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Discussion Starter #1
I will need some guidance along the way. Here's the quick version of the story.

Its 2008. A young boy likes burnouts and mustangs. 11 second cars are the fastest shit on the planet. So the boy takes a 351w junkyard engine out of 1969 galaxie 500 and takes it to a "reputable" Chevy builder. The kid says:

I want a torque happy pump gas motor with instant throttle response. Something that hauls ass 0-60 or stoplight to stoplight. Mostly street use with occasional grudge racing. I also plan to put a procharger on it in the future, so please build it accordingly. I don't know when I will get around to finishing this project, it may be years, so please put some extra lube on it. Also, I have these brand new AFR 185cc/58cc heads that cost me out the nose, so if you could make them work I would appreciate it.

Fast forward.

$12k and 10 months later, I go to pick up the motor. He says the valves are not lashed, because I didn't want to let the springs sit compressed for a long period of time.

No big deal, I'll drop the distributor in and finish this motor up when the time comes.

12 years later, the time has come. Except upon setting valve lash, there is a "click" or "ping" when I turn it over by hand. Upon further inspection, Chevrolet pistons were used, and they are hitting the valves.

Now I am at the disassembly stage (in my kitchen. yes really) and here is what I know:

393 stroker
scat forged crank, internally balanced
speed pro forged pistons (the fuckin wrong ones apparently) pn# LW2605f60
12cc dish
4.06 bore
3.85 stroke
1.6 roller rockers
quickfuel ss-650 carb
rpm air gap dual plane intake
comp 35-426-8 cam
Duration @ .050 236/240
Lift .555/.576
110* Lobe
Deck height: Piston comes out approx. .012
felpro head gasket compressed height .041"

So I'm coming up with somewhere around 11.75:1 compression, instead of the original planned 8.5 or 9:1, and pistons bouncing off the valves.

My choices are:

Option 1:
swap the cam to something better suited for blower, pull the choke out of the carb, add some nitrophyl floats, put a d1sc on it with low boost, and shoot for 600hp or so.

Option 2:
Spend the least amount possible. Get pistons/rods that work with the current combo, while maintaining low compression, and run it. Maybe hope for a little over 400hp, but enough torque to have lots of low end fun. When I get bored with the combo, go back to option 1.

Would like opinions, help identifying parts, what year is the block, suggestions for building this first one on my own since machine work is already done (or so I hope)

Tons of pictures to follow.
 

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I think option 2 is the way to go. While you’re getting your piston situation sorted out, sell your heads and intake manifold. Get some AFR 205’s or 225’s or a set of trick flow 11r 205’s. I would try to keep the compression around 11:1, get a bigger better cam, and a port matched Vic JR. Intake. You could pretty easily have a 550-600 hp pump gas motor that will last a long time.
 

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Did the machine shop assemble the engine? Is the machine shop still open? An engine doesn't care what piston is in it, if it fits the application. Do you know for fact the piston to valve clearance is wrong? Have you checked with clay? Post some pics of the witness marks on the pistons.

Take a good look at the girdle, that may be your problem. Any reputable machine shop will stand behind their work.

Look for witness marks on the girdle.
 

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2 schools of thought with boost. Turbo/super charger. It doesn't matter.

Make the most power, then add the power adder.

Let the power adder make the power, with low compression.

One wins everyday, the other worked OK before EFI.
 

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Discussion Starter #8
Did the machine shop assemble the engine? Is the machine shop still open? An engine doesn't care what piston is in it, if it fits the application. Do you know for fact the piston to valve clearance is wrong? Have you checked with clay? Post some pics of the witness marks on the pistons.

Take a good look at the girdle, that may be your problem. Any reputable machine shop will stand behind their work.

Look for witness marks on the girdle.
Guy retired 8 years ago. No clay needed. Girdle is fine. I'm not interested in just "clearancing" them, would rather buy ones that have proper reliefs

52616
 

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Option 3: The cheapest option,

If possible look into how much clearance is required and clearance the pistons. Save your money and build another motor on the side over the next few years that is a no compromise situation. I think you've already spent a tremendous amount on that motor, why not see if you can make it work.
 

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Discussion Starter #11
TAKE IT TO A REAL SHOP,GUNNA SAVE YOU IN THE LONG/SHORT RUN!!
False. That's how I ended up here in the first place. The guy built circle track motors for holland speedway in new york. was recommended to him by 3 racers. apparently couldn't handle a simple ford build.
 

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False. That's how I ended up here in the first place. The guy built circle track motors for holland speedway in new york. was recommended to him by 3 racers. apparently couldn't handle a simple ford build.
I know that you didn't know, but that is the type of thing that separates the "real" guys.

I'm a Ford guy but even I know that SBC's have different valve reliefs. Any half ass machinist should have known as well.
 

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You can have those pistons machined for not alot of money and they will be fine. Why waste money on new pistons (and a new balance job) when you dont have to? I cant remember the name, but there is a specialty shop that just does piston machining, they can do it in no time. I think is Rebco or something like that.
 

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Discussion Starter #14
You can have those pistons machined for not alot of money and they will be fine. Why waste money on new pistons (and a new balance job) when you dont have to? I cant remember the name, but there is a specialty shop that just does piston machining, they can do it in no time. I think is Rebco or something like that.
because compression is wrong?
it's internally balanced, does that change anything?
 

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That's a 1969 block. You should probably pull one piston/rod assembly out and measure the rod length, the pin and big end sizes to see what rod he used. Also, measure the compression distance of the piston to verify which pistons were really used. The least expensive way out would be to flycut the reliefs. Since the pistons are 0.012 out of the hole, you should probably use a 0.050 headgasket as well.
 

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Discussion Starter #16
You should probably pull one piston/rod assembly out and measure the rod length, the pin and big end sizes to see what rod he used. Also, measure the compression distance of the piston to verify which pistons were really used.
The piston still has the part number on it, so that is already verified. I will be doing the rod length this evening. i didn't have a 12pt 7/16" socket to get them out. Thanks for the info!
 

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because compression is wrong?
it's internally balanced, does that change anything?
It doesn't matter if its internally or externally balanced. The new piston weights will have to be considered and the assembly might have to be re balanced if the weight difference is material.

You can have more dish put in the piston at Rebco, not a big deal at all. Just tell him what cc volume you need. This will fix your compression issue. Use a .050 or .060 head gasket, cometic will make them for you.
 

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Not a Ford guy. But seems like cutting the pistons as said above and maybe thicker head gaskets and you are golden.
Out of curiosity, what lash did you set the valves at?
 

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Discussion Starter #19
Not a Ford guy. But seems like cutting the pistons as said above and maybe thicker head gaskets and you are golden.
Out of curiosity, what lash did you set the valves at?
1/4 turn. I'd need to turn 12cc pistons into 30-35cc pistons in order for them to get me down to the proper compression. a thicker gasket hardly changes compression enough to matter.
 

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1/4 turn. I'd need to turn 12cc pistons into 30-35cc pistons in order for them to get me down to the proper compression. a thicker gasket hardly changes compression enough to matter.
So hydraulic cam? You may have said that. Just wanted to make sure you didn't have a mechanical cam.
You can get almost 1 compression number out of a thicker gasket. Cometic MLS gaskets are available in thicker sizes at Summit. maybe even for Fords!
 
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