nick w Posted August 4, 2009 Share Posted August 4, 2009 i know its probably been asked before but i am considering changing the 2.5 for a 200tdi as it will couple straight to my lt77 gear box and are reasonably however as i use the land rover on the motor way to get to events i am wondering how the top end speed will be improved by just changing the engine as at the mo anything over 55 is a bit hairy and very loud and sounds like the engine may fly out from the bonnet at any time .also as the 200tdi is only really a upgraded version of my current engine is it worth it or is the 300tdi and matching gearbox a better option although much more expensive any help much appriciated Quote Link to comment Share on other sites More sharing options...
western Posted August 4, 2009 Share Posted August 4, 2009 200tdi will be fine on the motorway, mine likes to sit around 60 to 65 & will go all day without any problems Quote Link to comment Share on other sites More sharing options...
Aragorn Posted August 4, 2009 Share Posted August 4, 2009 the engine change wont affect the gearing at all, so the engine RPM's at 55 will be the same regardless of the engine. The 200TDI might be a little more refined than the older motor, but its still going to have the same limit based on the maximum governed RPM. If you have for instance a 1.67:1 transfer box, then the tdi is still going to be very noisey. Quote Link to comment Share on other sites More sharing options...
Ibex94 Posted August 4, 2009 Share Posted August 4, 2009 Hi, Changed mine years ago and would recomend it. Was comfortable to cruise at 70 - 75 indicated with 235 85 R16s on. Normal mixed running would give late 20s mpg and up to 30 on a long run. Rob Quote Link to comment Share on other sites More sharing options...
lrfarmer Posted August 4, 2009 Share Posted August 4, 2009 the engine change wont affect the gearing at all, so the engine RPM's at 55 will be the same regardless of the engine.The 200TDI might be a little more refined than the older motor, but its still going to have the same limit based on the maximum governed RPM. If you have for instance a 1.67:1 transfer box, then the tdi is still going to be very noisey. the engine will be a bit quiter but no faster i put a disco transfer box on now can do 75-80mph not that i like driving it that fast Quote Link to comment Share on other sites More sharing options...
Guppy Posted August 5, 2009 Share Posted August 5, 2009 the engine will be a bit quiter but no fasteri put a disco transfer box on now can do 75-80mph not that i like driving it that fast Of course the engine is faster - both in acceleration and top speed. This is due to simple physics: the extra 30 or so horses provided by the forced induction under the bonnet! The base 2.5 n/a diesel has 65 horsepower - compare that with the 107hp of the 200tdi. In real terms then you are giving the truck a 50% power boost! I've just done this conversion and can thoroughly recommend it. Whereas the ol' 2.5 needs a good run up on level ground to get near the national limit, the 200tdi can hit it with ease, laden, with a trailer, uphill. As Western says, it's much, much quieter as the engine doesn't have to work nearly as hard to generate all that puff. Naturally as Defenders have all the aerodynamic prowess of a brick there is still going to be a fair amount of wind/tyre noise at motorway speeds, but it's nothing you can't get used to. That's why you bought a Land Rover! As a sort of 'real world' comparison, I use my stereo. Listening to Terry Wogan in the mornings used to mean turning my radio's volume up to 34 (out of 40). Now I can hear quite easily at level 19 or 20. Assuming then that my stereo's volume control uses a relative scale, the ambient noise in the cabin has almost HALVED since the tdi implant. Hooray for bad science! All in all mate - go for a tdi. You will NEVER regret it. Ever. Quote Link to comment Share on other sites More sharing options...
Ex Member Posted August 5, 2009 Share Posted August 5, 2009 A few things. 1) 5th gear is lower on the older gearboxes, so road speed is not the best for the 200TDI. 2) If you have the 1.6 t. case, you won't be going faster..... 3) Note that earlier versions of the LT77 may not be strong enough for the 200TDI. I would check the suffix first. If you have a "G" box, it is OK. anything lower is iffy. Quote Link to comment Share on other sites More sharing options...
