The 4G63 NT Engine, and How to make a turbo kit for it!

[TimG]

How much can these pistons hold. I don't plan on driving at WOT very often at all and plan on staying away from knock as much as possible and tune the car around such pre-detonation.

 

[mavisky]

well seeing as how stock pistoned engines can make 400+ hp i don't see you breaking that barrier of their reliability any time soon. and above those levels its typically the rods that let go

 

[xhypno]

yeah I will post when the article is up

 

[TimG]

Thanks for the info on 1G pistons Mavisky. I've asked around and no one seemed to know but 400HP is really a good reliablity and I don't plan to exceed 350 ever. You made my life easier...

 

[laser9320]

I'm assuming thats 400 hp on a 6 bolt, how much can the 7 bolt take?

 

[HondaHunter2002]

i've been told that if i put a 14 stock turbo and run around 8 psi boost i will still need forged pistons or i will blow everythin up.. is this true?? from what mavisky was sayin mine can handle up to 400hp and there is no way a 14 stock turbo at 8psi runs anywhere near that much hp

 

[laser9320]

As I understand it the non-turbo has weak piston rings so its not going to handle 400 hp. But I don't think you will need new pistons if you only plan on running 8 pounds of boost.

 

[HondaHunter2002]

i wanna run the 14 turbo at 8psi and just get mls head gasket and new thicker piston rings.. mine are worn ne ways burnin a tiny oil but i still don't wanna blow all that money on forged..
so my question is can i get away with this?? or do i need turbo pistons or forged pistons or can i leave mine?

 

[steckelberg]

Ok, ive wanted to do a turbo conversion since i got the car, but it always seemd WAY too expensive. Now it looks like i can do it for fairly cheap and the GS will scream sleeper. BUT, if I already have forged pistons, and forged rods, and strong rings can i run more than 8 PSI?????

 

[mavisky]

Originally posted by steckelberg
Ok, ive wanted to do a turbo conversion since i got the car, but it always seemd WAY too expensive. Now it looks like i can do it for fairly cheap and the GS will scream sleeper. BUT, if I already have forged pistons, and forged rods, and strong rings can i run more than 8 PSI?????

remember 8psi isn't necesarily the max for each person's car, but just a reasonably safe level. each car will respond differently according to each car's modifications. you may well be able to run 10-15 psi on stock nt internals, but i'm not going to advise you to try it unless you have the money for a new set of pistons, rods, and rings.

the way i see it you can buy a new set of rods, pistons, rings, and bearings all forged for around $1000 maybe less. or you could simply have your nt pistons pressed off of your stock rods and install a set of stock 1g turbo pistons. i mean the 1g pistons have made some incredible numbers. and in case you were wondering the nt rods are identical to the turbo rods.

 

[TimG]

If you know for sure you have forged pistons and rods, I'd suggest a bearing change and a stronger head gasket. Mitsu has a 1.1mm 4 layer head gasket. That is what I suggest.
Theoretically, you can run over 30psi on forged internals.

 

[steckelberg]

Originally posted by TimG
If you know for sure you have forged pistons and rods, I'd suggest a bearing change and a stronger head gasket. Mitsu has a 1.1mm 4 layer head gasket. That is what I suggest.
Theoretically, you can run over 30psi on forged internals.

I just rebuily my engine, im just waiting on the tranny. The Forged is already taken care of its purchased and installed, just not broke in yet. So getting them is not in anyway an issue now its just a matter of seeing what i can do with the forged rods and pistons.

 

[HondaHunter2002]

Originally posted by mavisky


remember 8psi isn't necesarily the max for each person's car, but just a reasonably safe level. each car will respond differently according to each car's modifications. you may well be able to run 10-15 psi on stock nt internals, but i'm not going to advise you to try it unless you have the money for a new set of pistons, rods, and rings.

the way i see it you can buy a new set of rods, pistons, rings, and bearings all forged for around $1000 maybe less. or you could simply have your nt pistons pressed off of your stock rods and install a set of stock 1g turbo pistons. i mean the 1g pistons have made some incredible numbers. and in case you were wondering the nt rods are identical to the turbo rods.

so ur sayin that i should be able to run 8psi boost with my stock n/t pistons.. i plan on changing the rings and head gasket but i don't wanna change the pistons

 

[Vince]

The mileage of your motor plays a big factor on how much boost its going to take. I got a "low mileage" non turbo motor from soken and I run 14 psi, 20G turbo, stock everything everyday. But I would have never tried this on my original motor with 120+ miles.

 

[HondaHunter2002]

that's my problem.. i blew my first motor at 180km's.. don't ask long story.. so they sent me a new engine used from a junkyard and i have no clue how many klicks are on it.. i'm just gonna try to get away with mls metal head gasket and new thicker piston rings.. project is gonna go into effect once winter starts.. i'll keep everyone posted you'll probably be seeing alot of me asking questions.. : )

Vince, what are all the parts you've added to make ur car a turbo.. i'm just interested.. that's high boost for n/t internals i woulda thought.. what else did you upgrade?

