As you can see from this picture compression height is the distance from the wristpin to the top of the piston. So when drifting through transitions and reducing-radius bends off power, it will be easier to continue the drift when you come back on power. With the introduction of the 7A-FE, the 4A-GE tuners gained an easy option to use the longer stroke 7A-FE block to gain higher stroke figur... With the introduction of the 7A-FE, the 4A-GE tuners gained an easy option to use the longer stroke 7A-FE block to gain higher stroke figures previously reserved for the daring and the well financed. Those looking into more elaborate systems like turbo or high-rpm usage should, however stay with the 4A-GE design for it’s intended sporting nature and previous data and upgrade parts availability. check out the. When removing the head remember to loosen the bolts in the correct pattern and leave them in the head in their original positions so you can make sure the same ones go back in the same holes later on bore and stroke = 81 and 85.5mm I have been working with Arias to improve their designs and now we have new shelf pistons that are all much more correct and ideal. All of the new Arias designs use the stock compression height of 30.5mm. If the block gets decked it will be important to measure this as well. While I am not sure if you can find these pistons elsewhere you will find them in our 16v pistons section and they will all be titled new design. Change injectors take care not to damage the fragile seals, in fact you should replace upper and lower seals as they are probably very worn out! Like Trev said… Know what you want to build before you start to build. If you don’t what will happen to me will happen to you! Even a steel rod may expand more than the rod if it's average temp is higher than the block. Starting with a cleaned, adjusted and polished 4A-GE head, it can bolt right onto the 7A-FE block. I worked on my driveway, as I don’t have a garage and completed the swap in two days this was working very hard though I recommend taking your own time and making sure everything is correct. 7A-FE ECU is avoided because of it’s low rev-limiter and complexities in placing it in a car originally equipped with a 4A-GE. In faith there is enough light for those who want to believe and enough shadows to blind those who don't. If anyone has any questions or queries post them and I will try and edit this post to incorporate the answers! Like the 5A-GE and more so, the 7A-GE is a very universal in drivability and is highly recommended for street machines looking for that little extra push, who see occasional autocross or ET traps. Transfer all the studs and fit the engine mount and alternator bracket, the lower gearbox mounts can no longer be used as they don’t line up chuck them away. Thread starter Mogan; Start date 16 Jan 2011; Mogan RMS Regular. i built up a 7age with adjustable pullys and i am struggling to start the car. 4AGE to 7AGE conversion how-to by H7ERO. The birth of the 7A-GE hybrid. Including a Blacktop specific piston which to the best of my knowledge is the first production BT specfic design anyone has offered. For this examle we will use the 16 valve head. I have read of instances where race teams found this to be where they got the most power without detonation. Why not use a 7A-FE belt? 4AGE is very peaky, when you drop out of the power it is almost impossible to recontinue drift unless you have time to rev and then clutch dump, but sometimes it is too late by then and is not very smooth. This gives you a gap of .954 which is pretty good. They are also designed for 4AGE 20mm floating pistons. The new pistons are available in 8.5:1, 9.5:1, 10.5:1 11.5:1 and 12.5:1. The maximum power band usually falls at as little as 6800rpm, a sign of internal stress, meaning it’s way-past the physical redline. You may have to register before you can post: click the register link above to proceed. The characteristic of the 7A-GE is generally more subdued than in the peaky tuned 4A-GE, but for all of the maximum revs lost to the 4A, the 7A makes up in torque. The engineer we were working with at Arias left and started a company called Traum Pistons. I had posted some basic information on how to modify the 4G13 and 4G15 for those who not willing to change their factory fitted engine. For example Arias's designs used to be way off on some of their pistons. The 7A-FE made its debut on the more mundane Corolla sedans in 1992. Some smaller differences are not covered and there are also some differences between the first and second… Because of the taller block of the 7A, the 4A-GE timing belt proved to be too short for the increased deck height. I learnt the hard way so you don’t have to! You can run a 7age on stock electronics - find some slightly larger injectors and get some adjustable timing gears to fix the majority of the cam timing issues surrounding a 7age. We now have a 3D scanner and can design pistons for any application with the highest level of precision. Return removed bolts to their holes (this is because some bolts are made to be tightened up harder than others which just snap! The Toyota Corolla AE86 winning the 1987 BTCC driven by 2017 BTCC winner Tom Ingram!