grumpyvette

"What would you recommend doing?" talk to TRICKFLOW AND CRANE,CROWER as they will know the answers and may know a quick fix. IN my case I would sellect a set of BEEHIVE springs and titanium retainers and install offset valve locks that move the clearance out to an extra .050 and have a machine shop cut the spring seat about .060 but , you need to make sure the seat,full lift pressures are correct and the spring bind heights/clearancers remain in spec. a good machine shop can easily fix you up after you get the correct springs retainers and valve locks, and in many cases you won,t need to do anything but swap the new correct springs retainers and valve locks,onto the heads...in some cases just swapping retaines and valve locks and shimming the spring may solve the clearance issues if its a retainer to valve guide rather than a spring bind issue...a good machine shop and carefull measurement are the keys theres info here that may help,the links hold a good deal of info, http://www.racingsprings.com/PDF/beehive.pdf http://www.digitalcorvettes.com/forums/showthread.php?t=86226 http://www.digitalcorvettes.com/forums/showthread.php?t=81001

pparaska your forceing me to think back to college,to those horriable math classes I needed to pass, keep in mind when I was in college we still used SLIDE RULES and pocket calculators were not invented and a computer took up the whole first floor of the building we were in and took several operators with punch cards Ive always felt (rightly or wrongly) that your flow starts being a valid factor in maintaining the cpr at about .006-.008 lift, below that the time available and area in the valves curtain due to RAPID movement is basically meaningless in the big picture, keep in mind at idle rpms (about 900rpm in my case) the cam fully opens and closes the valves 7.5 times a second, that last .006-.008 in the ramp on the lobe takes an almost unmeasurable, in practical terms .0014 seconds or less now to ther pragmatic approach, Im running this cam currently, in my 11:1 cpr 383 http://www.cranecams.com/?show=browseParts&action=partSpec&partNumber=119661&lvl=2&prt=5 compare it to your sellection, I can tell you the power on a 200hp hit of nitrous is awesume, I break drivetrain parts frequently, DETONATION IS a problem unless I retard the timing and use octane boosters with the nitrous, off nitrous I still need high test and If I advance the total timing to more than about 37 degrees I get into detonation, and thats WITH a bunch done to limit the engines tendency to detonate, but ITS darn responsive and makes good power, so its a ballancing act/compromise

"At .050", the duration is 246 and 256 (I/E). According to the calculator (49º ABDC close), this nets to a dynamic 9.05 CR." whats the cam card say the timing is at .050 lift and the timing,? if its the 49 degrees as I suspect,it is at .050 lift youll need to add about 13-15 degrees too each open and closing degree point at .050 lift figures to get seat timing when the valve ACTUALLY opens, or if you have the .004-.006 you can use those, Id bet your TRUE DYNAMIC CPR is a good bit LOWER than 9.05:1 use all three calculators, CAREFULLY FOLLOWING THE INSTRUCTIONS and average the results http://cochise.uia.net/pkelley2/DynamicCR.html http://www.kb-silvolite.com/calc.php?action=comp2 http://www.wallaceracing.com/dynamic-cr.php

just some observations dsommer your real close, but the dynamic cprs on the high side, Id bet youll need to retard the cam about 4 degrees to lower the dynamic cpr just a bit, if your running average street/pump high test, and youll need to be very carefull about the octane, and ignition advance curve rate, engine temp. to stay out of detonation, but I bet its torquey and has great responce and power, its very similar to my vettes engine combo, and Ive got to be very careful about the octane especially on the giggle gas BTW you DID NOTICE the VALVE SPRINGS on the cylinder head are listed as a .540 MAX lift and even with the 1.5 ratio rockers youir over that...with 1.6:1 rockers youll be closer to .601 lift?? and please check the piston to valve clearance carefully every 5 degrees for 25 degrees each side of TDC, and check the quench/squish is in the .038-.042 range, it may help reduce detonation "Gross Valve Lift 0.552 0.564 Maximum Valve Lift (in):clearance 0.540 in." blueovalz you went the other route a bit MORE than ideal durration,on the cam, youll be giving up some low and mid rpm torque due to alittle more cam than ideal for the combo, Id bet the combo would be slightly better with just a bit less durration, something closer to 250 @ .050 lift on the intake you gentelmen may want to play with these http://www.crower.com/misc/valve_timing_chart.html http://cochise.uia.net/pkelley2/DynamicCR.html http://www.kb-silvolite.com/calc.php?action=comp2 http://www.wallaceracing.com/dynamic-cr.php http://www.diamondracing.net/cocalc.htm please let me know if IM wrong or correct, as you tune/test each combo,as I keep an extensive data base and can always use more first hand info

