|
|
Post by allanm on Oct 29, 2012 15:07:39 GMT
As a new member I`m experiencing difficulty finding the info required for this conversion, although it must be out there on the forum
|
|
|
|
Post by Kev on Oct 29, 2012 16:27:04 GMT
As a new member I`m experiencing difficulty finding the info required for this conversion, although it must be out there on the forum Hi, What's the problem then? I have a 4ltr cross bolted "new" P38 engine,only thing i needed for the conversion was a kit to block off the sensor module hole & a crank nose modifictation from RPi...give them a call, all will be revealed. Oh, & to retain the front cover. Big Kev. |
|
|
|
Post by allanm on Oct 29, 2012 21:20:26 GMT
Hi Kev, thanks for the quick response. By keeping the timing cover will I be able to modify to take a rotary shaft seal as I did on my P6B ? What autobox did you use ? Thanks , Allan.
|
|
|
|
Post by Kev on Oct 30, 2012 6:18:32 GMT
Hi Allan, what i should have said was you will need to use the original front cover from a SD1 rather than the P38 unit. I installed the original 3 speed box after reconditioning it.
Big Kev.
|
|
|
|
Post by Roy of the Rovers on Oct 30, 2012 16:26:18 GMT
I'm still looking into the possibility of the 5 litre stroker kit for the 3.9 engine...Waiting for some prices from real steel..
|
|
|
|
Post by barryr on Oct 30, 2012 23:14:37 GMT
It seems aLways written that the bw35 is marginal behind the v8 - is that a myth?
In so many rebuilds the formula seems to be lower compression pistons which lose power but sd1 heads which breathe better then maybe a 3.9 cam for good price/power combo. I've always thought bigger power will pop the box but is that true?
My engine is original still so I can only dream but I do have a spare sd1 engine knocking about in case...
|
|
|
|
Post by Kev on Oct 31, 2012 7:40:25 GMT
Hi, Yes the BW box is weak... my rebuild guy tried to uprate it slightly but i know if driven hard it will tear the guts out of the box. SD1 Vitesse heads are a must in my opinion. In hindsight i think an american V8 plus box & of course rear axle would have been the way to go.
Big Kev.
|
|
|
|
Post by Roy of the Rovers on Oct 31, 2012 14:29:03 GMT
Just found out the stroker kit is no longer available  The way I see it if you dont uprate the gearbox/axle then you have to use the power carefully, flooring it at every set of lights is going to leave you embarrassed with bits of clutch band and differential teeth all over the road! But for the increased overtaking and uphill ability it will be a godsend (and maybe exhaust note!) |
|
|
|
Post by allanm on Apr 10, 2013 18:28:15 GMT
I`m back picking some brains on the 4.6 engine. Do any other V8 exhaust manifolds fit inside the engine bay or am I stuck with the originals ?
|
|
|
|
Post by Roy of the Rovers on Apr 11, 2013 12:22:55 GMT
I`m back picking some brains on the 4.6 en ine. Do any other V8 exhaust manifolds fit inside the engine bay or am I stuck with the originals ? Hiya, if you take a look in P5B 'parts for sale and wanted' you will see an advert from 'Redherring' called V8 engine wanted. He had done the 4.6 conversion and was unhappy with it so wanted to change back. 1. You might find the parts you need right there? 2. He probably has invaluable advice for you... If I were you I'd get in contact but please share details on this forum so we can all benefit from the experience!  I have a pair of P38 tubular manifolds in the garage, I'm hoping I can modify them to fit the tight spaces with the P5 engine bay. They certainly look the part, unfortunately I'm not in a position to start the conversion yet... cheers Roy |
|
|
|
Post by Kev on Apr 19, 2013 6:32:42 GMT
I wonder why he was "unhappy" with the conversion?
4.6 ltrs.... a marked improvement in my eyes...unless the engine was ripping the BW box apart.
I had 2 tubular P38 manifolds that were to be used but i gave up as the space was so tight & refitted the originals.
