peej410 Posted July 18, 2011 Share Posted July 18, 2011 Background: I bought my Z in 01. I crashed it in 01. (eight days later) I tubed the front end and swapped in a V8. With a college kids budget this took two years. I finally got the car running drove about 1500 miles and the motor grenaded. (recon rebuild) I shelved the project and began assembling parts. In 2010 I came into some cash (aside from the mortgage and the bills) and decided to build her a motor she deserved. Story: I have posted in this section because I have a SBC swapped into my Z the car has run with two different iterations of this motor. due mostly to my own naive nature when it comes to trusting "experts" I built a kick ace motor on a block that wasnt so Ace Kickin. Issue: The motor is a 355 2bolt. 48lb Forged Scat crank, Featherweight eagle 6in rods, light weight SRP Forged pistons. Afr 195 Eliminators. Solid roller conversion .610 gross lift at valve. Jesel Sportsman rockers etc. etc. Somewhere along the way I never really thought about the fact that the block I had had sleeves in it. I made an error on the tune. (likely cause but not sure) and the sleeve on #4 dropped. This diluted the oil with coolant. The main bearings have some scuffs and need to be replaced. The crank needs to be polished the rod bearings are ok but I may replace them anyways. The Morel lifters are scuffed, I havent seen the cam yet. Pistons have a few marks but everything else looks minty mint. Solutions: A dart block ready to go is at least $1750 from CNC blocks. My local guy wants $2400 (local guy is very good and has helped me in the past)at this point I have almost $9000 into this motor and I just cant justify spending even more money on it. I saved up the money to repair it and now just cant part with it to have a $11k motor in a $2k car. Even from CNC it would cost at LEAST $2500 after the crank is polished, new bearings are installed and I install the new rings. I am at a loss and dont know what to do. Alternate solution: Part out motor. Find a decent LS6 or LS2 retool all the engine mounts, trans x member exhaust, fuel system ETC. Source a better tranny (currently t-5) and move on with my life. What to do, what to do? Quote Link to comment Share on other sites More sharing options...
cockerstar Posted July 18, 2011 Share Posted July 18, 2011 Why not punch a good factory 010 block out for your current internals? Have it It isnt an aftermarket block, but there aren't any sleeves, it has the 'high' nickel content, and also has 4 bolt mains. For the price of the dart block you could buy ten 010 blocks and have them all tested at your machine shop. Quote Link to comment Share on other sites More sharing options...
peej410 Posted July 18, 2011 Author Share Posted July 18, 2011 (edited) Why not punch a good factory 010 block out for your current internals? Have it It isnt an aftermarket block, but there aren't any sleeves, it has the 'high' nickel content, and also has 4 bolt mains. For the price of the dart block you could buy ten 010 blocks and have them all tested at your machine shop. By the time a new block is prepped it will be roughly $1400 in machine work. And my pistons at .020 over. Meaning I would need new forged pistons... Edited July 18, 2011 by peej410 Quote Link to comment Share on other sites More sharing options...
rags Posted July 18, 2011 Share Posted July 18, 2011 Having a gen1 and a gen 3 Chevy V8 Z car, I can tell you there is nothing like an ls/t56 combo. It just plain works. Get in,turn the key and go. I know you can Lso xo that with a gen 1 but it will take a lot longer to get there. My advice would be to cut your losses, make back what you can, and find yourself an ls2/t56 combo. You won't be sorry. Quote Link to comment Share on other sites More sharing options...
