Ant
Well-Known Member
If ya want gobs of air and want to look cool, go with triple predator carbs.
Sixpack on a 318 engine ?
- Thread starter roaddevil
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If ya want gobs of air and want to look cool, go with triple predator carbs.
If you want to spend the money, you can make anything "perform". When I bought my 340 cuda in '69, did I want a 318 and have to build it or did I want a 340 that was already factory built with all of the suspension parts included? Doesn't make you a "cultist", it's common sense.
Newbomb Turk
Well-Known Member
Skip the 6 pack and get a tunnel ram.
That would work as well, but not well on a 318 with a back yard, rabbit turd overhaul the Op is planning.
There should be no reason you can't put a 6 pack on a decent (hp) 318, there's only a 12-22 cid difference depending on overbore over a stock 340 and a stock 340 was a pretty mild and relatively small engine anyways, No reason a 300-400+ hp 318 can't handle it, I'd bet a similar built 273 could also.
It more about the power of the engine (hp=airflow=cid x rpm) then displacement.
It more about the power of the engine (hp=airflow=cid x rpm) then displacement.
Totally agree.
If you look at Chev's performance 302/327/350 all built pretty much with the same specs, they made basically the same power curves just at different rpms. And if you geared each engine to be operating in there powerband at any given speed each would be putting down similar hp and torque to the ground.
Bore size will have an effect, on 2.02" or small valves probably not gonna make huge difference especially at the power levels (cfms) most are trying to get out of a 318 250-400 hp
DionR
Well-Known Member
What about the port inlet size mismatch with the 318 heads? Assuming the OP doesn't put 360 heads on it.
no frett'n about the port size. not a problem.
Wasn't made for rpm cause they put a 273 2bbl top end on it, no reason you shouldn't be able to build a 8500rpm monster if you want, the bore is only slightly smaller but also is feeding less displacement.
318 wasn't "made" to turn rpms because it didn't get the "good parts" like a 340. I've seen 318's turn 7200 rpms for years with stock bottom end. 340's havent' been made for over 50 years, folks are working with what they have or what they can get. It's ridiculous that we can't get past that 340's are no longer in the junkyards for 75 bucks and 318's swap cams and heads and pistons just like ANY other engine being built, including the 340's. Yes, I'd rather have the 340, but no, I'm not paying the "340" tax.
I bet if the factory made a performance version of the 318 during the muscle car era we wouldn't be having these discussions. For some reason people have a problem not seeing an engine as a performance engine if there was not a factory one.
Here in Canada people asking $1500-2500 for just a rusty 340 block, a complete engine in need of a rebuild $3000+.
jos51700
Green Bearing thread connoisseur
This. There's no fundamental difference beyond an AVS or Thermoquad. You might not use all of the six pack, but it'll run!
and for what 3.3% bigger bore diameter.
Newbomb Turk
Well-Known Member
I technically agree, if cost and availability was no object.
And I agree again technically, I see displacement as cfm (cid x rpm x ve%) who cares what an turned off engine displaces what's important how much air is it displacing over time. But seems most don't want to run more than 5500-6000 peak hp rpm on the street and most don't seem to want run deeper than 3.55 which basically leaves more cid to make power at 5500-6000 rpms.
Richard Holdener considers anything that makes more torque than hp a milder engine.
I had one in a 65 barracuda. If you use the factory air cleaner it will hit structural supports of the hood. At least on a 65 it did.
Also, i read somewhere it would hit the hood torsion bars so I removed them. But it ended up clearing them fine.
Newbomb Turk
Well-Known Member
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