1.5T L15C9(1.5t non-Si) engine rebuild

[PangziXin]

Hey everybody，has anyone done a reinforced rebuild on the 11th generation engine? I noticed that the crankshaft is different compared to the previous generation, which means there might be differences in the connecting rods and bearings. This is just something I found out, and I’m not sure if there are any other differences. I’d like to figure these things out before opening up my engine. Thanks, everyone!

Sponsored

 

[Shankmeyster]

So far as I know there are no aftermarket options for the current engine.

 

[PangziXin]

So far as I know there are no aftermarket options for the current engine.

Yes, I noticed that too. The pistons seem fine, but the crankshaft, camshaft, intake manifold, and cylinder head gasket are not interchangeable.

 

[Two Step Performance]

The main hold up for now would be the connecting rods. Limited clearance inside engine block has made it difficult to design stronger rods that still fit. Hopefully we are not too far off from seeing some options come to the market.

 

[PangziXin]

The main hold up for now would be the connecting rods. Limited clearance inside engine block has made it difficult to design stronger rods that still fit. Hopefully we are not too far off from seeing some options come to the market.

Thank you for your reply. I hope TSP will soon sell suitable connecting rods. By the way, based on your experience, how does the strength of the current engine compare to the L15B7? Thank you.

 

[Two Step Performance]

Thank you for your reply. I hope TSP will soon sell suitable connecting rods. By the way, based on your experience, how does the strength of the current engine compare to the L15B7? Thank you.

They are pretty comparable for the most part. We have several manufacturing partners working on the rods. Once those are approved, we will move forward with offering a built shortblock for this platform, similar to our L15B7 engine program that has been very successful.

 

[PangziXin]

I’m planning to try using the crankshaft from the 10th-generation Civic to complete the engine rebuild for the 11th-generation Civic. I’ve noticed that the parts I need to replace are mainly focused around the mid-block, such as the oil spray nozzles and bolts, etc. I intend to perform the replacement after assembling the mid-block. I’ve also found that the timing gear （part12）and pulley（part14） are different. I’m unable to compare the differences between these two parts across the two generations of Civic. I just want to ensure that when using the parts from the 10th generation, I’ll be able to assemble the mid-block back into the 11th generation engine bay.

 

[Shankmeyster]

There are aftermarket options now for rods and pistons. Just reuse your crank unless it's screwed as it is larger on the CA. Block is the same and you can buy sleeved blocks already.

 

[PangziXin]

There are aftermarket options now for rods and pistons. Just reuse your crank unless it's screwed as it is larger on the CA. Block is the same and you can buy sleeved blocks already.

Thank you for your response. I’ve noticed that TSP is already selling aftermarket rods, but they are H-beam type. My engine rebuild experience is very limited, so I want to simplify the process as much as possible. I don’t want to modify the mid-block to accommodate H-beam rods, and I’m inclined to follow solutions from experienced 10th-generation Civic owners, as these solutions have been proven to achieve high horsepower while keeping the parts cost lower. I consulted with other enthusiasts who have used the 10th-generation Civic crankshaft for rebuilding the L15C, and they recommended that I purchase the crankshaft, corresponding timing gear and pulley, as well as the aftermarket pistons with dual-injector oil spray nozzles. I think I’ll go with this solution.

 

[PangziXin]

Let me give you a progress update. In the end, I used a brand-new 59B engine block, which includes additional water jacket support. Inside the block, I used a 10th-gen Civic crankshaft, forged connecting rods, forged pistons, and oil squirters. You will need to continue using the 11th-gen timing gear and crank pulley.


For the cylinder head, I replaced the intake camshaft with the Chinese-market CR-V version. It should have a 39mm high-pressure fuel pump lobe stroke, similar to the Si model. I also replaced the high-pressure fuel pump and injectors with the 2.0T 6B2 versions.


So far, everything is running fine. However, the coolant temperature behaves a bit differently—it tends to run hotter. I suspect this is due to the combination of the water jacket support system and the 11th-gen water flow guide plate, which may be reducing the coolant flow. Perhaps using the 10th-gen flow guide plate would result in better coolant temperature performance.

 

[PangziXin]

Temp issue update：
After testing, the coolant temperature issue was caused by the thermostat. I replaced it with a 68°C thermostat, and the water temperature now stays steadily at around 80°C. However, during ground cruising, the temperature often drops below 80°C, so I think I will replace it with a 73°C thermostat instead — the temperature might be just right then.

 

[blueroadster]

Temp issue update：
After testing, the coolant temperature issue was caused by the thermostat. I replaced it with a 68°C thermostat, and the water temperature now stays steadily at around 80°C. However, during ground cruising, the temperature often drops below 80°C, so I think I will replace it with a 73°C thermostat instead — the temperature might be just right then.

Where did you find a 73°C thermostat?

 

[PangziXin]

Where did you find a 73°C thermostat?

I'm in China, and suppliers here can provide custom thermostats at any temperature setting. Most off-the-shelf products, like those from Spoon, are set to 68°C — just like the one I'm currently using. I believe they're not suitable for street use, as the coolant temperature often stays below 80°C

 

[blueroadster]

I'm in China, and suppliers here can provide custom thermostats at any temperature setting. Most off-the-shelf products, like those from Spoon, are set to 68°C — just like the one I'm currently using. I believe they're not suitable for street use, as the coolant temperature often stays below 80°C

Thanks and I agree...68°C is a bit too cold for street use particularly when outside temps dip.

The FL5 also uses a 78°C-90°C thermostat.

Ideal coolant temps should be 75°C-85°C.

I have a replacement M&M thermostat (68°C-81°C (same temp ranges as others like Spoon)) but have hesitated from installing as it would be too cold for year round street use. A slightly colder thermostat in the range of 73°C-86°C would be ideal.

 

[PangziXin]

Thanks and I agree...68°C is a bit too cold for street use particularly when outside temps dip.

The FL5 also uses a 78°C-90°C thermostat.

Ideal coolant temps should be 75°C-85°C.

I have a replacement M&M thermostat (68°C-81°C (same temp ranges as others like Spoon)) but have hesitated from installing as it would be too cold for year round street use. A slightly colder thermostat in the range of 73°C-86°C would be ideal.

The thermostat is quite inexpensive. Although the one for the 11th-gen costs about twice as much as the one for the 10th-gen, it's still only around $30. Maybe I could send a few to fellow enthusiasts in the U.S. who need one.

Sponsored