DET headgasket related

[Liquid_Neon]

So i got my head off tonite, and looked at the gasket.. and wtf it looks fine!Also, the cylinder walls are all nice and shiny, i forget if thats a sign of something. there's pretty normal looking wear on the chambers and pistons. Number 2 does has a buildup because the injector had wireing issues before, but that got fixed.

now im pissed cause i think the only other reason the comp would be low is the dam rings.the numbers went (cam gears)140-130-120-140(transmission)

so i was thinking the middle of the gasket was all fubared... (she was blowing white smoke and running pretty ****ty before i took it apart).

But now i am sorta like... wtf!? I didnt buy rings and i wanted the car back like this weekend.. not in 3 weeks when nissan can get me new rings

any advice?And thanks for listening to the ranting i tossed in there.

PS- who would wanna shoot me if i put my DE pistons in my DET? With new rings of course... since my DE has 173,000miles(280,000K)

[float_6969]

It could still be a bad HG. It won't necessarily look bad if it's leaking. Can't you get rings from a local parts store and not wait 3 weeks?

As for the DE pistons and rings, you could do it, but you'd better be prepared to run 100octane fuel all the time to keep it from detonating and cracking the pistons.

[davidricardo86]

PS- who would wanna shoot me if i put my DE pistons in my DET? With new rings of course... since my DE has 173,000miles(280,000K)

Its possible but you would have to provide enough air/fuel and the correct fuel that will withstand those high cylinder pressures. Also the ignition system has to be able to handle the different setup aswell. Would the factory ecu be capable of this w/ the right tune? Just curious.

As far as the headgasket goes, are you going to use OEM 1.2mm HG or aftermarket MLS HG? I think at this point it would be safer to go with oem. It would conform to the small imperfections easier. Multilayered Steel headgaskets require a fresh straight block and head with the correct amount of force to seat properly. I have a oem hg that i was thinking about using but am now considering a Cometic MLS HG and ARP stud kit from Race Eng.com for around 195.00 i think.

[sideways danny]

look at the valves and valve seats. They will need grinding in and probably have a buildup which is stopping them closing properly

[Liquid_Neon]

most everything looks fine actuly, the walls are great looking. pistons look ok too.

Useing OEM style headgasket.Nissan can get them to me in about a week... not as bad as i kinda exaggerated about. The thing doesnt really look like she needs a rebuild.. ran strong until i hit the puddle.. and thoguht i blew the HG.

another question: do the DE and DET share the same time belt marks?

[sideways danny]

yes the timing is exactly the same

[themadscientist]

They should. I never use the marks on the belt anyway. Line up your timing marks on the gears and remember all slack goes on the tensioner side and the marks are unnecessary.

[boost_boy]

most everything looks fine actuly, the walls are great looking. pistons look ok too.

Useing OEM style headgasket.Nissan can get them to me in about a week... not as bad as i kinda exaggerated about. The thing doesnt really look like she needs a rebuild.. ran strong until i hit the puddle.. and thoguht i blew the HG.

another question: do the DE and DET share the same time belt marks?

You've popped your top, so why stop! I would personally get the head done and even do the rings and the bearings. It's is much wiser to do the necessary maintenance now, then realize later that you should've done something else. Gives you a chance to look at your piston side walls and ringlands as well. This is the time not to be lazy, so just a hint of advice, so the things I recommend will give you peace of mind.

Dee

[Liquid_Neon]

thx all, im gonna order the rings come tuesday. Ill inspect the bearings, but i dont doubt they are good.Has anyone seen DE and DET piston side by side? what makes the DE have 10:1 over the DET 8.5:1? The are rods are the same length, right? As in they might be swapable... that is if the DET ones are beefier. Im sure im gonna check anyway, but just asking in advance.If my parts come in a timley manor, i may get her up and running soon, yay!

[boost_boy]

thx all, im gonna order the rings come tuesday. Ill inspect the bearings, but i dont doubt they are good.Has anyone seen DE and DET piston side by side? what makes the DE have 10:1 over the DET 8.5:1? The are rods are the same length, right? As in they might be swapable... that is if the DET ones are beefier. Im sure im gonna check anyway, but just asking in advance.If my parts come in a timley manor, i may get her up and running soon, yay!

The DET's pistons are flat and the DE's piston's are considered domed which means the pistons' surface between the valve reliefs are raised higher than the valve reliefs and the surface on the outside of the valve reliefs.

