mikey4410 Posted June 25, 2014 Share Posted June 25, 2014 Heya guys,does anybody know why starlet piston tops have a different number on them ?An n/a engine I had opened up last year had number 2,2,1,4and I am sure its the same on the turbo engines alsowhy is this and what does it represent ?Surely they make all the bores the same from factory, they cant be different diameters ??!!Any help would be cool Quote Link to post Share on other sites
mikey4410 Posted June 25, 2014 Author Share Posted June 25, 2014 http://www.toyotagtturbo.com/forums/archive/index.php/t-100369.html ust found this after alot of searching Quote Link to post Share on other sites
morgey Posted June 25, 2014 Share Posted June 25, 2014 My 4age has them too, think the bottom of my block is stamped up with the coresponding number to cylinder iirc Quote Link to post Share on other sites
gorganl2000 Posted June 26, 2014 Share Posted June 26, 2014 those numbers at the top of the block correspond to the different size pistons for the respective cylinder the ones at the bottom of the block help with the identifying the correct bearings for the crank on the 4efte ( the crank will have numbers stamped on it as well to assist with this) however, its best to have everything properly measured so you get the correct parts Quote Link to post Share on other sites
ramses Posted June 26, 2014 Share Posted June 26, 2014 those numbers at the top of the block correspond to the different size pistons for the respective cylinder the ones at the bottom of the block help with the identifying the correct bearings for the crank on the 4efte ( the crank will have numbers stamped on it as well to assist with this) however, its best to have everything properly measured so you get the correct parts Exactly... Quote Link to post Share on other sites
5e colin Posted June 26, 2014 Share Posted June 26, 2014 (edited) those numbers at the top of the block correspond to the different size pistons for the respective cylinder the ones at the bottom of the block help with the identifying the correct bearings for the crank on the 4efte ( the crank will have numbers stamped on it as well to assist with this) however, its best to have everything properly measured so you get the correct parts most is true but no nrs stamped on the 4efte crank there but they are stamped on 5e crank counter loubes tho!!!!! Edited June 26, 2014 by 5e colin Quote Link to post Share on other sites
mikey4410 Posted June 26, 2014 Author Share Posted June 26, 2014 I just find it weird that all the cylinders arent just a set diameter.so when forging the engine and having the bores bored out the enginner will be told a set bore and have to work according to the block hes working on , ie less boring out of certain cylinders and more on some to match them all for a identical diameter forged piston etc Quote Link to post Share on other sites
turbo Grant Posted June 26, 2014 Share Posted June 26, 2014 Loads of gm cars have engines that are pretty much thrown together. Can cause all sorts of problems. At least the stock 4efte are part matched when being build. That's why they last so long with all the abuse they get Quote Link to post Share on other sites
GP82 Posted June 26, 2014 Share Posted June 26, 2014 I just find it weird that all the cylinders arent just a set diameter. If you look at the difference in size in each piston, you will see that it's not a big difference, but when your talking precision, it's continents apart. Think of mass production and the use of and life of the tooling. For cost effectiveness each one is used to it's limits to a set line that it won't go beyond, as the tool degrades so does the precision of the machining before the tool is replaced or refurbished. Quote Link to post Share on other sites
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