318 engine combos for 400hp

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tobysoldblue

tobysoldblue
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I thought since a lot of guys like myself like building 318s for what ever reason,id try to compile all the 318 engine combos i could find.Most of the engine builds ive found so far are 375 hp or more.A couple have made it over 400 hp,and the parts dont seem to be too exotic,so it wont cost much more than a standard rebuild.If this isnt the correct place for this,im sure somebody will put it were it suppose to be. http://www.popularhotrodding.com/tech/0901phr_mopar_318_magnum_engine/index.html http://www.popularhotrodding.com/tech/0810phr_chrysler_318_engine/index.html
 
I like the Hot Rod build best because it uses the 302 head castings. I just had one very similar built for my Barracuda. I used 1.88 intakes instead of the 2.02's also the machine shop just did a bowl blend instead of the extensive porting shown in the article. I also used KB-167 pistons instead of the stockers. Builder told me they worked out to 10.1:1 compression ratio.

I wish I knew a shop that could duplicate the port work shown in the article. I called Arrow (the shop that did the porting for Hot Rod) but they told me they only work on late model stuff now.
 
kdeboy said:
I wish I knew a shop that could duplicate the port work shown in the article. I called Arrow (the shop that did the porting for Hot Rod) but they told me they only work on late model stuff now.
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I wish I could duplicate half of what they do lol, Steve Dulcich is a pretty impressive guy IMO love reading his Engine Master's magazine, FYI it's popular hot rodding w/o the cars or anything but engine builds
 
I ported my 302 casting heads,and left the small valves in.My 318 screams all the way to 6500.I didnt go wild with the port work,just opened the bowls to valve seat size,and a good blending so the turns are nice and smooth.I also gasket matched the intake side to 340/360 size,and matched the weiand stealth intake too.on the exhaust side,i gasket matched also,and did more porting than the intake side.Ive done 2 sets of these heads now,and both perform remarkably well with such small valves.
 
The dyno they use is a bit "happy" and has a correction factor that adjusts about 4-5% up using the superflow software. The same engine on a DTS will come in the same percentage lower in HP. SF = 400hp DTS = 380-385, but it's the same engine. Hmmmmm????

On most dynos you can actually puff your hp numbers with the correction factor parameters.

I've seen engines run on both style dynos and the cars ran at the track, mph/weight, more consistent with the DTS numbers.

Dyno numbers are like flow benches, everyone seems to be impressed with big numbers. But, those big numbers don't always translate to the performance they imply.
 
tobysoldblue said:
I ported my 302 casting heads,and left the small valves in.My 318 screams all the way to 6500.I didnt go wild with the port work,just opened the bowls to valve seat size,and a good blending so the turns are nice and smooth.I also gasket matched the intake side to 340/360 size,and matched the weiand stealth intake too.on the exhaust side,i gasket matched also,and did more porting than the intake side.Ive done 2 sets of these heads now,and both perform remarkably well with such small valves.
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Good to hear Toby. I'm hoping to get similar results on my 273. Just mild head work and bowl blend with gasket match. I think stainless valves would do good too. Mike
 
just dont go too big,it will kill the flow velocity,and actually slow you down with a 273.I imagine the stock valve size would be optimum actually.
 
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