SUNNY Z Posted July 19, 2011 Share Posted July 19, 2011 LSx ftw! These engines are a godsend. They are incredibly powerful, efficient, and an absolute joy to work on. I will be LSx for evar. Quote Link to comment Share on other sites More sharing options...
peej410 Posted July 19, 2011 Author Share Posted July 19, 2011 I found a LS6 with trans clutch etc somewhat locally. How close are the SBC engine mounts to LS mounts? If they are close I can make new brackets for mine very easily. How much difference is there fore and aft? Quote Link to comment Share on other sites More sharing options...
jt1 Posted July 19, 2011 Share Posted July 19, 2011 At your hp level, you don't need the Dart block, even though they're very nice pieces. If you sell your current parts, you're going to take a big hit on them. My advice is to find a good 010 sbc block, upfit it with billet center caps, and reassemble your motor. The sbc and LS mounts are totally different. Fore to aft the motors are about the same. jt Quote Link to comment Share on other sites More sharing options...
rsicard Posted July 19, 2011 Share Posted July 19, 2011 Peej410: Summit Racing has late model Gen I SBC one-piece rear main seal blocks prepped for 383 stroker for $600-700. Much better than the earlier 2 piece rear main seal blocks as they used modern machining techniques. Stoke for stroke, bore for bore there is NO ADVANTAGE to an LSx block period. For equal displacement they will both produce the same horsepower and torque. The Gen I parts will be cheaper and just as good as the LSx parts. A Dart block is nice but has siamese cylinders where as the later production block has cooling jackets all around the cylinders. The Dart block is 2 piece rear main seal versus the 1 piece rear main seal. The LSx engines have cathedral type intake ports and the latest ones have rectangular intake ports. The rectangular ports have always had better flow characteristics and GM has gone back to them on the late LSx engines. AFR makes the best cylinder heads by far. The competition heads have the latest cylinder head CNC porting available. Extensive testing of flow values and port configurations has gone into these heads. Quote Link to comment Share on other sites More sharing options...
Michael Posted July 19, 2011 Share Posted July 19, 2011 I recommend trusting your local engine builder, sourcing another used block, going through the various machining steps, and reinstalling your components. All other options will be more expensive. That said, prepping a used block will likely require... - wash/clean $50 - crack-check (pressurize) $50 - bore/hone $200 - decking $150 - align-bore mains $200 - cam bearings $50 - freeze plugs $50 - ARP mains $100 Total is $850. These are rough numbers, and are likely to be low. I'm assuming that the main caps can be reused, and the lifter bores are fine (in the new block). Then there are the main/rod bearings, polishing the crank, maybe new rod bolts and resizing, maybe new balancing. After a decade, it is quite easy to have $10K "invested" in a $5K engine. Ask me how I know.... Quote Link to comment Share on other sites More sharing options...
leopard_125 Posted July 19, 2011 Share Posted July 19, 2011 Why not punch a good factory 010 block out for your current internals? Have it It isnt an aftermarket block, but there aren't any sleeves, it has the 'high' nickel content, and also has 4 bolt mains. For the price of the dart block you could buy ten 010 blocks and have them all tested at your machine shop. I agree the 010"casting #" is a great block and can handle up to .040 in high horse numbers,they made some in 2bolt main so you will have to look for the four bolt stuff. the nickel caps are the bomb! IIRC the really good ones where outfitted in boats. Quote Link to comment Share on other sites More sharing options...
peej410 Posted July 20, 2011 Author Share Posted July 20, 2011 Around here a used GM block machined and ready to go is about $1400. Even the little guys who are really good charge big coin for there work. I have contact a few people farther away. Quote Link to comment Share on other sites More sharing options...
peej410 Posted July 20, 2011 Author Share Posted July 20, 2011 Also, everything I have is for two piece seal. Scat crank billet flywheel etc Quote Link to comment Share on other sites More sharing options...
