jimlickster Posted October 25, 2006 Share Posted October 25, 2006 Recently bought a 1986 Chevy Truck. The Engine Smoked Badly. When i took it apart, the Pistons were wrong. I could move em around in the Cylinders. Not Good. A Buddy of mine Suggested that since i had the Engine down and was gonna rebuild it anyhow, i should make it a Toy. I agreed. I've Purchased Most of the Performance Parts that i'm going to use and some are Stock. I Made the Mistake of Jumping blindly into it. After doing some Research, i've found that building a Performance Engine means so much more than buying alot of Cool parts and slapping it together. The More i read, The more i'm concerned about things like My Valves hitting my Pistons and Not being able to use Gas From a Normal Gas Station. Perhaps i can give you a list of the Parts that i have and you can tell me if this thing will work. Block: 1972 Small Block 350 Chevy with a 4 Bolt Main. Cylinders are .060 Crank: NEW Nodular Steel Counterweighted. Stock Stroke of 3.48 Rods: Stock, Stock, Stock Pistons: Speed Pro STL-H345NP Hypereutectic Aluminum Flat Top Compression Distance 1.560 in Piston Head Volume +5.00cc Four Valve Releifs Pin Diameter .927 in Camshaft: Lunati Duration: 284IN/284EX (218IN/218EX at .050 Tappet Lift) Lift: 458IN/458EX (At 1.500 Rocker Ratio) Lobe Separation: 110 Heads: Stock 882s Combustion Chambers: 76cc Decked .052 Intake Valves 1.94 Springs: Heavy Duty Rated for .600 Lift Rockers: 1.6 Ratio (New Valve Lift is .488?) Intake Manifold: Edelbrock Performer (I think) Carb: Edelbrock Performer 600 cfm Manual Choke. Exhaust: Nice Set of Headers. I'm Currently Not concerned with the Drive Train Gear Ratio. I just want to know if this Engine will Go together and Run well. My Transmission is a 400 Turbo with a Shift Kit and i THINK i have 3.53 Gears. Quote Link to comment Share on other sites More sharing options...
kuntry Posted October 25, 2006 Share Posted October 25, 2006 Well desktop dyno says youll put out a whopping 281 hp and 355 ft lbs of tq. The main problem I see in your combonation is that the heads, although they are some of the best flowing factory heads out there, also have huge combustion chambers and small valves. With those heads and your piston choice, your looking at about 8.5:1 cr. You definatley dont have to worry about valves hitting the pistons. Im not sure how much performance you want out of this engine, but imo you need to spend on a better set of heads to help the flow and to get a better cr. For example, if you can find a good set of big valve 64cc heads, desktop dyno says youll jump to 332 hp and 383 ft lbs of tq. To be honest with you, Ive never been crazy about single profile cams since I tried a dual profile for the first time, they have been dual ever since. Just for fun, I tried changing a few things with your engine to a combo Ive run and heres what I came up with.... your block, crank and pistons a GOOD set of aftermarket heads (nothing fancy 64cc, 2.02/1.6, gasket matched and screw in studs) comp cams 268xtreme energy cam (224/230, 0.505/0.512 with your rockers) bump up tp a 650 carb run fel pro 0.015 embossed shim head gasket (a little more cr) Desktop dyno says it puts out 384 hp @5500 and 399 ft lbs @ 4500. That would be a nice little motor. I ran that engine in my old camaro for awhile, except that I had the Performer RPM intake. It was a great running motor and was constantly whooping up on rustangs. Hope this helps you a some. If you can get your hands on a program like DD it can save you a fortune in "lets buy this and see what happens". Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted October 25, 2006 Share Posted October 25, 2006 http://www.themotorbookstore.com/resmchstvi.html buy and both watch the CD, and read thru the info (ABOVE) then buy and read these HOW TO BUILD MAX PERFORMANCE CHEVY SMALL BLOCKS ON A BUDGET by DAVID VIZARD . JOHN LINGENFELTER on modifying small-block chevy engines youll be so far ahead of most first time builders, its amazing, MONEY VERY WELL SPENT, you won,t believe the info they contain then buy this (below) so you don,t get hurt durring the engine build and start asking questions on the site http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=4420 BTW hes correct,the dyno software is a huge help http://www.compperformancegroupstores.co...;Category_Code= cam sellection software http://www.virtualengine2000.com/DynoOverview.htm virtual dyno software BTW this thread below, may give you some very useful info http://www.chevytalk.org/threads/showflat.php?Cat=0&Number=1527608&an=0&page=0#Post1527608 Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted October 25, 2006 Share Posted October 25, 2006 The only thing that really really alarms me about your build is "stock, stock, stock" connecting rods. Get them resized and fitted with ARP fasteners if you do nothing else. Picking a matched set of rods is important as well, I don't know if those books cover how to do that but you'll need about 3 or 4 sets of stock rods to choose from and pick a set that has small balance pads on both ends. That means that they have more "meat" in the beam where it belongs. That applies to all manufacturers rods, nissan, ford, dodge, chevy, etc. Stock heads of any type don't flow that great with lifts over .500 but you want to be as near that as you can. 230 duration at .050 isn't that big of a cam, will have lope, sound cool and run good. Single pattern cams work ok, depends on what you've got. I run a single pattern in my 9 second z. Tighter lobe separation angle or lobe centers will work better with your combination IMO. Isky makes a hydraulic 284 cam, which sports 230 duration at .050 and .485 lift with your rockers that'd work pretty good. LSA is 108 so it'll lope pretty good. Run that with a manual or 2500 stall in an auto and you'll enjoy it. Quote Link to comment Share on other sites More sharing options...
jimlickster Posted October 25, 2006 Author Share Posted October 25, 2006 Thanks Guys. That's alot of Info For me to Digest. Does anyone know what the Stock Horsepower and Torque is for a Chevy 350? I'm feelin' Dr_Hunt when he says i should Get better Rods. That does seem to be one of the Weak links. I also understand what Kuntry was telling me about Heads. I am glad that my Valves won't hit my Pistons. I've spent so much on the Engine now, that i may Pony up for another set of Rods now, and Heads later on. Since Rods require Engine Removal, it seems to me that they would be the best Immediate Purchase. I can always bolt on another set of Heads later. At a Compression Ratio of 8.5:1 i could even Run Regular 87 Octane Gas is what i'm guessing (Not that i would on this Application). I was worried since the Pistons say they are 10:1 at 58cc. This Application will be driven on a Regular basis, so i don't want TOO MUCH performance. Just enough to make it sound and Feel good for now. I am a Rookie after all. You have to walk before you can Crawl. What are some of the advantages of a Dual pattern Cam? How would you select one correctly? Since i'm also Single with No Kids that i know of, i can build another one in my Living Room without a Wife Bitching at me. That is something that i will probably do. The Next one will be a Monster Though. Maybe i'll use a SBC 400 This time........ Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted October 25, 2006 Share Posted October 25, 2006 Thanks Guys. That's alot of Info For me to Digest. Does anyone know what the Stock Horsepower and Torque is for a Chevy 350? I'm feelin' Dr_Hunt when he says i should Get better Rods. That does seem to be one of the Weak links. I also understand what Kuntry was telling me about Heads. I am glad that my Valves won't hit my Pistons. I've spent so much on the Engine now, that i may Pony up for another set of Rods now, and Heads later on. Since Rods require Engine Removal, it seems to me that they would be the best Immediate Purchase. I can always bolt on another set of Heads later. At a Compression Ratio of 8.5:1 i could even Run Regular 87 Octane Gas is what i'm guessing (Not that i would on this Application). I was worried since the Pistons say they are 10:1 at 58cc. This Application will be driven on a Regular basis, so i don't want TOO MUCH performance. Just enough to make it sound and Feel good for now. I am a Rookie after all. You have to walk before you can Crawl. What are some of the advantages of a Dual pattern Cam? How would you select one correctly? Since i'm also Single with No Kids that i know of, i can build another one in my Living Room without a Wife Bitching at me. That is something that i will probably do. The Next one will be a Monster Though. Maybe i'll use a SBC 400 This time........ A hand picked set of rods would have been more appropriate for me to say. Just pick a set, and leave the copper colored ones out of your pick, if they have a copper coating then they were oversized on either the small end or big end. Have them resized and add arp fasteners, then you'll be more than fine for your HP level. Quote Link to comment Share on other sites More sharing options...
jimlickster Posted October 26, 2006 Author Share Posted October 26, 2006 I understand what you're saying, but i Figure if i'm gonna spend this much money on the engine, i shouldn't use the Stock Rods. That's the only thing that would have been left on by bottom end that hadn't been Replaced with a New Item. I found a Pretty good deal on some Legend Rods for $160 Shipped. I think i goofed and ordered the 6" Rods though. If i did, Would i have to worry about the Valves Clearing my Pistons? Kuntry said that my Compression Ratio was 8.5:1. If i use 6" Rods, what would that make it? Would i still be able to run Gas from a Gas Station (93 Octane)? I used to have an Old VW Beetle. When you Increased the Stroke on a Beetle Engine, you had to Clearance the Block so the Rods wouldn't hit the sides of the Cylinders at the bottom. Does this condition Exsist with a V8 Chevy? Quote Link to comment Share on other sites More sharing options...
kuntry Posted October 26, 2006 Share Posted October 26, 2006 your pistons are designed for 5.7 rods. the 6" rods wont work with them. the difference is where the pin sits in the piston. you might want to double check what you ordered and if its the 6", see if its too late to change the order. Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted October 27, 2006 Share Posted October 27, 2006 PERSONALLY, I would buy a set of used aftermarket heads of X brandname already assembled with appropriate springs, get some ARP bolts on your rods and forget about it. 9.5:1 is usually accepted as the maximum compression for 87 octane gas on iron heads. Add 1 point for aluminum (which would give you 10.5:1) Quote Link to comment Share on other sites More sharing options...
jimlickster Posted October 27, 2006 Author Share Posted October 27, 2006 My order for Rods is all taken care of. I will have NEW rods with ARP. Thank you for the Compression Information. Why does Aluminum allow More compression? What is the Differance in a Tunnel Ram Intake and a Normal Intake? Quote Link to comment Share on other sites More sharing options...
kuntry Posted October 27, 2006 Share Posted October 27, 2006 aluminum allows for more compression without detonation because the aluminum dissipates heat faster than steel. A tunnel ram is a tall intake with long runners, usually only good for high RPM engines. Basically worthless on a mild engine unless you just want it to look like it will go fast. Stick with a good dual plane intake like the performer or performer rpm. You will have good low end and mid range power, and its a much better match for your combo than a tunnel ram. Quote Link to comment Share on other sites More sharing options...
jimlickster Posted October 27, 2006 Author Share Posted October 27, 2006 I LOVE this Forum!! You guys are AWESOME. You realize that i'll probably bother the Hell out of you Guys forever now? I guess this is just what i need huh? First it was Computers, Now it's gonna be Engines. Do you think i'm Obsessive Compulsive? Quote Link to comment Share on other sites More sharing options...
specialk Posted October 27, 2006 Share Posted October 27, 2006 A question to ask yourself (honestly) is "what do I plan to do with this car?" If it's something that will get a lot of miles and be driven in a lot of traffic, you're better off building something that will run on 87 octane fuel, with good heads, good internals and a mild camshaft. But, if you're putting 350 hp already in a 2500+ lb car, I'm guessing this isn't a primary mode of transportation. In that case, step it up a notch. Get better heads, better internals and more cam. Chevy High Performance magazine has run article after article after article about what can be done with these engines. And they (for the most part) report pretty truthfully about the driveability issues too. Remember, build the engine you want as opposed to 'making due'. The costs up front are incremental if you do the former, but you'll pay for everything twice if the latter path is followed. Or, you'll never be happy with what you built and won't ever have the opportunity to build another one. Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted October 28, 2006 Share Posted October 28, 2006 My order for Rods is all taken care of. I will have NEW rods with ARP. Tensil, that is stretching, the rod is harder on rods than combustion until you reach roughly 1.5 times your engines designed power. So say your engine was stock with 260hp you will not start to push the limits of your rods until roughly 390hp. Your rods are OVERBUILT in relation to your 260hp because of centrifigul force which stretches them. The reason why this is so is because when your piston reaches the top of its stroke there is nothing to push it back down unless you have a combustion which presses it before it tries to reach equilibroum and then "jerks" back. Of course if you're wanting to crank something to 7.5k then that's a whole different story. I'm not really good at explaining things but I hope this has helped. Engine theory varies from person to person so take anyones advice (even mine) with a grain of salt and research things for yourself. Btw, I ASSume you know that you will have to balance the rotating assembly. So why not stroke it.... Quote Link to comment Share on other sites More sharing options...
