QD32 Piston Differences

[kiwinav]

Hi there,

First post to the Navara Forum. I bought a 98' QD32 D22 6 months back and I'm now looking to turbo it.

My question is are there any differences between the QD32 NA pistons and the ETi pistons? ie, gudgeon pin size, crown height.

Reason I ask is the guy I bought a turbo manifold off said when he turboed his D22 he cracked all 4 pistons very quickly at 12-14 Psi

Do I actually need the ETi pistons and can they be swapped straight in to my motor?


Cheers

 

[nedm1989]

I would say some of it depends on how much that guy had his fuel pump wound up by, I've had my QD32 turbo'd for over 6 months and it's been great, the turbo is leaking oil now but that's only because it was a 2nd hand turbo of unknown history.

I'm not sure how much info people have on the QD32ETi as they were never in the D22s or are common engines in general. I'm running mine on 11psi max and it seems fine.

Just saving for another turbo and to fit my W2A intercooler to keep temps down, thats the key, and to not start with a bad engine, you may only realise this one the turbo goes on if you don't get at least a compression test.

 

[kiwinav]

Cool thanks for the info. I think I'll give it a go and if worst comes to worst I'll be doing a rebuild which is not new to me. I got my hands on a brand new variable vane Garrett very cheap off a YD25 which I'm going to attempt to fit

 

[nuckin futs]

bought my son a qd32 with a turbo on it. all the receipts are there for everything done and no changing pistons, so stock ones should be just fine

 

[brendo]

Had my qd32 turboed for 2year didn't change anything and no problems it runs 10psi

 

[kiwinav]

Yeah I've heard of the same from a few guys. The only thing is that I don't know how the YD25 turbo will run so I want to overbuild just in case. I've just got myself a QD32ETi long block pretty cheap which will get a full strip down to do rings, bearings etc. so I'll have a good measure up and post the details up. It seems that info on them is pretty hard to find

 

[Dion]

14PSI, 21.9:1 compression ratio, dumped full of fuel... that's a high peak cylinder pressure! Maybe fit the thickest head gasket if you want to boost it a similar amount, bring that compression ratio down.

And well done to him cracking four pistons at once?

 

[Rumpig]

Not having oil squirters under the pistons of N/A motors probably doesn't help.

 

[tweak'e]

14PSI, 21.9:1 compression ratio, dumped full of fuel... that's a high peak cylinder pressure! Maybe fit the thickest head gasket if you want to boost it a similar amount, bring that compression ratio down.

compression is not an issue. guys are running up to 30 psi at 22:1 compression.
peak cyl pressure is all about injection timing.

if you drop the compression it will run like crap.

 

[Dion]

Not having oil squirters under the pistons of N/A motors probably doesn't help.

N/A QD32 motors have piston squirters.

guys are running up to 30 psi at 22:1 compression.

More details?

 

[tweak'e]

More details?

not really, it was a generic answer.

you need compression to ignite the fuel. dropping compression will make it run poorly.

have a look at what they run on TD42's in the patrols. they don't blow heads or pistons. they produce huge amounts of power/torque all at stock compression with large amounts of boost.

 

[davojohnson]

not really, it was a generic answer.



you need compression to ignite the fuel. dropping compression will make it run poorly.



have a look at what they run on TD42's in the patrols. they don't blow heads or pistons. they produce huge amounts of power/torque all at stock compression with large amounts of boost.

They're also a hell of a lot stronger motor then the standard QD32 even the NA TD42 would be a lot stronger then a top of the range QD32ti

 

[tweak'e]

They're also a hell of a lot stronger motor then the standard QD32 even the NA TD42 would be a lot stronger then a top of the range QD32ti

dunno. the qd32 is an oversized td27 which is simply a td42 minus 2 pistons.
even the weak td42 "light weight" version can still handle decent boost.

its not the boost that kills them, its the fueling.

 

[davojohnson]

dunno. the qd32 is an oversized td27 which is simply a td42 minus 2 pistons.

even the weak td42 "light weight" version can still handle decent boost.



its not the boost that kills them, its the fueling.

They're a completely different engine. If it was an oversized then why isn't it a TD32? They're a completely different engine and that's coming from someone who specialises in them. He's dealt with them before.

 

[tweak'e]

sorry don't know a whole lot on them. TD gear still bolts on to them. no idea on the bottom end.

still same old point to be made, boost is not going to kill it so no need to decompress it.
if your worried about strength make sure its well intercooled and don't run highly advanced timing.

i run 15lb boost on a toyota engine thats weaker than anything nissan has ever made!

 

[davojohnson]

sorry don't know a whole lot on them. TD gear still bolts on to them. no idea on the bottom end.

still same old point to be made, boost is not going to kill it so no need to decompress it.
if your worried about strength make sure its well intercooled and don't run highly advanced timing.

i run 15lb boost on a toyota engine thats weaker than anything nissan has ever made!

Cause Toyota are rubbish.