My combo

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dartfever

dartfever

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Well, Id like some opinions on my combo for my 69 dart.

The specs are
73 360 block .03 over
stock stroke
69 340 stock rods
kb362 pistons
rotating assembly internally balanced
mildly ported eddy mag heads
roller rockers 1.6 intake, 1.5 exhaust
cam 279/281 advertised, 229/235 .050 Lift .511" in .501"ex (with ratio taken into account)
eddy air gap intake
eddy AVS 800 cfm carb

I realize some of you would throw the carb as far as you could but that's what I have to work with.
Headers will be 1 5/8", either dougs or tti's

What numbers hp and tq wise should this combo put out?
 
If you can get that Carb to cooperate...I would say 420hp at the crank is sand bagging a bit.
 
roller rockers 1.6 intake, 1.5 exhast.






Why is that? I don't understand why you are using different int and ext rockers. Is that a normal thing to do? Not nocking you, just trying to understand is all.
 
The exhaust didn't gain anything past .500 so didn't figure it was necessary to go that big. The ratio is 75% ex to in. I might still change that in the future.
 
A few things. First, the rods and pistons... 340 rods, and indeed non mangum 360 rods will not fit those pistons without narrowing the small end to Magnum width. Also, the step needs to be machined off the top of the piston to run closed chamber Edelbrocks. (assuming yours are closed..I've never seen a set of open chamber LA Edelbrocks, but they do still offer them for a couple bucks more) If you leave the step and run open chambers, you will have no quench, and your static compression is way low and you'll lose a lot there. What heads do you have? Has the block been machined/rebuilt before?
 
moper, isn't the KB362 piston a magnum specific piston made to be used with the closed chamber magnum head? I thought they were esentially a flat top with a D shaped dish under the chamber to lower compression while maintaining the quench under the closed portion of the chamber.

dartfever, I would go with a KB107 flat top piston, there is no reason not to run 10.5-11:1 compression with aluminum heads. I am running 10.6:1 with iron magnums and run middle grad 89 octane gas with no problems. The higher compression will be good for power, throttle reponse and economy.
 
Should have stated this is already built. The KB362 is built for the eddy mag head. The rods have been narrowed. In hindsight, I should have went with the flattop. I only work out to 9.72:1 right now. I was aiming for 10:1. My first build, so I'll learn from my mistakes. Has been run on an engine dyno, unfortunately the dyno broke after 4 pulls so we didn't get it dialed in very much at all. The peak numbers were 367 hp at 5300 and 412 at 3600. Of course, considering the dyno broke, it's hard to say how accurate the dyno was. I was assuming a ballpark figure in the 410-430 hp range with similar torque numbers.
 
Sorry guys, I blew right past the Magnum reference on the heads, AND was confusing the KB362 and KB373 pistons. I think I'll just go back to bed today...lol.
IMO, it's way low down static compression, like at least a full point as it's built now. Also, the cam IMO is a little small. Nothing is wrong with the carb. You will need to tune it, but any carb needs tuning to be perfect.
 
Thats OK Moper, you don't miss much.

The carb will be the hardest thing to deal with. I hope your up to tuning tasks. They can be such a pain with a big carb and low stall and gears. Make ya mad/crazy.
I'd run with the Dougs.
 
I'll put it on a chassis dyno to get it closer once the car is done. Trying to dial the secondaries in will be the tough part. At least it's the AVS so I can adjust it somewhat. As for the headers, I was leaning towards the Doug's myself. The car is a 4 speed and will have 3.55 gears.
 
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