Big Kev.
|
|
|
|
Post by enigmas on Apr 19, 2013 12:38:44 GMT
The BW35 box can be made durable for this type of conversion if upgraded with BW40 & 51 components. Take a look at this link to a much modified P76. linkP76 |
|
|
|
Post by Dean Hovland on Apr 19, 2013 13:07:58 GMT
Hi Enigmas your link doesnt work.
|
|
|
|
Post by enigmas on Apr 20, 2013 10:33:44 GMT
It does now.
|
|
|
|
Post by Roy of the Rovers on May 11, 2015 13:00:21 GMT
To revive an old thread, is there a definitive list of what is needed to upgrade the BW35 to take a bit more power?
Following Enigmas link it says: Auto Transmission - BW35 Full Detailed Recondition (BW40 Heavy Duty Bands & Clutches) and valve-body BW51 type.
Is that the definitive list? Could I take that list to an auto recon shop (in the UK) along with my spare BW35 and say 'make it happen'?
thanks
Roy
|
|
|
|
Post by eightofthem (Andy) on May 11, 2015 15:22:51 GMT
Why not just fit a ZF 4 speed?. very easy swap, and the extra gearing really does help.
The BW will always be a 3 speed no matter how you work it.
|
|
|
|
Post by harvey on May 11, 2015 15:30:40 GMT
Auto Transmission - BW35 Full Detailed Recondition (BW40 Heavy Duty Bands & Clutches) BW40 clutch plates and bands are exactly the same as the BW35 ones, so no point in that. As for the valve block I'm not familiar with the BW51 item so can't comment. The rear friction plates used to be heavier duty than the front ones, so you used to be able to fit the rears to the front as an upgrade, but they're the same front and rear now. |
|
|
|
Post by enigmas on May 11, 2015 22:44:24 GMT
www.classicroverforum.net/viewtopic.php?f=1&t=15520Posted across from the above link. Re: BW35/BW40 by SydneyRoverP6B on Tue Jan 15, 2013 9:14 pm Hi Jim, When my transmission was rebuilt in 1997, the original Rover planatery gears etc were all replaced with Ford parts. The friction materials were also replaced, the rear band now being Kevlar lined. I don't know what the actual differences are in terms of dimensions, but during 2009 when it was rebuilt again, the gent said to me that it had received a partial upgrade in the past, so there must be obvious differences. He said he would do a complete upgrade to M51 standard, which was the last derivation of the BW35/40 box which came about around 1989 or even later. Both Castrol and Ford changed the recommended fluid from Type F to Dexron around 1983 for Ford Australia vehicles fitted with the BW40 transmission. Later the spec would change to Dexron 2 which was the recommended fluid for the M51. I spoke to three different transmission builders not including the gent who carried out my 2009 rebuild. They all said that these later transmissions would typically see 300 to 500,000km between rebuilds when used in Ford Taxis and that the Kevlar bands after that distance would show insignificant wear, so they would be used again in the rebuilt transmission. Ron. 4.6 litre Rover P6B End of quotation insert. PS. Do the UK BW35s have the wider flex bands rather than the narrow cast ones Harvey? The BW35s in OZ were also fitted behind 289ci Ford Falcon V8s of the mid to late 60s (XR & XT from recollection). www.uniquecarsandparts.com.au/falcon_XR_technical_specifications.htm. and the P76 V8 of the early 70s. www.leylandp76.com/technical/tech-rickv8dyno.html www.leylandp76.com/private/vic/motivator.htmlThe gearsets from the various versions are not partially interchangeable but complete sets can be changed across the earlier housings. The one way clutch from the 51 can be directly fitted to a 35/40 as it is heavier duty with more individual sprags. The 51 also has 3 bolts securing the rear servo to its case, not 2 as in the 35/40. The valve bodies in the 40 up were also much improved with a light part throttle shift into 1st gear, noticeable when rounding corners at slow speeds. The latest valve bodies enabled the trans to be more speed and load sensitive. Earlier versions of the BW35 as most restorers are aware, tend to go straight to 3rd gear and want to stay there. As I've stated many times previously, these transmissions were developed into the late 1980s. The Ford Motor Company in OZ fitted them behind some very grunty, big EFI 6 cyl engines up to 4.1 litres in their last incarnation. They are a durable and cheap to rebuild transmission if used sensibly. You can break anything though if you try.
|
|
|
|
Post by harvey on May 12, 2015 13:28:26 GMT
For about the last 4 or 5 years I've been trying to get pictures of the BW51 to see the differences, and for all that time no-one I've spoken to about them has been willing or able to come up with any. The BW40 is so similar to the 35 that I can't see why the number was changed. The fluid change to Dexron is similar. My own theory was that as it was for the Australian market only as that was where the majority of boxes were in use long after elsewhere, and BW wanted to keep taking the money from an outdated product, as they had no wish to develop another box to use because of the development costs associated with doing so. From their viewpoint providing the boxes outlasted the warranty period, the smoother shifts made the box appear more in keeping with its more modern counterparts.
