pump the oil through them to clean the old crap out, just like it says in the FSM.

Then when you put the engine back together, just crank it overa few times by hand before sealing up the valve covers and make sure you have compression. as long as you've got compression, you should be good to go. If you don't, then remove the rockers on that cylinder one by one and re-time the cams until your compression goes back up. if you find that, then simply smash them back down to get rid of the oil in the adjuster and reinstall. see where things are then and you should be good to go.

I also think it *might* have something to do with different years/production dates on the engines. I looked up the parts in FAST and there are three or four different variations on the lash adjusters in there, BUT they all supercede to the same final part #. Basically the consensus there is that if you change the full set with the new ones, then all is good and no worries. I dunno. I just replaced the culprit adjusters with some of the others I had laying around and all was fine on mine.

 

........................ And the saga continues...............

After ~500 miles on the engine, I did a compression check to see how everything was seating..

front head:
#2: 252psi
#4: 254psi
#6: 248psi

not bad, eh?

Rear head:
#1: 208psi
#3: 192psi
#5: 192psi

WTF?!?! So maybe my gauge took a ****? Nope. I retested the front head and got 248, 250, and 248.


So I dump some oil in each cylinder..
Front head:
#2: 270 (+18psi)
#4: 277 (+23psi)
#6: 265 (+13psi)
rear head:
#1: 235 (+22psi)
#3: 198 (+6psi)
#5: 210 (+18psi)

I was somewhat inconsistent with the amount of oil I dumped in each cylinder, as I as just sucking some out of a rubber hose and squirting it into each cylinder, but the results pretty much speak for themselves. the front cylinders gained a lot of pressure- most likely from the increased displacement of ~1oz of oil. the rear head is just a mystery. I'm guessing that if the rings weren't seated by now, the compression would have skyrocketed on the rear cylinders with the oil.. but they didn't.

I'm wondering if the machine shop did something different between the front and rear heads. I have no numbers as to whether they CC'd the domes or not after porting, but they did in fact reshape the combustion chambers slightly to unshroud the valves after cutting them.

Any ideas, guys? Is there a way that I can CC the head or check this stuff out without pulling the head off the car?

 

Honestly I wouldn't worry about it too much. All your numbers seem within reason. If it runs well and has good power I'd just go with it. Retest in a few weeks if you must.

I see wildly different compression results on the motors we sell here at work but never had a motor come back due to it being "weak", etc.

Fred

 

Matt. I don't think there's an easy/consistent way to cc the heads while they are on the motor. I would suggest an OBD1 scanner but you only have one 02! Is there the possiblity that the rear intake/exhaust cam is off 1 tooth?

 

I'm worried about it because I just spent $4000 on this engine and it IS feeling weaker than the stock engine at 220,000 miles and has obvious compression differences between the front and rear heads. it's too coincidental that the numbers are consistent across the head, but not between heads.

Jeffy, it's possible the cam timing is off a tooth (I've thought about that as well) but I don't think that's it. I'm planning on swapping intake manifolds anyway to work on this one some more, and I will pull the rear valve cover and take a look at the cam timing while I have it apart. I just don't want to do it!!

 

any updates for us matt?

 

still haven't messed with it. car runs okay and if I pay attention, I can keep it from stalling when I stop at lights. so I've been doing other, more pressing things..
hope to get to it later this week or over the weekend.

 

any chance that the machine shop didn't seat the valves properly? or possibly that the some valves may be bent a wee bit?

 

My intake adapter broke a few weeks ago, when i replaced it and put it all together,the damn thing would barely idle,and would die when the a/c was switched on,but the car ran fine past idle...I didn't get a cel,but checked for codes anyway,and there was none...

I suspected the maf might be the culprit,due to me working in that area,so i swapped it out with an extra one i had...I ran fine then...

I cleaned the original maf and tried it again...Still bad..

This may be your problem also...Just a thought..

 

I got it fixed several weeks ago. turns out I had the intake cam advanced one tooth on the front head. I had 5.5 links instead of 6 on it. simple enough to fix.

I also figured out just how easy it is to pull the cams out with the engine in the car. anyone who's scared of a VTC rebuild because of the labor involved to get the cams out is just a pansy. I had both front and rear valve covers off and the exhaust cams out in about 1.5 hours.

