MG-Cars.info
MG MGB GT V8 Factory Originals Technical Range Rover 3.9 What to do, what to do .... BBS discussion at MG-Cars.info
MG-Cars.info
Welcome to our Site for MG, Triumph and Austin-Healey Car Information.
Parts
MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.
|
|
MG MGB GT V8 Factory Originals Technical - Range Rover 3.9 What to do, what to do ....
| Hello Everyone, Well mine is going like a dream! Gradually getting the snags sorted out , stays cool (without an oil cooler), the oil pressure finally gets down to 25 on hot idle, and never goes above 60 on full throttle. Steering nice and straight and light, suspension just right now I went back to stock dampers after those awful Spax. Im still learning what she has to tell me, but what a great stress reliever. She is called Fifi by the way. Buy anyhoo - I have been offered a early 1990's 3.9 Range rover engine. I'm intrigued, as the conversion bug seems to have bitten me I thought about just getting it - you know - just in case! I don't know much about Rangies or 3.9s. Can I just take the EFI stuff off the top, and all the power steering stuff, and water and oil pumps etc off and just treat it the same as my SD1 3.5. Will a LT77 or R380 bell housing and P6 crankshaft pully, alternator mount etc just bolt straight on? I assumed that all V8's were the same in terms of the exterior mounting etc. but I don't know why I think that. Can anyone give me some advice? Thanks, Liam |
| Liam H |
| I believe they have similar mountings and you can certainly lose the power steering etc., but why on Earth would you want to regress 30 years and replace the injection with a carb (if that is what you are saying)?? |
| Bill Spohn |
| Good move. I went with the carb setup. As long as you enjoy it, that is what matters. I also went with a Mallory dual point distributor. Everything works great. The other advantage is that if we ever experience an EMP, all my 30 year old technology will still work. |
| Richard Morris |
| Liam, The 3.9 block is virtually the same as the 3.5 and a direct swap, the only major difference is the bore size, and even the crank is identical. All the 3.5 ancillaries, brackets, mounts etc will bolt straight on the 3.9. However, the 3.9 is the only Rover V8 that is externally balanced (so the pulley has balance weights on it). In theory this means you can’t just fit your flywheel and pulley from the 3.5 onto the 3.9, in practice you can, although engine balance may not be so good. Why you would want to use a carb instead of the far superior Efi is beyond me but you wouldn’t have any trouble selling the complete fuel injection system separately. Are you going to the Harrogate MG show at Pateley Bridge on the 4th and 5th August? Geoff |
| Geoff King |
| Hi, the answer is that I don't know the first thing about EFI, and the engine is out of the car - I don't know what bits I would need to keep, and how to troublsehoot when the inevitable starting problems arise. Reading through the archives I also see that variable degrees of skimming need to happen to get the thing to fit. I know what I'm doing with carbs, both in terms of set up and clearance. Liam. |
| Liam H |
| Hi Geoff Our posts crossed, mine was to Bill and Richard. I didn't know about the MG show in Harrogate, have you got any more details? It's only an hour or so from me. The 3.9 engine - it would be project number 2, so I'd be starting from scratch. So I would also need to find the flywheel to match the LT77 gearbox - is that right? The front pulley from the 3.9 - could I have that machined and balanced to take the alternator belt just as I did with my SD1 front pulley? What other bits from the injection system would I need? this engine has the plenum but not much else. Like I say - I have no expereince with EFI at all. Regards, Liam |
| Liam H |
| I'm using a 3.9. from a rangerover. I was under the impression that this engine was the first one internaly balanced. Could be wrong. Anyway , Im using a SD1 pully and a standard Rover style flywheel with no vibration problems at all. More power and torque than the 3.5 of course. The 3.9 is much stronger than the 3.5. Lots of extra aluminium around the crank. The 3.5's in Australia have a big problem with the blocks cracking and the sleeves moving. It is not worth using the 3.9 front. This has an "on the crank" rotary oil pump. You'd need to cut off the oil filter and tap in a line further up at the oil pressure switch. you'd probably need to weld etc. Quite possible, but more expensive that getting a 3.5 front and the oil pump adapter. These bolt straight on. I seem to remember using a spare distributor gear as a spacer on the crank, but it was a while ago and memory fades. Anyway simple spacer, very availiable. I used the 3.9 distributor. This had a different end on it to the 3.5 due to not having to drive an oil pump. I used the end off the 3.5 distributor. A simple matter of knocking out a pin and straight swap. I also used the 100Amp alternator but had to swap the pulley. I'd stick with the 75Amp if I did it again. You can't take the 100amp alternater apart. You should be able to sell the 3.9 front, and various brackets, for alot more than the 3.5 front costs. The serpentine belt front is supposed to be more desirable to rangerover persons. EFI is easier that carb's. Cost me $100 to have about an inch machined off the trumpet tray. Then you need the air intake monitor, the various sensors and injectors on the intake manifold, and computer box plus loom. I managed to get it all going without knowing a thing about it, so it's not hard. Plenty on the V8 newsletter site. But if you like carb's there's nothing stopping you putting those on. You'd need all the Carb' manifold stuff in the valley of the V, and none of the EFI Valley gear. |
| Peter |
| Liam, The 3.9 is the only version of the Rover V8 to be externally balanced, Rover used a 3.5 crank and compensated for the different weight of the reciprocating mass by adding balance weights to the pulley. As I said, in theory it’s not a good idea to change the pulley but in practice you can usually get away with it, especially if you don’t use high revs. Whether the 3.9 has a crank driven oil pump depends on the year. Up to 1994 it will have a cam driven pump the same as the 3.5. Later engines will require the mods that Peter described. A LT77 or R380 gearbox will bolt straight on the 3.9 as will a 3.5 flywheel (but not four-wheel drive). Efi is simple, a few wires to connect, turn the key and it will start and run better than with a carb. If the engine has the plenum it must have the manifold and trumpet base and probably all the sensors and injectors – everything is mounted on the manifold except the airflow meter and the ECU. A Range Rover Efi wiring loom fits very well in the MGB, so you need everything that was fitted to a Range Rover. Details of the Harrogate show here. http://www.harrogatemgclub.org.uk/our_show.htm I’ll be driving down on Saturday and back up on Monday. It’s a big event, don’t miss it, especially as you are only an hour away. Drop a message to king@banchory.idps.co.uk and I'll send you my mobile number. Geoff |
| Geoff King |
| Geoff, while you're there, can you clear my mind about these engines. As you know I have a 1979 SD1 3.5 engine and a 1991 Range Rover 3.9 engine. I will be using the 3.9 with the Efi, and will swap onto it the flywheel from the 3.5, as the Range Rover was an auto 'box. Will I need to change the spigot bush in the crankshaft end to mate up with the LT77 gearbox? Do I have to change the Rangie's front cover for the SD1 cover? From the information on this thread it appears that I might not have to. I know I will need a short nose water pump, and have bought one, but if I can use the original cover and distributor, that's one less thing to have to do. I quite fancy coming to the Harrogate show too - I'll need to see what's on the diary at home. If I do motor down it will be for the Sunday only. Have you and Claudine been before? It would be great to see Liam's car having read so much about it on the board. Mike |
| Mike Howlett |
| Hmmmm.....Harrogate , can we expect better weather than Callander last year ?....my car appears to be behaving...it's going to MiniSport for a rolling road run tomorrow...subject this Sheila and I are seriosly tempted... especially if Geoff (and Claudine) Mike and Liam could all make it. ! |
| M Barnfather |
| Liam, The 3.9 is virtually identical to the 3.5 except for the larger bore and is the engine that was fitted to the MGRV8. If you rebuild it to what ever spec you want and then bolt on the front cover and water pump and crank pulley from your 3.5 it will slot straight in. The 4.0 engine is slightly different in that although the same capacity it has the crank driven oil pump,no distributor, and the front of the crank is slightly longer, but can still be used by fitting the earlier SD1 type front cover and P5/6 water pump and crank pulley but you need a spacer for the front of the crank which you can get from RPI. I had not heard about the 3.9 front pulley being used to balance the extra weight of the 3.9 pistons before but if you had the engine balanced with the short bottom pulley it should not be a problem. I could be quite tempted to do this myself as 3.9 engines complete with Hot wire injection systems can be had for reasonable money off e-bay and with a reasonable cam and stage 1 heads will produce about 235BHP, but do I really need another 35BHP? with almost standard rear suspension. As an interim and relatively low cost move we are this coming week fitting a pair of the reverse spring eye 110lb rear springs which will reduce the the ride height and hopefully improve the awfull ride I currently have, and after inspection of the telescopic dampers (not Spax) but as yet of unknown origin, but possibly Koni as their are no external adjustors achieve a reasonable ride/handling compromise but in the longer term possibly this coming winters project. I intend to swap in a Jaguar IRS without the cage, I have sourced the crossmember and all the parts to do this and it is about half the price of a Hoyle rear IRS and will handle up to 600BHP and give excellent ride, handling and highly important greatly improved traction. Kevin. |
| Kevin Jackson |
