CA18DET powered sentra update........

[boost_boy]

I think it's only fair that I share my progress with my old lady's sentra. I just completed making the brackets for the radiator fans and am happy to report that I am in the process of completing this wicked journey. As many of you know, I sold my old CA18DET for no apparent reason and opted for a fresher unit to start over with. One of our members rookie_ca18 has my old motor which had been good to me for 3 years and he is problem-free. I purchased a RWD CA, converted it to FWD, it lasted for about 2 months, gave me good dyno results and over 50 dyno pulls, changed the kevlar to ceramic, and all hell broke loose. The short block is now on it's 4th crank, 3rd oil pump, decked, lightly honed on the stock bore, line bored, and meticulously cleaned. I just think I have one of the bad engines, but stay tuned, I should be firing this puppy up today.

(to be continued)

Dee

[float_6969]

*chews nails with anxious anticipation*

[boost_boy]

*chews nails with anxious anticipation*

The tramp lives I finally got that puppy back up again, but I got some tweaking to do because of the odd cam set-up (272 intake and 264 exhaust) I'm using. Took it around the block a couple of times (no boost) and oil pressure looked excellent. I'll go nicely on it for a thousand or so miles before I let the 60-1 take over. If that bottom end stays solid, I'm pretty confident I'll swing this thing to about 500whp or somewhere in that vicinity. I'll keep the progress updated.........

Dee

[originalsin]

if u got it running today we share the same bday

good luck dee, rly hope this one works out for you

[boost_boy]

if u got it running today we share the same bday

good luck dee, rly hope this one works out for you

Thanks man and Happy B-Day as well. If the machinist done his job correctly, this thing should last a long time.

Dee

[nismoplsr]

I cannot wait to see the final results!!!

[float_6969]

w00t! congrats Dee.

[CA19DET]

why the longer duration on the intake, thought it was practice on turbo cars to have the longer duration on the exhaust side??

and is this a stock or built motor?

[boost_boy]

why the longer duration on the intake, thought it was practice on turbo cars to have the longer duration on the exhaust side??

and is this a stock or built motor?

Yeah, I know that's standard practice, but I was testing the 272 cam on the intake side to see if there was a significant effect on idle/driveability since I've already had 264s on the intake side. So far, not so cool, but then again the car's not broken in yet and I won't try and dyno tune it like that either.

The engine is semi-stock/semi-modded seeing that it has cams, a slightly ported head, forged pistons, stock rods, re-ground rank, new oil pump, adjustable cam gears, yadda-yadda.........

Dee

[rico05]

Damn, that is a lot of cam Dee! Let us know how she turns out!! Congrats!!!

BTW, I got the regulator in, too bad it didn't fix my cold start crap. GGGRRRRR!!!

[boost_boy]

Damn, that is a lot of cam Dee! Let us know how she turns out!! Congrats!!!

BTW, I got the regulator in, too bad it didn't fix my cold start crap. GGGRRRRR!!!

Did you check and see if there's power going to the cold start solenoid? I will most definitely keep everyone posted.

Dee

[boost_boy]

Compression is still low (around 90psi per cylinder), but I'm still going to drive it and attempt to let the rings seat anyway. I have an AWD motor coming in sometime next month, so sink or swim, there's a replacement killer standing by. As for driving, the car is still somewhat edgy, but it drives. Vacuum is almost non-existent at times and when it's there it sits around 8-10hg. It's a bit hesitent, but mostly because I refuse to make an adjustment. Let the break-in process continue..............

Dee

[boost_boy]

Compression still sitting at 90psi per cylinder. The engine has a total of 60 miles on a fresh rebuild which consists of Line boring, light honing, balanced and polished crank, new rings, new pistons, all new bearings, new pumps, new radiator. So my question is this to all you gearheads including the dumb-@$$ mod-team , what are the chances of this thing gaining another 50-70psi per cylinder? I mean the car is fussy and I refuse to make any fuel adjustments as it doesn't have enough to barely keep the brakes pumping good at or around 400rpm. Fire away guys!

Dee

[zero_gripS13]

umm i have been told that rings usually seat within 20mins of being started... did u check the gap of the rings with them installed in the cylinder.. maybe the rings arent big enough to expand against the wallas to seal..(sorry if this is confusing i know what im tlaking about ubt its hard for me to explain i forget what the procedures and stuff are called)

[float_6969]

it doesn't sound well Dee. are you sure you're not getting some wicked overlap with those cams or something? Those compression #'s still sound shady to me though. Is it even across the board?

[pulsar gtr]

Hi Dee,

Congrats on the engine, But regarding the compression, you should be getting more than that even though it is a freshly built engine.I know you know your stuff, no arguement there, but I would have to agree with Ryan, it sounds that your valves might not be clausing completely due to the duration fo the cams. Do you have adjustable cam sprockets installed?

I suggest to do a leak down test instead of the compression to see where the leak is happening whether it is on the intake side or exhaust side as you can hear it leaking.