It still doesn't have the power I would expect after headwork and upping the compression, but it at least runs smoothly and reliably, so I'm driving it daily for the time being.. eventually I'll get around to looking at everything again. since the timing is all off the front head and it's the one with the cam timing issues, I have a feeling my ignition timing is way off now. I'm just too damn lazy to check it over again witht he heat outside and the free time I don't have.

 

After you get the last of the issues solved you should consider getting a dyno to see what were any gains and if it was worth it.

 

of course I will do that.. as well as CONSULT II logs and A/F ratios, which are all going to JWT to reprogram my ECU for me for the best gains. there will be before and after dynos on all of that as well.
there will also be more mods to come. i.e. custom cam grinds, VTC and power valve tuning, and possible headers. I just don't have time for it all right now.

Currently, I'm working 90+ hours per week and simply don't have time to do anything but put gas in it. today is my first day off in two weeks.

 

As long as you're being compensated for those 90+ hours it's all good considering where you were at before landing this job. Back when you were putting majority of your time into fabricating BBK's, suspensions mods, etc's. Back when that Miller mig welder was getting a weekly workout. Don't burn yourself out.

 

yup.. that's the way I am with just about everything.. 120% into it until I burn out and move on to something else.

Right now I'm trying to get house downpayment paid for, thus my million hour mission!!

 

I'm giving in... this much money in the engine and it still doesn't breathe any better..

While it's down having the new tranny built, I'm sending off my spare set of cams to be ground for 270 duration and 0.450" lift and some new valve springs when I get back home.

hopefully I'll get the tranny back together in time to do some dyno runs on it in current trim before I install the cams.

 

well your already in the 14's with your car before all this and your cars not light so your probably making decent power . before the work.

iam sure whither the dyno is alot higher or not you'll probably gain good time with those mods .
i wouldnt get worried unless your racing times are way off .

 

Cause its mad your giving the 240 more attention!

 

Wow, those specs are pretty sick.

 

I'm not really concerned with peak dyno numbers or insane 1/4 times... I want a good useable powerband to make the car more fun to drive.. mostly daily, but I'll bring it to the road course occasionally and even run it at the drag strip once or twice a year...

 

Maybe if you put in a used VQ30 out of a 2001 maxima in exchange for installing a vq35 in that same maxima

 

.....

 

Inside Joke!...I wanted matt to do my motor swap and as payment I was thinking of giving him my motor. Just a thought..

 

Oh okay Sorry for the misunderstanding. I thought I was going nuts cause I couldn't make out what you said

 

Actually if he could somehow adapt the VI to his motor, I'm positive it would make more power. Either that or basically copy the design of the VG30DE IM and put that on the VE. Either way both would make more power than the stock intake manifold.

 

Nothing beats the VE IM!

 

Nismo- the VE comes stock with a VI if its a 5 speed. If Vevolution wasn't clear that is.

~Alex

 

240 as in 240sx or a Z car? Pics of said 240?

I can't believe how long it's been since I first subscribed to your thread. Sorry for the engine troubles so far, and hopefully they will work out. Should be a great engine when it's all said and done.

 

only thing that's wrong with the engine now is valve stem seals I think.. it smokes a bit at idle or when I pull away at lights.. but there's zero leakdown on the engine so it's not the rings.

so I dunno what the problem is.. I'm assuming it's valve stem seals, even though they're brand new.
when I install the cams and valve springs, I'll swap them out again and see if that fixes it.

As for the intake, I'm going to leave it as it right now. The DE-K intake is very similar to the VE intake already. the only difference is the material and the overall dimensions. layout and principles are the same, so there may or may not be any gains from that. I'm not going to mess with swapping it out. I've ported the stock manifold as far in as I can go with hand tools and will be hogging out the other side of it when I pull it apart to do the cams.. I think I have a spare lower manifold too, so I'll port that one as well. next step would be extrude hone to get farther inside the manifold, but I'm not going to spend that much money on it. I'm contemplating a custom log-type manifold or something one of these days, so I'll save the money for when I go that way.

As for the 240, I've got an S14 for a track toy now.
random pics here:
http://blehmco.com/pics/240SX/
wish I had a 240Z, but the wife won't let me have another car until we get more parking space. when we move, I'll be getting a larger garage and more land so I'll be able to have a couple more toys... but for now, I can only have 3 cars.

