Author |
Message |
Joe Radisic
TryHard WA 2JZ GTE
Posts: 307 Reg: 10-2006
| Well just after thinking my mass spending spree with all you need mods and a 2jzgte upgrade is over!! And all the waiting!! I thought I knew what this felt like, Now i do!! Pa POW no6 piston has 90 pounds compression and 180~190 pounds on the rest, so here comes forged bottoms and what ever else comes with that!! |
Cihan Aday
Goo Roo The blue pill or the ultimate pill, make your choice. JZZ30
Posts: 2003 Reg: 07-2005
| Probably a valve job mate. |
Daniel Clarke
Goo Roo NSW TT 2.5L 6 cylinder
Posts: 1995 Reg: 03-2006
| Hopefully its a broken valve spring or something easier buddy. |
Joshua Rao
Tinkerer WA 2JZ-GE
Posts: 97 Reg: 09-2006
| Hope its not to serious Joe |
Miles Baker
DieHard Vic 66 Mustang GT Convertible, 55 Chevy Bel Air, 69 Firebird 455, 73 Corvette 4sp T-Tops
Posts: 684 Reg: 08-2005
| Squirt some oil in the cylinder and retest. If it goes up, probably rings. If not, probably valves. |
Joe Radisic
TryHard WA 2JZ GTE
Posts: 308 Reg: 10-2006
| Its probably rings as it drives normal (low power not pushing it) it doesn't blow smoke when driving or idle, it puffs smoke from oil filler or catch can, and has an awesome lumpy sounding idle. The tuner thinks it could be a cracked piston or a compression ring? Any way its got to come out and opened so definitely forged internals and cams are going back in as Im not opening her up again un necessarily. Then i can run big boost and more power haha Pricing up all the goodies now i think Greenline might be the cheapest option at this stage. |
Aaron Mead
Goo Roo NT TT
Posts: 1611 Reg: 03-2006
| Bugger... Good luck though mate, just try and keep control, its amazing how when you upgrade one part, you realise another part can now handle more power, which in turn makes you buy a bigger part, and so on...and so on! Hell, I just needed one wire re soldered and ended up with a haltech and a GT3540r??? |
Luke Nieuwhof
Goo Roo WA Soarer TT
Posts: 2171 Reg: 07-2005
| LOL @ Aaron. "Oh yeah it's a REAL bad wire. That one's going to require a whole new turbo set up. Nope too risky to use stockers again, best we be on the safe side. A GT3540r has a reputation for not breaking wires, we can only hope. God help us all." |
Joe Radisic
TryHard WA 2JZ GTE
Posts: 309 Reg: 10-2006
| Ok i did a wet comp test, firstly rechecked the compression dry on each piston while cold (does it make a difference hot or cold?) and I had approximately 1. 155psi 2. 155psi 3. 152psi 4. 150psi 5. 145~148psi 6. 110~112psi and it went up to 118~120 with a few small cap fulls of oil down the pot, i also re-did it 3 times to confirm. Is this enough rise to confirm piston failure or is it valve failure, or do I have to do it hot to get a more accurate result? |
Brian Timms
TryHard New South Wales TT Soarer Goodness.
Posts: 439 Reg: 12-2006
| Joe, If the valve is partly open, you wont get the compression readings, no matter wet or dry, as you loosing pressure through the valve that might be stuck open (also head to diagnost without taking the head off). Also, doing a wet test is cheating :p as the oil seals the rings up a bit better, so you always get a higher result from a wet test. Good for tricking nOObs into buying a car with a used motor. B. |
Miles Baker
DieHard Vic 66 Mustang GT Convertible, 55 Chevy Bel Air, 69 Firebird 455, 73 Corvette 4sp T-Tops
Posts: 686 Reg: 08-2005
| Hmmm.. could still be a piston problem I guess.. but it really leans towards valves. Next test - pump the cylinder up with compressed air and try and figure out if it's leaking past the piston/rings or valves. Listen and see where the sound is coming from.. Course it still *could* be a head gasket issue too. |
Mustafa Akgul
Goo Roo NSW JZZ30-GTTL
Posts: 1202 Reg: 07-2005
| like Miles said mate best way to find out is a leak down test.. |
Joe Radisic
TryHard WA 2JZ GTE
Posts: 310 Reg: 10-2006
| fark it sounded like it came from the eye candy chic hahahaha! |
Brian Timms
TryHard New South Wales TT Soarer Goodness.
