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All aluminum vs all iron. About 100 lbs on small block. Everything else is still steel and iron that 100 lbs is expensive unless you get boneyard engines and build them. There are a lot of used ls engines out there for cheap. But what about iron tall deck small block aluminum heads. There is a big block hidden inside it.
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Originally Posted by corey331
(Post 4511302)
Parts List:
Stock LS2 Block, bored .030 Callies 4" 4340 Crank Callies 6.125" 4340 Compstar Rods with ARP 2000 bolts Wiseco forged pistons -8cc dish Stock 317 truck heads with PRC (Texas Speed) stage 2.5 CNC Port, opened to 70cc's. Makes 10.5:1 it seems as thoughCompression Bob Madera cam, 243/250, .621/.613 112ls Its a carb motor running Daytona Sensors Smart Spark LS ignition To address the oiling issue, which is that the motors can actually pump too much oil over long hard runs, and can drain the pan before gravity can put the oil back down, I had a custom 12 quart oil pan made by Kevko Pans. I am also running a 29"x3" oil cooler with a built in thermostat and dual remote oil filters. All in all I have just over a 14 quart capacity. I am running Lightning headers. I fought reversion a big part of last year, so I completely dried up the exhaust. I tried to find my dyno sheets last night, but seem to have misplaced them. I'll have to get a new printout from my engine builder. I will however be dynoing it again here pretty soon. I am changing over to closed cooling and want to tweek the ignition a little. I feel like there is more power in the motor with a little more tuning. Here is a pic of the motor right after I set it in the boat and before I dried up the exhaust. https://s25.postimg.org/x7anfi4ov/image.jpg Here is a quick video of it idling at the dock my buddy took the first time I had it out last summer. I am in love with the way a cammed up LS sounds!!! https://www.youtube.com/watch?v=MtwwjdHgAr8 It seems as though there is no good way for oil to get back to the pan other than draining over the cam then crank. The windage also blocks the oil from getting past back into the pan. |
Put a drain back line from back of heads down to the pan a little above oil level. I'm in process of doin that now. Had same issue with my engines
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These are pics I got on line. I'm also going to install a plug in the low drain back hole already in the heads so the oil heads down the return line with out sending any down into the valley
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Originally Posted by veloc410
(Post 4603529)
These are pics I got on line. I'm also going to install a plug in the low drain back hole already in the heads so the oil heads down the return line with out sending any down into the valley
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Unfortunately the lifter side of the head is wide open on an LS so there is no way to block it off.
restricted pushrods are one option. I'm not sure you can get the drain hole lower than drain path on lifter side of the head. it may be best to put the drain line below the oil level in the pan at least on the port side. Otherwise the windage from the crank may keep it from draining or worse yet, blow oil/air up the hose into the head. A wet sump LS has some unique challenges when held at high RPM for a long time. Not a common application I'm afraid. Jeff |
I have restrictive pushrods from Smith bros. They flow oil and a seems like enough. .040 holes as opposed to .080 standard. Thats what i did to solve my issue last year. I still worry about enough flow over springs. Smith bro say its a 70-75% reductuction at top. I was thinking about opening them up to .050 or so.
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Once drain backs are in . I will go back to standard .080 pushrods first and see how it works out. Do not use block restrictors
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These yours?? They look pretty deep. Plenty of room for drain back line in bottom rear corner???
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Yep, I've got the cathedral port heads. I'll have another look tonight.
Jeff |
Let's see if this link works.
https://www.performancetrucks.net/forums/attachments/gm-parts-classifieds-23/52293d1274528758-rebuilt-317-heads-ls6-springs-0-miles-%24400-shipped-100_1339.jpg the area where the head bolt holes are in the middle is wide open to the lifter valley. This is lower than the outer floor where you would drill for a drain. Again, I'll have another look this evening. making a clear valve cover for this would be easy and informative too. Jeff |
I may be able to offer some answers to "go-fast" SBC application.
I have a 1996 Fountain Lightning 35 with 2 Marine Power 6.2 LSA small blocks. The original performance report had the boat at 77 mph at WOT with the 502s. I have been able to achieve 80 mph at WOT with the sbcs. There is room to improve, I haven't tested the boat with minimal fuel yet. Engines have around 80 hours and are mated to Bravo 1s. So far, I have had reliable power, always fill with 93 octane fuel. |
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This help?
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Maybe near valve spring rewards exhaust side
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Most of the oil should run along bottom side of head toward exhaust side before it fills high enough to spill into head bolt holes. Your just looking to divert some of the oil from going to the valley. You could also plug a couple of the those holes towards the rear, maybe threaded aluminum plug or something that snaps in. Doesn't have to be perfect seal. Just some ideas. Good luck. Nice job by the way looks really clean.
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Yep, just had a look at my heads. Looks like I can make plugs over the head bolt holes and add the external drains. Done deal!!
what shall I obsess over now? Jeff |
You get what you pay for! Merc gets a more reliable and less expensive to build with the BBC in the 400 plus torque.
yes you can charge a SBC to produce the same of a BBC. But you just hadded the cost of a charger and that charger can be added to a BB for the same cost has the SB. Stroking is good but it also has it limits. Again cost vs gain.... The LS technology is great. But more $$$ and great gain. It's all about torque for boat. Wile your torque curve climb, you are accelerating. Has soon has it peeks (regardless off your RPM) you are pretty close to top speed. |
I'm all BBC no doubt but I don't think I would have had room for twins BBC in my last boat which had twin 350. Had plans for twin little M darts 434cu in, boat sold the boat
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I’ve chosen 427cid small blocks with 652 hp each on dyno. BBC is possible but very tight on this boat. Cool thread. https://cimg9.ibsrv.net/gimg/www.off...526f0599f.jpeg |
Whoa. Nice, 652hp that's gotta be up around 6500rpm? Correct
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Originally Posted by ttrm007
(Post 4614484)
I’ve chosen 427cid small blocks with 652 hp each on dyno. BBC is possible but very tight on this boat. Cool thread. https://cimg9.ibsrv.net/gimg/www.off...526f0599f.jpeg Jeff |
Veloc410 and hallj, I pulled out the dyno sheets. The 652HP came in at 6200rpm and the highest torque mark was 610@5000. They make torque of 567 @3800 and 552 @6200. They make 602hp at 5400 and 435hp at 4000rpm.
No testing on the water yet but numbers seem to indicate they will do the job. |
What bore stroke did you use to get to 427? Also, what compression? Stout torque for sure. Jeff |
Originally Posted by hallj
(Post 4615297)
What bore stroke did you use to get to 427? Also, what compression? Stout torque for sure. Jeff |
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