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I have got a 350 that I am putting performer RPM heads on and wanted to switch out the stock cam for something with more power. I am running a dual plane intake with a holley econojet 650 (spreadbore holley) and stamped 1.5 rockers. I ran an 1104 in my 400/vortec heads and it got horrible MPG. I want a little more pep but at the same time want the best mileage possible. I preffer something that offers lower rpm power. what summit cam would you suggest?
 

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In my opinion, if you're after lower rpm power, you're using the wrong heads. I think if you short-cam those heads, you're gonna have a pig on your hands. Of course, I have been wrong before.
 

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I went from some lt1(early not 2nd gen) 75cc heads with a 2 barrell so it should still do better than that. why you say it wil be a pig? and which summit cam would you suggest? what kind of mpg do you think I can see with these heads.
 

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Posted by ehacker01:
"why you say it wil be a pig?"

Never mind, my bad. I was thinking that the Performer heads were 170 cc's and the RPM heads were 200 cc's, but I just went to Edelbrock's site and learned that both are 170 cc's. Now, I'm wondering what makes the RPM heads any different. I think I would call my favorite cam grinder for a recommendation.
 

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The Summit 1102 works well, it has the same .050" duration and lift as the Edelbrock Performer cam but the advertised duration is shorter which indicates it has a more aggressive ramp profile ( IF the numbers are correct ) and LSA is 112, IIRC the Performer is 114 LSA. It will improve power over a stock cam and at the very least won't decrease MPG. A friend ran one in a boneyard 305 in a '63 bel Air with a 200-4R and 3.08's and got 20-21. If you put much stock in DD2000 it also shows the 1102 to be an excellent all around cam for a mild 350. Good low and mid range TQ and fair HP.

The 1101 might get better mileage but the performance probably wouldn't be much better than a stock cam.
 

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cam

mynuffinfutsitch said:
this is impossible without fuel injection
you can either have power, or fuel economy not both
This is a "not true" statement..... Research what an engine likes for improved fuel mileage...

What makes an engine a pig and use alot of fuel is an incorrect tune, or way to much cam... Usually a combination of both.

Make sure you choose a cam that will maintain a good cylinder pressure.. You will need to spend a bit of time and some money. You need cc your heads, pistons, and know the head gasket, to find the true static compression then we can make a cam recomendation from there...

Keith
 

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Use a Q-jet carb.

If you are using headers then get a cam with the same duration on the intake as the exhaust. If you are using exhaust manifolds then get a cam with 6 to 10 more degrees on the exhaust as compared to the intake duration.

Try to run about 9.5:1 to 9.7:1 cr with those heads even with a small cam. More compression will help low speed torque and improve mpg. Aluminum heads allow more compression ratio on the same octane fuel as compared to iron heads. I know those heads come in 3 or 4 different chamber volumes, so pick the right one.

The difference between a rpm and the regular performer head is the heat riser passage. RPM's do not have them, which I don't like for a street engine. Heat under the carb helps distribute fuel better and quicker after a cold start up.

For good mpg in the city, use an intake duration between 200 and 206 degrees duration at 0.050" lift. For good mpg on the highway, use an intake duration between 206 and 212.
 
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