grumpyvette Posted August 21, 2008 Share Posted August 21, 2008 place a single rod/piston assembly with well oiled bearings and no rings installed on the first cylinders journal, and have the cam installed to check clearances ,now, rotate the crank thru a couple full rotations so the piston slides freely in the oiled bore, while you look closely at the rod too block clearance and rod too cam lobe clearance, if the cam lobes too close the edge of the rod bolt upper/edge of the bolt or rod itself needs to be filed/ground for clearance since you can,t grind the cam lobe, on the block the block gets clearanced ground, you want about a .060 minimum clearance. a large paper clip can be used as a crude feeler gauge, a 1/2" dia carbide cutting burr in a die grinder can do it in seconds,once thats done you move that piston & rod to the next cylinder and repeat 7 more times, etc. don,t forget to clean up afterwards, and DON,T forget the rodand piston has the exhaust/intake valve and rod bearing radius fit correctly in only one dirrection on that cylinder BEFORE AFTER Small Chevy Fastener Type Torque Spec 7/16 in. outer main cap bolt 65 ft.-lbs. 7/16 in. inner main cap bolt 70 ft.-lbs. 3/8 in. outer main cap bolt 40 ft.-lbs. 11/32 in. connecting rod bolt 38-44 ft.-lbs. 3/8 in. connecting rod bolt 40-45 ft.-lbs. Cylinder head bolts 65 ft.-lbs. Screw-in rocker arm studs 50 ft.-lbs. Intake manifold bolts (cast iron heads) 30 ft.-lbs. Oil pump bolt 60-70 ft.-lbs. Cam sprocket bolts 18-20 ft.-lbs. Harmonic damper bolt 60 ft.-lbs. Flywheel/Flexplate bolts 65 ft.-lbs. Pressure plate bolts 35 ft.-lbs. Bell housing bolts 25 ft.-lbs. Exhaust manifold bolts 25 ft.-lbs. Big Chevy Fastener Type Torque Specs Main cap bolt, 396-427 2-bolt 95 ft.-lbs. Main cap bolt, 396-454 4-bolt (inner/outer) 110 ft.-lbs. 3/8 in. connecting rod bolt 50 ft.-lbs. 7/16 in. connecting rod bolt 67-73 ft.-lbs. Cylinder head bolts, long 75 ft.-lbs. Cylinder head bolts, short 65-68 ft.-lbs. Screw-in rocker arm studs 50 ft.-lbs. Intake manifold bolts (cast iron head) 25 ft.-lbs. Oil pump bolt 65 ft.-lbs. Cam sprocket bolts 20 ft.-lbs. Harmonic damper bolt 85 ft.-lbs. Flywheel/Flexplate bolts 60 ft.-lbs. Pressure plate bolts 35 ft.-lbs. Bell housing bolts 25 ft.-lbs. Exhaust manifold bolts 20 ft.-lbs. http://www.fourwheeler.com/techarticles/128_9712_chevy_engine_specifications/photo_11.html Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted August 22, 2008 Author Share Posted August 22, 2008 IF your going to use ARP main cap studs THE TORQUE SETTINGS ARE DIFFERANT than the orriginal BOLTS, the STUDS ARE STRONGER, BUT,you might also consider that main studs generally install after cleaning the threads in the block with a tap,blowing them dry with high pressure air, oiling the studs fine threads with the ARP thread lube,the course threads with sealant,when you screw them into the block the full thread depth,by hand, then get backed out one turn, the main caps installed and the nuts torqued in stages to seat and hold the main caps, now LOOK at those STUDS the end in the block threads is SAE COURSE thread, the end your torqueing the nut on is SAE FINE THREAD with a much differant PITCH that requires less tq to give the same clamp loads http://www.arp-bolts.com/catalog/Catalog.html http://www.arp-bolts.com/FAQ/FAQ.html Quote Link to comment Share on other sites More sharing options...