sounds nice,what cam,PART#?? rear gear ratio ?, trans ? and IF its an auto...whats the converter stall speed

theres several engine familys , REGUARDLESS of brand that potentially produce massive power levels when correctly built and modified, but ALL of them make better power in the larger size displacements. lets stick with the chevys at the moment, look, I like the sound of a sbc spinning 6800rpm -8000rpm plus, but the fact is that as the rpm levels increases SO DOES the STRESS on the rotating parts, and keep in mind the STRESS LEVELS SQUARE as the rpms DOUBLE, or put a differant way, your much more likely to have component failures at 6800rpm-8000rpm than you are at 5500-6500rpm. its far easier to build a 383-396 sbc that makes 500 hp than it is to build a 302-327 that will make the same 500hp , and have a combo you can use in a street driveable car, and an engine that will last for years without needing frequent rebuilds and components replaced lets look at, youll rarely find a street driven combo exceed 1.3 hp per cubic inch of displacement with a N/A american V8, on a 302 thats potentially 393 hp, on a 396 similarly built thats 515 hp, if both have a 4000fpm in piston speed (which is about the max you can reasonably expect to hold together for long term use, and keep in mind that stress levels rarely reached , except briefly before you shift) the 302 will reach 8000rpm, the 396 will reach 6200 rpm. the 302 is far more likely to have valve train control problems, its got noticably LESS torque and the cost to build either combo will be similar. once you exceed about 550 hp the cost of building a competative sbc accellerates far faster than the cost of similar hp levels from a BBC, you just can,t overcome the huge advantage the larger ports, valves and increased displacement gives to the BBC as a reasonable cost without power adders like turbos or nitrous, and almost anything you can do to the sbc can be done in a similar manor to a bbc , too give even greater power. below about 450-500hp the sbc is a bargin in parts cost, but its surely not the only route , the pontiacs, buicks ,caddillac, mopar and fords can all be built to be potent combos. All Im suggesting is don,t jump into any engine build , do the research ,FIRST! find the best combo for the application and budget, and in most cases the car WILL BE FASTER , and have fewer problems with a well thought thru combo useing a larger displacement in that engine family

if you can exceed 800 ft lbs of torque and 750 hp with a 605 displacement or a turbo on a 540 displacement BBC or 528 hemi,and never break 6500rpm, I just don,t see the big draw for extra rpm

just to get you thinking thru your choices -------------------------------------------------------------------------------- I was asked why I build the engine combos that I do,.... why CHEVY? well, its mostly PERFORMACE PARTS AVAILABILITY, AND PRICES and the fact chevy makes CORVETTES, which I like the styling of.. most guys build off the basic stock engine that came in thier car ,mostly , because they can,t afford to drop large bundles of cash at one time and want to add or modify bits and pieces at a time to keep costs low. It helps if your friends know hopw to work on a car, and the greater number of similar cars out in public hands the greater the market for parts and the more skilled guys will be working to solve the little glitches and tweaks, and find the better ways to increase performance of those combos, and parts. theres MILLIONS of chevy V8s out there so thats a huge advantage many guys don,t have the skills, tools, knowledge or location to do projects that keep thier cars out of service for more than a few days at a time. Ive built and raced Big Block mopars(383-500cid) and 389-468 displacement pontiacs and in some ways they have better engine designs ,I would prefer the 392-417 DONOVAN hemi, basic design to anything out there,the pontiacs are vastly under rated, yes, in some ways the chevys are superior, but the parts availability and prices always seem to favor the chevy. I dislike sbf engines and the BBF is far too expensive, try pricing out a BOSS 429 stroker combo some time If all drivetrain parts were dirrectly interchangeable,and you could build an aluminum block/head 392-417 donovan hemi , 426-528 mopar hemi, 440-572 chrysler wedge or boss 429 ford based engine in the 500-600 cubic inch , or larger displacement range for exactly the same price as a sbc, I doubt they would be selling many sb chevy parts, I build far more BBC engines than all others combined, but its parts availability, and price that are the major factors face facts if it was not for the lower price and better parts availability why would anyone bother building less than 500 cubic inches in a performance engine, application? the smart route is to build a seperate drive train , to swap in once it up, tested and correct,or to have a differant car as a project to play with rather than, put thier basic transportation out of service, but most guys work on a very limited budget, on limited time and with limited tools and skills, and under those conditions and with todays prices and parts availibility the CHEVY has a STRONG FOLLOWING.

the LT1 will be simpler and easier and cheaper,to install and modify the LS1 will produce the better car once its correctly swapped, IF both engines are similarly equiped or modified

now heres something you probably don,t want to spend a fortune on, but you better think it thru...if it tips or brakes you could be PERMENANTLY CRIPPLED http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=47304.... Ive got several of these in the shop and they support a bbc just fine! these also work ok http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200305217_200305217 the cheaper (T) design base on the cheaper stands are not NEARLY as stable, you might want to consider welding on a 4 foot section of 2" x 3" box steel and adding two casters to the end of the center leg but by that time youll quickly see buying the better 2000 lb stands less work/bother and reasonably priced :thumbsup: this design ought to come with a mercury switch and auto dialer for the emergency room as it will tip or flip with almost no effort , an excellent way to be seriously injured, no matter how strong you are your NEVER going to be able to prevent a V8 from falling once its starts falling unexpectedly when your tightening bolts or turning the block, so if you buy something similar to this expect to get hurt its only a matter of time http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=32915 as a few of you gentelmen know, I recently replaced the small steel wheels on my engine crane with much nicer swivel wheels of about 8" dia. http://www.harborfreight.com/cpi/cta...emnumber=41563 these http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=41563 are very similar to what I used (6) of on the engine crane, having 6 large dia. CASTERS rather than 4 small casters and two wheels that don,t change direction is a HUGE IMPROVEMENT in how easily the engine crane moves once an engines suspended from it, well, it was an obvious improvement so I said to myself why stop there?? I put a set of 4 similar swivel casters on one of the shops engine stands and I just can,t believe it took so long for me to do that or how big of an improvement it was!! you get so used to having an engine stand thats a TOTAL P.I.T.A. to move around the shop (AND I sellected some of the easier to move stands) that once you do this mod your thinking how obviously stupid it is not to do it to all the engine stands in t6he shop.....so as finances and time allow Ill convert the other 4 engine stands not quite as good as good sex but its so much better than before I can,t imagine why I didn,t do this 35 years ago

"Since changing the duration of each lobe by 10 degrees also changes the overlap by 10 degrees," THATS not necessarily a true statement you can easily have cams with wildly differant durration with similar overlap, I would go no tighter than 105-106 on the LCA,if the cars ever used on the street,but as Im reasonably sure you realize widen the LCA to about 110-112 will drop cylinder pressure slightly and cost you some minor peak power but in exchange you get slightly less cylinder pressures at low rpms, less tendency to detonation and a slightly wider tq curve, and a noticably smoother idle and better street manors, with the same lift/durration. every change is going to result in a compromise in some charicteristic, but you generally spend far less time over 6000rpm than under 4000rpm on a car thats not 100% a race car so giveing up a few peak hp for better driveability is smart in most cases EXAMPLE I currently run this cam http://www.cranecams.com/?show=browseParts&action=partSpec&partNumber=119661&lvl=2&prt=5 I tried this cam http://www.crower.com/misc/cam_spec/cam_finder.php?part_num=00471&x=38&y=9 theres no question the crower cam makes better power, SO! why run the CRANE?? either cam has more power in my particular combo that the tires and suspension can handle with street tires and the cars 90% street driven as a old geezers weekend toy, the crane grind is a better street choice, as its noticably easier to drive around in traffic and I have a 250 hp nitrous system , that used over 3500rpm, in 3rd-0D so the powers never a problem IF I was only concerned with power Id run this http://www.cranecams.com/?show=browseParts&action=partSpec&partNumber=119681&lvl=2&prt=5 and a 3700 stall converter now Id isolate and fix the source of that ....."low frequency (knocking) valvetrain noise deep in the engine on one lifter" before going further before it potentially becomes a larger problem.

http://www.blackstone-labs.com/oil_viscosity.html http://www.bobistheoilguy.com/visc.html http://www.chris-longhurst.com/carbibles/engineoil_bible.html http://www.howstuffworks.com/question164.htm your REAR seals NOT usually under direct oil pressure,so oil pressure won,t dirrectly effect it. a good 10w30 oil meets those temp requirements

one old geezer

OK YEAH ITs time for a better posi or spool, you should have two nearly identical, tread wide, evenly dark accross the width,black marks on the pavement with a burn-out

glad to see it worked out for you!, Im sure with some tweaking of the suspension and tires and some fine tunning of the combo you can get into the low 11 second range

