fresh rebuilt ca18det blowing dip stick(pic)

[float_6969]

As others have stated, you missed the break in period, and the chances of the rings ever seating are slim. When you rebuild the motor, check the ring gaps yourself. My brother in law is dealing with a similar problem. He had a friend build his motor and used "straight from Honda pre-gapped rings", to which I told him was the cause of this low compression and high RPM oil consumption. He refused to believe me until a professional race engine builder told him that even pre-gapped rings need the gaps set. That it's next to impossible to have a set of pre-gapped rings, not need gapped.

Also, as was stated before, the break in procedure is CRUCIAL! You only get one shot at it. I followed this break in procedure;
http://www.mototuneusa.com/break_in_secrets.htm
IT WORKS! My self and MANY others have followed this procedure (boost boy does something very similar) and our engines are always reliable and powerful.

[silvios]

I know you don't want to hear it, but it sounds like improperly installed/gapped rings. Test the compression and let us know how it comes out.

Also, all of you saying you need an easy break in are full of it, IMHO. My break in procedure consists of warming the motor up to NOT, then full throttle in 4th to 3K rpm, then engine break back down to 2K, full throttle to 4K, engine break to 2K, etc until I reach redline. After that, I drain the oil, replace the filter, and the motor is broken in.

My motor was reading about 190psi across the board when I took it apart with 40K+miles on it. (failed oil filter ruined the head, main, and rod bearings) I have every intention of doing the exact same thing to this build once it's done.

The engine breaking in gear is important! It helps pull any metal off the cylinder walls to keep galling and over-wearing down.

Hi
Questions from Australia!

What is NOT?
I am going home this afternoon to put the final touches on my motor, and start her up for the first time.
Here are the specs and work done:

• Head sandblasted and cleaned
• block bored 40thou and honed
• Head machined
• block machined
• JE SRP forged pistons
• new piston rings
• new big and small end bearings
• new water pump
• new head bolts
• new timing belt kit
• new genuine Nissan oil pump
• Full durapro gasket kit
• new intake and exhaust and turbo gaskets

The oil i am going to use is a Penrite Running in oil 15-40w.
I will be following a similar method to yours - except i have been told to 'baby it' by a few people.

Also, how long should i use the run in oil for? I was thinking just to do the load, then engine brake, then load, then engine break etc.

Any advice appreciated.

[D_Stirls]

Run little boost (i.e. <10psi), once you have it running if you have hills near your place take it for a drive through the hills as the load will be varied constantly. If your driving on the street vary the revs as much as possible but try to keep the revs below 5000, and make sure you keep the idle periods as short as possible.
After driving it for half an hour let it cool down and take the opportunity to look for leaks. Once it is cooled take it for another half hour drive using the same procedure, after that let it cool and drop the oil and filter (you can open the filter at this point and look for any excess contaminates) . Refill with run in oil and drive it sedately for around another 500km's keeping the boost and revs down. After that change oil and drive like normal.

[silvios]

Hey D Stirls - thanks for the reply.

Got the motor in and running tonight.

Took it for a drive, and albiet doing 5 kms or so, when putting the foot down very slighty, boost would start to build, but it seemed like it was missing? is a 7 range plug too cold? BCPR7ES?

I had to re-route some vac lines, and also the vac line going around from the intake manifold to the induction pipe was disconnected.

Im just nervous going for a drive without a car behind me in case something goes wrong..
It did start right away, and there was a lifter noise, which went away...it just feels so weird - i havent driven a brand new built motor before...

[D_Stirls]

Put it this way, I'd be more worried about going to soft on new engine rather than going to hard.

[boost_boy]

Hey D Stirls - thanks for the reply.

Got the motor in and running tonight.

Took it for a drive, and albiet doing 5 kms or so, when putting the foot down very slighty, boost would start to build, but it seemed like it was missing? is a 7 range plug too cold? BCPR7ES?

I had to re-route some vac lines, and also the vac line going around from the intake manifold to the induction pipe was disconnected.

Im just nervous going for a drive without a car behind me in case something goes wrong..
It did start right away, and there was a lifter noise, which went away...it just feels so weird - i havent driven a brand new built motor before...

