New Internals for higher boost?

[EM.TT]

So I'm pulling my motor to resolve a compression issue and will be rebuilding it as well. As of now I'm not totally sure if I will be getting some Sport 500's or not but I would like to plan ahead a bit for higher boost levels in the future. So my question is, what all should I do/replace internally to ensure that I'm not going to be doing this all again in a year. Probably looking to run 13-17 ish psi?

[marty1mc]

If you are rebuilding, there are a couple of options. You could simply purchase a short or long block from either Z1 or ImportPartsPro.com. You can also buy a rebuild kit. Z1 sells two, but I would recommend this one:
http://www.z1motorsports.com/product_in ... ts_id=2833

For the levels of boost you are talking, stock internals are fine. I currently run sport 500's and boost around 18psi on high boost. The thing you need to look at is upgrading your injectors, ECU and intercoolers if you want to exceed 14-15psi.

[vulcanrush]

If you are rebuilding, there are a couple of options. You could simply purchase a short or long block from either Z1 or ImportPartsPro.com. You can also buy a rebuild kit. Z1 sells two, but I would recommend this one:
http://www.z1motorsports.com/product_in ... ts_id=2833

For the levels of boost you are talking, stock internals are fine. I currently run sport 500's and boost around 18psi on high boost. The thing you need to look at is upgrading your injectors, ECU and intercoolers if you want to exceed 14-15psi.

stop it, marty1mc, just stop with all the sensible and coherent advice.

[EM.TT]

If you are rebuilding, there are a couple of options. You could simply purchase a short or long block from either Z1 or ImportPartsPro.com. You can also buy a rebuild kit. Z1 sells two, but I would recommend this one:
http://www.z1motorsports.com/product_in ... ts_id=2833

For the levels of boost you are talking, stock internals are fine. I currently run sport 500's and boost around 18psi on high boost. The thing you need to look at is upgrading your injectors, ECU and intercoolers if you want to exceed 14-15psi.

stop it, marty1mc, just stop with all the sensible and coherent advice.

Lol @ vulcanrush. But yea I looked into those kits and thats probably what I'll do. I already have 555's but need the rest. Another question, is it worth it to get new manifolds?

[marty1mc]

stop it, marty1mc, just stop with all the sensible and coherent advice.

LOL. Yea, I don't even realize I am doing it until it's too late. Maybe I should go see someone about this problem.

[vulcanrush]

Lol @ vulcanrush. But yea I looked into those kits and thats probably what I'll do. I already have 555's but need the rest. Another question, is it worth it to get new manifolds?

yes, on the exhaust manifolds, get msp's. are your 555cc's injectors the new-style ones? if not, i'd opt for nismo740cc's, new-style ones.

[EM.TT]

Im pretty sure the are the old style ones, I didnt purchase them because they came with the car but are the 555's not big enough for what i want?

[vulcanrush]

they're fine for what you want, it's just they don't handle ethanol gas as well as the newer-style ones.

[kawininja91]

If your rebuilding your engine you might as well go with forged internals. Better do it now than later when you want to increase power and have to tear the whole engine down again.

[vulcanrush]

imo, in terms of wear and longevity and engine-noise (piston slap), nothing beats oem.
forged pistons are noisier from what i understand, i'll find out when i start/crank my engine.

[EM.TT]

they're fine for what you want, it's just they don't handle ethanol gas as well as the newer-style ones.

Will it run weird without the new style ones? also couldn't I just get the 91 octane fuel without ethanol (and tune?) or no

And I'll look into the forged stuff as well. Although my last NA made a ton of noise internally and it really pissed me off. I don't plan on getting over 420-450 rwhp and from what I understand stock internals are good?

[vulcanrush]

they're fine for what you want, it's just they don't handle ethanol gas as well as the newer-style ones.

Will it run weird without the new style ones? also couldn't I just get the 91 octane fuel without ethanol (and tune?) or no

And I'll look into the forged stuff as well. Although my last NA made a ton of noise internally and it really pissed me off. I don't plan on getting over 420-450 rwhp and from what I understand stock internals are good?

stock internals are good for that.
no, it won't run weird if your ecu is tuned for the nismo740cc's injectors.
i don't think you can get fuel (91 or otherwise) without ethanol. ethanol is everywhere, it seems.

[EM.TT]

They sell 91 w/o ethanol at a Shell station near my house, but yea it isn't very common...

And I was asking if it would run weird if I kept my old style 555cc injectors and ran 93 with ethanol? Wasn't really that clear there sorry.

[vulcanrush]

no need to apologize, i just think new-style injectors are better at handling ethanol gas, i've heard about old-style ones crapping out.

[EM.TT]

Huh, ok, well I guess I'll just run these until they go!

[itsa300zx]

If your rebuilding your engine you might as well go with forged internals. Better do it now than later when you want to increase power and have to tear the whole engine down again.

FYI stock TT internals are forged

[BigTDogg (MA)]

If your rebuilding your engine you might as well go with forged internals. Better do it now than later when you want to increase power and have to tear the whole engine down again.

FYI stock TT internals are forged

Close, but no cigar. They're cast pistons and forged connecting rods.

To the OP, OEM internals will be fine for your power levels and current goals, as are your 555s. You can run 91 octane and up on them without issue. The biggest issue is the ethanol in many fuels. If you currently have a source for ethanol free fuel, use it, as I'm pretty sure the hippydouchebags in government will be pumping it up to 15% shortly.

Also look into the switched +12V injector power mod. This will also save your injectors some life.

If the compression issue is in the heads, you can re use your OEM bottom end, provided it's in good shape. If the rings are the issue, you'll need a rebuilt bottom end. In that case, as previously mentioned, Import Parts Pro is one of (if not the) best large volume VG builder in the country.