slap a dana 60 and a correctly designed 4 link under a tubbed rear and forget about rear diff and suspension failures BTW I KNOW exactly what your going thru, as every time I installed decent slicks on my corvette and hit the giggle gas Id get a few passes then the rear IRS would start complaining or pukeing parts, so once I get the BBC installed with bthe 4L80E trans Ive got a DANA 60 lined up to upgrade the vettes rear too. theres NOTHING you can do to an IRS that will allow it to handle massive torque/and shock loads as well as a DANA 60 will, the parts just don,t have the size and mass, or the bearings to handle it like the DANA 60. on my 1968 corvette I went thru the same B.S. and once I installed a DANA 60 the problems disappeared, while an IRS may be great for road racing its just not as strong as a solid read for drag racing, and on smooth surfaces theres no huge advantages to an IRS

hey I exceeded that total cost building my 1985 corvettes engine alone (BY a WIDE MARGIN) and I get a few things wholesale

looks like the wife saw the spread sheet and choked his butt to death....before he could post it.....

those guys that think you need a killer cam to make decent hp may want to look at these http://www.angelfire.com/mech/l98/stats.html http://airflowresearch.com/articles/article031/A-P1.htm http://airflowresearch.com/articles/article043/A-P3.htm http://www.rustpuppy.org/chp/Welcome.html http://www.geocities.com/MotorCity/7610/dyno.htm http://www.ideasandsolutions.biz/HooverSB/ its all in the combo

good luck, and I would NOT try BONZI type high rpm launches, practice building the rpms up as you launch to just the point where your spinning mildly for the first 40-60 feet as you add power off the line, thats probably an under 3500rpm launch rpm

weldings like good sex, once youve done it a few times you wonder how you ever got along without it and want to do it frequently, JUST KNOWING, MORE PRACTICE seems like a GREAT IDEA!

"Anybody on this thread know where to seek instruction or recommend a course on how to build skills with a welder?" well many colleges,and trade schools have adult night classes, you can take, and MILLER welding sells CDs with info and hints, but in most cases Id say take a class of find an experianced welding shop and offer the guy some cash for a quick instruction , but the truth is the best teacher will be to find an experianced welder whos a corvette / hotrod club member in a club near you and have him instruct you, then PRACTICE on scrap a good deal with your equipment, find some old bits of exhaust tubing an old fender a frame ETC and just see what works. ask questions here http://www.millermotorsports.com/mboard/forumdisplay.php?f=3 http://www.hobartwelders.com/weldtalk/ books http://www.amazon.com/Welders-Handbook-RevisedHP1513-Cutting-Oxyacetylene/dp/1557885133/ref=pd_bbs_sr_1/103-3486570-0918205?ie=UTF8&s=books&qid=1191511556&sr=8-1 http://www.amazon.com/Welding-Basics-Creative-Publishing-international/dp/1589231392/ref=pd_sim_b_shvl_img_1/103-3486570-0918205 http://www.amazon.com/Welders-Handbook-RevisedHP1513-Cutting-Oxyacetylene/dp/1557885133/ref=pd_sim_b_shvl_img_4/103-3486570-0918205

yeah! IM a mild tool freak! I love to equip the shop with all the tools I can get access too! and I love gaining new skills the TIG may be slower but its the supperior process in my opinion, in fact TIG is REQUIRED and the ONLY method allowed on some critical suspension components in some racing formats, if I could only have two welders it would be a 250-350 amp TIG and the OXY-ACETOLENE torch. I bought a USED (late 1980s)330 amp MILLER INDUSTRIAL TIG and Im still learning to use it correctly, It cost me approximately 1K but it works very well and a NEW similar capacity TIG would be over 6K. Ive got several welders in the shop, each has its area of use where its supperior in some way to the others, but the OXY-ACETOLENE torch and the TIG will do 99% of all welding, the MIG welders fast and easy, but not as precise, (Im still getting used to useing it)the STICK welder has been in the shop for years, gets used alot when looks are not critical, but the mig could replace it. I can,t imaging a decent tool list in a shop, without a couple welders, they get constant use, everything from fabricating parts to welding nuts on broken bolts to make removal possiable

"cannot understand how I've gotten along without it all these years." CONGRATS ON THE NEW WELDER,I HOPE IT SERVES YOU LONG AND WELL yeah! I feel the same about my new toy http://www.welders-direct.com/merchant2/merchant.mv?Screen=PROD&Store_Code=WD&Product_Code=907321

what amazed me was the ladder bars both broke away clean and equally, allowing the rear differential/tires to roll the car up and over the wheels, usually one side lets go and the other bends and shears pitching the car at an angle when the rear suspension self destructs due to bad design or installation, almost as if the rear was simply bolted to the ladder bars and there were no rear springs , brake lines , pinnion snuber or shocks installed at all??