CA18DE engine

Discuss topics related to the CA18DE and CA18DET series engines.
User avatar
dhen
Posts: 634
Joined: Fri Jul 04, 2008 6:27 am
Car: MGA w/ CA18DET

Post

I got a good deal on what was sold as an NA JDM CA18DE engine. It was dirty as hell inside - I honestly think the oil had never been changed - but looking at the bearings, etc. it looks like it was a low mileage engine. It came with a girdle. I cleaned it out as best as I could, put in DET cam, and test drove it for a mile today to see what I've got.

It idles great and seems to run fine. I did a compression test and it came out 159/160/163/164. I thought that the DEs were higher compression, but this seems like the same compression you get with a DET engine.

I put a new oil pump on it and oil pressure is good.

Anyway, I've got a couple of questions.

1) Did they ever make 8.5:1 compression DEs? Everything I've been reading says that DEs were all 9.5:1 and some were 10:1. The reason I ask is the compression numbers I got.

2) How much boost can I throw at this with a stock tune? I read in an old thread that 10 PSI with 10 degrees of timing would be safe.

In the distant future I want to run water/meth injection so I can run more boost, but that's not going to happen any time soon.


User avatar
float_6969
Moderator
Posts: 19853
Joined: Mon Aug 26, 2002 1:55 pm
Car: CA18DET swapped 1995 Nissan 240sx (too many mods to list)
2015 SV Leaf w/QC & Bose (daily)
Location: Topeka, Kansas
Contact:

Post

IIRC the JDM CA18DE was 9.5:1. It's likely the rings are worn and the compression is low.

Ron240sx
Posts: 112
Joined: Mon Apr 26, 2010 1:55 pm
Car: 90 240sx ca18det
89 300zx vg30e

Post

With an adjustable fuel pressure regulator I turned mine to 43psi. And ran 10psi with a t28. All on a stock DE. It ran pretty damn good for like 500 miles till the snap ring broke and the wrist pin scratched the cylinder wall.

User avatar
dhen
Posts: 634
Joined: Fri Jul 04, 2008 6:27 am
Car: MGA w/ CA18DET

Post

I may be wrong, but I think a snap ring isn't related to the boost you throw at it. Is this right?

Thanks for the feedback, though. I have a t28 and that's what I was hoping to do. In any case I wanted to know if my other parts are ok before I rebuild in a couple of years.

boost_boy
Posts: 7162
Joined: Thu Nov 14, 2002 7:28 am
Car: B12 sentra w/built CA18DET, B12 sentra w/fully-built CA18DET, S13 coupe w/ CA18DET, S13 hatch w/CA18DET, 2002 maxima SE
Location: Miami, FL.
Contact:

Post

If the compression is indeed that low, then just like float says, your rings are worn which ultimately lowers compression. To Ron240sx: As for snap rings breaking, detonation caused the issues you experienced. I've boosted many CA18 engines through the years and never experienced one of the circlips or snap rings letting go. I did however, detonate the pisons so bad until they smeared all over my cylinder walls like butter. But if it did break, I still would blame it on detonation melting the piston and cause the snap ring to unseat itself. And as for boost, you should not exceed 8psi of boost. Remember the DE is high compression and the DET is low compression, so the mapping is totally different and more aggressive with the DET ecu which means your timing will be in the danger zone for those N/A pistons.

User avatar
dhen
Posts: 634
Joined: Fri Jul 04, 2008 6:27 am
Car: MGA w/ CA18DET

Post

Hi Dee,

I sent you a PM. Please let me know what you think.

Darian

boost_boy
Posts: 7162
Joined: Thu Nov 14, 2002 7:28 am
Car: B12 sentra w/built CA18DET, B12 sentra w/fully-built CA18DET, S13 coupe w/ CA18DET, S13 hatch w/CA18DET, 2002 maxima SE
Location: Miami, FL.
Contact:

Post

I've responded already!


Return to “CA18DE / CA18DET Forum”