abosely Posted July 6, 2018 Share Posted July 6, 2018 I know this has been talked about and have heard different opinions. How much hp & torque can a R380, rebuilt to new specs/tolerances and strengthened where possible, machining the case to take the bigger bearing and anything else that can be done to build it stronger. from what I understand, it’s not just higher power that is hard on them, but bigger 4 cylinder diesels can be especially hard on them because of the power impulses. Im rebuilding a Mercedes OM603 6 cylinder diesel for the 69” SIIA 100” I’m building. Rebuilding it to new specs/tolerances, balancing rotating assembly, rebuilt pump with 7.5mm elements, DPUK quick spool hybrid k14 turbo & custom manifold, set up for low end power. It will make a 270-280 hp & 400ft/lb (543n-m) torque and will be very smooth. Ollie North is building the adapter & custom flywheel and Clutchfix is making R380/Tdi clutch good for over 400ft/lb. using rebuilt & strengthened LT230, FJ60 diffs & modified axle housings with RCV chromoly axles. So rest of drive line is capable of handling the power. Im not concerned about the hp, from what I understand the 270-280hp, especially in a smooth 6 cylinder isn’t going to be a problem. But not sure how much torque the built & strengthened R380 can reliably handle. I know there are people that say the R380 is weak and can’t handle much power. Then others say it handles higher power well. I would think there is a substantial difference between an old, tired used gearbox vs a properly built and strengthened one also. Thoughts? Cheers, Allen Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 6, 2018 Share Posted July 6, 2018 A lot will come down to how you drive it, some people can break anything... Quote Link to comment Share on other sites More sharing options...
abosely Posted July 6, 2018 Author Share Posted July 6, 2018 (edited) Lol ok fair point, let’s put the proviso that I’ve spent over 2 years designing and building this truck, don’t plan on ever selling it and I’m not one to thrash it, will actually use it, but not abuse it. i don’t want to have to baby it and not use it as it’s designed & built to be utilized, but I’m not a idiot. Lol Cheers, Allen Edited July 6, 2018 by abosely Quote Link to comment Share on other sites More sharing options...
western Posted July 6, 2018 Share Posted July 6, 2018 R380 is able to handle 380Nm of torque hence its name the R = Rover built. so a standard one wouldn't last very long with 500+ Nm being shoved through it. Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted July 6, 2018 Share Posted July 6, 2018 Syncro Gearboxes do uprated versions of the R380, they may be able to advise on torque capacity. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 7, 2018 Share Posted July 7, 2018 TBH all you're going to get is speculation and guesswork unless whoever you buy the gearbox from is willing to make some sort of promise - even then , how long is a piece of string? If it lasts 10k or 100k, is that reasonable for a modified truck? Did the 606 come with a DMF, because I suspect that would make a difference to longevity. Quote Link to comment Share on other sites More sharing options...
Carloz Posted July 8, 2018 Share Posted July 8, 2018 (edited) I have read some time ago "somewhere on the www" that the uprated Ashcroft R380 can handle about 440Nm... But no garantees were given (of course). The upgrade consist of two bearings with much higher load capability. For this the housing has to be bored out. Max horsepower is not the mainfactor: it is the torque which breaks gearboxes. When you have a good programmed boostcontroller you can let de engine produce 300hp and 400Nm and give the R380 a fair chance. Those super high torque figures are mostly in a very narrow rpm range and therefore not very useful anyway. Edited July 8, 2018 by Carloz Quote Link to comment Share on other sites More sharing options...
miketomcat Posted July 8, 2018 Share Posted July 8, 2018 Retropower on here was building a 606 powered rangie with an r380. I think he's now going auto for life (his not the box) reasons but he might be good to talk to. Mike Quote Link to comment Share on other sites More sharing options...
steve200TDi Posted July 8, 2018 Share Posted July 8, 2018 (edited) As some people have said, you cant guarantee it wont brake even if it above or below the 380Nm torque limit. Give it a go and see what happens, you could end up replacing it in a couple of years, but it may work out cheaper in the long run over buying something like this: https://www.ebay.co.uk/itm/Land-Rover-R380-Quaife-Gear-Kit-Fitted-Comp-safari-strong-box/173375717997?hash=item285dff826d:g:10wAAOSwVxpbLM6f Which is on ebay at the moment! Oh and if this is your build thread....we need pictures! Steve Edited July 8, 2018 by steve200TDi Quote Link to comment Share on other sites More sharing options...