| Kevin, are you saying then that I will definitely need to switch the front cover from the 3.9 with the SD1 cover? Or will the short water pump and oil pump conversion fit the original 3.9 front cover? I'm sorry to keep harping on about this, but it isn't clear in my mind. Obviously, if I can use the front cover that came with the engine, then I will, as I will then have a complete SD1 engine that could be sold on. Thanks for your message, - Mike |
| Mike Howlett |
| Mike, Yes you need to use the SD1 front cover and use the P5/6 water pump and crank pulley or have the SD1 pulley modified. No problems with the oil pump, that did not change to crank driven until the 4.0 and 4.6 versions which also did away with the distributor. To be certain, which version of engine are you talking about the 3.9 and 4.0 are the same capacity but have the differences mentioned above. A useful book is the latest version of David Hardcastles "Tuning Rover V8 Engines" which gives youlots of information on the engine variations and what you can do to them. Kevin. |
| Kevin Jackson |
| Mike, Forgot to mention that the later engines have cross bolted 4 bolt main bearing caps, if you can see an extra 4 bolts on each side of the block just above the joint with the sump it is a late engine and of course would not have a distributor. Kevin. |
| Kevin Jackson |
| Thanks for all the input, I think I need to inspect some actual engines - like Geoff's! If I make it to Harrogate, I am pretty certain I can get down for the Sunday, but if Geoff's going on the Sat and is camping that sounds like fun. After all I have a tent, and drinking shirt and a conversation hat. I'm on my hols this week but will re-emerge next weekend and I'll see what some negotations with my wife re: looking after kids etc can produce. My own club (admittedly never been to any meetings, or know any of the people) has a stand, so I don't know about pre-booking or anything. I've never been to one of these events, but can see the importance of losing my reclusive (on your own in a garage at midnight for a year and a half) outlook to things MG. I'm keen to meet up with some faces. What does one bring to these events? Where do you pitch your tent! Is there a survival guide for a show virgin? Regards, Liam |
| Liam H |
| To Kevin, I actually have an older version of Hardcastle's book - I'll dig it out and have a read. I uncovered the engines today, and of course it is obvious that I need to swap the front cover when you look at it. Mine is a 1991 3.9, does not have the cross bolts, and does have a distributor. I bought it off ebay from a guy who breaks Range Rovers. It has only done about 130,000 miles and came complete with all the EFi kit including the ECU and AFM. To Liam, How do you manage to spend so much time closetted in the garage? My kids are both away and living their own lives, but I still get stoney looks if I start spending too many hours in the garage - the garden needs mowing, or something else needs to be done, and then I have to keep going to work. So I've had the MGB GT for over 4 years now and haven't got any further than cutting and welding new sills and floors. It's very frustrating. Still I retire next March. Regarding Harrogate, it is good to meet the folk you converse with over the BBS. I know both Geoff King and Mike Barnfather, Geoff better than Mike because he (Geoff) is near Aberdeen which I visit from time to time, and I have been welcomed into his home several times now. They say MG is the Marque of Friendship and so I have found. I won't be camping - I don't do that sort of thing. When I go to Silverstone I stay in a B&B, but I shall probably just come to Harrogate for the day on Sunday. I will only come down if the weather forecast is good, as it's a four hour drive each way for me. What do you bring to the event? Yourself and the car. Welly boots and a big umbrella. You then spend the day in a field talking cars and picking over unlikely spare parts on various stalls. I usually leave my lady at home, much to her relief. Mike |
| Mike Howlett |
| Mike, Remember my car started as a rolling shell, and I had to put every screw, washer, grommet on it - that's why it took so long. But it's a long story about how I actually managed to get to spend that amount of time on it without getting it in the neck. It was a one off, I doubt if I could negotiate that much time away from the kids again !(Mine are two and four). Liam |
| Liam H |
| Mike, You’ll need to fit a manual spigot bearing into the 3.9 crank (there won’t be one there at the moment). And, as Kevin says, you will also need to fit the 3.5 front cover and pulley onto the 3.9, everything from your 3.5 will bolt straight on to the 1991 3.9 but the short nose pump won’t fit the 3.9 cover. You also need an alternator bracket and either a P5/6 pulley or a machined SD1 – but you know that. It’s more difficult for Liam because he is considering another conversion and a 3.9 is not so easy unless RV8 parts are fitted to it; and they are made from unobtainium and/or are ridiculously expensive. Interim engines had a crank driven oil pump but still used a distributor, and these front covers appear to be sought after for those conversions that can use the improved oil pump but do not want EDIS. I also have the early edition of Hardcastle's book, I didn’t even know there was a later version and I found it rather disappointing, it explains what can be done without saying anything about how it is done. An interesting read for a very general overview of what is possible but useless if you want to do anything yourself or even to know what someone else is doing for you. In my opinion ‘How to Power Tune Rover V8 Engines for Road and Track’ by Des Hammill is far more up to date and much more detailed. ISBN: 9781903706176 Geoff |
