I need a set of ears, long post and not a normal noise

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My427stang
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Re: I need a set of ears, long post and not a normal noise

Post by My427stang »

Mark O'Neal wrote: Sat Feb 24, 2018 3:12 pm The skirt design we used on that piston was developed by Ford Motor Company. They are quiet. They have always been quiet.

You might want to contact Barry Robotnick at Survival Motorsports. He specializes in FE motors and may have some insight for you. He has also used hundreds of sets of Probe pistons in these applications which makes him aware of any quirks in combinations.

The SRS Series was also made of the same 2618-t6 everyone uses on forgings made by the same forging house everyone uses. Since I have never seen a single complaint of this nature, you would have had to have gotten the only "soft" forgings in the batch....of at least a thousand. That would be incredible bad luck. If the parts are soft, they would have had to have been heated to a very high temperature and normalized.
Thanks Mark, I know Barry well, as well as most of the FE builders. This isn't a one time stroker for me. I have been doing FEs for a long time, just my first run with these pistons, I am a Diamond guy, just wanted to save a couple bucks on this one. There isn't much more to this whole endeavor, at this point it's time to put these on the shelf.
Bullock's Power Service, LLC
Plattsmouth, NE
70 Mustang, 489 FE, TKO-600, Massflo SEFI, 4.11s
71 F100 SB 4x4, 461 FE, 4 speed, port injected EFI, 3.50s
My427stang
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Re: I need a set of ears, long post and not a normal noise

Post by My427stang »

Well, two lessons learned here.
1 - When you don't verify something, you can get bit
2 - When you go cheap, you increase the chances of it going wrong

Brent Lykins recommended seeing where I was with the heads bolted up, measuring from the bottom, I trust him like a brother and didn't have a smoking gun, so I did it, but really didn't expect it to pan out, I was wrong! I also talked to Barry in the interim and appreciate the advice from both.

Despite me wanting to hate the pistons, lI have to eat crow and say it looks like it likely is the block, and likely my "reblock" would have worked if I did my normal block prep (sonic check, square deck, torque plate hone) and didn't go cheap

When I replaced the block knowing it was noisy with .0075 clearance (with a fully square decked, align honed, torque plate honed block), I used a second block that was already finished for a buddy, it measured at .0045 clearance (no torque plate) and looked nicely done. In knew it likely would have moved a bit with the heads bolted on, but never expected a complete change in shape. In the end, I have one of two issues, or both, need to figure it out. But. knowing the shop by buddy uses doesn't have an FE torque plate. it could just be just crooked when things are bolted up or the cylinders are thin and moving around more than they should

1 - Mocked up cylinder to see how far the piston skirt hung out. Did not hang out very much, .250 max and checking point on skirt never exited bore

2 - Pulled crank, installed heads, torqued caps and heads with head gasket

3 - Checked 6 points on each cylinder from bottom, 3 pin direction and 3 thrust direction, checked bore gauge vs piston after each bore

Summary
- Pin direction - 7 cylinders the same behavior at .0045 to .0055, growing toward bottom of bore, most measurements between .0045 and .005 (one oddball at .005-.006)

- Thrust direction - All 8 cylinders were bigger than pin direction, but 2 cylinders grew bigger as approaching bottom of stroke, 6 cylinders got smaller at the bottom

When I look at cylinder #7 in multiple pics, it is certainly the weirdest, but it's hard for me to show you, but it does correlate with the numbers. Numbers in bold are outside of Probe's limits, and all of #7 is bold because it is likely the noisiest, but the inconsistency is the odd thing. I put away my tools and went to lick my wounds, but I do intend to pull the heads and crank and do this again, just to see how far off the numbers are without the heads. When I originally asked the question, I took a lot of measurements, but not as many as I did here, and not in as regimented locations.

In the end, if the cylinders are thick enough, my intention is to torque plate hone at a minimum oversize and put a set of 4032s to fit maybe shifting compression height up to 1.335 for a zero deck, but that is likely overkill

Cylinder Clearances
Top/Middle/Bottom - Thrust direction----------Top/Middle/Bottom - Pin direction

#1
.0065/.0070/.0070----------.0045/.0045/.0045

#2
.0070/.0065/.0060----------.0050/.0050/.0050

#3
.0075/.0070/.0065----------.0045/.0050/.0050

#4
.0070/.0070/.0065----------.0045/.0045/.0045

#5
.0060/.0065/.0065----------.0045/.0050/.0055

#6
.0075/.0070/.0065----------.0045/.0050/.0055

#7
.0080/.0080/.0065----------.0050/.0060/.0060

#8
.0055/.0070/.0070----------.0045/.0050/.0050
Bullock's Power Service, LLC
Plattsmouth, NE
70 Mustang, 489 FE, TKO-600, Massflo SEFI, 4.11s
71 F100 SB 4x4, 461 FE, 4 speed, port injected EFI, 3.50s
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Re: I need a set of ears, long post and not a normal noise

Post by rfoll »

If your clearances are for forged pistons, the block could be deck plate honed for cast hypers as you suggested. Find another block and bore it to re-use the pistons you already have.
So much to do, so little time...
My427stang
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Re: I need a set of ears, long post and not a normal noise

Post by My427stang »

rfoll wrote: Mon Feb 26, 2018 10:31 am If your clearances are for forged pistons, the block could be deck plate honed for cast hypers as you suggested. Find another block and bore it to re-use the pistons you already have.
So, you are correct, and the engine would live with hypers, probably even cast, but not a lot of availability there

I swapped a nice little 390 9.5 street motor in it, I'll come up with a plan and it'll likely be overbore with a set of 4032 forged, or prep another block.

The good thing about the overbore is it fixes the issue and I still have a set of pistons, if I prep another block, I have the money sunk in the fix with nothing left over after. But honestly, I want to see a good sonic map before I choose, if this is a flexi-flyer, I don't want to throw more money in the block
Bullock's Power Service, LLC
Plattsmouth, NE
70 Mustang, 489 FE, TKO-600, Massflo SEFI, 4.11s
71 F100 SB 4x4, 461 FE, 4 speed, port injected EFI, 3.50s
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