Posts: 448 Reg: 12-2006
| Leak-down test would be your best bet. Other thing you can try is to take the cam covers off, hook compressed air to the cilinder, and look for obvious signs of air coming up near the valve springs. other one is to drop the sum, fill piston 6 with oil, and hook compressed air to it and see if the oil blows down into the bottom end of the engine. You could also turn the engine over BY HAND and see where the oil goes, if it leaks down, you have an issue (but dropping the sump, and having the spark plug out of the cylinder could also show you light (which is bloody bad mkay). I remember doing the same in my Cordia, had 176psi in cylinder 1, 179 in 2, 169 in 3, and 101 in 4. did wet compression test in 4, and got 120psi (but got 200-ish in the other 3. Ended up taking the sump off and had the spark plugs out, and sadly for me, I could see the light of day through piston 4. Took the head off, and I had chipped the side of the piston, cracked the top of the piston, and there was a hole about 1mm by 2mm where part of the top had broken away. Needless to say, it was off the the wreckers for a long motor, but this was for a Cordia, so it was almost worth just removing the injector and spark plug from cylinder 4, and riving it around on 3 powered cylinders. B. |
Joe Radisic
TryHard WA 2JZ GTE
Posts: 311 Reg: 10-2006
| Thanks guys for responses, i'll be taking the head off soon, i'll poor fuel into the chamber and see if its leaking and a burnt valve should be obvious. I am doing Hks 272 degree cams with a Hks 1.6mm head gasket and very tempted to do forged pistons and rods and machining at the same time if the price of parts isn't too high, my plan is to drag race next season onwards (roll cage when needed) i think a new forged set up is the safest way to go and a good way to finish off my beast. |
Braden Murdoch
DieHard NSW Cressida 1JZ TT
Posts: 622 Reg: 04-2006
| 150's is borderline compression anyway for a JZ motor...unless 2JZ motors normally have lower readings? My 1JZ has mid 170's across all 6 cylinders, and a friend's one is in the 180's. Might need to just swap in another motor, or rebuild that one. Maybe into a 3.4 ;) |
Joe Radisic
TryHard WA 2JZ GTE
Posts: 318 Reg: 10-2006
| It was in the 180~190's while hot but 150's cold should there be a difference hot or cold testing metals do expand? I borrowed tool to do a leak down test, hopefully will find where the problem is. Looks like a rebuild will be the safest option considering unKnown history of import engines. I don't want to keep going thru similar dramas. |
Joe Radisic
TryHard WA 2JZ GTE
Posts: 320 Reg: 10-2006
| Ok i did the leak down test (cold) and could hear the air coming out the inlet manifold (I took off the IC pipe and opened the throttle) it was low on no.5 (15% @ 100psi) and bad on no.6 (50% @ 80 odd psi it would not go higher). I also had air coming out the oil filler on no.5&6 but then checked no.1 which was good it was doing the same, when I blocked the oil filler it pressurised on 1 and the air flow increased through the inlet throttle body while testing 5 and 6. Could this be leakage past the valve guides/stem seals into the rocker covers? No.1 6% @100 psi No.2 3% @100 psi No.3 4% @100 psi No.4 4% @100 psi No.5 15% @100 psi No.6 50% @80 psi Is it safe to say this confirms the valves being the issue? I'll wait until i have new cams, springs, retainers, locks, head gasket etc before i pull the head off hopefully that's all i'll be doing at this stage. I will possibly be doing oversized valves and porting if necessary?
Joe Radisic wrote on Sunday, June 03, 2007 - 01:40 am:fark it sounded like it came from the eye candy chic hahahaha!
Miles sorry mate this was a drunken response the other night i was just imagining air leaks. |
Cihan Aday
Goo Roo The blue pill or the ultimate pill, make your choice. JZZ30
Posts: 2010 Reg: 07-2005
| If you can spare the cash, its worth it to do oversize intake valves. I think 1JZ valves are 1mm larger on the intake, there are aftermarket kits out there that might go a lot larger. If you're porting the head, you won't need 272's unless its purely top end you're after. They sacrifice a lot of midrange for minimal to null gains within the factory rev range. For brag factor though, i think they do it well |
Miles Baker
DieHard Vic 66 Mustang GT Convertible, 55 Chevy Bel Air, 69 Firebird 455, 73 Corvette 4sp T-Tops
Posts: 690 Reg: 08-2005
| Have your mechanic confirm it, but I'd say a valve job is for you. Bonus is while the head is off you get too look at the pistons. Rings sound OK though to me. |
Joe Radisic
TryHard WA 2JZ GTE
Posts: 324 Reg: 10-2006
| Head is off and piston no.6 has a bit of it missing. New Hks forgies here we come!! Is it ok (worth it) to use factory conrods as they are forged and i have been told they are bl***y strong. |
Joe Radisic
TryHard WA 2JZ GTE
Posts: 325 Reg: 10-2006
|
Cihan Aday wrote on Thursday, June 07, 2007 - 12:43 am:If you're porting the head, you won't need 272's unless its purely top end you're after. They sacrifice a lot of midrange for minimal to null gains within the factory rev range. For brag factor though, i think they do it well
Are you talking 2jzgte or 1j? Because I've been told it would gain dramatically mid thru high range with some loss at the bottom which a stally would compensate? |
Cihan Aday
Goo Roo The blue pill or the ultimate pill, make your choice. JZZ30
Posts: 2014 Reg: 07-2005
| Sorry, i wasn't clear! They make a more power than factory, but lose a little to the smaller 264 or 256 profiles within the factory rev range (0-7000rpm). As i was saying mate, if it cops a thorough 'head job' there's no need for a huge cam profile. Although, as you've heard - with a factory cast head 272's are the go for topend. HKS has a graph comparing all of the cams available for the 2JZ on their website. http://www.hksusa.com/images_products/1440.jpg http://www.hksusa.com/images_products/1440.jpg |
Lew Radbourn
Trader Queensland jzs147 92 / 95 jzz31 98' / jzz30 ute92' / uzz30 93'/ 2 X uzz31 92' s
Posts: 2014 Reg: 07-2005
| Joe the stock rods will tend to streach at around 750hp If i had the motor stripped down that far mate I would replace the rods at the same time. that way you will know exactly what you have in the motor. it would be a sh*t to have to pull it all down in 6months time because a rod . |
Joe Radisic
TryHard WA 2JZ GTE
Posts: 326 Reg: 10-2006
| Looking at those graphs 264 looks a better option then? cheers for advice. |