Rebuild in action!

[chalander]

Hey guys,

I would first like to take the time to say thank you to the nico community, without you guys I would have lit my vehicle on fire and given up on life. (A bit dramatized but you get the point)

With that said and done, my new plans are to rebuild my engine. I feel confident with the head rebuild however I am creating this thread because the bottom end is what scares me...

My current compression test results:
Dry compression test:
155 psi cylinder 1
150 psi cylinder 2
140 psi cylinder 3
140 psi cylinder 4

Wet compression test:
180 psi cylinder 1
230 psi cylinder 2
230 psi cylinder 3
180 psi cylinder 4

My questions that I have are, what machining will be needed to rebuild the block with stock rings, stock bearings, original pistons, orginal crank, original connecting rods, etc.

As of right now, as long as everything checks out okay, I am going to use original internals with arp rod bolts, acl bearings, oem rings, oem gaskets all around for a power goal of 270 whp, or what ever I max the s14 t28 at, a bit over 300 crank hp. I will be doing the assembly myself while having only specific machining done that is a necessity.

Feel free to lay into me with the advice and guidance, for I am a noob that is wandering into uncharted territory.

[boost_boy]

With your compression all over the place like that, your bottom end scares me as well. From your dry test, the compression readings seems acceptable. From your wet test, if your rings and pistons were of the normal variants, your compression wouldn't have went up so high. This leads me to ask what type of engine is that (CA18DE, CA18DET Lo-compression or CA18DET Hi-compression)? Has this engine been bored for bigger pistons? So many questions to ask because at 230psi, that's N/A piston land IMHO.

[chalander]

Well that is all new news to me... The engine was a crate motor from japan (ca18det) swapped in by the previous owner. I was not aware of there being hi/low compression versions of the ca18det, so I cannot answer that, maybe a part number off the block would tell?? Idk... The wet test was done by placing oil into the cylinder, with the fuel injectors disconnected.

Unless it was done in Japan prior to the previous owner and I owning the engine, the motor has not been bored and still has the original factory assembled rings.

I have a question for you though, what are normal results from a wet compression check? I assumed this was done to check the condition of the valve seals

[chalander]

Well, bad news...

I tore off my head and found some bad s***...




At this point the only thing that looks good on the motor is the crank block and rods... The pistons and head both have sings of detonation. I am going to slap a new oem head gasket on it and sell it for cheap

[boost_boy]

A wet test will not show little to no increase in compression if the engine was mechanically sound. If your wet test bumped your compression up 30 to 90 points between cylinders, I would ask you to try another compression tester before determining that the bottom end is suffering. Are you cracking open the throttle body while you are cranking the engine? And lastly, there are two types of CA18DET engines. One has a static compression ratio of 150psi and the other one has a static compression of 180psi. I have both engines and love both of them as well .

[boost_boy]

Ouch! Classic nonetheless

[chalander]

I wish you were local boost boy, I would pay you I make me a mean CA! - maybe in the future when I have more money, thanks again for the help!!!

[mdb4879]

I would think the head is still usable, but the pistons are crap. I'll bet $20 the rings would be a pain to get off the pistons. I know this from the motor I'm building now. The head can be shaved to make sure there aren't any burrs. I wouldn't worry about any pitting. But the detonation probably compressed the ring lands and stuck the rings in their grooves. Now the ring lands are prone to breaking. I had to get two pistons from a friend for mine since I really didn't feel like boring and going forged for a beater/placeholder motor. I'm surprised you don't have a blown head gasket. Mine was super blown, lol. But in addition to the large signs of detonation like you have, I also had a ton of tiny marks.

[chalander]

Thanks for the input, I've seen people weld and shave there heads to fix the pitting. - I prbably didn't blow the gasket because it was a mls with arp studs.

[boost_boy]

I wish you were local boost boy, I would pay you I make me a mean CA! - maybe in the future when I have more money, thanks again for the help!!!

I'm not that expensive. You get a little more than what you pay for with me . I'll be here for you if at a later date you decide you want something a little more extreme.

[float_6969]

That's some insane detonation. It usually looks like something done with an icepick, not fully melted spots. Regardless, the head is totally repairable. Not even a huge deal. Weld up quench pads and re-surface.

Was it only 1 cylinder? If so, was it the 3rd cylinder?