Tony D Posted December 28, 2009 Share Posted December 28, 2009 It is my understanding that large bores on the L6 blocks is best left to those of us that love NA and the turbo boys should limit the bore to 88mm and not go any larger due to the issues 1 Fast Z has found with his turbo 89mm DOHC 3.1 build. This was known well before this time in Japan... Actually for mild turbo applications you can bore larger, but the specific output isn't really all that great. When you start pushing 200+HP/Liter, bore wall stability is a good thing. How thick are the liners on an Oldsmobile DCRE making 1800HP from 7Liters? (Or thereabouts...) This isn't rocket science, you just need to know where to look. Link to comment Share on other sites More sharing options...
rossman Posted December 30, 2009 Share Posted December 30, 2009 Actually for mild turbo applications you can bore larger, but the specific output isn't really all that great. When you start pushing 200+HP/Liter, bore wall stability is a good thing. I'm actually banking on that statement. Dave Rebello pretty much told me the same thing when I expressed concern about boring out my block to 89mm. I think the difference here is I'm looking to get "only" 450ish whp out of mine where 1 fast z is pushing out considerably more. Link to comment Share on other sites More sharing options...
NZeder Posted December 31, 2009 Share Posted December 31, 2009 This was known well before this time in Japan...That is were I got the info So how is the new bottom end coming along 1 Fast Z? EDIT: Re the Olds DCRE - min 0.250" even up to the max bore of 4.600" Link to comment Share on other sites More sharing options...
1 fast z Posted January 2, 2010 Author Share Posted January 2, 2010 Yea its coming. I sourced a couple sets of 240 rods, as with the z32 pistons, the Compression distance is shorter. Even though it is only going to be .040" overbore, I am still sonic testing the block and going to offset bore the block to maintain maximum bore thickness according to core shift of the mold. The new thrust bearing design is also time consuming. It is being incorperated right in front of where the flywheel bolts. I never liked how the thrust of a crankshaft is taken up in the center main. WHen you push thousands of pounds of pressure on a flywheel, you are trying to compress the back three cylinders on the crank, before the pressure gets to the center main. With my new design the crankshaft will basicly not see any front to back force, and therefore, relieving stress on the crankshaft also. Link to comment Share on other sites More sharing options...
sileightygx Posted January 7, 2010 Share Posted January 7, 2010 you sir deserve major complements for all the work. im amazed at all the nice builds on this forum, but after reading this i am just really really really amazed lol Link to comment Share on other sites More sharing options...
Careless Posted January 9, 2010 Share Posted January 9, 2010 Yea its coming. I sourced a couple sets of 240 rods, as with the z32 pistons, the Compression distance is shorter. Even though it is only going to be .040" overbore, I am still sonic testing the block and going to offset bore the block to maintain maximum bore thickness according to core shift of the mold. The new thrust bearing design is also time consuming. It is being incorperated right in front of where the flywheel bolts. I never liked how the thrust of a crankshaft is taken up in the center main. WHen you push thousands of pounds of pressure on a flywheel, you are trying to compress the back three cylinders on the crank, before the pressure gets to the center main. With my new design the crankshaft will basicly not see any front to back force, and therefore, relieving stress on the crankshaft also. I always thought the thrust bearing in the center allowed the load to be taken off the rear cylinder to reduce the wobble effect at high RPM that you would induce in an inline 6 if you were to slow down the rear-most cylinder/main and let front-most cylinder/main exert more rotational force at the opposite end of the crank... Just playing the devils advocate here. What's the reason? Did it fail on you before? Because I believe the RB engine platform was designed this way because it proved to be successful in distributing vibration/torsion throughout the crankshaft. I really don't think the center main is as much of an issue as the vibration is. Are the 2JZ's thrust washers not situated on the center main as well? Link to comment Share on other sites More sharing options...
wagon jon Posted October 16, 2010 Share Posted October 16, 2010 Reading through this thread is absolutely amazing. I am quite impressed with the amount of time and effort this project has acquired! So, when will these heads be in production for the general public? Link to comment Share on other sites More sharing options...
OustedFairlady Posted November 19, 2010 Share Posted November 19, 2010 I know this is super late, and I'm not contributing anything to the thread, but this thread is full of win. Absolutely sloshing full of win. It's everywhere. Link to comment Share on other sites More sharing options...
Kash Posted December 2, 2010 Share Posted December 2, 2010 a little more on the z32TT pistons, pin height, will they sit above or below deck and compression ratio w/240 rods/stroker crank? Will this set-up drop your displacement to 3.0? Link to comment Share on other sites More sharing options...
Kash Posted December 2, 2010 Share Posted December 2, 2010 (edited) Great work BTW... Edited December 2, 2010 by Kash Link to comment Share on other sites More sharing options...
Lucky Strike Posted January 1, 2011 Share Posted January 1, 2011 Not trying to take away anything from the work that you have done, i just happened to flip though a magazine today and saw a pick of a dohc l28 head made by osgiken. I guess the magazine was little behind the times as its older news, but cool no the less. http://community.ratsun.net/topic/23916-dohc-os-giken/ Link to comment Share on other sites More sharing options...
1 fast z Posted July 15, 2012 Author Share Posted July 15, 2012 Been driving the car 2-4 times a week and is still holding strong. The 800cc injectors are about maxed out with good afr's so will have to add another set or bigger soon. Link to comment Share on other sites More sharing options...
Tony D Posted October 7, 2012 Share Posted October 7, 2012 Muahahahaha! "It begins..." Link to comment Share on other sites More sharing options...
softopz Posted October 8, 2012 Share Posted October 8, 2012 Oh so its back?! Link to comment Share on other sites More sharing options...
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