abosely Posted July 9, 2018 Author Share Posted July 9, 2018 I contacted Like at DPUK to verify what the torque will be and to find out if the torque can be reduced without reducing the hp. It is capable of making 400ft/lb 543Nm of torque and it can be reduced by turning down the fuel screws, without changing the hp output. The torque can be reduced to 325ft/lb 440Nm no problem. I’m not wanting to run 400ft/lb 543Nm through the R380. :-) From what I understand the R380, with the bigger bearings and driven with a bit of common sense can handle 325ft/lb 440Nm reasonably well. We shall see. :-) i have a build thread here in the Series forum and a build page on FB that has more details and pics at: facebook.com/69Series2A/ I’m going to start a thread in this form on building the OM603 to go into the 69’ SIIA 100”. Cheers, Allen Quote Link to comment Share on other sites More sharing options...
Team Idris Posted July 9, 2018 Share Posted July 9, 2018 I would think oil was as important as bearings? To actually explode a bearing takes some doing unless the surface has broken up. That only happens if the oil film has broken down. Might be cheaper to fit a pumped oil cooler and run fully synthetic high-duty oil. Quote Link to comment Share on other sites More sharing options...
abosely Posted July 9, 2018 Author Share Posted July 9, 2018 I concur, I’ll be running an oil cooler for the gearbox, the R380 gearbox has a pump to run a gearbox oil cooler. Unless there is some reason not to, I’m going to use a small gearbox oil reservoir in addition to the cooler or if it is simpler/easier use a bit of an over sized gearbox oil cooler to have plenty of gear oil to keep it cool. If possible, I’m going to use a gearbox oil filter also if possible. I don’t know if the pr the gearbox oil pump is able to push gear oil through a filter or not, have to find out if this is doable or not though. Keeping oil clean and cool can make really improve the life of components. In warmer climates most R380s are equipped wit the oil pump & cooler. The R380 tends to run a bit warm from what I understand. I’ll be using Amsoil Synthetic oils in everything. Cheers, Allen Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 9, 2018 Share Posted July 9, 2018 People always think they run warm but they don't really - 50c is getting on for too hot to touch but gear oil is happy well into the 100's. I stuck temperature labels all over my trucks and they've never gotten anywhere near hot. This one's in the ambulance - so behind a 4.6 V8 hauling 2.8tonnes+ around, even blatting across France at 130kph in the sunshine it hasn't worried: I your hotter climate it's more believable that you may want a cooler, or you might throw a few pennies at temperature labels before going to all the effort I believe the R380 has a filter already to answer that question. A magnetic drain plug (ideally one of Nige's mega-magnetic ones) also helps. 1 Quote Link to comment Share on other sites More sharing options...
abosely Posted July 10, 2018 Author Share Posted July 10, 2018 That’s good to hear, I don’t have any experience with R380 yet. I’ll put an oil pump & run a gearbox cooler, and put temp labels on it to know what the temperatures really are. I’ll be using an Allisport Defender full width radiator with twin 13.5” fans & 2 built in oil coolers. One for the gearbox & one for the power steering. Engine oil cooler will be separate. The inlets & outlets can be rearranged as needed when ordering it. I like that super magnetic drain plug! Cheers, Allen Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 10, 2018 Share Posted July 10, 2018 I thought the R380 had an oil pump in it, otherwise what's the filter for? the factory cooler kit I believe you just unbolt the little lump on the side, exposing two ports which the cooler pipes then screw into. Quote Link to comment Share on other sites More sharing options...
elbekko Posted July 10, 2018 Share Posted July 10, 2018 22 minutes ago, FridgeFreezer said: I thought the R380 had an oil pump in it, otherwise what's the filter for? the factory cooler kit I believe you just unbolt the little lump on the side, exposing two ports which the cooler pipes then screw into. Indeed it does, according to RAVE. Looks like it's in the extension housing. 1 Quote Link to comment Share on other sites More sharing options...
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