jimlickster Posted October 28, 2006 Author Share Posted October 28, 2006 I can't Stroke it. I have the Wrong Pistons. Yes, I understand Tensile Strength. I didn't think about it in releation to Pushrods though. I guess if i make this a Hobby, Lucky me, I'm a Machinist in the National Guard. Quote Link to comment Share on other sites More sharing options...
jimlickster Posted October 28, 2006 Author Share Posted October 28, 2006 How do i balance the Rotating Assembly? Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted October 28, 2006 Share Posted October 28, 2006 http://em-ntserver.unl.edu/Mechanics-Pages/Luke-schreier/unzip/Tension%20and%20Compression%20in%20Connecting%20Rods%20VI.htm http://victorylibrary.com/mopar/rod-tech-c.htm http://www.stahlheaders.com/Lit_Rod%20Length.htm http://www.carrilloind.com/pdfs/10777_eprint.pdf http://www.hotrod.com/techarticles/choosing_the_right_connecting_rods/ Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted October 28, 2006 Share Posted October 28, 2006 I can't Stroke it. I have the Wrong Pistons. Well, here's where you need to do your homework before buying. If you have to balance the rotating assembly any way (which is probably around $200), which you do because you have mismatched the parts and completely changed their weight (you should balance it even if you just bought new rods unless they say they are stock weight), you should have bought the stroker crank keep the rods and bought some stroker pistons. It is possible to use stock pistons on a 383 stroker but I can't remeber the combination at the moment. Yes, I understand Tensile Strength. I wasn't trying to explain an engineering term, I was pointing out that your rods are or atlest should be stronger than you think. I didn't think about it in releation to Pushrods though. Now you've lost me. Quote Link to comment Share on other sites More sharing options...
jimlickster Posted October 29, 2006 Author Share Posted October 29, 2006 Are you saying that by Stroking a 350 i would have 383? I am planning on Running New Stock 5.7" Rods, a New Nodular Seel Crank and 10:1 Flat top Hyper Pistons. Not intending to Stroke the engine. As far as Tensile Strength, I can see where that would appy in relation to Connecting Rods, but not Pushrods. That's where i was also confused. I thought you were refering to Pushrods. I have Determined that i am Inept at Building anything other than stock. I sure hope this has a Happy ending. At the Very Least, I'll learn alot from this. I hope that it doesn't cost me too much to learn my lesson. Quote Link to comment Share on other sites More sharing options...
denny411 Posted October 29, 2006 Share Posted October 29, 2006 The single most common mistake made by a first time engine builder is impatience. Slow down, take a deep breath and read,read and re-read. Then come here, ask a few more questions, and go back and read some more. The links that grumpy posted are there for a very important reason. The information contained there is imense. If you want max torque then stroke it. i`m not sure where you aquired your crank and pistons, but if they could be returned for credit towads a stroker kit that is pre balanced, that`s what i would do. A good set of aftermarket heads is a must, as well a good cam with a profile to match the flow charactaristics of your heads. If this is going to be a "toy", then you can afford to take your time and do it right the first time. Just be clear with youself of what you really want from this engine, make a plan,and stick to it. Then get your shopping list togther and start bargain hunting. ebay and message boards such as this are litterd with items for sale by people who didn`t plan well and are sitting on parts that they can`t use. Denny Quote Link to comment Share on other sites More sharing options...
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