| Geoff King |
| Thanks Geoff. I love the word "unobtainium" - I know it's not original, but it's such a good description for RV8 parts, which seem to be priced way beyond their value. Mike |
| Mike Howlett |
| Back from my hols, OK, the 3.9 sounds like a harder job, I'll pass - easy is what I want, having cut my teeth on the hard. So, if I started again would the smarter move to be to fit a 3.5 with EFI from a Range Rover - I assume I would see a better peformance using this set up than with e.g a weber carb set up on a 3.5? Liam |
| Liam H |
| Liam, Will you be able to make Harrogate? We have booked an hotel for Saturday night, and Claudine & Geoff are coming...and Mike H I believe is threatening to make an appearance, so quite a V8 convention !!! |
| M Barnfather |
| Mike, In some form yes. I emailed Geoff about it but have been away for a week and got 2164 emails on my return, mostly spam which was filtered out so I don't know if he got back to me. He probably did but my machine here has lost it. Are you all staying in a/the same hotel? which one is it and how much? |
| Liam H |
| Geoff & Claudine and are at the St George, we are at the Kimberley with friends, best rates are on the hotel booking website hotels rather than direct, we used 'pet friendly hotels' as our friends are bringing their dog. Googling 'hotels in Harogate' should produce results....hope to see you there. |
| M Barnfather |
| I was under the impression that more fuel plumbing was involved when converting to EFi,including different hp pump and a fuel return to the tank. Plus machining down the plenum to fit under a standard bonnet. |
| Allan Reeling |
| Yes Allan, all that you say is true. Geoff, Mike and I have used / am going to use the RV8 style bonnet lid. |
| Mike Howlett |
Allan About $100 (or less) Australian worth of welding and machining on the trumpet tray part of the plenum. You tell a engine shop to weld up the 3 vacuum take offs then machine 16mm off the bottom and 10 off the top. You can shorten the trumpets yourself easily. Fuel, you need to buy a late model MGB sender, that has the fuel pick up incorporated into it (about $55) some fuel line, a bosh high pressure pump $150, and a feeder pump, peirberg part #12001, to draw fuel though a big filter and supply the bosh pump and keep it quiet. |
| Peter |
| In the UK we tend to do without the second pump, the trick is to have the Bosch pump as close to the feed as possible, and as low as you can, mine is on a plate immediately in front of the tank, I have a Rover SD1 axle, it may be that the different handbrake arrangement make this easier than an MG axle . The attached (somewhat blurry ) pic hopefully will show you. 
|
| M Barnfather |
| Mike, What was involved in converting your SD1 back axle for use? was it a tricky/expensive job? Liam |
| Liam H |
| Yes it was a s*d actually, wouldn't bother again quite frankly. The axle and half shafts have to be shortened ( my half shafts actually twisted and I ended up with some expensive seriously uprated ones) the hubs and drums have also to be re-drilled for 4 studs,spring mounts have to be fabricated for leaf springs and you have to modify the handbrake mechanism to match up with the MG handbrake. The Hoyle independant system would probably have been cheaper and certainly easier to fit. |
| M Barnfather |
| Liam, I sent a message, it would have been with the other 2164, I’ll send it again from home tonight. You would have just as much trouble fitting a 3.5 efi Range Rover engine as a 3.9, there is no external difference so go for the 3.9 and make the modifications needed. Andrew Harrison should be at Harrogate too but he’ll probably turn up in his Jag. |
| Geoff King |
| HI geoff, I just emailed you about harrogate. I was thinking about the SD1 Series 2, Vitesse 1982 on and VDP EFi 1984 on. (I'm not that knoweldgable! it got it from here http://www.roversd1.co.uk/tech_data1.htm) If I had to replace most of what was on the engine anyway, and still find a gear box, that might be a better way to go? I assume that with the EFI performance would be better than the with the weber/offy set up anyway. I would also leave the back axle as it was so I had more of a street car and had better peformnce lower down. One thing I notice with my 3.3 axle - the real power comes in not from a standing start but from 20 mph onwards. Probably limited by the fact that if I want to accelerate hard from a standstill I need to get out of first gear almost as soon as I hit the throttle, which in practice makes 2nd the first gear in such a situation, and it won't be as punchy as 2nd gear with 4 ratio back axle. In practice I dont find myself doing 70 mph anywhere anyways, so the top gear fuel economy is not that crucial. Liam |
