I paid for the pistons but it wasn't that bad... Quote Link to comment Share on other sites More sharing options...
rztmartini Posted November 1, 2006 Share Posted November 1, 2006 searched but couldnt get a difinitive answer, but would the block be weakened too much for a 20 psi max turbo motor to be bored out to 89mm to use the KA24 pistons? these seem to be easier/cheaper to get than custom pistons Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted November 2, 2006 Author Share Posted November 2, 2006 What we need is a sticky dedicated to stroker builds. I'm not talking about a bunch of opinions and retoric. I mean hard facts and data from each person that has ACTUALLY built one of these. This would include every piece of pertinent info such as specific rods used, piston and rings, etc. As I've scoured the posts on builds and the one thing always missing is specifics. For example, I know most are using the stock LD crank and either L24 (ARP bolts overcome the 8mm bolt issue if the 9mm rods aren't used) or L28 rods. Many seem to punch out the block and use a factory piston. Others go the custom piston route. There is also the engine calculator that can offer different combos but doesn't tell us what advantages there are one over another. I'd like someone to list all of the specifics supplied for custom pistons for example. In my case, I want to build that 2.9 using the N42 or F54 block, P90 head, LD crank, 9mm 240Z rods, and custom pistons for a roots supercharger application pushing about 8 psi. I'm guessing that 8:1 cr is about right but don't know exactly what the piston crown should look like. I really wish those that have gone before would make a comprehensive list of the parts they used and issues they came across. Block Head Camshafts (N/A or SC'd) Head gasket Piston(s) with all specific details Rings Pins Rods Crank Assembly issues or problems Things they would have done different (detonation problems, etc. due to piston, gasket, or head choice, etc.) Quote Link to comment Share on other sites More sharing options...
greenmonster80 Posted November 2, 2006 Share Posted November 2, 2006 searched but couldnt get a difinitive answer, but would the block be weakened too much for a 20 psi max turbo motor to be bored out to 89mm to use the KA24 pistons? these seem to be easier/cheaper to get than custom pistons I am not sure a stock KA piston would stand up too that abuse for very long. Quote Link to comment Share on other sites More sharing options...
rztmartini Posted November 2, 2006 Share Posted November 2, 2006 i guess i should have specified...dished forged pistons for the KA24. sorry. Quote Link to comment Share on other sites More sharing options...
greenmonster80 Posted November 2, 2006 Share Posted November 2, 2006 searched but couldnt get a difinitive answer, but would the block be weakened too much for a 20 psi max turbo motor to be bored out to 89mm to use the KA24 pistons? these seem to be easier/cheaper to get than custom pistons To be on the safe side personally I would go 88mm. Others on this board would call me chicken as there are documented motors that are boosted 3.1's. But if you are already questioning before building, go ahead and play it safe. Once committed to pistons and boring, worries will only intensify. Especially once it is on the road or dyno tuning.. Quote Link to comment Share on other sites More sharing options...
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