Good luck Dee and keep us updated.

RafiPULSAR GTR

[boost_boy]

umm i have been told that rings usually seat within 20mins of being started... did u check the gap of the rings with them installed in the cylinder.. maybe the rings arent big enough to expand against the wallas to seal..(sorry if this is confusing i know what im tlaking about ubt its hard for me to explain i forget what the procedures and stuff are called)

Ring gaps are well within spec and I've used this type of ring before, but with better results.

Dee

[boost_boy]

it doesn't sound well Dee. are you sure you're not getting some wicked overlap with those cams or something? Those compression #'s still sound shady to me though. Is it even across the board?

Compression is a perfect 90psi per cylinder, which is just too damn low for this engine to begin to even attempt to function normally. Spark plugs are completely dry on the electrode (brownish/tan) with the usual dry soot around the thread bad. Oil pressure is awesome, but the engine is @$$ed-out on good compression, which has me by the balls right now. Cam timing is good to go, but even with the upgraded cams, it should be giving better readings than this. Oh well, I'll contact the machinist to morrow to see what he says. That fresh engine is looking better than ever before.

Dee

Dee

[boost_boy]

Hi Dee,

Congrats on the engine, But regarding the compression, you should be getting more than that even though it is a freshly built engine.I know you know your stuff, no arguement there, but I would have to agree with Ryan, it sounds that your valves might not be clausing completely due to the duration fo the cams. Do you have adjustable cam sprockets installed?

I suggest to do a leak down test instead of the compression to see where the leak is happening whether it is on the intake side or exhaust side as you can hear it leaking.

Good luck Dee and keep us updated.

RafiPULSAR GTR

This engine is the satan in my life. I'm going to figure this out one way or another. It does have adjustable cam gears, but they are "0ed" to stock settings. leak down test is eminent. i'll keep you guys posted on this dilemma.

Dee

[tx_widebody]

Sounds good, so wat is the word on the piston and rings??

[zero_gripS13]

hopefully the leakdown will tell u something... maybe u should try switching back to your old cam setup and see what happends....

[1SlowCA18DET]

what type of cams do you have, i plan doin somethign similar but i plan on goin 264 on the intake and 272 on the exhaust. So where could i get a set and a sds system?

[float_6969]

I think he's running a custom regrind.

[CA19DET]

i am pretty sure its the CRAZY overlap you have from those cams, i have 260's with slight over lap. total seal rings and get 160 across..., otherwise you messed up the bottom end, either the machine shop over bored/honned your bores or your rings are shiet..

did you do any valve/head work?? is it a NEW headgasket?

good luck...

[boost_boy]

i am pretty sure its the CRAZY overlap you have from those cams, i have 260's with slight over lap. total seal rings and get 160 across..., otherwise you messed up the bottom end, either the machine shop over bored/honned your bores or your rings are shiet..

did you do any valve/head work?? is it a NEW headgasket?

good luck...

The head that I'm using was suspect once before. I got an equal 160 across 3 cylinders and 0 then 90 then 0 again. I put a stock head back on the thing and everything had equalled out and this was all before the dramas of the bottom end crapping-out. The head in question is ported and has had multiple sets of seals (machine shop incompetence) a few guides and valves. Because of the perfect compression, dry spark plugs and no oil/water mixture, I am going to rule out headgasket failure, which is a nismo metal unit dressed in copper spray.

Make no mistake about misaligning of the camshafts, I have never done it and I don't think in the CA18DET's case I ever will because of the method I use to set it. I however, had the timing belt jump on my 4G61T powered 1995 Hyundai Elantra and both cams were out a few degrees and the car had no power under boost. When corrected, the car hauls butt, nicely. The cylinder bores were not out of spec and did not require an oversized piston and ring set. Like I stated before, the ring gap ends were well within limits and piston to bor clearances were well within the maximum allowed limits.

Which brings me back to those head and camshafts. I only had this compression issue since I put those camshafts in, but the last time I tore the engine down and put a stock head, camshafts, and stock headgasket on it, compression went down from 80psi per cylinder to like 60psi per cylinder.

I have since poured oil into each cylinder and compression stayed the same on 3 cylinders, but one went to 120psi and then back to 90psi again all the way across the boards.

I will probably attempt the leak down test today or tomorrow depending on how I feel. I do drive the car to work and if stinking drinks gas like you wopuldn't believe. I even got pissed and gave a 15psi burst and the car darted from 75 to 115mph at which time I put it in neutral and just let it coast till 65mph. I'm not stumped yet, but I'm going to keep an eye on the bottom end period to see if I have the issue that I had before with the crank moving and eating bearings for lunch. Stay tuned!!!!!!!!!!!

Dee

[CA19DET]

Quote »Which brings me back to those head and camshafts. I only had this compression issue since I put those camshafts in, but the last time I tore the engine down and put a stock head, camshafts, and stock headgasket on it, compression went down from 80psi per cylinder to like 60psi per cylinder.

