4.2 ST diesel GQ on Gumtree

[ricster]

Hmmmm interesting. I believe that there is one type of silver top, but a few variations on the black top. Maybe in the 97 ( possibly even 96) model the change over to the black top with the alternator vacuum pump happened. Then in 98 with the introduction of the GU the next generation of black tops, without the alternator vacuum pumps graced our shores.

Still a fantastic motor though, and looks well maintained.

[TijmenvdS]

But I am still not sure if I should be patient for a GU or go with this GQ. It is much cheaper to start turboing from 70k than 100k. But the vehicle I buy I must marry because I do not what to put the effort into a vehicle again like I am planning to on my next vehicle.

[offroadbiker]

The other option is to look out for a hand grenade, that you can pick up for around R30k and then let Michael put in a new motor........

[TijmenvdS]

Dis dalk die beste opsie. Ek moet maar my geduld uitoefen, ek raak net heeltemal ooropgewonde.

[Michael]

I like this one, especially because it is so well looked after and I LOVE the GQ shape.
Tijman ek dink GQ en GU het discs agter.....so moenie daaroor worry nie.

Cedric, I know we have spoken about this a couple of times and I think this will still be a hot topic for many years to come
What is your opinion regarding the advantage of having a silvertop vs a regular black top?

[TijmenvdS]

Nou dat ek terug dink aan die toetsit het ek by 120km/h n gesing gehoor. Kan dit die klank wees van die ratkas wat resoneer op die 4.2s wat ek al raak gelees het???

[ricster]

Michael, yeah... here in SA we seem to have a mish mash of TD motors, but here is what I believe...

best for turboing:
GU turbo black top, has the turbo oil drain cast into the block. 28mm gudgeons, different bolt pattern on the back of the crank. Vacuum pump driving off timing gear below fuel pump.
Good for 900+ Nm if you build them properly with ceramic bits etc. EG: One Wild Diesel in Perth build by United Fuel injection and Zac. Shawn Swaffield's various vehicles over east.
precombustion chamber ports are larger. Compression ratio 22.5:1
Engine number starts with TD42T#######

second best:
Silver top (which dont all have silver rocker covers) Build date to somewhere around August 1995 ( again probably in Australia.... here we may have later registered models with these motors ). Vacuum pump on back of alternator. Good for 650-700 Nm at 30 psi in short bursts if you watch your gauges with standard internals. 30mm gudgeons. "small/standard" back end on crankshaft. small precombustion chamber ports. Compression ratio 22.7:1. I'd keep it to under 650Nm with these. Engine number starts with TD42########

Good for mild boost only:
non turbo GQ and GU "black tops" built post august 1995 approx (again, not sure if any GQ's here in SA have this motor. I assume its only found in the 98-99 GU, which was then replaced by the 3.0 ZD motor from 2000 onwards ). Vac pump driven off timing gear below fuel pump. No turbo drain cast into block, "small/standard" back end on crankshaft. 28mm gudgeons. ( mine and yours if I recall has the 30mm gudgeon pins )
12 psi non intercooled, 15psi intercooled, Reasonably lively engine due to the lower mass pistons, especially if you use 4.375 diffs. Small precomb chamber ports. compression ratio 22.7:1
the pick of the bunch for moderate applications because everyone wants the "strong" ones and the lower reciprocating mass helps performance.

[Michael]

Yes Cedric its a mash up here

See my reason for this question is because for our applications I don't see any benefit in having a silver top vs our black tops. I know they rate the silver top to handle 650+ Nm with standard internals, but I really doubt anyone in SA will even try achieving those numbers without stripping the engine down and building it properly. I mean you have to boost 2bar for that which is really high.
I guess if you want to turbo an engine without changing the internals the choice is obvious, but to be guaranteed that you have found a silver top is not possible without opening it up to see what is actually inside.

The engine mentioned firs is what I believe is the same one we have in our UD40 trucks as well as the TD42TI pickups we have here. I am building a UD40 motor currently and I have replaced the pistons with the pickup pistons and can confirm that it the EXACT same pistons as well as conrods, crank and head.
But the engine numbers don’t agree with what the Ausies say. The pickup has no T anywhere to be found in the engine number and the UD40 has a T in, but it is right at the back after all the numbers.
This engine is my first choice as I have seen the internals and they are built to last.

The NA black top engine like me and you have does not have the same pistons as the silvertop or the GU turbo/UD40 engine, but we share the same conrods (it seems, although the part number is different but looks exact and are shown as interchangeable on the catalogue) as the GU turbo/UD40.
I have also seen many of these engines crack pistons with time after being turbo charged mine and yours included.

Anyways, I am at the point where I am going to install the UD40 engine that I have built into the new owners Patrol which is a GQ shory with a wait for it wait for it……… a silver tapper cover TD42 engine. I sell my engines on a service exchange basis so it will be rebuilt after I have finished the one in line after the UD40 engine.
So yes it will be stripped down and built up again as a turbo charged engine. I will give some feedback on what I find as I would love to find an original silvertop to see what all the hype is about.

[ricster]

I do think though that the TD42 ( Silver top in Dirk and Andre Voster's GQ's) are genuine silvertops, as they were "grey" imports. There are a few of them around still, as they were apparently brought in in a bulk shipment. This one in the advert is a newer year model so it is an unknown like you say on those motors.... Ahhhh we love a scandal....hahaha

[Wilkie]

I do think though that the TD42 ( Silver top in Dirk and Andre Voster's GQ's) are genuine silvertops, as they were "grey" imports. There are a few of them around still, as they were apparently brought in in a bulk shipment. This one in the advert is a newer year model so it is an unknown like you say on those motors.... Ahhhh we love a scandal....hahaha

I wouldn't worry about a black or silver top...I would just fit a 4.8 PETROL motor