Mustang5l5's Progress Thread - Archived Progress thread '08-'20.

Status
Not open for further replies.
Now wonder the intake is so big it does not even come to the original valve reliefs. So in theory you could run a flat top piston.

Your right on the intake side, but it’s a maybe on the exhaust. The exhaust valve does line up with the relief so unsure if a flat top piston would allow the same clearance as I measured.

860CEF54-CD7E-409C-BED1-AAF68261200E.jpeg


It looks close on the left side radially but the depth perception is off in this photo. That side is pretty high up but the pic is deceiving.

I’m going to clay all 8 pistons. I just want to be sure. If this was a GT40 combo with 100k miles on original springs, I wouldn’t be so confident in the clearances I have. Realistically, I’ll prob drive 1-2k miles on some pretty good springs and then stuff this all on a 347 stroker down the road
 
Last edited:
  • Sponsors (?)


So checking my quench. Had to stop, but preliminary measurements were that my pistons are 0.000-0.003 in the hole. The 9333pt is 0.047" compressed.

So that might give me a quench around 0.050". Ideal is what? 0.035-0.045". I'd drop to a 0.040" gasket and call it a day but that will bring my valve even closer to the piston. Do I do that and flycut them? A quick touch would give me the 0.020-0.040" I need.

This sort of stuff is keeping my up at night. How do guys buy a bunch or parts and just slap them together? I've spent more time measuring and remeasuring stuff to the point I wonder if i'm just overthinking things. Slap it together and send it and blame Ford when it runs like crap?

Even my wife noticed i was "off" this weekend with my mind occupied over cam timing, PTV, and quench


tempsnip.jpg
 
Last edited:
  • Haha
  • Like
Reactions: 7 users
Very embarrassed as a detail person to admit what I'm about to admit. I've torn apart and put together various cars my whole life. I've never even heard of "quench." Come to think of it, I've also watched numerous engine building videos and never heard it from them. Must check into this quenching.
Still enjoying this excellent thread, btw! :nice:
 
  • Like
  • Agree
Reactions: 1 users
What would your PTV # be with the thinner gasket ?
My guess is you would probably never notice a difference between 0.045" (in range) vs. 0.050" quench.
So many variables with these performance builds, I stressed out a bit with mine but in the end I figured
I wasn't building it as an all out race car.
 
What would your PTV # be with the thinner gasket ?
My guess is you would probably never notice a difference between 0.045" (in range) vs. 0.050" quench.
So many variables with these performance builds, I stressed out a bit with mine but in the end I figured
I wasn't building it as an all out race car.

I believe 0.039" gaskets are the next size down. So the HG would be 0.008" thinner.

I'd need to know the angle of the valve to calculate how much PTV I would loose, but lets say 0.007. I'd be pretty close to 0.050"

Am I overthinking it and should just go with it, or should I grab a flycutter and kiss the piston for that extra 0.020" and run the 0.039" HG?
 
IMO I would run it with a stock head gasket as is. Those pistons probably rock alittle in the bore so your probably less then you think. Plus your on a stock bottom end so give yourself alittle wiggle room there. It will be more detonation tolerant just for the simple fact of the aluminum heads. If it were my build I would be tighting up the quench only if it were a iron head.

As a comparison my 331 is +.010 out of deck and a stock head gasket and sees 8K at times, it has a forged crank, 28oz external and for sure better rods. Were only talking a difference of .010, and with the way your externally balanced at 50oz from the factory I would not be surprised if that crank is flexing .010 at 6K. I have seen some charts floating around comparing the balancing at 6K of zero, 28 and 50. If true it's no wonder my 331 can hold up without problems at 8K at 28oz.
Scott

Scott
 
Roger. I think I’ve convinced myself to go ahead as is.

I just want to check cam timing one more time. After a degreed the cam I pulled the chain off to put some loctite on the cam pin. I’m pretty sure I put it back in the same spot but need to triple check.

I had to devise a way to mount the degree wheel with the timing cover and water pump on the engine. I think I have it
 
I believe 0.039" gaskets are the next size down. So the HG would be 0.008" thinner.

