trowa47 Posted April 25, 2007 Share Posted April 25, 2007 ok so this is what i have so a l28 block overbore 1mm p90 head 1mm gasket l20a crank so a 69.7 stroke ok and so I think, I need to gets some rods made 140mm long and some flat tops with a pin hight of 32.97 and with ozdat math this gives me Displacement:2.486 litres Deck Clearance:0.030 mm Rod/Stroke Ratio:2.009 Bore/Stroke Ratio:0.801 Static Compression Ratio:7.591 this is going to be a turbo car so any help would be cool is a deck clearance of 0.030mm ok ? and any thing any one can tell me Quote Link to comment Share on other sites More sharing options...
myplasticegg Posted April 25, 2007 Share Posted April 25, 2007 Why destroke on a turbo car? Torque is your friend with boost. Quote Link to comment Share on other sites More sharing options...
trowa47 Posted April 25, 2007 Author Share Posted April 25, 2007 well I'm only going for 300 350 hp rang but i'm wanting usable power say past 8000 rpms. i really want to build a crazily over square engine, i just rather have a 3.5l Ferrari f355 engine then a stroked and built Chevy small block. Quote Link to comment Share on other sites More sharing options...
myplasticegg Posted April 26, 2007 Share Posted April 26, 2007 so buy a ferrari f355 and let it rev out. If you're set on it, then go for it. I am sorry that i can't help with your math. Quote Link to comment Share on other sites More sharing options...
naviathan Posted April 26, 2007 Share Posted April 26, 2007 Any deck clearance will be fine so long as it's not negetive. I've looked at destroking an L28 before as well. Except I was planning to use an L24 crank and rods with L28 flat tops, L26 "C" stamp cam and an E88 head. A friend wanted an engine for a turbo project with high compression and could wind out to at least 8k. I figured going that route and keeping moderate boost, say 12psi, would be fairly quick, reliable and have a crap load of top end. Might want to think about trying that instead of custom rods and pistons. it'd be cheaper. Quote Link to comment Share on other sites More sharing options...
Tony D Posted April 26, 2007 Share Posted April 26, 2007 L20B Rods would work well, that is what we are running in our L20A Powered Bonneville Car. That car's Peak Power occurs at 8750rpm, and our shiftpoints are between 9300, and 9500rpms. Matter of fact, we are taking that to the Dyno this afternoon to recal the ECU for the new headers and full exhaust we put on the car in the off season, and then it's off to the races next weekend up at El Mirage. Maybe I should charge the video camera and see if I can capture the sounds....muahahahaha Anyway, I digress. We were able to get a tolerable ring stack using the L20B rods in the engine, of course we have custom pistons made---I'd say that is the route you're headed anyway. Make sure you verify the deck height on your block so you don't run into a previously decked unit that has your pistons popping up, say, a few thou from a previous deckheight alteration from a warped block. Quote Link to comment Share on other sites More sharing options...
TimZ Posted April 26, 2007 Share Posted April 26, 2007 L20B Rods would work well, that is what we are running in our L20A Powered Bonneville Car. That car's Peak Power occurs at 8750rpm, and our shiftpoints are between 9300, and 9500rpms. Matter of fact, we are taking that to the Dyno this afternoon to recal the ECU for the new headers and full exhaust we put on the car in the off season, and then it's off to the races next weekend up at El Mirage. Maybe I should charge the video camera and see if I can capture the sounds....muahahahaha Anyway, I digress. We were able to get a tolerable ring stack using the L20B rods in the engine, of course we have custom pistons made---I'd say that is the route you're headed anyway. Make sure you verify the deck height on your block so you don't run into a previously decked unit that has your pistons popping up, say, a few thou from a previous deckheight alteration from a warped block. Very good advice on getting deck height measurements. No telling what's been done to your block in the last ~30 years (unless maybe you've owned it that whole time)... Tony - is your Bonneville car turbocharged? IME it's not a trivial matter to get a turbo'ed engine to make power at really high rpm (it can be done, but the normal tricks like long duration/overlap on the cam don't necessarily work). Getting an L-series head to breathe at 9000rpm with cam timing that works for forced induction sounds like a challenge to me. Any thoughts on this? Quote Link to comment Share on other sites More sharing options...
trowa47 Posted April 26, 2007 Author Share Posted April 26, 2007 Tony d How long are L20B Rods ? Quote Link to comment Share on other sites More sharing options...
Shuyun Posted April 26, 2007 Share Posted April 26, 2007 Well….. According to the Engine Design Utility L20B/Z22S rods are as follows: Length: 145.9 mm Piston End Bore: 21.0 mm Piston End Thickness: 25.4 mm Big End Bore: 53.0 mm Big End Thickness: 26.8 mm Quote Link to comment Share on other sites More sharing options...
Chewievette Posted April 27, 2007 Share Posted April 27, 2007 I am planning a similar engine, but I was going to use LD28 rods because I finally have a source. If I can find L20B rods, I would rather have those to keep the rotating mass down. I was also planning to bore it out a bit more than you are, 89-90mm. Tony D - We Definately want to hear that engine at full song! Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted April 27, 2007 Share Posted April 27, 2007 You can purchase a set of L20B (U60) rods from me if you'd like. They are not cheap and are becoming more scarce than the infamous V07 LD28 crankshaft. PM me if interested and we'll discuss the costs. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.