Hi all,
have been doing some digging and reading and the information below might be usefull to someone.
All information is taken from LR orininal manuals, (but it aint complete)
The LR 5 brg supplement speaks of 3 differant engine numbers series, in relation to crankshafts. 361, 991 and 366. It states that series 366 is the 2.25 diesel, we know that the series 361 is a petrol 2.25 so at this time I am assuming that series 991 is also 2.25 petrol. Now the strange part as it goes on to say that the engines were manufactured at 2 differant locations. cast crank and forged crank. It states that the cast crank CAN ONLY be used in the 361 series (petrol) and must not be fittered in the other engine numbers sreies. Now we all know that the diesel has to have a forged crank because of the torque, the question is why not series 991, when it is suggestered by the wording that it is indeed a petrol????
Further study of the manuals, this time fron the 90 / 110 manual showed the following, very back page it has a supplement to the 2.5 petrol engine, and lists the differance between the 2.25 and the 2.5. and goes on to say and I quote, "some of these new features were, however,introduced on the later 2.25 petrol engines"
The 2 inportant differances that I noticed were and I quote "camshast same as 2.5 litre Diesel engine" and "camshaft sprocket simular to 2.25 litre petrol engine, but with a single keyway positioned to alter the exhaust value peak from 109 deg to 104 deg"
This is telling me that the 2.5 petrol and the 2.5 diesel has the same camshaft, but to inable the petrol operate and use this cam they had to alter the exhaust peak to 104 deg by using this single keyway sprocket.
Now the 2.25 exhaust peak is at 95 deg which is 9deg less, prehaps this is how they acheived more power?
Back to the 5 brg supplement manual, it confirms that the serise 361 uses a cam with an EP of 95 deg and the thread is UHF, then it states that the valve timing for camshaft fittered to eng series 366 Diesel and this mistery series 991 has an EP of 109 deg. But when using the single key way sprocket it adjusts the EP to 104 deg, it then states that the thread in the shaft is "Metric"
It gives you an easy way to tell the differance between the cams, as follows, 95 deg EP cam, the number 1 EP is on the centre line of the key, and the 109 deg EP cam, and I quote, "number 1 EP on the shaft fittered to serial number range 991 is 7 deg to the right of the key way center line viewed from the key way end.
So here we are again with this mistery series 991 suggesting it is a petrol.
For what it is worth I think because it stated that some of there differances between the 2.25 and 2.5 werew introduced on the later 2.25 engines, I think the 991 series engine is a 2.25 petrol using the same cam as the 2.5 and using the single keyway sprocket to adjust the EP for a petrol engine and remember it stated you MUST NOT FIT THE CAST CRANK to this series so prehapes the torque from this configeration is around the same as the Diesel.
Any comments??????????????
I might be wrong suggesting the 991 is as it is, but if I am please forgive me.
Rabet
