Brad-ManQ45 Posted January 17, 2004 Share Posted January 17, 2004 Hi Grumpyvette! Hope to take advantage of your expertise which has always been highly valued... I am having a real problem deciding on what engine series to base a turbo SBC on: PRO's for each as I see 'em: 1st Gen - around forever/cheap 2nd Gen - LT1 - Reverse Flow Water Cooling 3rd Gen - LS1 - Choice of Aluminum or Iron Block and strong bottom end, R/S ratio. CON's for each as I see 'em: 1st Gen - 2 piece rear seal, less flexible w/accessories like A/C w/JTR 2nd Gen - Less Flexible w/accessories w/JTR mounting 3rd Gen - More bucks The telling factor here is that I will be using an aftermarket engine management system, as the stock for LT1/LS1 doesn't handle boost. I haven't heard of a good MAF one out there yet, but maybe I'm out of touch, and I understand that there may not be the neccesity of the reverse flow of the LT1 with the LS1 because of better head design as far as keeping the combustion chamber temps lower. By going to speed density and an aftermarket system, I realise with the LS1 I am giving up a lot of what makes the engine so great from a fuel efficiency standpoint, but wonder which engine series would wind up being best for the $'s. Perhaps others would also like the benefit of your wisdom, I know that I would. A thought on the intake manifold design as it pertains to turboing (Stealth, LT1, LS1) would also be appreciated... TIA, Brad Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted January 17, 2004 Share Posted January 17, 2004 while all options have thier weak points I think youll find that the gen 1 sbc engine has significantly greater choices on parts and at significantly lower prices as an example the main problem youll have is finding great large port heads and super strong blocks and rotating assembly parts all are very easy to obtain for a GEN1 and YOULL TEND TO GET BETTER PARTS PER DOLLAR SPENT, if you have a thick wallet, gen,two has not nearly the parts selection and I don,t think its going to get better, the LS1 is a good but expensive choice look this over AND THIS http://www.montygwilliams.com/ thought on the intake manifold design as it pertains to turboing (Stealth, LT1, LS1) would also be appreciated... since your intending on a pressurized intake Id look into a highly ported modified single plane intake like the STEALTH RAM if MAX FLOW is the MAIN CONCERN AS THE DIRECT SHOT INTO THE HEADS WILL HELP THE POWER POTENTIAL or if max flow and HOOD CLEARANCE ARE BOTH MANDATORY,a EDELBROCK SUPER VIC CONVERTED TO EFI or the IF YOU HAVE THE HOOD CLEARANCE http://www.holley.com/HiOctn/ProdLine/Products/AMS/AMSM/7540P.html http://www.holley.com/HiOctn/ProdLine/Products/AMS/AMSM/f9901-101-1.html http://www.holley.com/HiOctn/ProdLine/Products/AMS/AMSM/300-110.html Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted January 17, 2004 Author Share Posted January 17, 2004 Thanks for the reply Grumpyvette, I'll try to be alitle more specific in what I am looking for: I do not want a lot of low end for this engine as it will be going in my Z, and want to bias toward the top. A lot of this will be compressor-side related, but package-wise would like the intake to follow the same guideline. Which of the 3 generations intakes might prove better in this scenario? I obviously don't need a lot of low end torque in the Z and will rely on the turbo(s) for building the high end. Ii'm not looking for much more than 6-7 hundred HP, so if I went the LS1 route simply replacing rods and pistons should do me, so between early and LS1 might have a wash on prices (maybe wishful thinking here), so would the LS1 intake be better or the Stealth Ram? What would you expect lowend/midrange/topend torque wise (everything else being equal, which of course can't really happen but let's say so just for kicks and grins) out of these three manifolds? Since I'm not going super-high on HP I would probably sick w/stock heads in the case of LT/LS 1's, and eithe TFS or AFR for early gen... Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted January 17, 2004 Share Posted January 17, 2004 judging from that reponce it would seem your interested in building a an LS1 (Z) theres little doubt that a properly modifyed LS1 with turbos will make a killer combo a combo that will provide spectacular performance, while Im reasonably sure I could build more power for similar money with the older GEN1 engine I doubt the ENGINE weight could be lowered to similar levels since the LS1 has an advantage as to total weight and already has the aluminum block AFR has 225cc heads that when matched to a good INTERCOOLED turbo combo should easily get you what your looking for 225cc LS1 Mongoose Strip Head The Ultimate Bolt-On Emission Legal Street/Strip Weapon For the maximum street/strip LS1/LS6 aluminum cylinder head AFR’s all new 225cc emission legal head are hands down the best choice. Specifically designed for 1995 to present Gen-3 Chevy Corvettes, Camaros, and trucks. AFR’s LS1 head offers unmatched flow performance and features 2.080 intake and 1.600 exhaust valves with AFR’s iron ductile interlocking valve seats. The 225cc is ideal for normally aspirated 396C.I. to 427C.I. It is available with 66cc and 76cc combustion chambers. An affordable “as cast†version is also available. AFR’s LS1 is a direct bolt on, no special parts required. Structural features like Air Flow Research’s