Part 5: CA18DET Engine Woes, Time to Build it Better

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Some of us get lucky, we import a motor from Japan, swap it into our car and drive off into hybrid heaven. But sometimes things just don’t seem right and unmistakably, as I pile the miles on my latest CA18DET, it has started to feel off. The smoke the car leaves behind after trips to redline is less concerning than the strong gas smell present at the next oil change. Since crankshafts that find themselves lubricated with gas tend to kill blocks, it is time to open the motor up before it grenades.

CA18DET rebuild before/after

Before and after of the rebuilt CA18DET.

Diagnosis
It always starts with something small and in this case, the #2 injector was stuck open. With the #2 cylinder having more fuel dumped into it than can be burned, the fuel was washing down the cylinder wall and into the oil. At the same time this process degrades the piston ring leaving the motor with compression of 150, 115, 150, 150. Luckily, this condition was caught before things got bad.

Image showing a CA18DET on an engine (motor) stand

Looking at the picture of the CA18DET on the motor stand makes me wonder what can be done to clean up that intake manifold.

Image showing the gunk built up on the #2 cylinder's valve stems of the CA18DET motor.

This image shows the rich condition in cylinder #2. Notice all of the gunk on the valve stem.

Half full
Engine rebuilds can be a beautiful thing. All internal components of the motor will be inspected and clearanced. The cylinder head and block will be cleaned then decked and honed. A new water pump, oil pump and head gasket will be installed along with ARP studs. Basically, a better than new CA18DET will emerge, faster, stronger (not to mention cleaner) and ready to handle a slew of upgrades to send this motor towards 300whp.

Rebuild pics

The cylinder head of a ca18det motor after cleaning.

It took time, patience and access to a machine shop with cleaning methods I don’t have to get the head this clean.

The intake and exhaust camshafts being reinstalled into the cleaned head.

Reinstalling the camshafts.

The cylinder head, valve covers, lower manifold and fuel rail installed on the freshly built CA18DET.

The newly prepped cylinder head.

Cleaned ca18det block ready for reassembly.

The cleaned block ready for reassembly.

The crankshaft is reinstalled into the block with new bearings.

The crankshaft is installed into the CA18DET using new bearings.

The crank girdle lays on top of the main caps on the ca18det motor.

The crank girdle and main bearing caps installed into the new block using new main bearings.

Top view of the ca18det block.

Image showing the top of the CA18DET block, minus pistons.

Image showing the left side of the ca18det block with new water pump and oil pump.

Left side of the CA18DET block with new oil and water pump installed.

Image showing the right side of the ca18det block.

Another image of the prepped CA18DET block. (right/driver’s side)

The ring compressor around the newly installed piston rings.

The ring compressor is a very simple tool that makes installing piston rings a walk in the park.

The piston half way in the cylinder of the ca18det.

Installing the pistons.

Piston #4 installed in the CA18DET

1 down, 3 to go.

New headgasket and ARP studs waiting installation on the CA18DET.

New head gasket and ARP studs awaiting install on the CA18DET.

Unlike the factory head bolts, the ARP studs need to be threaded on the block first.

Unlike the factory head bolts, the ARP studs are thread into the block before installing the head.

Valve cover and ignition installed on the CA18DET.

It’s getting there. Only a few more odds and ends and the CA18DET is back in action.

The intake side of the newly assembled CA18DET.

A shot of the intake side of the rebuilt motor.

The exhaust side of the rebuilt CA18DET

And for good measure, a pic of the exhaust side.

The front side of the rebuild ca18det.

The CA18DET is almost ready to install. (fullsize)

Top mount mainfold on the ca18det.

Top mount manifold on the CA18DET. A little unusual for a t25/28 setup but this engine will be a breeze to work on once finished. (fullsize)

More pictures coming soon.

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About the Author:

Chris Simmons

Chris Simmons is a race car driver, instructor, business owner and all around gearhead. His passion for motorsport started in the drifting community and progressed into wheel to wheel racing of all kinds. When off track Chris can be found training and working on a myriad of projects. After a hiatus from writing, he is back to share his passion, knowledge and experience in regard to motorsports on and off the track.

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