Hey guys Its been a long time since i been around in the Slantsix.org website, yesterday was my birthday, happy belated birthday to me.

So...what I am trying to get at right now is, my friend has a 1973-1974 Dodge dart, with a slant six, with optional (yet not working) Air Conditioning he got one I think cause I had one. I had a 1971 dodge dart with a 225 as well. But I plan to be back in the A body business soon enough!

I was thinking of giving a nice decent build for a NA Slant pulling out maybe 200-250-300 HP. I heard its possible without digging deeper into, say, the lower end.

First thing I was thinking was getting a nice fatty cam so that the car can breathe better, I was thinking, and looking, on the most aggressive cam I can get that is streetable, and I think 256, .473 sounds good, Its the cam only, and i was also looking at 2 cam kits, one that comes with a 264, .440 cam, and flat tappets, Both Kits come without or with the timing chain set (Changed it from that plastic crap to metal, which I am thinking of getting with the kitpersonally, causeits totally worth it).

The question I have here is, Should I get the 256, .473 cam, or the kit that comes with a 264, .440 cam, tappets and Timing chain and 2 timing sprockets?

I am going for a stock lower end build, a bit quick yet, streetable. I also want to discuss carburators as well. and should I port out the head/manifolds.

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71 dodge dart custom

1988 Honda Civic ((Because racecar))

2005 VW Jetta

1963 AMC Rambler American 440

264 .440 cam = Quite mild

Ive got a 264 .436 cam right now, very torquey, I would consider it to be a 'low end' cam.

the 264 cam that you mention: I'm gonna go out on a limb here and say that its the Comp cam, correct? If so, I would suggest you stay away from it, and other Comp cams, I believe they are having not the greatest of times with their slant cams (read up on it with the search function)

You say stock lower end build, I hope you are shaving the block? You could take it all off the head, but I'd recommend some, if not the majority, be shaved off the block for a compression bump.

Look at the Engine Build Matrix in the Engine FAQ
While there, look at OCG cam sheets

200 horse=quite attainable
300 horse=ya ain't gonna run that thang on tha street

I kinda had that idea that i'd have to shave some off the block and/or the head to attain that type of extra compression, since there is like a room for a mansion in each cylinder on a stock 225 slanty.

Thanks for mentioning how bad Comp cams are, I was looking at the other one with the bigger lift, thats a howard cam.

If you have any other suggestions please make them,

And what about 250 hp? is that attainable?

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71 dodge dart custom



1988 Honda Civic ((Because racecar))



2005 VW Jetta



1963 AMC Rambler American 440

Yes, look at the engine build matrix thread.

The biggest place to spend effort and money is HEADWORK. Bigger valves and porting. Everything else will give you less gain than this.

If you are serious about HP, then you will need a high stall torque converter and a bigger cam than those.

Lou

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Home of Slant6-powered fun machines

Thank you Dart270, I was also planning to get the head ported out, I have a spare one lieing around actually....Its just stuff I would do without touching the lower end of the engine (Crank, con rods, pistons, etc)

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71 dodge dart custom



1988 Honda Civic ((Because racecar))



2005 VW Jetta



1963 AMC Rambler American 440

For 190-200HP it is pretty easy...but you will be leaving anything under 270 duration cam (but limited to not more than the 280's) and need to start looking at a .470-.480 lift....compression will have to match the bleed down of compression from the cam, so you will be designing toward a "lou" build at about 10:1 SCR...you will be looking at a 4 barrel carb and intake with good exhaust (headers are better as a power adder, but anything to improve your tailpipe will help mileage and power)

I ordered a Comp cam CCX with a 256/256 and a .470 lift @1.5 at a 9.6SCR, and the engine only shined above 2000 rpm...luckily it was a manual tranny or the automatic would have stalled the car at low rpm (700-800) at the stop light...it might have been better for a low SCR/turbo build to make up for that low end lag...

The heart of this style of engine building is getting access to a DCR calculator and trying to stay at about 8:1 DCR...here's where you get to fiddle with the SCR, and the cam and see that short duration cams and lots of compression build high cylinder pressure and high DCR meaning you will have to run lots of octane (and kill your timing and mpg) to handle it....or massage the cam and compression to work with each other.

Once you decide on a build, a distributor recurve is mandatory, and the longer duration cam will want a little more rear gear because it makes more power at a higher rpm (so run the calc for your rear ratio and tire size vs. rpm to match the power band rpm...most likely a 3.2X rear gear will be a good match with stock tire sizes).

Good luck, when learning the calcs and how and why we build in this range for street, you are moving to the advanced level of slant building and understanding...

This may sound dumb but what is DCR and SCR, im assuming both mean _____ Compression ratio.

Not much for headers except maybe, Dutra duals and the clifford type, but that is pretty much it unless I custom make headers for it

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71 dodge dart custom



1988 Honda Civic ((Because racecar))



2005 VW Jetta



1963 AMC Rambler American 440

SCR=Static Compression Ratio...this is just the swept volume of the engine

DCR=Dynamic Compression Ratio...technically the cylinder does not begin to build compression until the intake valve shuts...the DCR calculator takes into account your cam characteristics and installed cam phasing along with the static compression ratio to determine what is really going on in there, a lot of engine builders will use this as a good tool to determine how their build will function and the DCR will let them know what gas they will be required to run (a DCR higher than 9:1 in a slant can be anything above pump super depending on the build)...

Just a FYI. I am running the Howards .473 lift cam you speak of in my race car. I have engine builder valves , 4 barrel, headers , and 3.91 gears, and @ 3200 stall speed convertor. Car went 15.11 and probably would have gone 14.9 but I had a self imposed 5200 RPM limit.

Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6