[Dale123]

hey guys.. i got a black top td42 with 368k kms on it.. had a turboglide system on it most of its life running 10/11 psi. its a september 93.

i want more power out of it and am aware of its age. am also aware the black tops are not as strong as silver tops motors, however i was reading a thread on here saying the td42s with vaccum pumps on alternator have the strong components anyway..which mine has. is this correct? are ther any other clear signs it may be the stronger motor?

i was talkiing to a bloke from united fuel today asking if i could wack an intercooler on it and wind up the boost to say 15psi.. hes suggested it may not be safe if my motor is the later/lighter model with those kays. he said the gudgin pins arent as strong and the blocks have bigger water jackets giving them thinner walls which can crack if you lean on them too much.

has anyone had any problems with running high boost in the later breed of the black top td42 motors? say 15psi plus?

thanks guys.

 

[tim75b]

the gudgeon pins are the same in all the n/a td42 (28mm) and they all have oil squirters as for the pistons i can show photos of pistons from a black top motor if someone has photos to compare them to from a silver top motor so we can see any differences

as for the factory turbo there are a lot of little differences 30mm gudgeon pins and different rockers amongst them

i have a 95 model motor in pieces in my shed if you need pick of anything let me know

 

[ITS A FORD NOT A NISSAN]

an intercooler itself should produce better power , it should allow you to add more fuel without increasing boost , i would think a few psi extra on a black top wouldnt hurt either

 

[tye1986]

i have a 98 black top it has 30mm gudgeons and the piston crown is lighter and they crack i cracked all 6 running 20psi. have heard off a reliable source that it was 96 onwards the ones that came out with the vac pump under it injector pump that have the lighter pistons but that is the only difference.

 

[Dale123]

tim75b, would it be possible for you to put up photos of the pistons and maybe conrods?

and if someone has photos of conrods and pistons from the earlier model im sure alot of people would wanna see what scale changes were made.

tye1986, been a 98 with 30mm gudgeon pins im guessing its a gu td42t, which i thought would have been the strongest of them all? maybe the pistons in these are weak. was the boost motor dyno tuned for 20psi?

im hoping my motor is the earlier model so it can handle 15psi with ease.. going to assume it is because the vacuum pump is on the alternator...?

has anyone on here broken

 

[tye1986]

nah mate all td42 from 96 onwards have the same 30.. gudgeons and the same rods only diff is the piston and nissan backed this up to. was all tuned correctly with a w2a intercooler. heres a pic of my new turbo pistons with ceramic and teflon coating. 3 are the orginaly rods and 3 are new rods from nissan. second is the old ones now real visible differences measure up the same on diff is the weight.

 

[MikeH]

They know their stuff with the TD42 listen to them. Many times they have talked me out of things which would have made them money. They want happy customers and a good reputation.
If you want a little bit more out of yours I'd put it on LPG and help it breathe a bit better, see if you can lose some weight out of the vehicle. Don't turn the wick up any more. It'll go forever like that.
If you want more than that then you need to look at an engine swap. If you chose not to follow the experts advice and put too much stress on your engine you'll be doing an engine swap eventually anyway.

You'd be amazed just how much performance gain you get from removing the rock sliders, subwoofers and recovery gear.

 

[Bruza 2]

Not disputing United in any way, but have heard that there were some silver/black tops on opposite motors during the change.???

 

[Dale123]

tye1986, how much did it cost you to buy the ceramic coated pistons? i was looking under my bonnet last night and my vacuum pump comes off my injector pump.. which means i have the weak motor.. bugger.

i want to be able to run 14psi no dramas.. if pistons are the only change i'd be happy to get better ones and install them myself. if i was going to do a motor swap should i be looking for the older silver top motor or the gu td42t?????

i know all the extras weigh it down a bit but i need to carry them when im on holidays.. and thats when i want the extra power for over taking and sand driving.

i reckon 14psi and a real good intercooler would give me what i want.

 

[tye1986]

yeh mate you could probably get away with it for $1400 i got mine already coated off a fella i know for a bit cheaper. either motor would be good might be hard to find a silver top with low klm's. i seen a while back that they had brand new nissan td42t's for sale for $6500.