I have since poured oil into each cylinder and compression stayed the same on 3 cylinders, but one went to 120psi and then back to 90psi again all the way across the boards.

I will probably attempt the leak down test today or tomorrow depending on how I feel. I do drive the car to work and if stinking drinks gas like you wopuldn't believe. I even got pissed and gave a 15psi burst and the car darted from 75 to 115mph at which time I put it in neutral and just let it coast till 65mph. I'm not stumped yet, but I'm going to keep an eye on the bottom end period to see if I have the issue that I had before with the crank moving and eating bearings for lunch. Stay tuned!!!!!!!!!!![/quote]well you shouldnt be raggin on the motor like that: a) as you are now breaking in a fresh rebuilt motorb) you seem to have some engine porblems

the head you are using sounds suspect with the valve seals being replaced a few times..

you sure you are not over fueling it and washing teh oil of fthe cylinders... that could eb the HUGE fuel smell you are getting as oil is in the oil pan and going through the breathers etc..

obviously something is wrong and 15psi will not help.. good luck

[boost_boy]

Even I go through moments of frustration. I know I shouldn't be abusing my motor as it did cost me money and time, but I had a moment where I let frustration and a stupid fast moving 18-wheeler provoke my car's innocense. I won't let it happen again, rest assured. I'm going to either swap in some stock cams or swap the others around to their respective destinations. We'll see how this goes..........Later!

Dee

[pulsar gtr]

Hi Dee,

As I mentioned, we can all sit here and jump into assumption until you do the leak down test, we can only assume things.

My suggestion, is after you do the leak down test, and I would say that your valves aren't shutting off completely, to disconnect the timing belt only which will force the valves to close then do a leak down test while the timing belt is off and see if you have any improvement.I don't believe it is a fueling problem as if it is, it shouldn't effect his compression.I rebuilt a ca18det and drove it for two days which then I did a compression test on it and it was 160psi all accross.

If your rings don't have the right gap as some one might have suggested, you should be getting some blow by oil, are you getting blow by ?

Good luck man,

RafiPULSAR GTR

[boost_boy]

Hi Dee,

As I mentioned, we can all sit here and jump into assumption until you do the leak down test, we can only assume things.

My suggestion, is after you do the leak down test, and I would say that your valves aren't shutting off completely, to disconnect the timing belt only which will force the valves to close then do a leak down test while the timing belt is off and see if you have any improvement.I don't believe it is a fueling problem as if it is, it shouldn't effect his compression.I rebuilt a ca18det and drove it for two days which then I did a compression test on it and it was 160psi all accross.

If your rings don't have the right gap as some one might have suggested, you should be getting some blow by oil, are you getting blow by ?

Good luck man,

RafiPULSAR GTR

Hey Rafi, there is air coming out of the exhaust side cam cover. Although it is not excessive, it appears to be somewhat normal for a fresh rebuild. There's no oil coming from this spout like you would normally find in a car with worn rings or worn cylinders. I've swapped the 272 cam back to the exhaust side and put the 264 cam back on the intake side so that I can narrow down my issues.

Like I've stated in previous posts, the plugs tell a story and there is no oil coming in the combustion chambers that is considered excessive or to my knowledge at all. All plugs look the same, all cylinder pressures were exactly the same. I was more expecting some unven cylinder pressures, but i suspect the machinists did a magnificent job at lightly honing the cylinders, the bottom end seems to be holding up pretty good at over 130miles on the engine, I even got careless and gave the thing a burst of boost to see if it would spit any oil or change oil pressure and to no avail (all was good).

I didn't do the leak down test because I forgot to pick-up the tester, so I'll put it off for tomorrow after work. All timing was on (this I didn't doubt), but I did find a small oil leak that needs my immediate attention from the plug just above the oil pump. My machinist removed it to get a deep cleaning in the engine's oil galleys and gave me bootleg custom piece to put back and now it's apparently dripping a bit of oil around, so I need to square this away ASAP. I seriously see me pulling this head, but for what remains to be told. I hope I don't, but I know it wasn't the camshafts that have the compression sitting at 90 psi. These are HKS pieces and they are not that eccentric in overlap nor lift. The adjustable cam gears are intact as I do things by the book when it come to engine mechanics.

So in short, we'll see! Thanks for chiming in as usual as you know you are a valuable member to this forum as well who's opinion has weight and bearing. And Thanks to everyone else as your opinions are welcomed and appreciated as well.

On a side note, I'm human like everyone else and am entitled to some mistakes, but when it comes to me and this engine, I exert myself to leave very little room for mistakes. If I make one, I'm man enough to say admit, correct and move on, but this is not my doing here. If this continues, this motor will have to be replaced as I've been told to do so by many go faster guys in my neck of the woods.

dee

Dee

[sdtouge]

was this compression test done cold or hot?