zgeezer Posted July 21, 2011 Share Posted July 21, 2011 I recommend trusting your local engine builder, sourcing another used block, going through the various machining steps, and reinstalling your components. All other options will be more expensive. That said, prepping a used block will likely require... - wash/clean $50 - crack-check (pressurize) $50 - bore/hone $200 - decking $150 - align-bore mains $200 - cam bearings $50 - freeze plugs $50 - ARP mains $100 Total is $850. These are rough numbers, and are likely to be low. I'm assuming that the main caps can be reused, and the lifter bores are fine (in the new block). Then there are the main/rod bearings, polishing the crank, maybe new rod bolts and resizing, maybe new balancing. After a decade, it is quite easy to have $10K "invested" in a $5K engine. Ask me how I know.... Yeah, I've walked that road several times. First a GEN I, then a GEN II, and, now, a GEN III LM7. I presume you are looking for a solid quick street machine and not building for the track or to some association's race rules. SBCs today are like Flathead Fords, OHV Olds/Cadillac/Chryslers in 1957. They still make good HP and parts are "cheap", but the writing on the wall is clear: SBC are obsolete; the aftermarket research is focused on the GEN III. Any GEN III 6 liter iron truck engine with a good camshaft, long tubes, flat pistons, and a good tune on the computer is an easy 550HP. All day long, all night long, and it will crank every time. The point here is not that the CSB is a bad choice, only that when you factor in horsepower and reliability the GEN III can be a "cheaper" build that a SBC. The "best buy" or biggest "bang for the buck" for used motors would be the 5.3 iron truck engine. In my neck of the woods, these will go for $750-1500.00 with transmission, loom, and low mileage. I paid $2K 5 years ago for an LM7 with all accessories, transmission, loom, driveshaft, and 21000 miles. If you like new, look for a GM LS3 crate engine. If smog is a street legal issue for you [given what you have in the SBC, I don't think it would be] stay away from iron block truck engines. The swap from a csb to a GEN III is not that difficult. The process is well described in these forums. Best of luck on whatever decision you make. G Quote Link to comment Share on other sites More sharing options...
peej410 Posted July 21, 2011 Author Share Posted July 21, 2011 Yeah, I've walked that road several times. First a GEN I, then a GEN II, and, now, a GEN III LM7. I presume you are looking for a solid quick street machine and not building for the track or to some association's race rules. SBCs today are like Flathead Fords, OHV Olds/Cadillac/Chryslers in 1957. They still make good HP and parts are "cheap", but the writing on the wall is clear: SBC are obsolete; the aftermarket research is focused on the GEN III. Any GEN III 6 liter iron truck engine with a good camshaft, long tubes, flat pistons, and a good tune on the computer is an easy 550HP. All day long, all night long, and it will crank every time. The point here is not that the CSB is a bad choice, only that when you factor in horsepower and reliability the GEN III can be a "cheaper" build that a SBC. The "best buy" or biggest "bang for the buck" for used motors would be the 5.3 iron truck engine. In my neck of the woods, these will go for $750-1500.00 with transmission, loom, and low mileage. I paid $2K 5 years ago for an LM7 with all accessories, transmission, loom, driveshaft, and 21000 miles. If you like new, look for a GM LS3 crate engine. If smog is a street legal issue for you [given what you have in the SBC, I don't think it would be] stay away from iron block truck engines. The swap from a csb to a GEN III is not that difficult. The process is well described in these forums. Best of luck on whatever decision you make. G Everyone has made good points Geezer you pretty much hit the nail on the head. swapping the LS in (by buying a ls6 t56 pair) gets my car close enough to running that I can muddle through the rest and have it running this month. Id have to liquidate what I own to do it but being paranoid about my SBC and the fact that ill be changing valve springs and lash and constantly worried about it vs giving up some power and all the hi-po parts for some peace of mind... I end up with a 6 year old motor with 50k vs a 55 year old design thats been reworked so much that nothing in the motor was even designed by the same people! in ten years I have put 1808 miles on my car. When it ran i drove it EVERY DAY. (even in the snow) because it was too much fun. losing money is not my concern. losing more time in life not driving something i built with my own two hands does. If I put another short block together and swap all my parts in, whats next? bad lifter? broken valve spring? bad tune? I dont know if I have the energy to obsess over every detail again. With the exception of the bad cylinder my motor had 2% leakdown and ran perfect. I was just messing with it to try to get it closer to "ideal" when things went wrong. Any other opinions given the fact that I am not concerned about losing money so much as I am worried about having an ancient design fail, leak, annoy me. Quote Link to comment Share on other sites More sharing options...
