Thread: sbc pros please help

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Okay guys I'm new name is jeffery and i need some direction and advice thia is gonna be a long one I'm gonna give as much detail as possible so hopefully i can get accurate reaponses i need help bad i have a mud truck its custom chassis with s-10 body rockwell axles 6.72 gears 57 inch tractor tires never.sees asphalt mud races only it has a 406 i recently tore down to add some power here is what ive got for it aluminum heads 64cc chamber 2.02 and 1.60 with1.5 rocker rollers weind high rise aluminun intake holley 750 thats extremely beefed up and a 175 shot now my questions are any suggestion on new cam and pistons also does anyone recommend turbo over nitrous? Or see anything wrong with the combo I'm trying to set up( this is my first sbc build) any advice guidence or help would be greatly apreciated!! Also anothet option i have is a 350 bottom end 010 casting so could easily be a 383 would anyone reccomend that over my 400 bottom thanks in advance

Hello Jeffery and welcome to the club! While I can only offer the most modest of suggestion.. ( I am not a chevy kind of guy!) I'm thinking the old adage applies here - there's no substitute for cubic inches!

But hang on a bit and the real engine guys will check in (Pat M. & Techinspector) and offer advice. Good Luck and glad to see you here!

i have customers that run stuff like what you have there all big engines .chevy and fords . any one ever tell you how much hp the rockwell axles take to run ? they eat power . what is the weight of the truck .

thanks for your replies as for the rockwells when i had the 406 in it with basically stck components it performed well it would light the tires up and i hooked back to back to a 3500 cummins dodge with flatbed weighed 11000 and my weight is around 5000 and i drug him on asphalt but the class i have to run called mega truck is stricktly because my axle and tire size has no limits on what u can do and most of the guys have sponsers however im some what budgetted and they wher waxing my time so im just trying to keep upi dropped the block off at machine shop today to go up to .40 over changing my bore to 4.165 and he recommended staying with nitrous and going to flat tops probably forged he also reccomended around 260 at .50 on duration and max of 575 lift on mechanical lift roller cam does that sound good? torque is the key in what i do also i pulled the granny gear four speed and went to a turbo 350 manuell valve body shift kit and b and m slap shift i was told 3500 stall would be good how does that sound? im looking for 500+ hp and as much torque as possible my origanal motor was estimated to have about 300 from local engine builders based on them seeing it perform so i thimk 500 plus more torque can be achieved around 2000 dollars hopefully and should see a big difference plus i have the bottle on top any input? thanks thanks thanks

Originally Posted by biggestchevy

thanks for your replies as for the rockwells when i had the 406 in it with basically stck components it performed well it would light the tires up and i hooked back to back to a 3500 cummins dodge with flatbed weighed 11000 and my weight is around 5000 and i drug him on asphalt but the class i have to run called mega truck is stricktly because my axle and tire size has no limits on what u can do and most of the guys have sponsers however im some what budgetted and they wher waxing my time so im just trying to keep upi dropped the block off at machine shop today to go up to .40 over changing my bore to 4.165 and he recommended staying with nitrous and going to flat tops probably forged he also reccomended around 260 at .50 on duration and max of 575 lift on mechanical lift roller cam does that sound good? torque is the key in what i do also i pulled the granny gear four speed and went to a turbo 350 manuell valve body shift kit and b and m slap shift i was told 3500 stall would be good how does that sound? im looking for 500+ hp and as much torque as possible my origanal motor was estimated to have about 300 from local engine builders based on them seeing it perform so i thimk 500 plus more torque can be achieved around 2000 dollars hopefully and should see a big difference plus i have the bottle on top any input? thanks thanks thanks

boy 040 over on a stock 400 block ? and make 500 then hit Nos no i would not do it. but good luck. maybe in low lock the rockwells are not a big deal .but i know better if you run hill.n.hole the axles take power to run a hell of alot more then smaller axles .guys i have worked with run hill.n.hole all big engines and do very well check out . buck nasty

everywher i run is straight pit no hills and when i had the four speed the axles are geared so low (6.72 vs most guys running 4.11 that makes up for there weight also they are true 4 wheel drive all time no peg leg stuff) first and second where useless and fourth was to far out third was only gear i used the block was already 30 over my machinest recommend 10 more to true the cylinders back up do you think the cam specs he recommended wher accurate and do u think 500 hp is out of the questions

very vague cam numbers were the lobe sep. is that 575 before or after lash . . for the block 040 over and making 500 hp then hosing it for Nos ?? 175 ???? sure your stopping there? the stock 400 blocks were not the best some better then others sonic check would not be a bad ideal and a short fill at the least. what rods and crank ? what pistons 2618

Big Things from Buck Nasty Racing! : BNR Motorsports 411!

http://www.youtube.com/watch?v=GTSMvOeQZ2c

this guy buck nasty mega jeep. sht the link did not work . well buck nasty mega jeep. yep you got it pepi

Thats what in trying to learn...what rods and what length what pistons what is a good duration and lift and lobe sep? And will i be okay without forged crank

how can your machine shop do any work with out the pistons ? i know i do not . you need a good bottom end 2618 pistons H or I beam rods . and a forged crank . what rods what pistons has abit to do with what rod 5.7 or 6 ? scat rods and crank at the least pistons .icon or Je

whats the difference in running 5.7 or 6 im sorry im trying to take all of this in very fast since you seem very knowledgable what combination of everything do u reccomend especially on cam thats what im having the most difficulty understanding. if this was your build based on the top end i described and the nitrous what exact set up would u run in the block i have if your budget was around2200 thanks thanks thanks

short rods stock length 5.700 or 6.inch .many have there thoughts about the ideal rod length. but the short rods let the ring pack down from the top of the piston that helps with Nos. piston pumping speed and piston dwell . but if you run the 6 inch rod you can go to a 043.043.3mm ring pack and that helps with the ring pack for nos . as for cam ..give me what CH your going to run and RPM were you want the TQ to come in at . marker of head .what size head port CC runner .valve size .. not to sound like a hard ass but if i was machining and building helping you with your engine and you second guess me all you parts would be setting in my parking lot . i can not build the engine over the computer . i machine and build engines . and spend alot of time on working the combination out the guy doing your machine work just doing the work or are you taking some of his knowledge ? i have soft ware . i think it the same as what tech has he may run it till the last drop for you tell you the full shopping list you will need . i really only care to do may customers builds . as this takes alot of time but i could weed it down for you but Tech is the guy if he wants to help you . i am the guy to talk to about were to put thing for size to keep the engine running

Pat.the 6" rod and pin location needing ring spacers make me cringe. Comments??.

Originally Posted by 1gary

Pat.the 6" rod and pin location needing ring spacers make me cringe. Comments??.

not worth the worry its called a oil ring spacer and used many they never gave me any trouble