O.K.,here are two pics I took.The first,the FLAT top piston that slapped the valve.............
(http://i216.photobucket.com/albums/cc205/Vinnietbird/000_0951.jpg)
The second pic,my new center caps for the Sport's chrome Cobra R wheels.They represent the 5.0 H.O/Thunderbird hybrid (so to speak) I rock!!!!!!.........
(http://i216.photobucket.com/albums/cc205/Vinnietbird/000_0956.jpg)
Its weird...I too have flat-tops BUT about 3/4" in from the edge of each piston, it was indented like not even a 1/16th of an inch all the way to the center. Like imagine a smaller piston punching into the center just slightly. I dunno.
Vinnie has forged flat tops from a HO. The T-bird/Cougar flat tops have a dish like you have.
I like the center caps. How did you make 'em?
Hey Vinnie,you keep at it all of the pistons will have valve reliefs!! Lol
Alright then its the terminology that keeps messing me up. Maybe its just me, but when I hear FLAT TOPS, I think.....FLAT....TOPS....as in flat. Solid NO indentations or surface irregularities of ANY kind. I would think those would just be referred to as having reliefs. At least I know now. This has been confusing me for at least 2 years. Frigin part designers. Oh well.
Vinnie has flat-tops from an HO
with E6 heads(86 Stang/86-87 LSC) I should add Vinnie now has 1 valve relief piston :hick:
The indents or "dishes" are about -2 cc's
HO pistons -- Dishes with valve reliefs are listed as -4.6 cc's
I believe that -4.6 is for the valve reliefs only though.....Not 100%, but it makes sense if you compare compression ratios with the SO and HO motors and take into account the difference in combustoin chamber size (4 cc's).
Those wheel center caps are cool! :D
The caps are something I've been messing with for a while.Finally got 'em finished.I have a larger emblem like that on my fan shroud.....for now,until the electric fan goes on.My engine came from an '87 Lincoln Mark VII.It was an E-6 flat top piston engine.Now it just has the flat tops left.Everything else has been changed.The car is running great again.I now have to swap my steering rack.I have to fill the steering pump every day.Time,I need more time !!!!!!!!
Kitz,no more valve reliefs.If anybody asks me if my pistons have them,I'll say "I have one valve relief.It's all I need".
Great job on the caps Vinnie.
OHHHHHKAY. Haha sweet. Now it all makes sense. Thats all I can do, still dont know jack, just tryin to learn whatever I can so I can at least act like I know what Im talking about :hick:
AND vin great job on those caps theyre awesome! And great to hear that the beast is roarin again!!! :headbang:
There are flat tops like Vinny's(and mine, '86 HO)... Also flattops with reliefs, dished, dished with reliefs, and domed(never seen any of those without reliefs)...
Got it???
Not really but yes.Ford luvs us all!!
I'm glad the Sport is back in business as well.Hopefully next weekend the new doors and fenders will go on,then,paint around the corner.Finally.The Sport has come a LONG way since it was towed home from the salvage yard.In appearance,it's worse than when I got it,but overall,miles ahead.Tomorrow,I'm off work and I want to go drive for a while.I don't care where,I just want to drive.
lol im just trying to figure out what half of you guys are talking about most of the time,,,,,, no idea what an e6 or whatever all the numbers mean!!!! i just know if i can take it apart and and tork it down correctly .. i should be fine....my bb swap is definately my first big project..... hoping to learn a bit....
by the way,,,, vin your are quik at fixin the bird,,,you got that thing back up and running pretty fast!!!
:laughing:
E6 and E7 are just part of the casting numbers in the heads.
They are different heads.
As far as being quick,It wasn't that bad of a problem to work on.I've had the thing apart so often it seems like just another day almost.It appears that if tomorrow is a decent day,part of it may be applied to swapping the steering rack.It's been leaking from where the inner tie rods connect.I have a new one in the box,but just haven't had a lot of time for swapping it out.I have to fill the pump every morning.That has to stop quick.
I would personally rather have your pistons than the vinnies.
Yours are dished,,
In a line up,, I would take flat tops with valve reliefs over flat tops or dished.
Your pistons are pretty much the same design as the 3.8 pistons. You dont need all that open area in the center of the piston,, thats why there are flat tops with only valve reliefs. The more piston metal you fit in there, the less cubic centimeters of air there remains inside with the piston at top dead center.
With vinnies pistons, you can float a valve in a situation where you rev R's so high that the valve can not get out of the way of the piston in time. The valves are limited in speed proportional to the tension on not only the springs but the quality of the spring inside the lifter as well.
The more you play with the fine tolerances of a motor, the more important things like slack in the timing chain, ect become important. YOu ahve a cam that lags a lil too long and you end up with a crash. Ill bet it took a lot of r's for vinnie to do that. not sure whay he didnt think about marking and grinding valve reliefs in while the head was off. the least little bit would help. I would always be afraid to hot dog it with those pistons personally. A thinker gasket would be my only sound solution to give the valves more room to float.
with less room and the fuel mixed with spark makes for a bigger presure difference when pushin the piston back down.
think of it like letting a firecracker go off on your open hand vs a closed hand.
Same fuel source,, but one can take your fingers off while the other will burn your skin.
Domed would be sort of convex and are the ideal piston because the leave the least amount of cubic centimeters in the combustion area with teh piston at tdc. messing with domed calls for more smarts than i have because you gotta know your cams , the grind, the time inwhich the lobe will lead the lifter / pushrod/spring and valve into action and avoid a crash for max compression and best bang for the same buck.
In my next engine,I'll have aftermarket pistons with valve reliefs,and different heads,probably GT40's or a set of aluminum heads if I can find a set at that time that I can afford.These work fine because they are what I have.The engine has been fine until I over revved.It's actually been trouble free for months.I'm on the lookout for a new block,then I'll get busy acquiring parts for it.
http://sbftech.com/index.php/topic,3472.0.html
**EDIT** You have to log in to read the thread -- Here's what's important concerning the above quote. Keep in mind it is for all things being equal
including compression ratio.
BTW; Its1FastCat is a member here as well. He doesn't post too often, but when he does one should pay attention because he knows his stuff.
FWIW, if I wanted a smaller combustion chamber, Id take from the head instead of adding to the piston...
Right on.
jcassity - thanks for all that but I *am* pretty familiar to that extent. It was really just the names that everyone uses to refer to each particular component that threw me for a curve, and the different combos that occurred...as TurboCoupe50 pointed out. Now lets hope I dont forget or I can at least find the thread again :hick:
Nice work Vinnie, let us know how the long drive goes. You could drive to Choctaw where I used to live for about 10 years :D
I'll have to wit for tomorrow to go driving after I swap steering pumps at Autozone after work.I can't wait.I spent the mid morning hours swapping the power steering rack for a new one,new tie rods,very nice.I then picked my boy up from school and we stopped and had the front end checked to make sure the tie rods were right.I was close,but not where it needed to be.No charge for that since the boss was gone from the tire place and I know the people who work there.Sweeeeeet !!!!