down on power 360 magnum

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MOPARCODY

MOPARCODY

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Location
ROCKLIN, CA
00 dakota block (stock)
395 hp crate motor cam
eddy heads (stock)
1.7 rr mpp
holley 750
edelbrock rpm air gap intake
4" spacer
1 3/4 headers long tube

3500 stall with 3.91 gears

car weighs 2780
best et of 12.54 @ 105.9

holley red fp with 7psi

timed it several times between 30-40 degress doesnt seem to change et or trap

car seems like it doesnt pull hard on top end

any ideas? im at a loss
 
4 inch spacer?

did you check the plugs for proper jetting...usually a spacer will tend to lean the engine out...
 
70aarcuda said:
4 inch spacer?

did you check the plugs for proper jetting...usually a spacer will tend to lean the engine out...
Click to expand...

I actually swapped carbs at one point and it didnt make a difference, jets were 94s i belive, not sure what was in the front
 
wow...that is alot of jet for a 750 dp...

my 950 dp only had 78/86 in it at sacto early in sept...
 
yea, the carb came off a 72 duster with the same engine but its the iron headed crate motor. he went 11.85 at 115 on street tires shifting on the column
 
well...12.50 is about right for the 105 speed....might need more converter...more gearing...
 
converter will only stall to 2500 on the foot, my breaks wont hold it, but flashes to over 3k. and im going through the lights at around 6k
 
With 12.54 @ 105.9 your definately gettin' down the track efficiently. Plenty of secd. jet that's for sure. More gear, converter ain't gonna get ya' a whole lot more imo. Need more engine......i'd look at a cam, more duration, and possibly some head cleanup.....bowl work & short side.
 
70aarcuda said:
wow...that is alot of jet for a 750 dp...

my 950 dp only had 78/86 in it at sacto early in sept...
Click to expand...

No kidding. 94 square... That's 1050-1150 level jetting

It may not be pulling because it's fat. Even if the PV are plugged that's a ton of jet. I'd look at what stock jetting is and maybe go up 2-4 a side, no more.

105mph at that weight is not very good for what you have. Like 300-320hp
 
Definetely gettin short changed on HP. My calc. with a 200lb. driver came in even lower at 290-300. How many runs/miles are on the engine. Have you done a compression/leakdown on it?
 
motor only has 40k on it, and should be around 400 hp, i weigh 250lbs but my race weight is a lil over 3k, i difinetly am down on power
 
believe your carb is way too fat....which make the engine run like slug
 
Look up what the stock jetting is and go back close to that. My guess it's 8-10 sizes larger than stock right now... VERY BAD!

Have secondary block or a metering plate?
 
770 should be a avenger. Stock jets are 72/75. They don't come in single inlet?
 

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I agree you should be close to 400 hp. What do observers see on your runs? Are they clean or are you smoking at all. The rings may be washed out? I really recommened a compression check.
 
as far as i can tell it doesnt dump fuel, and im sure my carb only has one set of jets
 
Your times/mph look in sync, fuel pressure should be suffecient, different carbs and timing changes didn't help. If the shortblock is still solid, i'm guessing the valve springs are are getting weak.
 
I'm going to do a compression/leak down test tomorrow. I also have had issue with my rockers backing off and having to adjust them every time I go out to the track
 
If the adjusters are backing off there may be more issues than just tuning. What does teh wear pattern on the tip of the valve stem look like?
 
moper said:
If the adjusters are backing off there may be more issues than just tuning. What does teh wear pattern on the tip of the valve stem look like?
Click to expand...

It actually look like they are walking around a bit, I've had to replace my pushrods twice from running on the guide plates, what would cause this?
 
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