boy howdy, the gals i've known could give event horizon a run for the money.
300 HP out of a 318, is it possible with bolt ons?
- Thread starter madjak.06
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how about 330 at 5700?
zero deck, flat top piston of choice (i used KB167's), felpro 1008's, 10:1 (static), purple shaft P4452761 (.450"/.455" 268/272 110LSA 108cl), 302's with a 3 angle and pocket port/bowl blend, port matched to a performer RPM, 750 3310 on top, TTI long tubes.
and that's verified on a dyno with 13 second time slips to corroborate. could it make a squeak more with a bigger carb, a spacer and turning it another 800? maybe?
but none of that is magic. right combo of parts, careful selection, good machine work, attention to detail on the tune.
From what I understand you need around .250-.300" of space between the wall/chamber and valve for there to be no valve shrouding. So Probably every small block has some valve shrouding, I imagine in almost all cases less is better so yes 340/360 will have an advantage over a 318 bore but by how much ? In all the years on here people go on about it but yet see anyone ever measure it. And generally most aren't using up all of the available power potential that any given heads offers anyways. But we do know a 318 has more than enough bore to satisfy most people power demands especially ones starting with a 318, I bet a 273 bore is capable of suppling more then the power that the average A Body owner wants. Does that make them the best choice, obviously no but an capable choice if one chooses for whatever reason.
Most of the valve doesn't come near the wall and where most the flow goes isn't near the wall either, not saying there's no effect but probably a lot less then most are assuming. I remember a flow bench comparison between a chevy 3.75" vs 4" bore and I'm pretty sure there was something like a 5-7 cfm difference on that one particular test. And the difference between 305 and 350 bore is .250" same as between 360 and 383 which I find funny cause most that say that the 318 .90-.130" less bore is a huge deal but gaining a .250-.375"+ with a 383/400/440 bore ain't worth the trouble lol
Again no one is saying a 318 is more capable than a 340/360 that there just more capable then a lot want to give them credit for, if the naysayers were more realistic with their naysaying we wouldn't have most of these 318 debates.
Most of the valve doesn't come near the wall and where most the flow goes isn't near the wall either, not saying there's no effect but probably a lot less then most are assuming. I remember a flow bench comparison between a chevy 3.75" vs 4" bore and I'm pretty sure there was something like a 5-7 cfm difference on that one particular test. And the difference between 305 and 350 bore is .250" same as between 360 and 383 which I find funny cause most that say that the 318 .90-.130" less bore is a huge deal but gaining a .250-.375"+ with a 383/400/440 bore ain't worth the trouble lol
Again no one is saying a 318 is more capable than a 340/360 that there just more capable then a lot want to give them credit for, if the naysayers were more realistic with their naysaying we wouldn't have most of these 318 debates.
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That look like a real nice combo for the 318 crowd.
That's what bugs me the most, when the naysayers act a 318 won't respond to basic hot rodding, if the bore is smaller than 4" normal physics stops apparently
almost the exact same as a 400hp 318...That look like a real nice combo for the 318 crowd.
That's what bugs me the most, when the naysayers act a 318 won't respond to basic hot rodding, if the bore is smaller than 4" normal physics stops apparently
moar cam, moar rpm, moar carb... hmmm...
Whatever you do, do NOT say more rpm.
That creates hysteria, paranoia, foaming at the mouth, insomnia and acne.
Please don’t do that again.
No it's the 318 cast on the side of the block - black magic fuckery that stops it responding to modifications like any other engine. 1HP/CI is relatively easy to build, a 400hp 318 is 1.25hp/ci - a little trickier but still within reach of most guys with a bit of knowledge.That's what bugs me the most, when the naysayers act a 318 won't respond to basic hot rodding, if the bore is smaller than 4" normal physics stops apparently
On the valve shrouding I think it's just something people latch on to, sure you might see a 10cfm or so difference flowing the head on a 4.04" bore compared to a 3.91" bore but that wouldnt make me pull a set of 250 - 260cfm heads off to run a set of 180 - 200cfm small valve heads with no shrouding.
Why not? The 3.31" stroke & a solid shaft mounted rocker setup makes the 318 & 340 an excellent candidate for a high rpm screamer in my opinion. Information on oiling mods to help keep it happy at high rpm are readily available and not hard to do.
Yeah I was taking the piss
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