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NEED power out of my 351w!

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NEED power out of my 351w!

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Old 02-20-2007, 04:54 PM
  #11  
1jsmith
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Default RE: NEED power out of my 351w!

When I took the car to the dyno I had 500 miles on the engine. Right now I have about 1000 miles on it. The compression ratio was supposed to be at 9.4 to 1 or so and I have not done a compressoin check if those are the #'s your looking for. Looking at my dyno paperwork I cant tell what my air/fuel ratio is, but it does follow the ideal mixture line pretty well.
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Old 02-20-2007, 05:52 PM
  #12  
NeoTokyo
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Default RE: NEED power out of my 351w!

Hmmm, the problem seems like it is in the heads to me. I would see about having themchecked at a shop, it would be more than worth it to lap the valves, it should be done to every new engine anyways after it has some run time, it almost always picks up power. The bottom end sounds perfect in every way, the cam looks like it would work great and the carb isnt too large for the application... Well I am not going to say that, get some jet info on that carb and see if you are not giving it enough fuel, our fords love to eat

Sean Highland Motorsports laps the valves on all of their engines after a little bit of run time and claim that their 400hp cobra engine series get roughly 20hp just out of lapping the valves, and if a valve is having a problem (Like in one of their worst race engines 400hp) lapping the valves gained nearly 40hp.

Its not expensive and you are bound to get power out of it anyways, also ever concider that you might have a set of valve springs that are too strong and not letting the valves open up all the way? Another thing is, I rarly hear people using 1.6 rockers, usually its 1.73 and that will help a little too, as long as you have the clearances.

And lastly, no one asked this.... But what gear did you run in? With a manual you should be in 4th for a 5spd and 3rd for a 3 speed to get as close to that 1:1 ratio. For the auto I think its just D.

Another problem that you may be having is that you transmission is slipping (if an auto) not allowing full power to the diff. Also if you are using a C6 then you are losing a little bit more percentage than with a C4, its a larger trans with larger, heavier moving parts.

And if you are ever really pissed off at your heads then you can check out AFD and get a set of their Aluminum 351C 4V heads, they claim 680+ hp out of the box. Personally I would love to make a Clevor but im still working on my mod motor.

Best of luck

-Eric-
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Old 02-20-2007, 06:07 PM
  #13  
1jsmith
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Default RE: NEED power out of my 351w!

When I had the machine work done I also had them go through the heads even though they were new (the valve guides were a little sticky and the valve seats seemed a little thin). As far as tranny- I have a C4 and I was in 3rd gear on the dyno. The carb was also re-jetted with new rods put in as well (at the dyno). Really, I don't feel like I cut any corners and I just don't see why my numbers are so low.
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Old 02-20-2007, 06:18 PM
  #14  
samseed101
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Default RE: NEED power out of my 351w!

It's pretty cheap and easy / fast to check the compression. It may be worth it to make sure that everything is up to par.
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Old 02-20-2007, 07:23 PM
  #15  
PONY GUY
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Default RE: NEED power out of my 351w!

I bet maybe the valves are not opening and close all the way
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Old 02-20-2007, 08:19 PM
  #16  
NeoTokyo
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Default RE: NEED power out of my 351w!

Yea, I would go with Samseed too, but it also really sounds like a head problem, things can happen even if they are freshly gone through.

I have worked in assembling engine to hot testing/Dyno testing them and then breaking them down again for a company called SRC, trust me, it really sounds like a head problem. Lapping the valves and checking if they are opening all the way is one of the more important check list items to go over. Dont forget about the comp test too though, Samseed did make a good point, and get a stethoscope (sp?) and listen for anything tapping or rubbing, the mechanic will tell you where to listen, they are specific points and just getting into the general area isnt good enough.

Good luck, hope the power comes out of that block for ya.

-Eric-
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Old 02-21-2007, 12:09 AM
  #17  
92BOOSTED
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Default RE: NEED power out of my 351w!

How does your car run? Does it feel like its got more than 230hp? The reason i say this is the correction factors used on dyno's differ.I'm not saying that your making 300rwhp but it's possible that you could be making more power than you think because the dyno does not have correct information in it for proper load testing.
One way to test it is by taking it to the track and making a few (roughly 5) passes and evaluating them.
Are you near a dragway? (hopefully it's warm where your at)

Ryan
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Old 02-21-2007, 04:23 AM
  #18  
Li0nHart
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Default RE: NEED power out of my 351w!

If you can, run it on another different dyno...then you can be positive its your engine and not the dyno or operator
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