Aragorn Posted August 5, 2009 Share Posted August 5, 2009 Guppy: it all depends on the current gearing. If the current engine can pull to the governor in top gear, then the new one isnt going to go any faster, regardless of how much power it has. Quite a lot of 2.5 NAD 110's were fitted with a 1.6 transfer case, and if thats whats fitted it will need changed to make use of the extra power available. Quote Link to comment Share on other sites More sharing options...
jimmy_neutron Posted August 6, 2009 Share Posted August 6, 2009 It always tends to come down to how much you want to spend... I have a 200tdi and find no great problem with it. I've also driven a 300tdi and found that there wasn't much difference between them in terms of cabin noise or performance. The 200tdi is often stated as the strongest engine but if your getting a second hand one then I'd say just get the best engine you can lay your hands on at the time. If you are going to be doing alot of motorway miles then i'd definately fit an R380 gearbox with an oil cooler otherwise your gearbox will leak oil and wear out very quickly due to excessive heat. Also as someone else said fit a transfer box with 1.22 ratio like the 300tdi disco then tweak the fuel pump just a little. As mine is a 1991 i made a short R380 so i could keep the engine in the same place. Best R380 to get is a suffix L from a TD5 defender. This will give aprox 20% increase in gearing when both boxes are combined making everything much quieter and much more usable everyday. Quote Link to comment Share on other sites More sharing options...
CURLY Posted August 6, 2009 Share Posted August 6, 2009 3) Note that earlier versions of the LT77 may not be strong enough for the 200TDI. I would check the suffix first. If you have a "G" box, it is OK. anything lower is iffy. how can you find this out? Quote Link to comment Share on other sites More sharing options...
reb78 Posted August 6, 2009 Share Posted August 6, 2009 how can you find this out? Check the box serial number which can normally be found on a flat bit of the casting near the drain plug. The look at the suffix. Compare the number to those on Ashcrofts site for more infoo on the boxes. Also check the serial numbers on the transfer box normally found on the back above the drain plug although there is another spot on older boxes (cant remember where - again, see Ashcrofts site) - if you are lucky, there will be a sticker giving the ratio if it says 1.6:1, you really need to find another that says 1.4:1 from a later defender, or for extra top end on the motorway (not so good if you tow), a disco box which is 1.2:1. Here also contains some info: http://members.shaw.ca/red90/gears.html Quote Link to comment Share on other sites More sharing options...
Guppy Posted August 6, 2009 Share Posted August 6, 2009 Guppy: it all depends on the current gearing.If the current engine can pull to the governor in top gear, then the new one isnt going to go any faster, regardless of how much power it has. Quite a lot of 2.5 NAD 110's were fitted with a 1.6 transfer case, and if thats whats fitted it will need changed to make use of the extra power available. Aaah. Didn't know that. This is how we learn - cheers! Quote Link to comment Share on other sites More sharing options...
Ex Member Posted August 6, 2009 Share Posted August 6, 2009 how can you find this out? Serial number on the back of the box. Last letter is the suffix. http://www.ashcroft-transmissions.co.uk/part_1.html#pa1 The LT 77 was introduced to the Landrover range in approx 1983 with the suffix D box and was developed over the years to the suffix H which was last used in 1994.The D and E are very similar the only difference being the reverse gear was a little fatter in the E, When they went from E to F larger layshaft bearings were used. The G was further improved by all the gear teeth including the pinion getting approx 20% thicker. Also a much wider pump was used to increase the lubrication and cope with the fact that some of the LT 77"s were now being supplied oil cooled, ie V8 NAS 90, 3.9 RR Classic and the 3.5 EFI Discos. The H (termed the LT 77S) was the same as the G in terms of strength but used a different syncro set up called the "Double Syncro", In reality it didn"t work much better. Quote Link to comment Share on other sites More sharing options...
reb78 Posted August 6, 2009 Share Posted August 6, 2009 Serial number on the back of the box. Last letter is the suffix.http://www.ashcroft-transmissions.co.uk/part_1.html#pa1 Its on the right side under the filler plug on the LT77 isnt it? The transfer box number is on the back of the transfer box normally. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.