Building up a 7mgte from the ground up. I'm just stuck on what pistons to use. I've heard good and bad things from CP and JE pistons. So im just looking for more info on these two company's or if anyone as had really good feed back... Thanks
Piston decisions for a 7mgte
- Thread starter Mk3Dreamer
- Start date
There's a guy here selling some probe forged slugs for cheap in the for sale section. They've gotta be better than stock castings.
I have good feedback for my JE pistons. They have held up well to all my use and abuse, mildly questionable tuning, and racing. Had then coated last rebuild and made a bunch of power on 'em without an issue.
I have a bud local to me who melted Probe pistons where the valve reliefs were- seemed like it got a little too narrow on the crown (or his tune/lack thereof)
No experience with CP.
Another local guy had Ross pistons which clattered a bunch, but held all of his power (never dyno'd before he threw a core plug)
I have a bud local to me who melted Probe pistons where the valve reliefs were- seemed like it got a little too narrow on the crown (or his tune/lack thereof)
No experience with CP.
Another local guy had Ross pistons which clattered a bunch, but held all of his power (never dyno'd before he threw a core plug)
What are your power goals for this motor? And how are you going to use it?
JE pistons run a higher compression ratio at 8.9:1 vs the CP's 8.4:1. So the JE pistons will create more low end power but you are at a higher risk of detonation (with good tune it wouldn't really be a problem). The CP pistons are about 5 grams heavier then the JE pistons, this will also affect the responsiveness of the engine (I don't really know how big a difference it will make though).
http://www.briancrower.com/makes/toyota/7mgte_pistons.shtml
Now I used the JE pistons on my first engine build and can't say I would do it again. It was mostly the fault of the engine builder but the motor was built on the loose side of the tolerances, this caused the pistons to rattle until it was at full operating temp.
Next time I'll go with a piston with a longer skirt, make sure it is built a bit tighter and possibly get the pistons coated.
JE pistons run a higher compression ratio at 8.9:1 vs the CP's 8.4:1. So the JE pistons will create more low end power but you are at a higher risk of detonation (with good tune it wouldn't really be a problem). The CP pistons are about 5 grams heavier then the JE pistons, this will also affect the responsiveness of the engine (I don't really know how big a difference it will make though).
http://www.briancrower.com/makes/toyota/7mgte_pistons.shtml
Now I used the JE pistons on my first engine build and can't say I would do it again. It was mostly the fault of the engine builder but the motor was built on the loose side of the tolerances, this caused the pistons to rattle until it was at full operating temp.
Next time I'll go with a piston with a longer skirt, make sure it is built a bit tighter and possibly get the pistons coated.
AbsoluteSpeed;1975885 said:
I'm trying to make as much power as i can while being safe. I'll be driving the shit out of the car ha...
I bought Wiseco's, but I really can't say if they're good or bad, as I've never started the engine.
I CAN say that they haven't rattled ONE BIT so far... lol.
I CAN say that they haven't rattled ONE BIT so far... lol.
supraguy@aol;1976039 said:
Ha.. i've heard bad things from Wiseco. Like the rattling and braking rings do to it.
I dunno, never heard that. plus the skirts are coated, and it has offset pinbores to reduce slap found in other brands, so...
Now I've never heard of coating pistons. Can someone explain the hole idea behind it and the reason for doing so...
Is there like different coatings you can do for what your looking for?
Is there like different coatings you can do for what your looking for?
Basically there are three different coatings.
Coating the top of the piston with a thermal barrier reduces heat transfer and prevents hot spots causing detonation.
Coating the side of the piston with a dry film lube reduces friction. Less friction= More power.
Lastly, coating coating the bottom of the pistons will help shed oil. This keeps the weight down and is supposed to keep the piston cooler.
http://www.techlinecoatings.com/articles/Coating_Pistons_Article.htm
If I had to rate each piston.
Probe= Cheapest
Wiseco= Most street friendly
JE= Full race piston
CP= Happy medium between JE and Wiseco
Coating the top of the piston with a thermal barrier reduces heat transfer and prevents hot spots causing detonation.
Coating the side of the piston with a dry film lube reduces friction. Less friction= More power.
Lastly, coating coating the bottom of the pistons will help shed oil. This keeps the weight down and is supposed to keep the piston cooler.
http://www.techlinecoatings.com/articles/Coating_Pistons_Article.htm
If I had to rate each piston.
Probe= Cheapest
Wiseco= Most street friendly
JE= Full race piston
CP= Happy medium between JE and Wiseco