402 stroker forced induction questions

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73_dartfan

73_dartfan

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I have a 73 dart/swinger with a 402 stroker that has 9.5:1 compression. I been having issues with the holley 650 double pumper and have been contemplating installing a holley sniper self tuning efi kit then possibly a blow through turbo. My questions are is this possible and worth it or is there another route one might recommend. For instance maybe a roots style blower with carbs?? I'm just trying to get a little more power out of it. Thank you in advance for any help given
 
73_dartfan said:
I have a 73 dart/swinger with a 402 stroker that has 9.5:1 compression. I been having issues with the holley 650 double pumper and have been contemplating installing a holley sniper self tuning efi kit then possibly a blow through turbo. My questions are is this possible and worth it or is there another route one might recommend. For instance maybe a roots style blower with carbs?? I'm just trying to get a little more power out of it. Thank you in advance for any help given
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Throwing money at a problem is not going to fix it. Now throwing money at someone that knows how to tune it, is not a waste. If the motor was not build for boost, it won’t last, so you might as well had smoked the cash.

As the other guys will ask. You have any more specs for the motor? What block, cam, heads, bottom end, valve train, ya know the details of the motor that matter...

Ah..... fu*k it, throw a 500 shot of gas at it and call it a day....
 
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It was a crate motor bought from the dodge dealership so I'm not sure of the internals. I know it's a magnum block m1 single plane intake msd 6al holley 650 dp. My dad was the brains behind this project. But since then he has passed away and I'm now trying to finish this with less than half his knowledge. I just moved to gainesville and am unsure of someone trustworthy to work on it. I just want it to be quick
 
73_dartfan said:
It was a crate motor bought from the dodge dealership so I'm not sure of the internals. I know it's a magnum block m1 single plane intake msd 6al holley 650 dp. My dad was the brains behind this project. But since then he has passed away and I'm now trying to finish this with less than half his knowledge. I just moved to gainesville and am unsure of someone trustworthy to work on it. I just want it to be quick
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It sounds like a 380 hp crate magnum which have dynoed at 400 hp ,Which i would think twice about putting a blower on as it it most likely has hypereutetic pistons at best. Do your research on the heads to see they will support 400 hp plus the 200 the blower will add. I’m am taking a chance on my magnum with hypereutetics with a 150 shot of gas. There are others who will disagree with me just my two cents.
Don’t know enough to speak about the sniper.
I’m in Leesburg
 
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The horsepower on the motor is 435 and 500 lb. ft. Of torque. It has 8qt oil pan. Why I don't know. But I will try to research the motor as much as I can. Is there any way to tell what the heads are without taking them off. Thank you for your patience with me. I really appreciate the help
 
73_dartfan said:
It was a crate motor bought from the dodge dealership so I'm not sure of the internals. I know it's a magnum block m1 single plane intake msd 6al holley 650 dp. My dad was the brains behind this project. But since then he has passed away and I'm now trying to finish this with less than half his knowledge. I just moved to gainesville and am unsure of someone trustworthy to work on it. I just want it to be quick
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Check out KSR Performance in Gainesville. Sharp guy!

Michael
 
Seems like a lot of compression for forced induction.
 
I think you may want to forget about the boost with that compression. I would go with a 100 shot of NOS. Much cheaper and that would get you to 535hp. Ask around, 535 hp is nothing to sneeze at. One I know for sure is Jimjimjimmy's Duster. It is a real fun ride.

Jack
 
Brooks James said:
It sounds like a 380 hp crate magnum which have dynoed at 400 hp ,Which i would think twice about putting a blower on as it it most likely has hypereutetic pistons at best. Do your research on the heads to see they will support 400 hp plus the 200 the blower will add. I’m am taking a chance on my magnum with hypereutetics with a 150 shot of gas. There are others who will disagree with me just my two cents.
Don’t know enough to speak about the sniper.
I’m in Leesburg
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Read below.

RustyRatRod said:
Seems like a lot of compression for forced induction.
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Read below.
Coyote Jack said:
I think you may want to forget about the boost with that compression. I would go with a 100 shot of NOS. Much cheaper and that would get you to 535hp. Ask around, 535 hp is nothing to sneeze at. One I know for sure is Jimjimjimmy's Duster. It is a real fun ride.

Jack
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I disagree with all of you since it is not the static compression ratio that is the defining point but ultimately the running cylinder pressure combined with the amount of boost. Or the total pressure running under boost. Careful attention should be paid to the timing of the ignition because the Hyperutecic pistons do not take kindly to detonation. And THIS is where the Hypers get a bad wrap and forged pistons get recommended with the mod to long life under boost.

This crate engine should not have any issues with low boost levels. (Under 10 psi.) Some here have pushed well past that. Read up and on it.
 
rumblefish360 said:
Read below.


Read below.

I disagree with all of you since it is not the static compression ratio that is the defining point but ultimately the running cylinder pressure combined with the amount of boost. Or the total pressure running under boost. Careful attention should be paid to the timing of the ignition because the Hyperutecic pistons do not take kindly to detonation. And THIS is where the Hypers get a bad wrap and forged pistons get recommended with the mod to long life under boost.

This crate engine should not have any issues with low boost levels. (Under 10 psi.) Some here have pushed well past that. Read up and on it.
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I agree to some extent rumble. I am not thinking about the internals of the engine, as most of the bad things that can happen to the engine can be controlled to some extent by timing control. I am thinking more along the lines of fuel. To be able to run much more than 4 lbs of boost with a 9.5 to 1 static compression engine you will have to raise the octane level of the fuel past pump gas levels or seriously back off on the timing. Both of which are not the best answer.

Jack
 
If you do nitrous, I would get an MSD 8680 timing controller
And keep it at a 150 shot. I don’t know what your suspension setup is but 435 plus 150 is close to 600 hp and if you don’t have a serious upgraded suspension (not to mention the driveshaft and trans) you have a great burnout car but little traction. I’m assuming that you want to race the car ??
 
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It has a Ford 8.8 rear end with 3:73 gears and posi. 8 stack leaf spring on the passenger side and 6 stack on the driver side. Torsion bars in the front. The Trans is a tci street fighter model 727 torqueflight
 
Coyote Jack said:
I agree to some extent rumble. I am not thinking about the internals of the engine, as most of the bad things that can happen to the engine can be controlled to some extent by timing control. I am thinking more along the lines of fuel. To be able to run much more than 4 lbs of boost with a 9.5 to 1 static compression engine you will have to raise the octane level of the fuel past pump gas levels or seriously back off on the timing. Both of which are not the best answer.

Jack
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I agree. There are fuels not at the pump for this type of combo. Darn shame now ain’t it!
 
My personal opinion just from seeing some problems with the Holley sniper stuff is, disregard that setup. Run a holley terminator if you’re wanting efi (it’s not that much more than the sniper) it is leaps and bounds better as far as efi goes. Put it on e85, Use the magnum distributor for cam sync,magnum crank sensor and flexplate with 4 of the holes welded up, and you’re choice of efi intake whether it be an m1 or a LA with the heads drilled. Put a gt45 on with truck manifolds (no power steering this way) or truck manifold on passenger side and jeep manifold on driver side with jeep power steering pump and bracket and you can have your cake and eat it too.
 
So far, I’ve made 900whp on 92 octane with 9.5:1 compression and water meth at 14psi. I should be able to find another 100 pretty easily.
 
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