trademark 3/4†thick head deck, a must for blown and nitrous applications, reinforced rocker stud bosses and thick wall runners provide unparalled durability. An exclusive new modern combination chamber design with double quench pad area helps the LS1 generate huge low and mid lift airflow numbers. If you need a snake charmer for that pesky neighborhood “Cobra Mustang†look no further! Note: Hydraulic roller cams typically experience valve float at 6000-6200 RPM because of their fast ramp rates. AFR suggest you upgrade your springs to AFR part #8019, 1.450 O.D. double with dampener valve spring with higher pressures to reduce the chances of valve float at higher RPM’s. -------------------------------------------------------------------------------- 225cc Mongoose LS1 Racing Head Part Numbers CNC Ported Pairs of Cylinder Heads Complete With Parts and Ready to Install CNC Street Porting Description Part Number 225cc CNC Ported w/parts 66cc 1610 225cc CNC Ported w/o parts 66cc 1620 225cc CNC Ported w/parts 76cc 1630 225cc CNC Ported w/o parts 76cc 1640 220cc As Cast w/ parts 64cc 1650 220cc As Cast w/o parts 64cc 1660 220cc As Cast w/ parts 74cc 1670 220cc As Cast w/o parts 74cc 1680 220cc As Cast w/ parts 66cc CNC Chambers 1650-1 220cc As Cast w/o parts 66cc CNC Chambers 1660-1 220cc As Cast w/o parts 76cc CNC Chambers 1670-1 220cc As Cast w/o parts 76cc CNC Chambers 1680-1 http://www.tradezone.com/vette/engine.html Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted January 17, 2004 Author Share Posted January 17, 2004 Not necessarily - I was inquiring as to what intake manifold would be a better match for the requisite - mid to high end power/less torque at the low end. I'm not sue as I wouldn't use an iron block (Vortech?) I would assume from your answer you skipped stating that the Early Block/Stealth would create more low end than the LS1 w/it's intake, possibly less top end. I hate to assume anything which is why I asked your opinion of the intakes and what their strengths/weaknesses in this scenario would be. It may be that by its' design that the LT1 manifold may be better....of course, I could use the LT1 on an early, but I could get the LT1 block and not have to adapt it.... LS1 might be more $, but over the long run? Little more enlightenment from the GURU please... Quote Link to comment Share on other sites More sharing options...
silicone boy Posted January 19, 2004 Share Posted January 19, 2004 I am in the home stretch as far a putting a pair of turbos on a 383, and I have several observations and biases. As appealing as an LT1 and even the LS1 is, Grumpy is right. You can't beat the bang for the buck of a first gen motor, and if you don't spend the money on making your bottom bulletproof, your motor is going to go bang. The higher compression of the newer motors argues against them, although the reverse cooling and aluminum components helps out here. You could resleeve an LS1 and add lower compression pistons (LT1 also), but the budget gets eaten up. Advanced engine management (I'm using an Electromotive TEC3) will be especially helpful in preventing detonation with these higher compression motors. As for which intake to use, well you're asking for about 700 hp which your setup should should be able to make without breaking much of a sweat. So does it really matter? You'll be at warp speed in the blink of an eye . All kidding aside, yes, the LT1 intake does give you higher top end than a "stock" stealth ram, at the expense of a little bit of low end. See "stealthram.com" for a comparison of the two. The LT1 peaks at a ridiculously high RPM (more in line with my RX7). Still, it is an appealing alternative to a Stealth Ram if you can get one cheap. You would need to modify it for use on a Gen I motor (see http://www.lt1intake.com for directions), but it's not hard or expensive. I'm going with a Victor Jr. style intake set up for fuel injection for now. One of the most difficult problems I have had is coming up with suitable exhaust manifolds. Many people have bench raced on this board and said "sure, there's plenty of room, you could put it in X location without any problems". Unfortunately, I've come to the realization that turbos and all their plumbing take up an awful lot of space, and there's not really a lot if space in the engine bay for it. The Turbomeister has done it, and placed them in front of the block. I've elected to place them to the side, just lateral to the valve covers. This allows me to swap out turbos easily if I want and helps the weight distribution (remember, we speak polar moment of intertia on this board). I've tried many different manifolds, and eventually had to make my own. I'll be posting pictures soon. By the way, Corvette LT1 manifolds flipped over look like they will work, and I'll be getting some soon. Good luck and let me know about your progress. Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted January 19, 2004 Author Share Posted January 19, 2004 Thanks for everyones help. I hadn't been aware of the superram.com site. All said and done, cost isn't so much of a consideration as doing it right to start with. I was actually thinking of going with an iron block for the LS1, but have no idea what the intake is like compared to the LT1 or StealthRam... Quote Link to comment Share on other sites More sharing options...
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