I'd need to know the angle of the valve to calculate how much PTV I would loose, but lets say 0.007. I'd be pretty close to 0.050"

Am I overthinking it and should just go with it, or should I grab a flycutter and kiss the piston for that extra 0.020" and run the 0.039" HG?
I know they make head gasket in quite a range of thicknesses I would think you could find something in between,
although that might not be the case for standard bore.
 
Got some garage time in tonight.

Degreeing the cam with timing cover no big deal. Some 4” standoffs and bolts, and a laser cut plate I made at work and viola!

Align zero with the 0 mark on the balancer, and adjustbthe pointer to tweak. Ran the numbers and found my cam timing spot on. I did not accidentally install the chain a tooth off

837FB9BE-D8BF-4926-BCB3-C0BA345EB342.jpeg



Measured my quench carefully this time. Found they ranged from 0.002” to mostly 0.000” and some spots +0.002. There’s some piston rock, so I’m happy with the 0.047” head gasket and my quench number with that.

Clayed the back piston. Same results 0.065” or so.

Decided I’m going to run it. With the right springs there should be some deflection in the pushrod so it might open up a tad more. I’ll take the $150 or so I was going to spend on a flycutter and upgrade to the tool steel retainers on my spring kit. Supposedly ~30% lighter. The reduction in mass should help control the valve better.

Started my last round of cleaning the deck and pistons. Hope to bolt the heads on soon

1BD57605-ADA1-48D2-84FA-548D77F6E7A5.jpeg
 
  • Like
  • Hell Yeah!
  • Winner
Reactions: 5 users
Flipped it over and installed my new Melling oil pump, with ARP hardware and oil pump shaft. I have the pan stud kit on order from LMR along with an oil level sensor gasket, so going to be another week before I throw the new NOS pan on.

69DC29B9-E09B-4418-9E04-2A033B9F0D9D.jpeg


After, I checked PTV on a few other cylinders, and after convincing myself was good to go...bolted the heads on. I also mocked up the lower intake just to see how the porter runners lined up. They fit quite well. Curious to see how this thing runs

2D891CEE-6F59-4C25-82A9-F8761D5CD091.jpeg

7B983BC8-5B30-4349-BF76-EA78CDBC8720.jpeg





Yeah...I know
E883E69F-CC43-4800-B0D3-81E9591089B3.jpeg
 
  • Like
  • Haha
Reactions: 3 users
Flipped it over and installed my new Melling oil pump, with ARP hardware and oil pump shaft. I have the pan stud kit on order from LMR along with an oil level sensor gasket, so going to be another week before I throw the new NOS pan on.

69DC29B9-E09B-4418-9E04-2A033B9F0D9D.jpeg


After, I checked PTV on a few other cylinders, and after convincing myself was good to go...bolted the heads on. I also mocked up the lower intake just to see how the porter runners lined up. They fit quite well. Curious to see how this thing runs

2D891CEE-6F59-4C25-82A9-F8761D5CD091.jpeg

7B983BC8-5B30-4349-BF76-EA78CDBC8720.jpeg





Yeah...I know
E883E69F-CC43-4800-B0D3-81E9591089B3.jpeg
That’s like one of those tags you see on pillows when you buy them- “only to be removed by consumer” - rip it off and carry on!!
 
  • Haha
Reactions: 1 user
@Mustang5L5, did you buy a high flow Melling oil pump? If so, it won’t fit a stock pan without taking a hammer to the pan. For that reason I have a standard flow on my 347 and it seems A ok.

No, I bought the standard flow. I read up on all the "watch-outs" with the HV and decided I didn't need it
 
  • Like
Reactions: 1 user
I think I may have made a discovey today.

93-97 Ford Taurus rear calipers are 43mm. They swap right onto the SN95 pad hangers. Now, with a stronger rear brake to even out brake bias, I may go with the ATS Brembo fronts now.

But this is interesting.

4F8BBBC2-D04A-479A-8053-4F6B6856F3A9.jpeg
79A9D8D6-1190-4996-9DCB-5C21E6725BA0.jpeg
 
  • Like
Reactions: 2 users
So just a different piston size? I forget, what is the size of the cobra rear piston?

38mm rear piston on the SN95's.

This one is 43mm. Would give you a little more rear clamping force, which normally you don't want except in the case of sticking Brembo brakes up front and finding your front bias is a little too much.
 
Status
Not open for further replies.