I'm aware of the poster you quoted, and a very nice bloke he is from the dealings I've had with him, and he has a very nice car which he has a very long personal history with, but, as far as the gearboxes are concerned he is totally reliant on what other people tell him, and in the case of some of the "experts" he's spoken to, repeating some of the things they have told him has made him look very foolish indeed when he has passed them on as fact.
|
|
|
|
Post by enigmas on May 12, 2015 14:25:26 GMT
I'll make it a mission to get a photo of a BW51 for you Harvey but you won't notice much difference from the outside of the casing. As far as some internal components go. The main differences are in the thicknesses of the gear shafts, the 3 bolt rear servo and the more sophisticated valve body.
I fitted a BW51 one way clutch with its increased number of sprags to both the current gearbox in my coupe and to the spare trans I have. (BW40 internals in MK3 cases 20 years ago).
I asked a question earlier about the 'bands'... Did the UK BW35s or whatever the last version of this transmission was in the UK have the wider flex bands, rather than the narrow cast ones of the early 35s Harvey?
As for the story about durability of BW35s and 40s in cabs the story has validity. Many of the cabs (at least in Victoria) that were fitted with early versions of 4 speed automatics were erratic in operation and very costly to repair.
|
|
|
|
Post by harvey on May 12, 2015 14:39:47 GMT
I'm just interested in seeing the internal differences between the 35 & 51. I'd want to see bigger clutches and more of them, and I don't think that's possible within the confines of the BW35 casing or the clutch drums. The 3 bolt rear servo would address the problems with the 2 bolt one cracking and coming loose.
The late 35 boxes had a flexible front band, and it's wider than the solid band. BW65 had flexi bands front and rear.
|
|
|
|
Post by Roy of the Rovers on May 12, 2015 15:31:41 GMT
Loving the discussion, I know nothing about gearboxes but I would want to know what to say to my local autobox repair place to uprate mine. As a business Im pretty sure they would only want to replace what is already there but if I had exact requirements presumably they would be more happy to make the mods. The 4 speed zf is great but getting the correct one with appropriate speedo drive, oil cooler and gear selector is akin to guessing tomorrow nights lottery numbers. They are rare. At least an uprated BW 35 is a bolt in upgrade to sit behind a more powerful engine, would take a bit more lively acceleration and should be fine to sit behind John W's overdrive upgrade when I can afford one. And it still look standard. |
|
|
|
Post by barryr on May 12, 2015 22:38:08 GMT
Well said Roy! - like you I'm fascinated and looking forward to getting some solid recommendations!
|
|
|
|
Post by enigmas on May 13, 2015 10:26:37 GMT
|
|
|
|
Post by Roy of the Rovers on Jun 4, 2015 14:26:07 GMT
I popped into my local auto gearbox place at lunchtime to pick up a new BW35 sump gasket. I asked if there was an upgrade spec for a BW35 that he could build a box to but the answer was no. He said the new bands would be made from better material and should cope with a more powerful V8 and he really didn't seem to acknowledge that different parts could be fitted. I guess their bread and butter nowadays is modern high mileage/abuse delivery van transmissions so its more of a conveyor belt of replace the worn bits for like parts only. It doesn't pay him to investigate which better parts might fit (and thats what makes the info in this thread more invaluable).
So in summary if I wanted to put together an upgrade kit for my BW35, so that it could be used behind a powerful RV8, what would my kit list read like? You've mentioned clutch bands, flex bands, friction materials, clutches and front pump sizes ?? Im a gearbox ignaramus but with a new 4.6 coming soon with a new diff, I'd rather not just destroy my BW35 when I have a spare that could be rebuilt to a better spec!
Enigmas, Harvey I would really appreciate your help with a wish list and maybe I'll be putting an order in for parts down under! Might also make a nice feature in the club mag..
Many thanks
Roy
|
|
