I replaced the head gasket on my h22 civic due to coolant mix with oil. The machine shop checked the block and head and checked for leaks etc.. I reassembled everything according to specs. Used new oem head gasket and new head bolts. I set the timing correctly and turn the crank by hand and verify the timing again. I haven't started the car yet, I did a compression test and the results shows 0,20,100,160.

 

For starters check valve lash.

 

Yes definitely check the valve lash. If you don't want to go through the whole procedure just loosen them up so you know they all go slack when the rocker arm is up and the valve should be closed.

Driving overheated can ruin the rings.

 

I will do the valve adjustment tomorrow and let you know guys. I hope it will be fine

 

I waiting your answer, its okay now or no ?

 

I checked the clearence and there was 6 valves bit out of adjustment.According to the service manual the intake side should be 0.15mm-0.19mm & the exhaust 0.17mm-0.21mm. I had some intake valves 0.20mm and exhaust 0.23mm. I havent done the compresssion test yet.

 

You're more concerned about too little clearance, because then the valve won't close all the way and let pressure leak out.

 

Yeah, too loose on the valve adjustment will NOT affect the compression test results. Too tight will allow valves to potentially be stuck slightly open and create a situation where some pressure is bled off when conducting the compression test... returning lower than expected results.

 

If compression is still low after the valve adjustment, pour a cap full of oil into each cylinder and retest. If the compression jumps up its in the rings/cylinders. If it stays low then the leak is in the head/valves.

 

After adjusting the valve clearence compression 130,160,100,160. Cylinders 1 and 3 too low and after pouring oil the pressure increased so the rings are shot. I will perform leak down rest and I think I will tear the motor and sleeve it

 

Does it run now? Are those numbers with the engine warmed up? That's how it is supposed to be tested for official specifications. Compression is usually lower when engine is cold, you only test that way because the engine doesn't run.

You'll know if the rings are shot from overheating because it will burn oil like crazy.

 

It is with the engine warmed up and at wot. What happened is the car is boosted making 300+ HP. I flet that the power is less so I did a tune up but nothing changed so I went to the dyno and I had very low numbers 177hp only at 7psi, and the radiator always turns the coolant to brownish color and always loosing coolant. So I took the head off and send it to machine shop and bought new oem head gasket. The compression test before pulling the head was almost the same. My mistake I didn't diagnose the issue properly. Anyway it is not my daily, I already pulled the engine and tranny out and will work on it slowly.

 

thats what happened lol. 2 pistons cracked.

 

Bummer.

Usually they crack ringlands because of aggressive timing, leaner AFRs in boost(12:1 or so) or just too much heat in the cylinder in general. The ring end gap closes up with enough heat, ring ends touch, and force the ring down onto the ringland resulting in the cracking you're seeing. Doesn't necessarily always have to be from a detonation event.

Nippon makes cast Type-S pistons that use the Mitsubishi turbo piston alloy. Much stronger than the stock Honda alloy and still compatible with FRM sleeves. I believe they are $540 a set and include custom SCAT H beam rods that fit the pistons. If your cylinder walls are in good shape that may give you another avenue for a build if you don't want to sleeve. Just cut the rings a little wider when you put it together and send it.

 

What did you gap your rings at for boost?

 

I remember the tuner saying about he set the timing at 16 degrees and he said he is increasing the fuel to avoid cracking the ringlands. The cylinders are still in good shape no deep scratches. How much hp the nippon pistons and rods support? good for around 350hp?

I didnt touch the bottom. The motor is stock with turbo kit and upgarded fuel system walbro 255 pump, id injectors,fpr,aem fuel rail tuned on niptune.

 

well...if the bottom was stock its time you inspect it, after the leak down test that is

 

Forged internal FTW now lol

 

They claim 350whp but people regularly run Nippon pistons up to 500whp+ with no issues. Just be generous with the ring gap and I would say 400whp+ should be attainable reliably.


Edit: Here is a link for your convenience.

 

Thanks guys. I will inspect the bottom and since am short of $$$ i will give nippon pistons a try.

 

I know h22 cylinders can't be hone, so what can you do?

 

As i know that you don't need to hone FRM cylinders unless the cylinder has deep vertical scratches. The cylinders all in a good shape no scratches , I am still researching before i take final desicion i dont want to fu** up things for the second time lol.

 

If you need any h22 parts my cousin has some new parts that were unused and sitting around, arp studs and mains, piston rings hastings bearings, yadda yadda... If you're interest just shoot me a pm with a contact # and I'll forward it to him. Cut out the middle man.