jt1 Posted July 21, 2011 Share Posted July 21, 2011 For a daily driver type build, I think the LS is the obvious choice simply because it's easier to go EFI. EFI doesn't make any more horsepower than a carb, but the hot start, cold start, drivability in different weather conditions, and fuel mileage are all vastly superior to a carb setup. All these factors are very important to a DD, not so much to a weekend toy. You'll probably wind up with more in the LS swap, even after selling the sbc stuff, because the bits and pieces add up fast, but for a DD that's the way to go. jt Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted July 24, 2011 Share Posted July 24, 2011 anyone read the hot rod mag junkyard ls turbo test yet??? september issue, page 76, good read. junkyard 5.3 they wanted to see how much power it would make before it blew up all they did to the shortblock was open up the ring gap from 14 thou to 28 thou stock heads were worked by TEA and bigger valves were installed. high perf springs were installed comp 281hr cam, 228/230 at 50 lsxr intake and and 75lb injectors. fast efi Naturally aspirated it made 450hp/380ft lbs of torque peak power at 7000rpms they added two ebay 76mm turbos and 118 octane race gas ill let you guys read it to see what it made on 26.3 psi . the efi couldnt keep up past this point. lets just say they made over 50 pulls at more than 1000hp. they also FAILED to blow it up surprise ending???? it turned out to be a lowly 4.8 Quote Link to comment Share on other sites More sharing options...
rsicard Posted July 24, 2011 Share Posted July 24, 2011 Read that article. Amazing that the pistons, rods or crank DID NOT FAIL. Really says something about heat and the top ring gap when using a lot of boost. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted July 24, 2011 Share Posted July 24, 2011 anyone read the hot rod mag junkyard ls turbo test yet??? september issue, page 76, good read. It is one of my all time favorite magazine articles. It's like you cannot go wrong with an LSx motor by just doing a few minor mods and then turbocharging the beans out of the motor. I mean, how much power does one really need in a Z to make it fast??!!? I have a 5.7L SBC and I am thinking that once the car is together, simply buy an LSx motor and do the same. I think 600 hp is more than enough for my tastes Davy Quote Link to comment Share on other sites More sharing options...
peej410 Posted July 26, 2011 Author Share Posted July 26, 2011 Thank you guys for all of the responses. I have decided to stick with the SBC. In order to get what I want out of the LS motor for the car I would end up settling/waiting now or tearing into whatever I buy to put into it. Which pretty much defeats the purpose. I also finally used my copy of PipeMax and plugged in all my numbers and now am sure that the sleeve moved due to detonation. Dynamic CR is 9.26 calculated. I need to get the heads CCed for accurate numbers but a small error In the tune on my part likely yielded the pop. Dart SHP will be on the way soon... according to PipeMax we are looking at 550+ at 7200 If it launches, Ill grab a 5.3(4.8) and turbos. Quote Link to comment Share on other sites More sharing options...
peej410 Posted August 7, 2011 Author Share Posted August 7, 2011 Thank you guys for all of the responses. I have decided to stick with the SBC. In order to get what I want out of the LS motor for the car I would end up settling/waiting now or tearing into whatever I buy to put into it. Which pretty much defeats the purpose. I also finally used my copy of PipeMax and plugged in all my numbers and now am sure that the sleeve moved due to detonation. Dynamic CR is 9.26 calculated. I need to get the heads CCed for accurate numbers but a small error In the tune on my part likely yielded the pop. Dart SHP will be on the way soon... according to PipeMax we are looking at 550+ at 7200 If it launches, Ill grab a 5.3(4.8) and turbos. Update: In talking to a few local guys they have reinforced the whole 010 block thought process. So I had a question... The main caps are the supposed weak link in a 4 bolt block. This is "usually" in a drag car or circle track car. Most of which are abused a whole lot more and "usually" a whole lot heavier. Is one to assume that, like a transmission or rear end, that the light weight of the car and the different loads associated with street and road racing use would stress the main caps less? If I went this route is there an inexpensive way to strengthen the caps besides going billet? are there any chevy blocks that came with Nodular caps? Quote Link to comment Share on other sites More sharing options...
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