Tuesday, Mar 02, 2010 at 07:07
G'day Greid
We have a 19Ft BT with 5 tanks, 4 panels, 4 batteries.
We tried towing it (when is was 3 tanks, 3 panels,3 batteries) with our 94 GQ Patrol D/Side 4.2L Diesel ute, and this worked very well unless we wished to overtake an army convoy doing 80kph.
We found that 3rd gear got you started in such situations and when required to drop into 4th gear (90kph is about tops for 3rd gear) the revs were too low to give adequate acceleration torque to complete the manouvere within acceptable distance. (5 vehicle convoy took 2 km to get past with this set up.)
We then upgraded the exhaust size to 2.5" and fitted a good quality turbo.
This made a remarkable difference to the available power to the ground, but the downside was an increase in radiator coolant temperature on very long climbs, which required the radiator to be stripped and the cores cleaned. The engine block was also air water flushed with the thermostat removed. End result, a marked improvement in heat dissapation.
We still were not entirely happy and were seariously considering a V8 Chev diesel motor change over,(then priced at $18,000) when we became aware of the Gov't subsigy for conversions to LPG. (While a diesel can never run on LPG alone the combustion process is enhanced by the inclusion on a whif of LPG into the intake air, which provides a significant increase in the HP to the ground at the same time.)
We live in Qld., and are penalised within our registration fees for an increase in the number of cylinders. (A 8 cylinder vehicle being dearer to register than a 6 cylinder of the same horse power)
After the conversion to Diesel-Gas fueling of our 4.2L Turbo'd engine, we gained an extra 20 HP to the ground at the drive axle, and significant improvement in the grunt in 4th gear after chainging from 3rd.
The dynamometer test after conversion to diesel-gas suggested an equivalent HP to the ground as could be expected from a naturaly aspirated Chev V8 diesel with a considerable price difference.
We recommend that once a turbo is fitted that an exhaust gas temperature gauge be fitted and monitered to ensure that the engine operates below the maximum recommended exhaust gas temperature, as we have found with our set up that while the engine demonstrates a willingness to continue to pull on long grades or at speed into head winds, the end result of doing so could take the combustion temperature at the piston above the acceptable range for the piston and cause permenant damage.(The foot to the floor going up hill in a high gear instead of a lower gear syndrome) Easily overcome by monitoring the gauges and changing down a gear sooner rather than later.
What would we do differently?
We feel that the V8 diesel option could be a fall back position for us if our power plant gives up the ghost.
We would upgrade to a 3" exhaust system.
We recommend that as well as air water flushing of the engine, that the radiator be upgraded from a 2 core to a 3 core type. This would have to be done in a V8 conversion any way. So far we are managing with our 2 core radiator and monitoring the gauges, and have recently completed an around Australia trip with our tug and the BT without any difficulty.
Our GQ Patrol is fitted with manual locks on the front wheel hubs, and we normaly run with these in the unlocked position. This allows us, while on bitumen, to utilise the aditional grunt available with low range 1st or second gear on really hard steep pulls. (By experience we have found that low range to high range on the move changes can be accomplished successfully by allowing the peak engine revs to die right back with the lowrange gear leaver in the neutral position before engaging the high range 4X2 position.) The change must be accomplished by the double declutching method. Old square mesh gearbox truck drivers will know exactly what I mean.
It is a skill that can be aquired, if you don't already have it, by practice using the double declutch method for all gear changes weather needed or not.
To change from high 1st to low 1st while in motion requires double declutching with a rapid engine rev change while in neutral. Also a skill which can be aquired.
Hope all this detail doesn't confuse you.
We will be at Tepon for the Muster with our BT and the GQ if you want to take a peek and discuss further.
Cheers
John
AnswerID:
579970