[itsa300zx]

"Close, but no cigar. They're cast pistons and forged connecting rods."

OH! My bad then. I always thought the TT pistons were forged and NA were cast. OOps

[es.biggs]

Piston slap is caused by worn pistons and cylinder walls, or when there is excessive clearance between the two. Forged pistons won't make any more noise than cast if everything is done properly

[BigTDogg (MA)]

Piston slap is caused by worn pistons and cylinder walls, or when there is excessive clearance between the two. Forged pistons won't make any more noise than cast if everything is done properly

On cold start lower end forged pistons tend to slap prior to warming up. This is normal and expected.

From what I've read/seen, arias and other higher silicon content pistons won't slap as much. This is just what I've read from other first hand accounts, not my own experiences.

[EM.TT]

Close, but no cigar. They're cast pistons and forged connecting rods.

To the OP, OEM internals will be fine for your power levels and current goals, as are your 555s. You can run 91 octane and up on them without issue. The biggest issue is the ethanol in many fuels. If you currently have a source for ethanol free fuel, use it, as I'm pretty sure the hippydouchebags in government will be pumping it up to 15% shortly.

Also look into the switched +12V injector power mod. This will also save your injectors some life.

If the compression issue is in the heads, you can re use your OEM bottom end, provided it's in good shape. If the rings are the issue, you'll need a rebuilt bottom end. In that case, as previously mentioned, Import Parts Pro is one of (if not the) best large volume VG builder in the country.

Rebuilt as in take it to a shop and have it bored and so on? or a new shortblock?

And at that point would it just be cheaper to buy a new shortblock? I have no idea what a shop would charge to do that kind of work.

[BigTDogg (MA)]

Rebuilt as in take it to a shop and have it bored and so on? or a new shortblock?

And at that point would it just be cheaper to buy a new shortblock? I have no idea what a shop would charge to do that kind of work.

Rebuilt as in replace the pistons, rings and hone the cylinders yes.

Check out some of IPP's packages:

http://www.importpartspro.com/vgshblpa.html

IMHO, I wouldn't mess with a local shop unless they have a demonstrated track record of rebuilding high performance engines. Did you determine the source of the compression issue? When doing the compression check, get your initial numbers. Then on the low cylinder, pour a tablespoon of motor oil in the spark plug hole. If your numbers go up, chances are your rings are shot, and the bottom end needs a rebuild.

[EM.TT]

Ok, and as for the compression I think I'm going to put the starter back on and test it again just to be sure, and add oil this time as well.
These were my numbers from the first two compression tests (the car overheated, has been sitting for roughly 5 months, and hasn't ran since it overheated)

1 - 110
3 - 90
5 - 90

2 - 30
4 - 15
6 - 50

That wouldn't be a head gasket would it? Those results were without adding oil and the plenum off.

[BigTDogg (MA)]

Ok, and as for the compression I think I'm going to put the starter back on and test it again just to be sure, and add oil this time as well.
These were my numbers from the first two compression tests (the car overheated, has been sitting for roughly 5 months, and hasn't ran since it overheated)

1 - 110
3 - 90
5 - 90

2 - 30
4 - 15
6 - 50

That wouldn't be a head gasket would it? Those results were without adding oil and the plenum off.

I think it could definitely be a head gasket. All the driver side numbers are way low. Compression check should be done with the engine warm for maximum numbers, but I doubt there's any value in doing it again on this one.

[es.biggs]

Woohoo time to pull that baby out and fixxer upppp

Sorry vulcanrush...didn't realize that about the piston slap...I've never heard it before, but I've never listened closely either.

[vulcanrush]

Piston slap is caused by worn pistons and cylinder walls, or when there is excessive clearance between the two. Forged pistons won't make any more noise than cast if everything is done properly

On cold start lower end forged pistons tend to slap prior to warming up. This is normal and expected.

From what I've read/seen, arias and other higher silicon content pistons won't slap as much. This is just what I've read from other first hand accounts, not my own experiences.

and wisecos too, Tony, appreciate the explanations so i didn't have to do the typing.
ross pistons are also quite noisy from what i understand.
i have cp's, i hope they'll be good, and run for a long time.

[car nut]

On cold start lower end forged pistons tend to slap prior to warming up. This is normal and expected.

From what I've read/seen, arias and other higher silicon content pistons won't slap as much. This is just what I've read from other first hand accounts, not my own experiences.

The reason forged pistons slap before they warm up is that they expand slightly once they're warm. Higher silicone content minimizes this growth, so the pistons don't slap the cylinder walls as much when they're cold.

[EM.TT]

Woohoo time to pull that baby out and fixxer upppp

Sorry vulcanrush...didn't realize that about the piston slap...I've never heard it before, but I've never listened closely either.

Lol, yea that was basically my only option after seeing those numbers! But I'm looking forward to it. Its basically ready to come out already and I want to delete all the useless systems and repaint the engine bay as well. This car I bought has THE DIRTIEST engine bay i have ever seen on a Z... it's ridiculous.

[BigTDogg (MA)]

On cold start lower end forged pistons tend to slap prior to warming up. This is normal and expected.

From what I've read/seen, arias and other higher silicon content pistons won't slap as much. This is just what I've read from other first hand accounts, not my own experiences.

The reason forged pistons slap before they warm up is that they expand slightly once they're warm. Higher silicone content minimizes this growth, so the pistons don't slap the cylinder walls as much when they're cold.

Right, forged materials in the same (relative) volume are more dense than a cast part, longer to warm up. The silicon content also makes sense, I just didn't want someone bitching to me if they bought them and they still slapped

EM.TT, pulling an engine and rebuilding and cleaning the bay is a great project. Lots of fun and you really get to know your car.