 

I know the VE has a VI stock, what I mean is that the Z32 VG30DE makes almost 20whp more. The cams have almost the same specs, the motor has 0.5cr more compression but the big difference is in the IM. Maybe with 270* cams + new headers it should make big power.

 

I don't think the power of the VG30DE over the VE is in the intake.. Or at least thats what Im assuming.

 

there's a LOT of differences between the VE and VG when you get into the heads. they have a very similar setup, but everything is more compact in the VE heads.
the VG intake and exhaust manifolds all have larger diameter ports and different design.
The VE head CC is a bit smaller and the valves are at less of an angle on the VE than on the VG.

conversely, the VE valves are 1mm larger than the VG.
(They're also longer and the same stem dia as the VG, so it would be easy for the VG guys to go up 1mm in valve size. just buy a bunch of VE valves and machine the stems down.)


the Z32 cams also have slightly more lift than the VE cams. they're 4mm taller overall, but have a base circle 2mm larger as well... what that means after you move all of the rockers and such around, I dunno.. but if you machined the VG cams to fit in the VE, you'd wind up with more total lift.

you've also got to take into account the ECU tuning and several other things.. but you get where I'm going. there's a lot of similarities in these engines, but there are also a lot of differences.

there are also a lot of other different things

 

Just wanted to sympathize....I knew 2 guys that finally rebuilt their higher (150-200k) mileage 2.4L Altima engines and went 10.5 compression....

One went from a best time of 14.5 ('93 Altima with I/H/E/ecu stock 9.2 CR) to 13.9 IIRC and this was after 10.5 compression, full rebuild/balance and Racetep cams..

The other dumped $4k into his and only dynoed around 10-15whp more despite running 10.5:1 vs the stock 9.2:1 CR....

So I understand your desire to have it perfect and justify the money...

Hope all works out in the end....I wish I could afford a DPR head myself...

Jeremy

 

They needed ITBs and tuning hehehe. Your talking about the KA24DE. Lots of people dont look at the whole setup when modding that engine. You cant expect lots of HP out of those cams na either.

~Alex

 

Bad example IMO. The KA is limited n/a, built or not.

 

The engine wasn't the point, it was the frustration resulting from investing a chunk of money and not being happy with the outcome (so far)....again, sympathy, not a comparison of NA tuning potential between the two...

However, not to go OT, but a NA KA24 that runs a 13.9 in the 1/4 is putting down 180+ whp, with only a JWT ECU for engine management. Not too shy of the 200whp benchmark that so many fought to attain on the NA VQ30 for so long....

Jeremy

 

I was comparing it to other n/a 4 cylinders (SR20VE and honda B-series come to mind) with comparable mods. Just saying i probably wouldn't build an n/a KA when you consider the $/HP quotient. Then again, the V8 boys are prolly saying the same thing about people building all-motor V6's...

I do see your point though. I'm more into the all-motor side of things and quite a few people think i'm nuts when i tell them how much im gonna spend on my n/a buildup and how i should just boost blah blah blah. I don't care.


And due to recent advantages in engine management technology 225+ WHP on stock internal'd VQ30 is possible!! Hooray nissan...lol

 

I've got a local buddy putting down 215hp at the wheel in his KA24E S13...

but yeah, I've been there. and my friend above has thrown cubic yards of cash at his professionally built engine.... and it's nowhere near street legal (SCCA E Prod race car).

it's all about how much you want to spend.

even then, I've got easily $4k in this engine, and it still doesn't put out any more power than my old 200,000+ mile engine. frustrating to say the least.

 

That should change with the cams, no?

 

I'm hoping so.
If not, Im' going to take out an insurance policy covering all the money I've got in this thing, then drive it off a cliff. Take the money and buy me a used Z06 with it. (yes, I've got that much invested in the car)

 

Thanks for not misunderstanding me...I was hoping I didn't sound argumentative,etc...

I have a fully modded KA in my Altima but next to the VQ, it's nowhere as smooth or powerful as you guys know...

Matt, do you plan to dyno it just to verify power? What are your plans now?

Don't give up....yet

Jeremy