| Liam H |
| Liam If I was going to upgrade I would be looking for a 91-94 Range Rover 3,9 with 9.35/1 compression. you should if your not in a hurry be able to find a good engine with all the ancillaries inc air flow meter, a ECU and loom. If you fit your front cover water pump and pulley alternator bracket etc you will have a drop in engine, I assume you would give the engine a rebuild. The front cover and ancillaries from the 3.9 could be bolted on to the 3.5 and then you have got a complete engine to sell on with or without carb and inlet. All you need for the EFI is a return fuel line a large diesel type filter to act as a swirl pot and the high pressure pump, your existing pump can feed the swirl pot. You could give these guys a ring they would probably sell you the whole lot at a very competitive price. Harvey Taylor Vehicle Management. Ian Wilson 01332 740411 or Mob. 07763 403864 I bought a complete distributor from them from a 3.9 for £40.00 and they quoted me approx £200.00 for a complete Hot Wire EFI system. and I think that included the pump. Kevin |
| Kevin Jackson |
| Liam, I bought exactly what Kevin mentions, a 1991 Range Rover engine, only 130,000 miles, complete with all the Efi kit and ECU and loom for £500 off ebay. I don't suppose the outright performance of the Efi engine is any better than a properly set up 4-barrel, might even be slightly less. But the Efi is easy to set up, will start much more easily, run nicely hot or cold, and will be more economical. That'll do me. I don't have an email for you Liam. Could you drop me a line on mikeATbalcomie.nadsl.net so that I can ask you about your steering? Obviously you put @ in place of AT. Thanks, Mike |
| Mike Howlett |
| Kevin/Mike, You both mention a 91 engine - what about a 1990 engine, it has been converted to LPG - does that make a difference? The thing is, its still in the car so i can see it running and its local to me, so I can make sure i get all the bits I need. Plus its an auto so I'm hoping will have been less stressed than a manual. Liam |
| Liam H |
| Liam, The 3.9 was produced from 88 to 93/94 so a 90 should be fine, just do the usual checks. If it's still in the vehicle and running thats a bonus, check oil to see if it's reasonably clean and if poss take of a rocker cover to see if it's heavily sludged which could indicate poor maintenance. I'm sure your aware, but you want an engine with engine no. prefix 35D or 36D for a 9.35/1 compression. Can't advise you about LPG, have heard some comments that it can cause damage but have a look at RPI's site, they have a section on LPG conversions but they can be a bit doom and gloom about anyone else's kit. If you decide to have it make sure you get all the EFI bits including the airflow meter, ECU, loom and the pump if possible. I must admit a LPG conversion could make for a very economic high performance machine. RPI do a tank that fits in the spare wheel position! Good luck. Kevin. |
| Kevin Jackson |
| Hi Kevin I would ditch the LPG stuff, just too much take on. Not knowing anything about it, I was concerned that once you went down that route with an engine you could not then go back to petrol, or that it damages the engine. Thanks for the heads up on the prefix. Liam |
| Liam H |
| Liam, Normally switchable so you could use either if you so desired. Kevin. |
| Kevin Jackson |
| Cheers Kevin, Has anyone ever used the manual gearbox that occasionally crops up with a 3.9? Liam |
| Liam H |
| Liam, I don't think any 3.9s R/Rover's came with manual boxes, what you may have seen is the low ratio selection lever which i believe is step down ratio for off road use, but I could be wrong. Kevin. |
| Kevin Jackson |
| Liam, the 3.9 will not improve anything in an BGT V8, it is allready beyond the limits of the car's construction with a SD1 engine. So the 3.9 only makes sense as a spare engine. The only plus would be to use it as an EFI with the right ECU, catalytic converters and all the other stuff that was realised in the RV8. Aldough you can put all the nessecary parts from the 3.5 to a 3.9 and it would give you more torque than the smaller engine can produce, the car would not go faster or be more economical at all. I have a 3.9 spare engine in my garage, just for piece of mind, but hope that i will not have to install it as i never had any joy at speeds in exess of 120 MpH wit the GT and it was no fun to go 130 although more would have been possible on the Autobahn as suspension and roadholding becomes very critial then. Even with lots of money spent into mods of the suspension the B does not become a safe car at high speeds! Concerning torque, the 3.9 will deiver wheelspinn earlyer but will also wear out the prop shaft and axle earlyer! Just consider upon optimum (that you have now) and maximum (that does not give any rear benfit to the driver in an MGB) and than find your solution what to do. Ralph |
| Ralph |
