|
Author
|
Topic: Forged or Cast pistons ?
|
DocVoodoo
Gearhead Posts: 147
From: Plainfield CT USA
Registered: Feb 2003
|
posted 12-06-2003 10:19 AM
   
I am building a performance engine but I am not going to supercharge it . Should I go with Cast or forged Pistons.
IP: Logged |
SteveLaRiviere
Administrator Posts: 43789
From: Saco, Maine
Registered: May 99
|
posted 12-06-2003 11:29 AM
A high performance engine should run forged pistons because they are more resistant to detonation, and more resistant to damage when detonation does happen. I've dropped valves in engines with forged pistons and was able to just change heads and get them back and running. Hypereutectic pistons are better than cast because they have much lower expansion characteristics and they are great because they can run tighter clearances, but the problem with them is that they come apart with even moderate detonation and break like glass, while forged pistons are plastic enough to deform instead of shatter. A deformed piston can be changed and you are usually on your merry way, while a shattered piston usually takes out everything else in the engine. I'd only consider cast pistons for a stock or really mild engine with a 300hp/5500 rpm limit. ------------------
'70 Mustang Mach 1 351C 4V/FMX/3.25 Open
'70 Mustang Convertible 250 I6/3 speed/2.79 Open
'72 Mustang Sprint Coupe 351C 4V/FMX/4.30 Trac Loc
'94 F-150 XL 5.8L/E4OD/3.55 Limited Slip
IP: Logged |
Mooney
Gearhead Posts: 1691
From: Marietta, Ga
Registered: Oct 2003
|
posted 12-06-2003 11:49 AM
http://www.enginepartsone.com/Faq/pistons.html
Lil tidbits of info on the hypereutectic pistons.
Also, not sure what your plans are but i think 85 (4V only) and 86 through late 92 302's had forged pistons.
IP: Logged |
N266fords
Gearhead Posts: 1586
From: Spokane ,WA USA
Registered: Apr 2003
|
posted 12-06-2003 01:13 PM
for a couple hundred more go with forged and lighten the valve train with ss valves and titanium retainers roller rockers. it will live long and you will prosper(spelling). Steve was right on in his post. Bruce
IP: Logged |
DocVoodoo
Gearhead Posts: 147
From: Plainfield CT USA
Registered: Feb 2003
|
posted 12-06-2003 01:15 PM
Its a 1966 289 Block is bored 30 over, 600 cfm Holley on a edelbrock 60's F4U version intake , JBA headers , Heads have been worked Milodon Valves 1.85 intake 1.55 exaust Ported and polished. Roller rockers and Hydrolic roller comp cam 270HR with roller lifters. I am waiting on the machine shop to come back with what the crank had to be cut to so I can order the rebuild kit through Summit.
At this point I am trying to decided I i should go cheap with cast pistons and what the compression should be . From what I see 9.6-1 is were it should be in order to have no problems with Fuel octane . ------------------
1966 GT light blue VERT
IP: Logged |
DocVoodoo
Gearhead Posts: 147
From: Plainfield CT USA
Registered: Feb 2003
|
posted 12-06-2003 01:22 PM
Also I want to ask the machine shop about balanceing the Crank and Fly wheel. Whats that going to set me back for ? When you balance and engine what else do you balance I would guess the rods and pistons.------------------
1966 GT light blue VERT [This message has been edited by DocVoodoo (edited 12-06-2003).]
IP: Logged |
N266fords
Gearhead Posts: 1586
From: Spokane ,WA USA
Registered: Apr 2003
|
posted 12-06-2003 01:55 PM
Balancing the rods pistons crank harmonic bal. and fly wheel. is around 120-200 depending on the condition of the equipment and what type of balance zero bal or 28oz or 50oz.ect. Also flat top pistons will be ok for your valves and heads. I ran a 289 with tri-y headers and forged pistons trw at the time (Heavy pistons). and I had no problems with it. I have turned it to 7000 rpms a couple of time and also valve foated a couple of times I was running comp cams 280 and the springs got weak after ten years. yes ten years it was mostly daily driver and tracked as often as I could make sir. Seattle international. Bruce
IP: Logged |
Mustangsandmore Forums
