| From | Message |
88 SC DAK
Dodge Dakota
JOIN HERE
1/22/2004
20:21:56
|
 Subject: 318 Magnum Forged Pistons
IP: Logged
Message:
Hello All
I'm looking for a set of 318 Magnum forged street blower pistons. Any suggestions on who might have them. I know I can get them made but am hopeing to find someone that has them in stock. On the same lines if I get them made any company better than another. I will not use TRW, I had a motor lock up on me when the crown of the piston expanded and locked in the cylinder. Any help would be appreciated. Thanks, Jim
|
R/TBlues
Dodge Dakota
JOIN HERE
1/23/2004
20:19:25
| RE: 318 Magnum Forged Pistons
IP: Logged
Message:
Hey 88'
I'm sure you know this already. Just in case you don't, the forged piston requires the bore to be at least .007" larger than the piston. That is very sloppy by todays standards. There are some manufactures claiming high-slicone forgings that can run tolerances almost as tight as a cast piston, but the ones I've used in 350 chevy racing engines don't hold up. They break! If you intend to use this truck as a daily driver you will have more oil comsumption and lower fuel economy and less HP. The seal you get with the quality cast pistons available is much better than the forged pistons. Of course, if you plan to race this thing only, then forged is the only way to go.
There is a scientific reason for the forged piston expansion problem. When something is forged it is literally compressed. The molecules (atoms) that make up the metal are forced closer together by using large amounts of external force. This makes the metal denser (heavier) and stronger. There is a down side. These molecules have to have room to expand when they heat up. Becuase they are all crammed next to each other by the forging process they have no room to expand. That means the piston has to grow larger as it heats up to give the molecules room to expand. That is why the high silicone pistons fail. The silicone/aluminum alloys can't expand because the silicone won't let the aluminum molecules to "move around". This causes the piston to retain more heat and once it gets hot enough it breaks. It's like puting too much air in a tire. TRW made some of the best racing pistons I ever used. The worst pistons I ever used were Keith Black. Keith Black was even one of our sponsors. We couldn't turn down their products when they were helping us. It cost us a lot of races though. The TRW's were half the price and we never had one fail.
|
88 SC DAK
Dodge Dakota
JOIN HERE
1/27/2004
11:37:47
| RE: 318 Magnum Forged Pistons
IP: Logged
Message:
Thanks for the info. I'll think about using a quality cast piston. I'm trying to make the bottom end as strong as possible. I'm not going to running that much boost for daily driving, but am thinking about juice or maybe more boost for racing (just for chuckles and grins)
The motor that locked up was built correctly, we checked it before and after. On my motor we had to break the piston out of the bore.
Anyway, thanks again and I'll be on here somemore for questions and opinions.
|
christopher
Dodge Dakota
JOIN HERE
1/31/2004
03:21:59
| RE: 318 Magnum Forged Pistons
IP: Logged
Message:
call dave at hypurr engines of new mexico (505)275 7877 he can get you your pistons . and rtblues point about forged expansion is only w/nos usually
|
| | P 1 |
|
Post a reply to this message:
Username Registration: Optional
All visitors are allowed to post messages
|