Dee

[Liquid_Neon]

THx dee, i figured that was about the only differance between them. Are the rods from DETs tougher too? or are they the same? I will see for myself in a few days when i open up my DE, but just thought id ask ahead of time.

[float_6969]

Is the compression on the CA18DE really 10:1? I was always under the impression it was 9.5:1. If it is I've got way higher compression pistons in my motor than I thought I did...

[boost_boy]

THx dee, i figured that was about the only differance between them. Are the rods from DETs tougher too? or are they the same? I will see for myself in a few days when i open up my DE, but just thought id ask ahead of time.

If you have the JDM RWD DE's rods, they are the same as the DET rods. Can't confirm about the JDM FWD rods because I've never had one in my posession. But the USDM's rods are much thinner than the DET rods.

Dee

[boost_boy]

Is the compression on the CA18DE really 10:1? I was always under the impression it was 9.5:1. If it is I've got way higher compression pistons in my motor than I thought I did...

If you're using the USDM's pistons, then the answer is "Yes" in the fact that the pistons are 10:1 compression. The JDM CA18DE boasts 9.5:1 compression which I guess makes them a wee bit different.

Dee

[float_6969]

Did I have you send me a single piston, or was it Sean?

[boost_boy]

Did I have you send me a single piston, or was it Sean?

Wasn't me! Or I just don't remember.................

Dee

[float_6969]

I thought it was Sean. Man I hope that was a 9.5:1 compression piston.....

[Liquid_Neon]

Sorry to worry ya, float. Im pretty sure the silvias had 9.5:1. My stock pulsar NX motor had 10:1 125hp.

I also jsut thought of something else, whats the break in thingy for rings? im still debateing.

[float_6969]

What do you mean break in thingy?

[Liquid_Neon]

heh heh, guess my odd wording lost ya.I mean what is the procedure to break in new rings, obviously no 8500rpm launches for a lil while. Im not planning on rehoning anything, just rings and the headgasket. im gonna check the head for straitness too.

[boost_boy]

Drive the car and don't be a wuss about it. If the rings are installed correctly, you shouldn't have any problems. Just don't cruise around at the same speed for the first 500 miles. It's okay to go into boost, but do not try to sustain it for the first 500 miles. Down shifting will help with the break-in process. Load is the key here, but not too much. Again, don't be afraid to drive under boost, but be nice about it .

Dee

[float_6969]

There isn't any cut and dry ring break in procedure.

I agree with what Dee said with the exception of the cruising part. Don't cruise around in town, but going 60-70mph on the highway with the stock turbo is actually just about the perfect amount of load.

Also, I'm not 100% sure, but I think you need to re-hone the cylinders whenever you replace the rings, or they won't seat properly. As I said before though, I could be wrong....

[Chris859]

True on the honing, you need to "de-glaze" the cylinders to allow the new rings to properly seat. I have yet to build a ca18, but I have done a few domestic engines, as well as a couple sr20's. IMO a ball-hone gets the job of de-glazing done the best without actually enlarging the bore. With a normal stone type hone, you will notice all of the low spots in the cylinder walls - and in turn have to remove more material to clean up the bore. Just my .02

[boost_boy]

True on the honing, you need to "de-glaze" the cylinders to allow the new rings to properly seat. I have yet to build a ca18, but I have done a few domestic engines, as well as a couple sr20's. IMO a ball-hone gets the job of de-glazing done the best without actually enlarging the bore. With a normal stone type hone, you will notice all of the low spots in the cylinder walls - and in turn have to remove more material to clean up the bore. Just my .02

I'm one of the tri-stone users and unless you have experience with using the stones, stay away from them. the stones are very good for taking-out small imperfections, but you had better be constantly checking your ring gaps to make sure you don't bore the engine out of spec for whatever piston diameter you're using.

Dee

[float_6969]

Call me a newb, but how does a ball hone not remove any more material than a stone hone?

[themadscientist]

Ball hones sort of regulate themselves by the spring tension on the whiskers the balls are on. Stone hones swing out with more force as the speed increases. If you are figety on the trigger and don't apply even smooth strokes you could seriously **** yourself and the cylinders.

[sideways danny]

I always have machine shop hone my blocks, it costs me £12

[float_6969]

12 pounds of what?

I'm a looser....

[themadscientist]

And you can't spell either.

[sideways danny]

12 pounds of what?

I'm a looser....

well you know I'm in the UK so take a guess.