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need info about different year model diesels in the gq
Posted: Tue Jun 27, 2006 10:40 am
by dreaded monster
can anyone tell me if there are any differences in the year model 4.2 diesel motors in gq's, ie im looking at buying one of 2 gq's one is a 1990 the other is a 1994
Posted: Tue Jun 27, 2006 1:10 pm
by of4x4
Not 100% sure, but seem to recall reading somewhere that the later model GQ diesels (93 on???) had lighter weight pistons. Generally don't believe it's a problem unless you intend to turbo it and turn up the boost.
Posted: Tue Jun 27, 2006 1:17 pm
by dreaded monster
cheers mate
Posted: Tue Jun 27, 2006 1:23 pm
by GQ TROL
August 1993 was the build date whereby they had a change to lighter rods and pistons. Started using 28mm dia gudgeon pins instead of 30mm etc. Were also some changes to oil squirters for piston cooling.
More changes again in August 1995, with brake vacum removed off the back of the alternator, different glowplug setup, closer ratio'ed gearbox and I think 4 bolt engine mounts too.
gq trol
Posted: Tue Jun 27, 2006 2:02 pm
by dreaded monster
are these good or bad points.and why?
Posted: Wed Jun 28, 2006 6:01 am
by GQ TROL
Only the first point is bad..i.e prefer to use the earlier (pre august 1993) engines if you're going to turbo it and run a decent amount of fuel and boost.
The other points are good as without the brake vacum on the alt, its easier (and cheaper) to find uprated alternators. I've found the later gearbox is better of off-road work, ratios are better suited.
Best would be a late model (GU) turboed engine as it has the right rods and pistons, plus oil squirters and brake vac mounted off the front cover instead of the alt.
Posted: Wed Jun 28, 2006 11:30 am
by dreaded monster
cheers trol
gq
Posted: Wed Jun 28, 2006 6:14 pm
by DR Frankenstine
GQ TROL wrote:Only the first point is bad..i.e prefer to use the earlier (pre august 1993) engines if you're going to turbo it and run a decent amount of fuel and boost.
The other points are good as without the brake vacum on the alt, its easier (and cheaper) to find uprated alternators. I've found the later gearbox is better of off-road work, ratios are better suited.
Best would be a late model (GU) turboed engine as it has the right rods and pistons, plus oil squirters and brake vac mounted off the front cover instead of the alt.
Ive touched on this before and didn't get a real answer. Whats a safe amount of boost for the later model engines.
Posted: Wed Jun 28, 2006 6:15 pm
by GutSquisher Media
This is going to open up a bag of worms.
In the process of building up another TD42 motor (this is number 5), I wasn't sure what year model the one I had sitting in the shed was. The only way other than contacting Nissan was tho strip it down and measure piston pin hole size. Now this is where it got interesting pin hole size measured 28mm (shit post 1993 motor) or so I thought.
I called up a friend to see what the specs for a TD42Ti motor was, he sent back a fax showing the diference between the TD42 pre 1993/5 TD42 post 1995 TD42T and the TD42Ti and bugger me if it showed that between 1993-5 the piston pins where a mixed bag after 1995 they all went to 30mm and thats the way it stayed.
Now not sure about the pistons themselves but I've just been looking at nissans FAST System they do have different pistons listed for the TD42Ti than the post 1995 TD42 and TD42T. So the pistons may be stronger heavier etc but outside of buying one of each to look at........?
So it now looks as if the motor in the shed was a pre 1995 motor.
Posted: Thu Jun 29, 2006 3:40 pm
by fnqcairns
This is going to open up a bag of worms.
In the process of building up another TD42 motor (this is number 5), I wasn't sure what year model the one I had sitting in the shed was. The only way other than contacting Nissan was tho strip it down and measure piston pin hole size. Now this is where it got interesting pin hole size measured 28mm (shit post 1993 motor) or so I thought.
I called up a friend to see what the specs for a TD42Ti motor was, he sent back a fax showing the diference between the TD42 pre 1993/5 TD42 post 1995 TD42T and the TD42Ti and bugger me if it showed that between 1993-5 the piston pins where a mixed bag after 1995 they all went to 30mm and thats the way it stayed.
Now not sure about the pistons themselves but I've just been looking at nissans FAST System they do have different pistons listed for the TD42Ti than the post 1995 TD42 and TD42T. So the pistons may be stronger heavier etc but outside of buying one of each to look at........?
So it now looks as if the motor in the shed was a pre 1995 motor.
That's new information and good information also
, I own a 96 so it should be identical to all the GU turbo TD 4.2s out there if I understand correctly and it will use the 30mm pins and very probably the GU turbo TD/TDi pistons.
Yoo ho! now gas is an option if I decide
cheers fnq
Posted: Thu Jun 29, 2006 4:01 pm
by GQ TROL
Gut Squisher,
From the spec sheet, does it show that all engines (N/A and turbo alike) after 1995 used 30mm pins, or just the turbo ones? Another recent example is a late 1996 N/A engine with aftermarket turbo that has let go (cracked pistons and precomb chamber)....its got 28mm pins.
I was aware of a rumour about the varying pins between 1993 and 1995, but from what I had seen, it was the N/A engines that had the 28mm pins (seen this firsthand from engines pulled down), so we assumed it was the turboed engines only that still had the 30mm pins and also the better pistons, plus oil squirters etc.
Posted: Thu Jun 29, 2006 6:11 pm
by GutSquisher Media
Yes,all TD42's after 1995 use 30mm pins.
The TD42T and TD42Ti had 30mm pins but list as having different pistons. If you have access to Nissan FAST part system you can see the different listings.
The strange thing is it was the pre 1993/5 that had, what you would think as the weaker pin as it's a smaller size that is untill you think it's not the pin you have to worry about but the top of the rod end. With the larger pin you have 2mm less metal around the top of the rod, that is unless the rods are different (god back to FAST).
Will edit latter after seeing if the rods are different.
Back again just finished looking, Nissan has listed 3 Rods for the TD42
12100-43G01 listed for 08-87 to 06-96
12100-0W801 listed for 06-96 to 10-97 Alt part 12100-0W802
Posted: Thu Feb 12, 2009 12:08 am
by SLASH
Hi guys, does anyone have an update to this issue? i have a 98 GQ TD42 and im curious to know what internals i have. Regards.