DavyZ Posted August 22, 2008 Share Posted August 22, 2008 BUT,you might also consider that main studs generally install after cleaning the threads in the block with a tap,blowing them dry with high pressure air, oiling the stud with the ARP thread lube,when you screw them into the block the full thread depth,by hand, then get backed out one turn... Why do they get backed out by one turn? I'm trying to think of the physics behind it, but I can't think of any good reason. What is the physics answer, Grumpy? Davy Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted August 22, 2008 Author Share Posted August 22, 2008 IF your going to use ARP main cap studs THE TORQUE SETTINGS ARE DIFFERANT than the orriginal BOLTS, the STUDS ARE STRONGER, BUT,you might also consider that main studs generally install after cleaning the threads in the block with a tap,blowing them dry with high pressure air, oiling the studs course threads with the thread sealant and fine threads end with the ARP thread lube, when you screw them into the block the full thread depth,by hand, then get backed out one turn, the main caps installed and the nuts torqued in stages to seat and hold the main caps, now LOOK at those STUDS the end in the block threads is SAE COURSE thread, the end your torqueing the nut on is SAE FINE THREAD with a much differant PITCH that requires less tq to give the same clamp loads http://www.arp-bolts.com/catalog/Catalog.html Why do they get backed out by one turn? I'm trying to think of the physics behind it, but I can't think of any good reason. What is the physics answer, Grumpy? the threads must bear evenly and align correctly with the studs centerline, for the stud to apply max loads over the total threaded surface ,the threaded section must be under tension alone and engage the total threaded surface in the block, if the stud is torqued into place, youve preloaded the threads bearing the load and they are partly under compressive loads ,your basically jacking the bottom of the threaded hole away from the threaded section, and appling THOUDANDS of lbs of extra stress to the blocks web area if you torque the threads to the same 100 ft lbs the original bolts were tightened to, the threads in the block will now have added stress once the full tension loads on the studs and main caps is applied by torqing the nuts on the studs ,theres added stress on the block, if the studs have bottomed out and are pushing on the bottom of the threaded hole making the block web area more likely to crack or the crank saddles to distort. keep in mind FACTORY BOLTS are made slightly shorter to PREVENT the bolt tip bottoming out in the hole, but bolts cause wear on the threads because they are tightened while the bolts still advancing deeper into the threaded block, studs cause far less wear because they fully engage the threads bearing the loads before the tensive load is applied heres what ARP says "STUDS vs. BOLTS ARP recommends the use of main studs over bolts whenever possible for several key reasons. First is the ability to obtain more accurate torque readings because studs don’t “twist” into the block. All clamping forces are on one axis. By the same token, there is less force exerted on the block threads, which contributes to improved block life (very critical on aluminum blocks). Finally, there are factors of easier engine assembly and proper alignment of caps every time" ARP's instructions (for head studs)state that you should thread the studs into the block until they're hand-tight, but with the head on the block, this is difficult. Fortunately, ARP was thoughtful enough to incorporate a fitting for an Allen wrench into the head of each stud. So, using an Allen wrench, I threaded the studs into the head until I could no longer turn the wrench with two fingers. This method seems to have worked nicely 1. Clean and chase appropriate threads in block to ensure proper thread engagement and accurate torque readings. 2. All hardware (and caps) should be cleaned and inspected prior to installation, looking for any shipping damage or defects. 3. Screw studs into block, finger tight ONLY. For permanent installation, apply Loc-tite (or similar adhesive) sparingly to threads. Be sure and install the caps promptly before the cement sets to prevent misalignment of studs in block. 1. Clean and chase appropriate threads in block to ensure proper thread engagement and accurate torque readings. 2. All hardware (and caps) should be cleaned and inspected prior to installation, looking for any shipping damage or defects. There are a number of important considerations when installing ARP main studs. 3. Screw studs into block, finger tight ONLY. For permanent installation, apply Loc-tite (or similar adhesive) sparingly to threads. Be sure and install the caps promptly before the cement sets to prevent misalignment of studs in block. First and foremost is making sure the block and studs are as clean as possible. Foreign matter and debris can easily affect the quality of thread engagement and cause erroneous torque readings. Do not re-cut threads in the block – use the special “chaser” taps as listed on page 87 of this catalog. This will preserve the integrity of the threads and provide better engagement. Calibrate your torque wrench – even new wrenches have been known to be off by as much as 10 foot pounds! Use consistent tightening techniques. 