 

[tim75b]

tye1986, how much did it cost you to buy the ceramic coated pistons? i was looking under my bonnet last night and my vacuum pump comes off my injector pump.. which means i have the weak motor.. bugger.

i want to be able to run 14psi no dramas.. if pistons are the only change i'd be happy to get better ones and install them myself. if i was going to do a motor swap should i be looking for the older silver top motor or the gu td42t?????

i know all the extras weigh it down a bit but i need to carry them when im on holidays.. and thats when i want the extra power for over taking and sand driving.

i reckon 14psi and a real good intercooler would give me what i want.

when i talked to three different machine shops they could only supply turbo compatible pistons with 30mm pins so if you have 28mm rods you would need to replace them as well

 

[tye1986]

it will have 30mm gudgeons.

 

[Dale123]

i've been reading about this everywhere.. i think from august 93 they started putting weaker pistons in the td42 (30mm gudgeons) then sometime around 95-96 they thinned out the block.. until the td42t came along.

so if the only thing different about mine is the pistons i could just change the pistons myself for the turbo ones out of the td42t or similiar as they both have 30mm gudgeons and i shouldnt have to change con rods etc..

would this mean i should change the sleeves? i seen a full rebuild kit on ebay for a td42t for $2300 or something so $1400 seems a bit steep for just pistons.

if i have to rebuild the motor or the block is thinner i'd probly consider doing a v8 conversion..

 

[tye1986]

they never thinned the block out.

 

[tye1986]

thats genuine nissan pistons not ebay ones.

 

[ovq355]

i have a factory 9/98gu td42 blacktop turbo motor in a gq so what, sort of motor do i have is it a weak one or is it stronger, due to it being a factory turbo. And my old boy has a gu with factory na td42 blacktop in it which i have just put a dts kit on, is his one of these weak motors as yes it is a gu td42 but its not factory turbo ?

 

[RHYS_MAV]

which is stronger black or sliver

 

[ovq355]

anyone ?

 

[MikeH]

later model black rocker cover factoiry turbo motor is strongest.
simplest indication you might have one of these is that the oil filters are different.
vac pump is run off the timing gear below the fuel pump.
pistons are stronger.
30mm gudgeon pins.
bigger hole in the precombustion chamber inserts in the head.
Later ones have wires coming out of number 1 injector.
I would hope that the engine numbers on these start with TD42T

next strongest is the earliest non-turbo motors which have a silver rocker cover.
both oil filters are the same
vac pump is on the alternator.
28mm gudgeon pins
smaller precombustion chamber holes.
Engine numbers start with TD42 (anyone near the crossover point please post your engine number leaving the last digit out for security reasons)

"weakest" which is still a bloody strong motor, is the later GQ NA black top motors.
both oil filters are the same
vac pump is run off the timing gear below the fuel pump.
28mm gudgeon pins
smaller precombustion chamber hole
Engine numbers start with TD42 (again please post your numbers)

two versions I dont know about...
Factory turbo "GQ" safari import motors.
non-turbo GU TD42 motors.

At the crossover point there will probably be some mix and match motors. this crossover point is in the second half of 1995. Engines have a build date on a sticker on the rocker cover near the alternator. There are 2 simple ways of telling what you have. 1: dismantle the engine and inspect the pistons. 2: tune it like it's a strong motor and if it blows up you know you lucked out.

All of the above is hearsay which I have picked up over several years of messing with these motors. Nothing is gospel because I've stuck to the silver top motors and never blown one up. yet. 20 psi and counting.

 

[GU4.2ST-L]

My TD42 Engine Number Is - TD424209709 It Has The Vacuum Pump On The Alternator And Black Rocker Cover, Has Both the Same Oil Filters And Was Built 10/93 But Sold As A 94 Model GQ ST UTE Coil Cab What Would Be The Go With This? Because Soon I will Be Chucking A Turbo On And Winding Her Up A Bit. Cheers For The Info Very Interesting - Mitch