Why are 318's low HP and torque?

saying 318s have small bores and cant be hotrodded is bogus. the LS guys run smaller bores in those new LS327s and make big power. biggies are cam and compression, good flowing cylinder heads or lack of. this may be the rodney dangerfield of mopar V8s because it was a rather pedestrian engine and used in everything. it doesnt mean it wont respond to a good cam, higher compression, and some better breathing like headers, and a good intake. all engines respond to these basic principals. the way most folks think of these engines as boat anchors just means you can get em super cheap to even free. i am all about fast n cheap if you can.

look at it this way, the 340 X castings are good castings for their time of course. they are better than a stock pre magnum 318 casting. but these were designed back in the day when sunoco 260 was .35 cents a gallon. volumetric effiency wasnt a word in mopars vocabulary back then. yes you can get a set of 65 to 67 273 closed chamber head castings, port the snot out of them, and add bigger valves, but then you got a whole lot of money and time in an old set of castings which if they crack, or get damaged if you grenade an engine will probably not be easily or cheaply replaced. a stock magnum casting will outflow a stock 340 X casting any day of the week. this is a proven fact, plus 1.6 ratio rockers and 62CC chambers are stock. this and the fact that they are a bolt on swap to the older LA engines made me a believer in them except for the cracking problems.

check out my newest thread on mopar magnum heads titled magnum heads redux. there is now an aftermarket supplier for these heads available with both intake manifold bolt patterns, $399 per head machined with hardened seats and silicon bronse guides installed Enginequest A&A specialty midwest has corrected the cracking problems associated with these heads by beefing up the castings where they crack on the stock magnum heads, revising the water passages, and flowing the runners & ports better than stock. these are being used in dirt track and paved circle track competition. they have 62CC chambers, and with some KB flattopps can yield 9.8 to 1 compression which is plenty of pop for pump gas. they also use 1.6 ratio rockers. a set of engine quest magnum heads are on my list for my 74 318 rebuild. i will gladly work overtime and pay the $399 each for em. i feel they are well worth the money

popular hot rodding did an article on this setup as a bolt together with no gee whiz machining a mopar 318 with flat tops, the right cam and some EngineQuest magnums, and a holley 750 made 402 HP 341 ft lbs of torque, at 6200 RPM. id say thats not so rodney dangerfield these are very respectable numbers for a bolt together setup with no porting on a pretty much stock cast crank refreshed 318 with no laughing gas either. they did this as a what if that anybody with basic engine rebuilding skills and basic machine shop work could duplicate in their garage.

now think how much more you could get out of it by beefing up the bottom end, adding a hughes stroker kit to make it into a 390, and porting the snot out of em. is 500HP on motor w no juice a feasable number with the last combo i mentioned? maybe someone will try it and find out. i will build my bolt together "boat anchor" 402HP 318 in my basic garage and have fun with it. maybe get another "cheap free boat anchor 318" that someones giving away to make my future 390 bottom end for a later hotter swap.

every cloud has a silver lining ! EngineQuest magnums make this one brighter :)

matt