Yes in the fact that that the BCPR7s are too cold for the standard CA18DET. They will foul fast and cause your engine to break-up upon acceleration. And since you said missing, what kind of missing are you talking about (ie intermittent, dead cylinder, etc)?

[float_6969]

If you've got vac lines unhooked, it could be causing the running issues. As has been stated, DON'T BE TOO EASY ON THE MOTOR, you only get one chance to break it in. If you miss it, there's no going back.

[silvios]

Well, just an update.

that issue i had previously - was due to my intercooler hose popped off

10kms after driving the motor, the car has developed a terrible knocking noise - which i am linking to bearings.

I cannot believe it - just as a i started driving the car, it sounded like it was running on 3 cylinders and now it is knocking.

My mechanic is bringing over a compression tester this afternoon to check it.
Oil pressure was not a problem - tested at around 75psi on first startup.

Could this be spark related?
I really hope not - but i do think that the bearing were incorrectly installed.

[D_Stirls]

Unfortunately it sounds like a spun bearing, ask him if he checked the bearing crush when he comes around.

[silvios]

What is the Crush?

What should it be?

[D_Stirls]

Bearing crush is what provides the force that holds the bearing in place (against the journal) once torqued up.

Have a read of this,
http://www.precisionenginetech.com/tech ... ch-part-1/

[unrealskill239]

update: i removed the motor about a month ago orderd some oem rings turns out the oil rings i had in there are where really wrong! but i must ask are oem rings pre gaped?



black is oem, lol

[float_6969]

That's fine, they're just different styles, not wrong really.

No such thing as pre-gapped rings. Even pre-gapped rings, need gapped, LOL!!! Seriously though, you'll want to get a ring grinder and gap the rings yourself, Just follow the clearances in the FSM and you'll be fine.

[float_6969]

you don't gap the oil control rings BTW. Just the 1st and 2nd rings.

[unrealskill239]

i gaped the rings yesterday installed the pistions today.

[float_6969]

Great!

[unrealskill239]

head is on! now for the fun of vacuum lines

[float_6969]

They're not too bad on the CA. Are you hooking up the butterflies?

[unrealskill239]

yep im going to try and hook them up lol i had took out the valves befor but i put them back in this time. no point taking them out on a stock motor.

[s13drifter88]

Cut an aggressive cross hatch in the cylinders with a 3 stone glaze breaker (I dont use dingle berry hones). Make a slow pass down and back up to remove any contaminates or imperfections and then make a series of fast past passes up and down till you get those pretty up and down spirals, reassemble and install. Follow the break in procedures float posted above, Ive been drag racing marine engines for a while and we do the same thing. We hammer right from the box, just a little oil rich though (32:1 instead of the regular 50:1). The cylinder is only rough for a short while and cylinder pressure is what blows the rings out against the cylinder wall forcing them to hold more pressure. If you dont use that right away then youll never get your rings to properly seat for a solid seal. You dont have to go crazy bouncing the rev limiter and jamming gears but some hard pulls in boost is what you want. Load the engine, make the turbo spool and pull a few gears out on the highway. The rings will cut themselves to the cylinder and visa versa under this pressure

[unrealskill239]

good to know

[nickhebert]

When I did my build I check all the end gaps and only needed to gap one ring, is that odd?

[float_6969]

Yes, and no. I've never been so lucky, but I've re-ringed a couple of engine that didn't need all of the rings gapped either.

[nickhebert]

so should I be worried about it? I didnt make all the end gaps the same just as long as they where within the limits of the fsm.

[float_6969]

Ideally they're all pretty close, but if you're not looking to make lots of HP, and are conservative with the tuning, you'll be fine.

[nickhebert]

I am looking at about 270hp, it is has still stock pistons so before I go for anymore hp it will get a set of forged pistons so the new set of rings would need to be gaped.

[float_6969]

270HP is nothing. You don't even need pistons for that.

Pure strength is not really an issue on the stock pistons until well over 300hp. Maybe even more. What you gain with forged is insurance in the form of detonation resistance. It's way easier to break a ring land from detonation on the stock cast piston than it is a forged piston.

The flip side to that is that if you know your tuning is conservative and safe, the stockers are fine.