Teardown on the 352 and future plans....

[blykins]

Brent, do you think the RPM had anything to do with the piston kissing the cylinder heads ? Would’ve it hit on a 6000 RPM limit ?

I'm sure it did.  It's a heavy piston (550-ish grams) and we were pulling to 7500 after the heads were ported.   I also noticed it when I pulled the heads the first time to send them to Joe and we were only going to 6800 then. 

Would they have touched at 6000?  Hard to say. 

[blykins]

I disassembled the heads this afternoon and checked the valve spring pressures against what they were new. 

They are PAC 1238X small diameter springs.  They are only 1.275" in diameter and I set them up at 1.760". 

When they were new they set up at 280 lbs seat at 1.760" and 675 lbs open.  Now they are at 260 lbs seat and 665 lbs open.  Hmm.  That's only a 7% loss in seat pressure, but normally when I use PAC springs they don't lose as much spring pressure.  Now granted, I normally run their 1200 or 1300 series springs and these are the "RPM series". 

[Stangman]

Well Brent does that mean your gonna change them or that’s an acceptable for all the Dino runs you got on it. What is the unacceptable number for you.

[blykins]

Well Brent does that mean your gonna change them or that’s an acceptable for all the Dino runs you got on it. What is the unacceptable number for you.

I'll probably find another spring.  The cam wasn't that wild, so it shouldn't be eating springs.  If this were a bracket engine and I had to change springs every 50 passes, I would opt for another spring.

[Falcon67]

Teardown started on the 352 last Saturday morning.  I didn't have an engine stand freed up, so I completely tore it down while it was sitting on an engine cradle.  I'm expecting a medal based on my bravery and my ability to lay on the floor, brace my foot up against the bellhousing flange and use a breaker bar to loosen the rod/main bolts.  Well, it was either bravery or stupidity.  Maybe a little of both.  On second thought, it was pretty much all stupidity.

Total throwback memories.  Around 10 yrs old, I would mow lawns and the local ABC Wrecking would sell me a core motor for $10 which I would take home in the truck of mom's 57 Ford.  I would then, with friends sometimes, take it apart, mess with the pieces, then take the pile back to ABC and do another LOL.  Yes, this was my hobby.  With some help, we'd roll the motor out of the trunk into a wheelbarrow, truck that into my garage, chain fall the thing onto a big green bench.  Crank was last to come out - a breaker bar and a couple of kids jumping on the bar is how we broke those loose.

[TomP]

What's the reason for the tiny Chevy style valve springs? I think the smallest i've ever used on an FE are 1.46" and a 1.88" height.

[blykins]

What's the reason for the tiny Chevy style valve springs? I think the smallest i've ever used on an FE are 1.46" and a 1.88" height.

I think things are moving more toward smaller springs, smaller diameter retainers, etc.  They're much lighter. 

Even on my higher end engines with 1200-1300 lbs of open pressure, the springs are only 1.500" in diameter.