4. Install main caps, checking for binding and misalignment. Lubricate threads, nuts and washers with oil or ARP moly assembly lubricant before installation. Note that torque specs will vary by lubricant. Moly lube is most consistent. Have block align honed. 5. Using the instructions provided with the studs, tighten the nuts to proper torque values three times. NOTE: If using Loc-Tite or similar cement, proper preload must be achieved prior to it setting up. http://www.arp-bolts.com/FAQ/FAQ.html I usually use this sealant (sparingly)on the course ends of main cap studs that screw in hand tight, and ESPECIALLY on head studs that enter water jackets http://www.permatex.com/products/Automotive/automotive_gasketing/gasket_sealants/Permatex_Super_300_Form-A-Gasket_Sealant.htm keep in mind the course thread section is not being screwed in or the threads moved as the nut on the fine thread upper end is torqued to spec. and that thread requires the ARP thread lubricant to get the correct stretch and that stud needs to be cycled up to full torqure then released and retorqued,a minimum of three times to get the stretch/tq correct Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted August 25, 2008 Author Share Posted August 25, 2008 I got asked recently what hydrolic roller cam ID suggest for a street/strip 383 combo?(obviously theres a wide sellection that may work,) ONE GENTELMAN pointed out ,after shopping around one of the least expensive deals seems to be the EDELBROCK CAM BELOW http://www.jegs.com/i/Edelbrock/350/22015/10002/-1# SB-Chevy 283-400 Hydraulic Roller Camshaft Kit Duration Advertised 296° Intake/300° Exhaust Duration @ .050'' 234° Intake/238° Exhaust Lift @ Valve .539'' Intake/.548'' Exhaust Lift @ Cam .359'' Intake/.365'' Exhaust Lobe Separation Angle 112° Intake Centerline 107° Intake Timing @ .050" Open 10° BTDC Close 44° ABDC Exhaust Timing @ .050" Open 56° BBDC Close 2° ATDC IVE used similar cam designs (durration/lift/)in the past with excellent results and $709 for the cam, roller lifters and pushrods is a good value, naturally the REST of the components and the cars drive train and the cars intended use will effect the choice the only thing that makes me hesitate is the quality of edelbrocks cam cores.AS most IVE SEEN are not billet but cast cores which are less durable and on a 383, PLUS you want a small base circle cam......for rotating assembly clearance issues ,one reason I usually suggest this cam in similar combos http://www.cranecams.com/index.php?show=browseParts&action=partSpec&partNumber=119661&lvl=2&prt=5 http://www.jegs.com/i/Crane/270/119661/10002/-1# http://www.jegs.com/webapp/wcs/stores/servlet/KeywordSearchCmd?storeId=10001&catalogId=10002&langId=-1&N=0&Ntt=11532-16&Ntk=all&Nty=1&D=11532-16&Ntx=mode%2Bmatchallany&Dx=mode%2Bmatchallany&searchTerm=11532-16 Grind Number: HR-230/359-2S-12.90 IG Operating Range: 3000-6500 RPM Duration Advertised: 292° Intake / 300° Exhaust Duration @ .050'' Lift: 230° Intake / 238° Exhaust Valve Lift w/1.5 Rockers: .539'' Intake / .558'' Exhaust Lobe Separation Angle: 112° Max Lift Angle: 107° ATDC Intake / 117° BTDC Exhaust Open/Close @.050'' Cam Lift: Intake - 8° BTDC (opens) / 42° ABDC (closes) Exhaust - 56° BBDC (opens) / 2° ATDC (closes) with either cam youll want a 3000rpm stall converter , about 10.5:1 cpr and a 3.73-4.11:1 rear gear to maximize the preformance and a low restriction exhaust, headers and a high flow intake IM currently running the crane 119661 cam in MY 383 and Ive tested over a dozen cams in that engine, so if its a street/strip combo ID suggest going that route, SMALL BASE CIRCLE AND BILLET CORE.....yeah! YOU GET WHAT YOU PAY,FOR and DURABILITY FOR PARTS TENDS TO COST MORE Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted August 25, 2008 Author Share Posted August 25, 2008 BIGGER is NOT always BETTER, and since both the header primairy dia. and length and the collectors , which have a huge effect on the resulting scavaging can,t be changed as we change engine rpms, we need to maximize the cylinder scavaging charicteristics so as to maximize the cylinder filling and extend the rpm band of the torque curve but once your have the collectors and headers primairy designed to maximixe the scavaging in your chosen and intended rpm range and run the collectors to a (X) to induce both increased scavaging and lower restriction to flow theres not much that a larger exhaust past that point can do badly but increase the noise levels while it should be rather obvious that a smaller than ideal exhaust will hurt the upper rpm band as it tends to be a restriction yes if you have a smaller exhaust dia. it tends to act like an extended collector and increase low rpm torque at the cost OF being A restriction ONCE THE RPMS BUILD PAST A CERTAIN POINT. having both collectors empty into an (X) pipe EFFECTIVELY instantly doubles the cross sectional area of the exhaust pulse and significantly reduces the return reflected pressure wave, almost making the collectors act as if its running without any restiction compared to a true dual exhaust IF the exhaust pipes are large enough to provide a very low restriction at that point as I POINTED OUT ABOVE... theres plenty of fluid dynamics math and research out there to show that the distances the exhaust travels between exhaust pulses and the diam. and length are easily calculated, and past that length the second previous pulse has little effect compared to the current and previous pulse energy and reflective wave and lets not forget the cam timing displacement and intake port all effect the cylinder scavaging the headers