 

[steckelberg]

Honda hunter, i wouldnt put money into the performance of an engine if i didnt know where its been. You dont know how many miles are on it. I know that these engines dont tolorate heat at all. If it has overheated once its not worth it for performance. I would sudgest either a rebuild, or a crate engine. I know the delicacy of these engines. Be careful. A forged rebuild will run about $3000. In my opinion its worth it as far as this turbo, nitrous, basically a bulletproof engine.

 

[HondaHunter2002]

the engine came in and it was super clean and it ran perfect.. only problem is it has idle surge.. tried cleaning tb, and doing all the vfaq stuff but ti's still surges for the first 2 or 3 minutes when i start it than it goes away.. other than that she runs nice.. it overheated once but now it was because my rad was still oe.. 10 years old i'd say it lived it's life.. now i am runnin a fluidyne rad and the temperature hasn't moved past half once and i've ran it hard a few times

 

[xhypno]

I am sorry to tell you all this, but my friend built the kit for is 94 GS, and at 7psi he cracked a ring shelf.

Stock NT piston (on the 1g) have very thin weak ring shelves. There is no way to get them to handle the tempature and pressure of more then 5 or 6 psi. Unless you put multiple MLS head gaskets on the car. That would lower the compression MAYBE enough, but you won't get a good seal between the heads and the block.

If you want to stay with the stock NT Internals, you can't go more then 6psi. I found that out from Hahn. I finally got an E-mail about there Stage 1 and Stage 2 turbo kits for the 1g NT. The Stage 1 came with a TDO4-10b (10g compressor), and a fuel mods. It gave the car 4psi, and about 30hp at the wheels, not worth 2000 (thats why they discontinued it). And the Stage 2 had a T-25 and a Alamo SMIC, and provided the car with 6.25psi of boost, and about 55hp at the wheels (but not worth the 3000 dollar price tag). That is why they no longer make the kit for the 1g NT, but they said if someone was interested, and beg enough, they might consider make them one.

xhypno

 

[steckelberg]

Originally posted by HondaHunter2002
the engine came in and it was super clean and it ran perfect.. only problem is it has idle surge.. tried cleaning tb, and doing all the vfaq stuff but ti's still surges for the first 2 or 3 minutes when i start it than it goes away.. other than that she runs nice.. it overheated once but now it was because my rad was still oe.. 10 years old i'd say it lived it's life.. now i am runnin a fluidyne rad and the temperature hasn't moved past half once and i've ran it hard a few times

When i got my eclipse the engine it was clean showed no obvious simptoms of damage. So I drove it home about an hour away and it worked fine. I drove it for a day and then dead....I spun two rod bearings. I dont want to discourage you just be careful especially with an engine that you dont know where its been.

 

[HondaHunter2002]

thanks guys.. i'll just rebuild forged.. you need special tools to change pistons though eh?

 

[steckelberg]

For the sake of balancing everything I would suddgest having it done professionally. But, if you have the will the smarts and the tools go for it, it can save you alot of money.

 

[HondaHunter2002]

i'll just have the pistons put in professionally.. i'll do everythin else myself..
do you have to bore out the block to put in the forged or do they fit right in??

 

[Vince]

If you guys read my profile it tells you just about all I did to my engine.
The ECU swap, knock sensor, turbo MAF, fuel solenoid with injector wiring harness and 550cc injectors. I have a HRC 20g turbo with 3 in downpipe/o2 eliminator with HKS external wastegate with 14 psi spring, no boost controller and I drive it everyday, really hard too. The biggest reason for my motor surviving that psi is the knock sensor. It has pulled timing away on many occasions but since I got the 550's the problem is gone. The headgasket is the same one that came with this motor and I've never taken the head off. I'll also be the first to say that it's not going to last forever, but it's been 5 months now and I do monthly compression checks and theyre the same as before I turbo'd it.
I was also told that the bigger the turbo, the less backpressure on your motor, which is bad for your high compression engine, hence will keep you going longer and safer. So if somebody else tries a 20g and all the mods I did you might be surprised at what your motor can take.

 

[HondaHunter2002]

"20G Turbo, 14psi w/ HKS external wastgate, stock sidemount intercooler (Spearco frontmount soon), 2g manifold, 3in. exhaust and Nitto 555r drag radials with custom Centerforce clutch. Turbo ECU swap with knock sensor, turbo MAS and fuel pressure solenoid and injector resistor pack wired in(stock non-turbo wiring harness) 550cc injectors, turbo cams, AC, power steering and cruise control removed. The NON-TURBO longblock is completely stock, never had the head off."
WOW.. so i should have no problems if i don't #*@( with my head and just add stock turbo from 1g and run 8psi

 

[laser9320]

how did you guys that have done it connect the throttle body to the upper i/c hose? I got a t-body elbow but I don't think it will fit without some modification to my t-body.