I wasn't really sure where to post this up, its a little sideline idea/project ive been looking at recently. A few people have popped up on facebook doing the Gordini head swap onto the c1j bottom end, giving a crossflow head setup. This has quite a big benefit for the old C1j, 1, the valves are bigger from the off and 2, its of crossflow design, meaning the air and fuel in and out of the engine don't have to reverse direction. This makes it a better more efficient design netting a decent increase in power. For comparison my old inefficient gordini turbo was making over 120bhp with 6 psi of boost an no intercooler, vs the gtt running 10psi intercooled to get 120bhp. The idea of this is to build a low budget parts bin crossflow engine. The only thing i didnt like too much with the gordini head conversion was the inlet being at the front and the exhaust at the back, This has it flipped the other way, inlet at the back like the original C1J and the exhaust at the front so little in the way of manifold design restrictions.
Anyway im pikey, i dont like spending money (must be the northern decent) and i like to do things a little different. Im by no means finished but the idea is there. I have done a fair bit of measuring and this should work. So you want a more efficient engine that is from the house of Renault and it gives you a cross flow head without the easy £2K+ you need for the gordini conversion. look no further than the 1.4 energy engine (E7J), a 1390cc (like the c series) over head cam 8v that is crossflow and has big valves compared to the C1J, in fact the the exhaust valves are bigger than the gordini head too
For comparison
E6J/E7J
Exhaust valve
33.6mm
Inlet valve
37.5mm
C1J
Exhaust Valve
28.9mm
Inlet Valve
34.3mm
Gordini C6J
Exhaust Valve
30.3mm
Inlet Valve
38.7mm
Internally the engine doesn't differ in crank spacing to the C series engines, so spacing between the liners (its also wet lined like a C) is the same. The liners are shorter though, Pistons are shorter in the skirt, Piston tops measure up the same as a flat topped c1j piston but the rods are smaller/thinner. The oil pump is also chain driven. The original idea was to fit the C1J pistons liners and rods into the E block but the difference in height has stopped that idea. Next in the pipe line is to fit the stronger C1J rods to the E pistons and try them out.
The head will need machining to decrease the compression ratio, there is plenty of meat there to remove and the aim is to get the combustion chamber to hold as close to 40cc's as possible. Ideally if i can get to 44cc it should match the volume of the C1J head, giving me nearly the same compression ratio. I currently measure the head at about 32cc, This still needs to be measured properly and a final figure worked out. I have the energy as 9.5:1, which actually isnt too low if you went full efi.
Might seem like a silly idea to run with, especially with the amount of custom bits needed, exhaust manifold will need to be custom made and the inlet adapted to take a carb/efi but i thought id see if i can get some crosflow gains for little money
Another side note, this engine complete is lighter than a c1j, the cast iron block is smaller in depth and height. I can lift one of these complete with not too much bother, the c1j on the other hand gets me a little worked up.
Anyway im pikey, i dont like spending money (must be the northern decent) and i like to do things a little different. Im by no means finished but the idea is there. I have done a fair bit of measuring and this should work. So you want a more efficient engine that is from the house of Renault and it gives you a cross flow head without the easy £2K+ you need for the gordini conversion. look no further than the 1.4 energy engine (E7J), a 1390cc (like the c series) over head cam 8v that is crossflow and has big valves compared to the C1J, in fact the the exhaust valves are bigger than the gordini head too
For comparison
E6J/E7J
Exhaust valve
33.6mm
Inlet valve
37.5mm
C1J
Exhaust Valve
28.9mm
Inlet Valve
34.3mm
Gordini C6J
Exhaust Valve
30.3mm
Inlet Valve
38.7mm
Internally the engine doesn't differ in crank spacing to the C series engines, so spacing between the liners (its also wet lined like a C) is the same. The liners are shorter though, Pistons are shorter in the skirt, Piston tops measure up the same as a flat topped c1j piston but the rods are smaller/thinner. The oil pump is also chain driven. The original idea was to fit the C1J pistons liners and rods into the E block but the difference in height has stopped that idea. Next in the pipe line is to fit the stronger C1J rods to the E pistons and try them out.
The head will need machining to decrease the compression ratio, there is plenty of meat there to remove and the aim is to get the combustion chamber to hold as close to 40cc's as possible. Ideally if i can get to 44cc it should match the volume of the C1J head, giving me nearly the same compression ratio. I currently measure the head at about 32cc, This still needs to be measured properly and a final figure worked out. I have the energy as 9.5:1, which actually isnt too low if you went full efi.
Might seem like a silly idea to run with, especially with the amount of custom bits needed, exhaust manifold will need to be custom made and the inlet adapted to take a carb/efi but i thought id see if i can get some crosflow gains for little money
Another side note, this engine complete is lighter than a c1j, the cast iron block is smaller in depth and height. I can lift one of these complete with not too much bother, the c1j on the other hand gets me a little worked up.
Last edited:
