The 350 Chevy Should Have Built

I,ve built similar large bore shorter stroke SBC engines, based on the larger 400 SBC bore, in the past and while thats impressive the engine really shines if you take advantage of the engines true rpm potential and boost the compression a bit higher, and it REQUIRES the high flow rate heads like AFR 195-210CC depending on the cam selected, intake and other various matching parts,boosting compresion, to lets say 10.5:1) and a solid lifter cam in the 235-240 degrees range on a fairly tight 106 LSA) yes that required a change in rear gears to something in the 3.73:1-4.11:1 range and a manual transmission, or a torque converter upgrade. )a few changes like that boost power over most of the rpm band .
your mention of the 377, SBC has merit as it allows even more displacement resulting in a higher and wider torque curve. something like a crower cam #00350 with 1.6:1 roller rockers wakes a combo right up on the street
keep in mind theres no real replacement for added displacement
the increase from 350-383 in a sbc generally benefits you in two ways, it obviously adds the 33 extra cubic inches of displacement
and youll generally find your N/A engine makes about 1-1.3 hp and ft lb of torque per cubic inch, it also tends to effectively increase compression if the similar piston design is used simply because you compressing an increased volume per cylinder into the same size combustion chamber.
one other factor often over looked is the longer stroke of the 383 increase's mid and lower rpm port speeds this generally increases cylinder fill efficiency, in the lower and mid rpm ranges.
obviously if your going to supercharge or use turbos the piston and rods and crank assembly should be made to withstand the stress levels so a 4340 forged steel crank, forged pistons and after market forged connecting rods with the significantly stronger 7/16" ARP rod bolts are strongly suggested as is dropping the static compression to the 8:1 range to increase the potential volume of compressed fuel/air mix to be stuffed into and burnt above the piston.
Id point out that most transmissions are designed to shift at well under 6000 rpm and most hydraulic valve trains won,t retain best stability above about 6300 rpm, so going the 383 or the 406 SBC stroker route tends to maximize the SBC potential on a mild or mid range performance build
 
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You've tried every possible combination we all could possibly dream up, haven't you?:D
 
probably not, I don,t think I've built more than about 90-100 SBC engines over the last 45 years, ( I don,t count the engines where I only help plan or help assemble parts at friends garages or shops) I have gained invaluable experience! (as I rarely avoid helping any of the local guy with their projects or help trouble shoot problems)
Keep in mind thats only an average of 3 or maybe 4 engines a year and back in the 1970s-1990s I built a great many more engines for the local guys, than I have over the last few years,
(because I made it a rule that the engine owner MUST be on site and do ALL the machine shop runs and parts purchase,s after we discuss each step)SO THEY GET TO SEE EACH STEP AND why WE DO EACH BIT OF MACHINE WORK,
YOU WOULD BE AMAZED AT THE NUMBER OF PEOPLE THAT SEEM RATHER AMAZED THAT THE MACHINE WORK AND PARTS COSTS LEAVE ALMOST NO PROFIT FOR THE GUY DOING THE ACTUAL LABOR, WORK!
WHY YOU MIGHT ASK?
well when done correctly it takes a few weeks time and the costs for parts and machine work add up rapidly , I want the engines owner to see each step, why it was done and the costs involved, so they know for certain each part of the assembly was carefully checked and the costs were NOT going into my pocket!
that way, when a 383 costs them $7K, or a BBC 496 build costs $11K they know where the money went and why,
I only built 4 engines this year and two were for relatives,and one was a rebuild for my personal, older 1985 vette.
if your doing the job correctly and carefully checking clearances, youll spend a great deal more time and effort than those average guys who watch the TV show about cars would initially believe!
I prefer the BBC ,and a few BB MOPARS in most of my builds.
Ive easily built 60-70 of those (mostly chevy BBC engines)
but I.m obviously in the minority simply based on what all my friends and neighbors ask me to build,
because I get asked to build SBC and lately LS engines regularly

they also get to understand that the cheap crap quality engines they see advertised are cheaply made and you save that cost for a reason, lower quality parts are used or steps in checking clearances or carefully fitting components were skipped.
theres NO FREE LUNCH!
 
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So Grumpy, does this mean to get you to rebuild a motor you must be Unemployed , retired or on extended vacation to always be there? Your asking someone who may not want to work in extreme heat and humidity, using the bathroom back at your house and you obviously have to commit to staying with the customer that day and lose your freedom to run off and do errands or generally anything that comes up including if you just want a break that day? Sounds like the customer must be on call and may at times work only an hour maybe more, maybe less let's say to disassemble something, deliver it to the machine shop and that's it for the day?
Sounds more like "Build your own engine with professional help, no tools required!" LOL!
 
It may sound like that, but it generally involves someone committing too, several succeeding weekends (usually 3-or-4) planing and ordering parts,
and waiting until all the required parts, and gaskets,are on hand, and bringing their parts ,and supplies from a check list,
that I can,t machine in my shop, to a local machine shop and retrieving them during the week days in between.
yes theres generally a weekend that gets missed due to the machine shop not meeting the promised commitments

BTW having a good quality engine stand to work with , and several engine bags to greatly reduce the chances of dirt or moisture getting on a partially assembled engine is a big plus
G1009.jpg

http://garage.grumpysperformance.co...-crane-and-engine-stand-mods-accesories.3724/

anyone contemplating a sbc engine build,should find this series of articles where they take a basic 350 and build it in stages useful


http://www.corvettefaq.com/c3/goodwrench/GM Goodwrench 350 test part 1.htm

http://www.corvettefaq.com/c3/goodwrench/gm3502.htm

http://www.corvettefaq.com/c3/goodwrench/gm3503.htm

http://www.corvettefaq.com/c3/goodwrench/gm3504.htm

http://www.corvettefaq.com/c3/goodwrench/gm3505.htm

http://www.corvettefaq.com/c3/goodwrench/gm3506.htm

http://www.corvettefaq.com/c3/goodwrench/gm3507.htm

http://www.corvettefaq.com/c3/goodwrench/gm3508.htm
 
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chromebumpers said:
So Grumpy, does this mean to get you to rebuild a motor you must be Unemployed , retired or on extended vacation to always be there? Your asking someone who may not want to work in extreme heat and humidity, using the bathroom back at your house and you obviously have to commit to staying with the customer that day and lose your freedom to run off and do errands or generally anything that comes up including if you just want a break that day? Sounds like the customer must be on call and may at times work only an hour maybe more, maybe less let's say to disassemble something, deliver it to the machine shop and that's it for the day?
Sounds more like "Build your own engine with professional help, no tools required!" LOL!
Click to expand...

Hey, that's the deal. Sounds about right to me. They are building the engine. You are assisting them and giving "expert" advice.
I wouldn't have it any other way.
 
VERY good point, Grumpy is basically giving his time to teach them how to build quality performance engine, them doing the golpher work is small price to pay!
 
Potential for a big bore 350 is crazy, forged would be only way to go on rotating assembly, dart shp block. So you could use 2.45 main 327 crank. That engine could turn 7500-8000 rpms, solid roller cam for sure and single plane intake. Wow! But would it live long?
 
Couple of the first Chevy 400's I ever built were back when parts were expensive and labor cheap.

I machined the squish ring off of the stock piston to make them flat top's and replaced the shorter rods with regular 350, 5.7" s.

I'm not a long rod convert, I just needed a flat top piston!!

Worked very well.

Thanks
Randy
 
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