| torque is nice to have. I am not after top speed. Unless you are lucky enough to live near an autobahn you can't legally use it & Ralph is right about it being suicide to go over 130mph in a B. I have tried 125 and didn't like it much, very twitchy. But torque in an MGB makes for a very fun and easy car to drive. A figure of 350 lbs was mentioned in an adjacent thread, as the limit on a Salisbury axle. If you set the engine back a little, or move the radiator forward to the slam pannel, there is easily room for the standard rangerover waterpump. Thats what I have done. 3.9 Balance. My 3.9 was an almost new short motor, a replacement for an older worn out one. This could explain why I don't have any of the balance problems Geoff mentions. Perhaps they internally balanced the later replacement motors, along with the 4.6's. |
| Peter |
| The age of the 3.9 engine is not related to how it was balanced, all 3.9 engines used the 3.5 crank but with larger (and heavier) pistons, the balance correction was made on the pulley. All other capacities (3.5, 4.2, 4.0 and 4.6) were internally balanced on the crank. |
| Geoff King |
| Ralph, Germany- I do not understand your statement that a 3.9 will not improve anything over a 3.5 in a BGT. Forgive me for being old and, perhaps, stupid, but after driving a 1974 BGT for 230,000 miles with a 4.2L, driving a 1973 BGT with 5.2L is a big improvement. I realize that at some point aerodynamics limits top speed, and perhaps accelleration, so if this is what you mean, O.K., but a 3.9L engine is not going to reach either limit. I used to have a small sail boat with a hull speed of 4.5 knots, but caught in a bad storm with 60mph plus winds, the boat exceded 10 knots with no jib & 2 reefs in the main. The point is, with sufficient power, theoretical limits are often overcome. |
| Jim Stuart |
| Jim, glad to hear from an other old fellow that also is involved in yachting. It is through, that you can surf with a sailboat if crusing into a gale, although the hull speed says that there are limits due to the length of the water line. I had this experiance several times on the north sea too. With the BGT V8, mine is fitted with a 3.3 rearend, the power of the 3.5 V8 (mine has 184 RWHP) will allways be bejond the capabilities of the chassis. I drive mine since 1979 and have changed a lot of details on the suspension, breaks, engine, cooling... Adding more power makes it exellerating more 'dramaticly' but does not make it faster (Wheels/Tyres 5.5/14/175-80 HR 14), concerning road use. May be it is an other situation in here, where it is normal to drive on the freeway/Autobahn at 80 - 100 Mph, sometimes faster too. The larger engine would give benefits in exess of 120 MpH, concerning excelleration and topspeed on top, but how much can you (and the car itself) handle? If the car is concerned to be a quarter mile performer, you are right , i think, but for a daily driver this is not an option to go for an engine larger than neccessary if the chassis has not been designed for this feachers! Safety Fast! Ralph |
| Ralph |
| So if I moved the rad panel forward, in addition to the water pump culd I keep the crankshaft pulley (to keep the balance) and alternator? They woudl all be on the same fronat plave line, yes? Liam |
| Liam H |
| I believe now that you could keep the same harmonic balancer pulley. In fact this is a good move given Geoff's remarks. I must have been very lucky because my motor revs freely to 5500 and will go to 6000, or possibly further(too chicken to try!). Perhaps the previous owner had it balanced? In the standard motorlocation, the 3.9 pulley will clear the steering rack. When I did my conversion I was under the impression that overheating and bonnet clearance were big problems. This is not true. However, with this in mind,I placed the engine as far back as possible and had to use a longer neck pulley to clear the steering. Further back gives both greater bonnet and radiator clearance. I also wanted to get the gear lever in the same spot (supra gear boxes are shorter than MG ones). I thought that handling would only get better. This last was not true, but was band-aid fixed with some good Michelin tyres. The bonnet clearance is not an issue I realize now. The motor may be placed down a further half inch than usual without problems, which I've done and in fact, gives a lower center of gravity :). I would also consider mounting the motor to the front crossmember, which should get the it even lower, and be actually easier to do, no Rubber bumper body brackets needed, plenty of room, so much easier to get the motor in and out. Also with "through the guards" extractors the chrome bumper steering universal joint may likely become not a problem, engine being an inch or so lower down. Also, if necessary, up to 33-34 mm (you actually don't need anything like that much) may be machined off he plenum. So you see, heaps of bonnet clearance. To address the cooling problem, I used an expensive monster (biggest available) electric fan directly behind an alloy radiator for maximum efficiency, so needed plenty of room. With the air flow advantages of through the guards extractors this was overkill in the extreme. Much better to use two smaller fans placed asymmetrically, one front top Right corner, one back bottom Left corner. This would take up lots less room and give similar coverage. The rear fan motor would not get in the way being away from center line and the water pump. Especially true