After owning an AE86 for a long time and enjoying the car to the fullest, I had the chance to ride with Bobs orange monster. His Ae86 had overgone several transformations including a mildly tuned 4age 16V to a semi built 20V with 190bhp. But nothing lasted in the car for too long. Finally, a 7age 1.8l found its place in Bob’s car! The 7age is a hybrid engine build with a 7afe Celica/Carina bottom end and a 4age 16V head. The big advantage is more torque throughout the rpm band.
Starting with a bone stock 7a-fe engine
I never thought I would have the chance to feel the torque of the 7age when I sold my AE. I always wanted to try something like this. Just to own the bit of extra torque and power generated through 200cc more displacement. The ride was very impressive. The engine is properly built and has a superb powerband and was really screaming to 8k rpm. Compared to my old engine it was like sitting in a V8 with lots of torque. Even with 2 passengers in the car and the long 4.3 final gear, Bob shifted to 5th gear on the long straightline in AdR, where I barely touched the limiter in 4th with the short 4.8 final gear! The engine was a blast. But honestly, compared to my low budget build and tune, the 7age lacks response. It’s way better than any stockish 4age I’ve ever driven, but with a light flywheel, modified pulleys and a few tweaks to the head, my old engine was more eager to hit the limiter – still slow but revy. Bob’s engine on the other hand is a true rocket!
As usual the engine is stripped to the bare block.
The key points of building the 7age engine are really in the detail. The 4age engine is built with performance and passion in mind while the 7afe is built with torque and granny’s shopping tour in mind. To summarize a good quality build – it’s really in the detail. Bringing the right parts together and blueprinting it is the biggest part of the build. In Bob’s case all started with a 7a engine out of a Carina E.
The piston and conrod assembly
The bottom end was balanced and the flywheel and crankshaft lightened. The rods are Spool conrods, which are still very cheap ones – but nonetheless a lot better than the 7age components. For pistons he went with a set of Wiseco 4age 20mm pistons and chopped the crown by 1mm. As a matter of fact, most budget 7age builds use OEM conrods and a set of 4age redtop 20mm pistons. The assembly looks like a super high compression one, and yes it is! Bobs engine has around 12.3:1 static compression ratio, which is considered to be perfect for his dream cams – all suggested by a professional builder!
The right cams are one of the most important parts to determine peak power and band.
Still a few details on the block. The oil pan is a genuine 7a pan, which is already bigger than our 4age pans. Another nice detail is, that he finally fixed his/my oil drain problems and fitted an oil return line in the head. The mod the Ae86 racers have been waiting for! No more smoke, no more panic mode!
This is how the 4age should have been designed – proper drainage!
The head is nothing special. It’s just a regular, cleaned up 16V bigport head with a set of Kellford 193-B cams, just about the one rally-midrange cam you can choose without changing to undershim buckets and still enjoying 9.2mm lift! Here as a side comment, due to the increased stroke of the 7a setup, the engine needs more ‚cam-duration‘ to push the torque or power peak to the same revolution range. While a 4age on stock cam peaks around 6600rpm, with the 7age block the nature will be moved further down the revrange and the engine’s volumetric efficiency peaks earlier, at more like 5800rpm.
I love ITB’s and their incredible sound.
The last bits on the engine are the ITB system, valvecover and an exedy clutch assembly. The final step is the break in and the ecu tuning for the new engine. Overall a nice build.
Sometimes the dynosheet is just a value – not emotional enought!
Tomorrow we will interview Bob and find out a few more details about all the engine questions!After owning an AE86 for a long time and enjoying the car to the fullest, I had the chance to ride with Bobs orange monster. His Ae86 had overgone several transformations including a mildly tuned 4age 16V to a semi built 20V with 190bhp. But nothing lasted in the car for too long. Finally, a 7age 1.8l found its place in Bob’s car! The 7age is a hybrid engine build with a 7afe Celica/Carina bottom end and a 4age 16V head. The big advantage is more torque throughout the rpm band.
Starting with a bone stock 7a-fe engine
I never thought I would have the chance to feel the torque of the 7age when I sold my AE. I always wanted to try something like this. Just to own the bit of extra torque and power generated through 200cc more displacement. The ride was very impressive. The engine is properly built and has a superb powerband and was really screaming to 8k rpm. Compared to my old engine it was like sitting in a V8 with lots of torque. Even with 2 passengers in the car and the long 4.3 final gear, Bob shifted to 5th gear on the long straightline in AdR, where I barely touched the limiter in 4th with the short 4.8 final gear! The engine was a blast. But honestly, compared to my low budget build and tune, the 7age lacks response. It’s way better than any stockish 4age I’ve ever driven, but with a light flywheel, modified pulleys and a few tweaks to the head, my old engine was more eager to hit the limiter – still slow but revy. Bob’s engine on the other hand is a true rocket!
As usual the engine is stripped to the bare block.
The key points of building the 7age engine are really in the detail. The 4age engine is built with performance and passion in mind while the 7afe is built with torque and granny’s shopping tour in mind. To summarize a good quality build – it’s really in the detail. Bringing the right parts together and blueprinting it is the biggest part of the build. In Bob’s case all started with a 7a engine out of a Carina E.
The piston and conrod assembly
The bottom end was balanced and the flywheel and crankshaft lightened. The rods are Spool conrods, which are still very cheap ones – but nonetheless a lot better than the 7age components. For pistons he went with a set of Wiseco 4age 20mm pistons and chopped the crown by 1mm. As a matter of fact, most budget 7age builds use OEM conrods and a set of 4age redtop 20mm pistons. The assembly looks like a super high compression one, and yes it is! Bobs engine has around 12.3:1 static compression ratio, which is considered to be perfect for his dream cams – all suggested by a professional builder!
The right cams are one of the most important parts to determine peak power and band.
Still a few details on the block. The oil pan is a genuine 7a pan, which is already bigger than our 4age pans. Another nice detail is, that he finally fixed his/my oil drain problems and fitted an oil return line in the head. The mod the Ae86 racers have been waiting for! No more smoke, no more panic mode!
This is how the 4age should have been designed – proper drainage!
The head is nothing special. It’s just a regular, cleaned up 16V bigport head with a set of Kellford 193-B cams, just about the one rally-midrange cam you can choose without changing to undershim buckets and still enjoying 9.2mm lift! Here as a side comment, due to the increased stroke of the 7a setup, the engine needs more ‚cam-duration‘ to push the torque or power peak to the same revolution range. While a 4age on stock cam peaks around 6600rpm, with the 7age block the nature will be moved further down the revrange and the engine’s volumetric efficiency peaks earlier, at more like 5800rpm.
I love ITB’s and their incredible sound.
The last bits on the engine are the ITB system, valvecover and an exedy clutch assembly. The final step is the break in and the ecu tuning for the new engine. Overall a nice build.
Sometimes the dynosheet is just a value – not emotional enought!
Tomorrow we will interview Bob and find out a few more details about all the engine questions!