Now that my 67 GT rag top is mostly sorted out in the engine department I have been wondering what can be done to increase its power output.

Some of you may recall my engine set-up, for those not familiar, here is the present tune: 225 bored 0.030 over; head filled with engnbld valves, ported, shaved with calculated static compression of 9.5:1; some unknown cam that likes a lot of rpm, and smooth idles over 1000 rpm. Clifford intake & shortly headers twin piped to the bumper, Holley 390 4V; orange box with Blaster 2 coil providing fire, and a nicely recurved distributor. She pulls real good between 2800 & 4000 rpm. Oh, 3.55:1 rear so what I have now is fairly balanced in the rpm & torque department going down the road A bit busy, as cruse rpm is in the 2700 to 3000 rpm range.

Would a torque cam make more power, or just slide what power I have now down the rpm scale, necessitating changing to a taller rear gear, but a less harried riding experience?

Obvious power multipliers would be artificial induction from a blower, or turbo, both of which would most likely require cam & possibly compression changes, as well as addition of fuel injection from what I have been gleaning from the site. Fuel injection & forced induction are big steps from where my car is now, and would make nice winter project.

Maybe I should ask this question another way: what kind of build will get me to the mid 14 second quarter range, while keeping the package streetable. I know some of you out there in Slantland have cars running low teens, and perhaps could share what your recipe is.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

more power; is Tim Taylor in the house?

Bill
You nee toget some accruate measurments...You need the CC's of your chambers the amount your piston is in the hole at TDC and ALL the numbers for your cam (if you dont have a degree wheel kit now is the time). Once you have all this we can give you some pretty good ideas.
All this would take is time and a new head gasket.

Frank

_________________
Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

And a dial gauge with a magnetic base, so you can accurately see where the top of the lobe is and be able to see where the lobe lift is at .020 or .050....

-D.Idiot

66cuda:
[quote]You nee toget some accruate measurments...You need the CC's of your chambers the amount your piston is in the hole at TDC and ALL the numbers for your cam (if you dont have a degree wheel kit now is the time).[/quote]

0.153 down in hole, 44cc , with a 0.075â€￾ shave for about 9.5 cr. calculated.

And that damn cam… Crap!

This little Sherlock project will require pulling the timing chain cover, and chain, or can the wheel be attached with the chain in position? I believe there in an Erson cam installed as there are two little Erson window stickers on both rear windows.

Looking on 225 slant six cam shafts chart (also Erson group buy), with the micro sized print, I downloaded from this site ( I think), there are two out of four [url=http://go.mrgasket.com/pdf/ChryPlyDodge.pdf] Erson [/url]cams listed that seem to fit my engine’s MO:

Erson E470621 rpm range 2000 to 5000 strong mid range with fair idle ( my idle more or less smoothes out around 11–1200 rpm)
Erson E470302 rpm range 3000 to 6000 strong mid range, 9.5 to 10.5 cr, four speed

I’m betting on the first one. Can’t imagine winding this engine to 6 grand, but 5000 rpm comes up real easy, and torque seems to kick in around 27-2800 rpm maybe sooner.

I’m thinking a few pulls on a dyno would help to figure out where I’m at with this build, and where I can go.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

E470621?

If it is a 270/270... your lobe separation and overlap event are going to help determine what to do, if the LSA is tight and you have a big bleed off window you might have to raise compression more to make up for that... also if the cam comes on "that late" then you might be needing some 3.91's to put the cam back into it's "happy spot"...

That 280/270 I'm running is much like your cam...it makes the same power as any of the typical short cams under 2K... once over that point the thing just wants to go...but it's not happy with the 3.55's I have, it wants to have a little more rpm in it's power curve to keep happy...
after looking at how the engine's Dynamic Compression Ratio looks, I never thought I could run a "street' engine with a 10.3 SCR on pump gas (plus or super depending on the timing curve and driving style...but it's not needing 112 leaded daily...but then it does love about 3 gallons of that at the track...)

Once you figure out which cam you have, a guided plan can fall into place pretty easily...

-D.Idiot






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