using a range rover front cover, that has the larger water pump offset up and to the right. Also two fans give redundancy,so you can take a chance on buying cheap secondhand ones. With this arrangement I believe you would not have to cut the front tray at all and may even be able to place the motor forward a little. You could also use that two stage thermostat they use on VW's to run the fans more efficiently. You should be able to work out whether you need to cut the tray or not by comparing you current V8 set up with the following information about mine. With the motor placed so there is 10mm between the closet point of the RHS head and the rear bulkhead and the front oil cooler tray cut forward to level with the top slam pannel; I have 72mm between a standard rangerover water pump nose and the radiator core. Thats level at the sides, the radiator, and the bottom tray is of course straight and the top slam panel curved. Alternator- Range rovers have a heap of brackets that spread alternators , steering pumps and god knows what else liberally all over the place. No room in an MGB. At one stage I was using the original balancer when the motor sat half an inch higher. I used an SD1 pulley bolted to the original balancer. A cast "air conditioner" style water pump pulley and a rover P5/6 MGBV8 (same thing) alternator bracket that was spaced forward to line up with the water pump and bottom. The problem of radiator clearance is of course the nose of the pump, not the position of the belt or bottom pulley. |
| Peter |
| Peter, Thank you very much for that detailed and fascinating explanation which answers a lot of questions I hadn't even thought to ask. Do you have any pics of your front end by any chance? Liam |
| Liam H |
| Liam, I’ll bring a 3.9 front cover and pulley with me to Harrogate at the weekend, and then you can compare them to the 3.5 items. For the RV8 MGRover used a 3.9 cover with a shortened water pump to obtain the clearance from the radiator. Geoff |
| Geoff King |
| Thanks Geoff, looking forward to meeting you. Lets hope the weather holds - I saw about 10 old MGA's in Morpeth yesterday with German ??? plates - beautifully restored. They must be on their way. BTW - do you think 150 is a good deal for an untested supposedly low mileage LT77 with bellhousing and remote? Liam |
| Liam H |
| Liam, If it's the right LT77 it's a bargain, bellhousings are getting hard to find and are fetching £150.00 on their own. The codes for gearbox you are looking for are on this useful site at the bottom of the page. Kevin. C:/Documents and Settings/KJ/My Documents/RoverV8 Engine No.s.htm |
| Kevin Jackson |
| Liam, http://v8scimitar.co.uk/index.htm Not sure what happened, go to the main site click on site map and then under Technical, engine numbers and this gives the gearbox codes. Kevin. |
| Kevin Jackson |
| This business of engine balancing. I intend to do away with the huge pulley assembly on my 3.9 and fit the machined SD1 pulley as shown in Roger Williams' book. Is this going to give me problems with the engine or not? Will I need to get the reciprocating components balanced? I'm confused. Mike |
| Mike Howlett |
| Thanks kevin, its a D suffix I'm after isnt it? Liam |
| Liam H |
| Liam, I don't own a digital camera I'm sorry. One of these days I'll get around to buying one. The caste pulley for the water pump is one that I have seen on both rovers and rangerovers, all of which happened to have airconditioning. This pulley has it's grooves about 10mm further forward than the pressed metal pulley. The advantage of this is that it happens to line up with either the 3.9/4.0 balancer with the SD1 deepest/largest pulley bolted to it OR the SD1 balancer with its flattest pulley bolted to it. You could of course use a 10mm spacer under the pressed meal pulley. Mike, It didn't with me. I believe that I have an answer. My engine may be a 4.0. The guy I bought it off had got the newish short motor very cheaply off someone he knew and built a 3.9 engine around it, heads EFI etc, with the intention of selling at a profit. It came with the post 95 front with the "on the nose" oil pump, but with the "3.9" on the plenum. My 4.0(?) has the provision for the cross bolts, but not the actual cross bolts, which I believe that they put on the 4.6 only. Also the end of the crank where the balancer/pulley bolts onto is a little longer than the 3.5. Perhaps 10mm, its hard to see in there. I do recall that when I initially did up the bolt on the SD1 balancer, he pulley was still loose and I had to use a spacer. The spacer was nothing special, just a left over piece out of the cracked block 3.5 I had. It might have been a distributor drive, this was over three years ago and since I found a spacer directly at had I did not think about it too much. Just to be clear on terminology. The "Balancer" is the cast heavy thing with the rubber bonded bit on it that is held to the crank by a single bolt. "Pulleys" are the grooved "fan belt track/wheel" things that you bolt to the Balancer. With your balancer with its vast collection of pulleys, I believe that it is very likely that most of the balancing is going to be on the actual balancer itself. The collection