can effectively provide also http://www.engr.colostate.edu/~allan...ngth/pipe.html http://www.rbracing-rsr.com/runnertorquecalc.html http://victorylibrary.com/mopar/header-tech-c.htm http://www.headerdesign.com/ http://www.pontiacracing.net/js_header_length1.htm http://www.slowgt.com/Calc2.htm#Header LETS ASSUME I WANT MY 383 TO MAKE MAX POWER IN THE 5000RPM-6300RPM BAND (mostly so I can run street gears and pump high test gas and a low maintinance hydrolic roller cam, and IM willing to sacrifice a good deal of street driveability to maximize my corvettes track potential) useing the above calculators we quickly find I should have about a 3 sq inch intake port cross sectional area, the exhaust should be about 39" long in the primairy 1.825 dia,and about 18" -20" long in the collector, about 3"-3.5" dia. a matching compression of about 10.5:1-11:1 and a cam in the 230-235 durration range at .050 lift, heads that have the same 3 sq inch port and flow about 280cfm this will tend to maximize the power at THAT rpm band, and ideally a 3.90:1-4.11:1 rear gear ratio and a 3000rpm-3500rpm stall converter but that above will NOT work nearly as well as a smaller and less radical combo in the 1500rpm-4500rpm most cars spend 90% of thier time in its all a compromise and most people don,t realize how miserable that combo will make the daily driven car that rarely get above 4500rpm, where a smaller and longer exhaust would scavage more effectively but give up some of the potential for max power when the cars raced Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted August 25, 2008 Author Share Posted August 25, 2008 your 100% correct if you were looking to cruise at 2500rpm , the cams above will be a P.I.T.A. on a car designed mostly for mid rpm cruiseing, you could get good performance from them but the street manors in traffic will be less than ideal....certainly manageable but not exactly smooth youll be far better off with something similar to these, if street manors and low to mid rpm cruising are a higher priorty, but have a LONG talk with the manufacturer of your choice about your combo and expectations before sellecting your cam and matching your combo gearing and compression, head lift restrictions and flow charicteristics http://www.tpis.com/index.php?module=catalog_page&catalogPageNumber=147&catalogSubCategory=Cams-Hydraulic+Roller ZZ-9 HydraulicRoller: Intake Exhaust This is an emission legal cam which makes Advertised Duration 282/ 287 over 400HP with our CNC"D LT heads and Duration at .050 212 /226 F-car headers. Great with an auto or six Gross Lift .483/.520 speed. Lobe Separation 112 http://www.crower.com/misc/m_cat.shtml http://www.crower.com/misc/cam_spec/cam_finder.php?part_num=00466&x=38&y=9 http://www.cranecams.com/?show=browseParts&lvl=2&prt=5&Vehicle_Type=Auto&Cylinders=8&Engine_Make=CHEVROLET&Year=1984&Engine_Size=262-400%20C.I.&partNumber=119821&partType=camshaft Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted August 25, 2008 Author Share Posted August 25, 2008 http://www.scatcrankshafts.com/index.htm rods designed like the 3 SERIES generally won,t work with stroker cranks while the 2 series usually will the connecting rods you sellect make a huge differance in the rod to cam lobe clearance, even a small base cam won,t clear some designs, it should be obvious that the connecting rod with the thru bolt has a great deal less cam lobe clearance potentially than the cap screw design next to it., and the cap screw rod probably clears the blocks oil pan rail area easier also Quote Link to comment Share on other sites More sharing options...
DavyZ Posted August 26, 2008 Share Posted August 26, 2008 ...the threads must bear evenly and align correctly with the studs centerline for the stud to apply max loads over the total threaded surface. The threaded section must be under tension alone and engage the total threaded surface in the block. If the stud is torqued into place, you've preloaded the threads bearing the load and they are partly under compressive loads and you're basically jacking the bottom of the threaded hole away from the threaded section, thus applying THOUSANDS of lbs of extra stress to the blocks web area... That certainly makes sense, Grumpy. Good explanation, thanks! Davy Quote Link to comment Share on other sites More sharing options...
tkach Posted August 27, 2008 Share Posted August 27, 2008 I love this info ! Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted August 27, 2008 Share Posted August 27, 2008 The rod to cam lobe clearance issue is on cylinder #'s 2 and 5 respectively, so if assembling an engine using anything else is pointless. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted August 27, 2008 Author Share Posted August 27, 2008 Im running that crane 119661 cam retarded 4 degrees BTW but detonation has not been a problem, remember that the coolant temp, air temps the engine sees, QUENCH distance, type of head gasket and its construction ,ignition advance,plug heat range,piston to bore clearance, exhaust valve seat width, and oil temp and pollishing your combustion chamber and piston domes, and your AIR/FUEL RATIO , and the effective DYNAMIC compression ratio, have a noticable effect on detonation and if you do see detonation, theres octane boosters like TOULUENE http://www.gnttype.org/techarea/misc/octanebooster.html http://www.team.net/sol/tech/octane_b.html http://www.elektro.com/~audi/audi/toluene.html 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.