273 Supercharged...ITS HAPPENING PEOPLE!!

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Im going to turbo a 273 myself. Not even going to tear into it to see whats up, Im just going to throw a T-56 turbo on it into a 600 Carter and see what itll do for how long. Oh, I do have a Turbo grind cam for it.....Fear the 4.5!
 
The Paxton idea,kicks ***.. If you have a well built transmission already,use it. If not,build what you have. Love centrifugal superchargers, don't blow the tires low end,like a Rooted based...
 
So I went to the Garage Saturday to clean up the short block and found a freeze plug that was crappy. Easily stuck a small screw driver through it. Well one thing lead to another and now I'm in full rebuild mode. Lol bearing surfaces looked fine but timing chain was loose and the block had a bunch of crud in it. Cylinders are fine so just a light hone will clean them up. More money!! Ugg.
 

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I popped a core plug on my slant and found a 14 piece of coat hanger size wire in there, WTF? easier to do it now....
 
You should check your comp ratio while you have it apart and try and raise it to the safest level you can with the boost your using, Check the cam profile too. If you stick with the 727 auto ( poorest choice in my opinion) then you will need a custom torque converter.
Running the 727 and the blower is going to put load on the engine from the get go, so you need to produce as much low end as you can to compensate or it may not like to idle in gear or be a real slug down low until you build some boost, which is typically only up in the higher rev ranges with a centrifugal blower.
 
Bakerlite said:
You should check your comp ratio while you have it apart and try and raise it to the safest level you can with the boost your using, Check the cam profile too...
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I agree to check piston height while apart and cam specs. 273's are not compression challenged as late 318's and 360's. Check to see how cast pistons will hold up under the boost levels you plan to run. Had a friend with a newer Mustang that was assured that his engine would hold up. After a year or two one of the hypereutectic pistons failed catastrophically taking out the whole shortblock. I seriously doubt it will be a slug with or without a 727.
 
Bakerlite said:
You should check your comp ratio while you have it apart and try and raise it to the safest level you can with the boost your using, Check the cam profile too. If you stick with the 727 auto ( poorest choice in my opinion) then you will need a custom torque converter.
Running the 727 and the blower is going to put load on the engine from the get go, so you need to produce as much low end as you can to compensate or it may not like to idle in gear or be a real slug down low until you build some boost, which is typically only up in the higher rev ranges with a centrifugal blower.
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Comp ratio will for sure be checked when going back together. I am a bit stuck on the cam. Was planning to replace but I'm not sure what to go with. Was going to talk with local shop guy next week Do you guys have any thoughts on specs?

I'm only thinking 5 lbs on this thing. BUT.... Eagle forged rods are do able. I'm thinking about a set of custom forged pistons also but I haven't fully decided if the juice is worth the squeeze. How much more boost is safe on a stock block and stock heads? How much power will the stock cast crank tolerate? Any thoughts? It's about another grand for rods and pistons. Might set my time schedule back but might net me a big jump in power and reliability.

I'm sorry but the 904/727 debate is getting old. Not to seem like I'm taking it out on you but I understand how it draws more power. I understand it's not what some would choose. For me it makes sense. It's a 727 going in the car. If I hate it or later down the line I will go at the 904. I have bigger fish to fry right now.
 
This looks bad. Seems like this piston and a valve might have touched.

The timing chain was pretty sloppy. So I'm assuming that's the cause. But now I have serious reservations about reusing it with the supercharger installed.
 

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I'm not worried about the trans thing, at the end it's your choice. When you build small engines , the key is to try and build lite, don't waste any power unnecessarily. I think you will need to contact Paxton and get some specifications on the blower your going to use. That will help dictate other engine parts selections.
 
Bakerlite said:
You should check your comp ratio while you have it apart and try and raise it to the safest level you can with the boost your using, Check the cam profile too.
Click to expand...

Bakerlite said:
When you build small engines , the key is to try and build lite, don't waste any power unnecessarily. I think you will need to contact Paxton and get some specifications on the blower your going to use. That will help dictate other engine parts selections.
Click to expand...

Chris, he does make sense and it is good advice. I hear on the trans choice and the "Bigger fish to fry" right now comment. A custom cam grind designed for use with the S/C is a golden idea. If your going to choose one yourself, there is a lot to look at. If your not used to looking at cam specs or understand the different lobes available, it maybe more of a chore than it is worth.
 