of pulleys bolted to it will be contributing very very little to any unbalance compared to the crank plus pistons. I would suggest that you keep the original balancer and that you can quite safely unbolt any extraneous pulleys. Since you already have an SD1 balancer, you might consider selecting a suitable pulley from the SD1 balancer collection as I did at first. They are interchangeable. For those with rangerover fronts, the deepest biggest pulley lined up with that caste water pump pulley. The alternator is not a problem. Just spacer the entire bracket forward. I set it up with longer bolts and stacks of big washers, and then when I had time, cut three small blocks of aluminum which looks much better. This approach has the added advantage that you can use any alternator you like, much more room as you are effectively moving the plane of the fanbelt forward without moving the water pump nose. This also has the advantage of moving the belt away from the bottom radiator hose, which is a plus as it is a little too close otherwise. I used a piece of stainless tubing there in case of the belt cutting the hose. |
| Peter |
| Peter, you are a star! If I ever make it to Oz, I'll pay you a visit. So simply put, you can stuff a 3.9 RR front end into a rubber bumper with out clearance issues. I want to clarify - I'm not doing an engine swap (I have only just finished!)- I'm doing another conversion - this time th easier way! A good value 79 Roadster has come my way, and I have a Land Rover breaker both 5 miles and 15 miles away. On the over heating issue - thought I'd report - I have never had to switch on my 2nd fan yet - and that was with a 20 minute wait to get into the Tyne Tunnel on Sunday. Liam |
| Liam H |
| Liam, 'D' suffix gearbox if you can find one from a late SD1 or possibly from a Jag which used the LT77 but of course the bell housing would be different. don't know if the remote is the same, you would have to measure. Kevin. |
| Kevin Jackson |
| Thanks Kevin, I looked back through my old notes and thought is was a D. It is from a SD1 V8. I just bought it for £150 - remote, bellhousing and box. Now I just need to hump down the A1 to collect it. Wonder how much it costs to get a casting done from a bellhousing? 2 years ago I bought a complete SD1 VP for 650. had all the bells and whistles, as a donor. The bloke couldn't get rid of it, he even drove it half way to me from York. I made more money selling the left overs on ebay than it cost me. Now I can't find one for love nor money. The V8 and LT77 it seems are en vouge. Cheers, Liam |
| Liam H |
| Liam, SD1's have become quite rare, my Vitesse donor (a runner, but MOT fail ) cost me £650, but the deal was I gave the car back after I had taken out engine,electrics, box, axle, and brakes....looking back it was a bargain. |
| M Barnfather |
| Folks, Just stumbled onto this thread whilst surfing for advice on transfering the torque convertor/ drive plate/ ring gear assembly between rover v8 engines for auto use. Struggling to find some info, and sorry to butt in, but can you folks help, please? I am midway through an engine replacement, like for like in a classic range rover. I am at the point of swapping over the torque convertor/ ring gear assembly between the duff and the replacement engine. So far I've removed the torque convertor, also the 4 bolts securing the drive plate assembly from the duff engine, and it looks like a puller should now remove it and butress ring together in one go and reveal the spigot aligner/ bolts... So is it simply a matter of using a puller on the drive plate to bring it and the buttress plate off together? None of the manuals discuss this detail of disassembly... Thanks. John H |
| John H |
| John, there should be 4 bolts holding the torque convertor to the drive plate & 6 bolts (1 offset) holding the driveplate to the crank. Once the bolts are undone, a tap with a hammer or lever with crowbar or long screwdriver shouild be enough to release it. It's not an interference or pressed on fit. Barrie E |
| Barrie Egerton |
| Barrie, thanks very much. John |
| J Hinks |
| Liam, Here are some approximate measurements (to within 5mm) so you can tell for sure, Distances are between Right angle lines from each point. From the middle of the heater to the nose of the standard range rover water pump is 772mm. From the nose of the water pump back to the portside front of the block (left hand when sitting in the divers seat, right hand when standing in front looking at the engine) is 223 mm from the slam panel, middle, deepest part of the curve, it is 150mm to the water pump hose. The original location of the bottom tray is lost on my car. Measure the thickness of your radiator and add that to 772mm. If you have more than that between the bottom tray and the center of the heater, then you don't have to cut the tray, which is not such a big deal anyway because the place where you cut and shut is hidden by the radiator anyway so can be as rough as you like. |
| Peter |
This thread was discussed between 12/07/2007 and 01/08/2007
MG MGB GT V8 Factory Originals Technical index
This thread is from the archives. Join the live MG MGB GT V8 Factory Originals Technical BBS now