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first off 305's are junk and i shouldnt even post this but i gotta...the plan was to get a 350 from a impound lot my dad worked at but that fell through cuz he passed away and his bosses are being assholes so now im stuck with a 305(im not sure if ill waste my time)but i wanna build a race engine with the stock reciprocating rods and crank.stock heaviley ported heads and a 2200-5500 cam what else would work and wut would be better its crazy but i might have to do it with my very tight budget
If you're gonna bolt a 305 together because of limited budget, o.k., but don't spend one red cent trying to port those turd heads. Run 'em like they are with a good valve job until you can afford some decent heads. Figure you exact compression ratio before you ever try to pick a cam. If you don't know how to figure it, see this paper I wrote....
http://streetmachinesoftablerock.com...opic.php?t=124
Here's a dyno-proven combination....
http://www.goingfaster.com/spo/325_h...chevrolet.html
i got the heads resurfaced and deburred the inside of the engine...it needs to be bored to 4.000 but doin that and adding new pistons is probably just as much finding a cheap 350...i need new heads these are really crapy anyone have some vortecs?
thanks tech
Autocity...bore it out to 4.00" ? um you cant bore it .265". the stock bore on a 305 is 3.735"...so to get 4.00" youd need to boreit .265"....your right...you shoulnt have started this thread
I know there's an advantage in cubic inches, but there's also an advantage in smaller displacements in being able to spend them quicker. Wouldn't you be able to spin a 305 faster than a 350 produce higher horsepower but less torque?
:whacked: :whacked:Quote:
Originally posted by firebird45331
I know there's an advantage in cubic inches, but there's also an advantage in smaller displacements in being able to spend them quicker. Wouldn't you be able to spin a 305 faster than a 350 produce higher horsepower but less torque?
Answer < NO > You have the same stroke in both. If there were even the slightest gain in rpm which I doubt, You are pissing up a rope. :LOL:
Fire, if it was a short stroke engine, like a 302 or 307, than yes, they can spin up quicker. The only rev factor that the 305 MAY have over a 350, is the fact that because the pistons are smaller...they are lighter, & also less ring friction....but its not enough to hardley mention....so ..in this case ..no.
that's what I was thinking of reciprocating mass. I knew the stroke was the same. That's what makes the 283's and 289's so cool
Hi RPM motors are kewl, but they have their quirks, Narrow power band, etc. (Ok Scooter, you can jump in now!!!) I prefer big cubes, big torque, and lower RPM.. JMO
not that ricers are in anyway cool, but they can spin the hell out of their motors and sound like pissed off weedeaters while still have crap for torque and still spend 7 times as much to do it.
torque is really important coming off a turn.RPM dont have anything to do with the diff of a 350 and 305 its the pistons heads and cam "soft cam" but since im changeing all that ecept the heads and getting it borred to 4.000 its like a 350 with a crapy 2 bolt main.i have a ? is it normal for a crank to rub against the main caps and block im not sure? whats wrong with racers firbird?we got just as good of cars as you do just a little modified and i have a semi hot rod to 76 camero so im not just a race car driver
autocityman4, didn't you read stepside454's answer to this. You CANNOT bore a 305 block to 4.000"
yes the bore allows like .30 over and i know someone who does the odd bore sizing
HUH?Quote:
Originally posted by autocityman4
yes the bore allows like .30 over and i know someone who does the odd bore sizing
i dont meen allows it but a 305 can be bored that large not a safe thing but it can be done
hhhaaaaaaaaa i was wriong a 3.800 bore
I knew I shouldnt have responded to this thread..I just knew it. man I never learn.
i got the 350 so this was useless.....does anyone know how the chevy heads 70-80 flowed are they good ones i got a free set. the engine came out of a 87 pontiac grand prix so i dont know its origanality.it has a 4 brl quadra jet if that helps...sry bout the stupid bore threads i wasnt thinkin right.....thanks......... tech this is a question for you
What's the casting number on the heads?
Here is some flow data on Chevy heads:
http://chevyhiperformance.com/techarticles/41598/
Actually the 882 heads look pretty good in these tests but most folks tell me they are marginal. With my limited finances I have opted for using these heads with a three-angle valve job and a smooth cleanup of only the exhaust ports, leaving the intake ports rough for good fuel mixture turbulence. My heads came from a '76 Corvette which was rated at only 165 H.P. and probably represents a detuning of the earlier high compression heads for the 327s which flowed much better, BUT for low rpm torque the heads with 210-215 cc inlet port volume are great for high rpm H.P. but may not be so good for low rpm torque. The problem with most of the 327 heads is that they had smaller combustion chambers and with the larger volume of the 350 cylinders the comnpression ratio can get over 10:1 easily making use of regular fuel less likely. Get the casting numbers off the heads between the rocker studs and let Tech1 know the last three digits and he will advise you based on great expertise.
Don Shillady
REtired Scientist/teen rodder
333882 don got it right
am i wrong in saying that you can bore a 305 to .080 over? I think it works out to be like 312 or 315 or some odd number.
the standard bore size on the 305 is actualy 3.736