I took a little time to check out the FAST EZ EFI 2.0 instructions in this link
www.jegs.com/InstallationInstructions/200/244/244-ezefi20.pdf

On page 62 it states "The EZ-EFI ® system is intended for naturally aspirated engines only – no turbos or superchargers. "

Just to be clear, EZ EFI was originally fuel only. EZ EFI 2.0 Is fuel and ignition.
The only FAST EFI system available with forced induction support is the XFI series.
 
So the block is off to the machine shop for some simple stuff so in the meantime I dug out more of my parts. I have two options for intake. One is a Edelbrock performer the other is a 340 4bbl casting #3512100. I've read that the stock 340 intake outflows the eddy. My question is in my forced induction application which would you choose?
 
I was able to get to the machine shop and get the block work started. Hot tank, hone, and change the cam bearings. While I was there of course he tried multiple times to sell me a 408 for the same supercharger set up.... I resisted and explained my madness. I think he still thinks i'm nuts but hey who cares.

I have learned a lot about my set up so far. I will be going with Eagle Forged Rods and I am working on finding a early Forged crank to build off of for added insurance. Yes I know that I will have to change the balancer, and the converter. Thankfully we haven't gotten a converter yet so its easy enough to do. My pistons will be the weak link as the only viable option is a set of cast speed pro pistons or a custom set of forged and the cost is silly. ($950ish). Maybe someday but for now I have so much more to concentrate on. The Pistons should withstand 10 psi as long as the tune is correct and its not seeing that type of stress for long periods of time. So for now that's the plan. The Bearings will all be Clevite, cloys timing chain, Melling oil pump, and the heads are all freshly worked. so the engine will be all redone. Ive gone further with the motor for sure than I planned but its worth it for the added security.

My Fuel injection control is actually a Fast XFI sportsman unit which is capable of handing the supercharger. I will be using the Fast Distributor as well for the ease of plug and play. It requires a control box and for that I will be getting a MSD 6AL-2 Box. So I can control the timing and the fuel pretty accurately so I should be able to sneak up on a good tune.

I still have a ton to get sorted out. Cam spec is a debate right now. I am not smart enough to talk intelligent about cam numbers but my conversation was that I wanted this motor to come in quickly. I don't want to have to rev the thing to the moon to get into wear the cam wants to work. He said he would look at some stuff and let me know what he thought would work. I also have to select a converter. Haven't even started on that yet.

The intake I think I am going to throw the old 340 Iron back on it. He agrees it will outflow the aluminum Performer so the only advantage would be weight. Since its not a race car I'm fine with the cast one.

So as you can see I have been working on stuff just not alot of exciting stuff yet to post.
Happy thanksgiving!!
 
frosty_the_punk said:
I took a little time to check out the FAST EZ EFI 2.0 instructions in this link
www.jegs.com/InstallationInstructions/200/244/244-ezefi20.pdf

On page 62 it states "The EZ-EFI ® system is intended for naturally aspirated engines only – no turbos or superchargers. "

Just to be clear, EZ EFI was originally fuel only. EZ EFI 2.0 Is fuel and ignition.
The only FAST EFI system available with forced induction support is the XFI series.
Click to expand...

its an XFI sportsman. so i should be good!!
 
You mentioned a cast crank, I thought all 273's had forged cranks. The ports are much bigger on the cast iron 34o intake than the 273 heads. Thanks Webby.
 
chrissock said:
To start.. I know this is not a popular build. That's why I'm doing it... I know I could get a 360 and do some minor stuff and make the same if not more HP. I know... But whats the fun in that??
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The fact you can do all the work you did to the 273, and the 360 will make power. Which the fun lies in pounding the GO pedal on a track...
 
$950 for good forged pistons is insurance, cheaper than a broken pile of cast iron.
The cast pistons "might take 10 psi a couple of times" I would not take them over 5.
Also throw in about $250 more for a good balance job.
Do not cheap out on the short block, it is the foundation of your build.
 
sireland67 said:
$950 for good forged pistons is insurance, cheaper than a broken pile of cast iron.
The cast pistons "might take 10 psi a couple of times" I would not take them over 5.
Also throw in about $250 more for a good balance job.
Do not cheap out on the short block, it is the foundation of your build.
Click to expand...


Good advice. I know it's easy to spend someone else's $$ via the net,but better to do it right the first time. Maybe hold off until you can afford those forged pistons. Sell something?
 
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