ZF 4HP22

It is a nice box, Lee. I've really noticed the difference even just around town. The shifting is very smooth, and I like the way I can essentially control the box manually (both up and down shifts) by use of the throttle. I've made a few adjustments to the throttle valve cable and I've now pretty much got it how I like it, with moderate throttle upshifts taking place at about 2500rpm. That, to me and my car at least, feels about right for the usual pull away from the lights. Anyway, it's so easily adjustable (apart from having to remove the air filter to do it) that you can just play around until you've got something you're happy with.

The car is so much nicer to drive with the ZF, it really is.
 
Good news! The latest round of frigging with valve bodies has nailed my final outstanding problem - lack of torque converter lockup using the Land Rover valve body. It is now present and correct, and makes its presence felt as a very noticeable drop in revs at 50mph, very much like an upshift to a fifth gear. Thank goodness! My first motorway test tonight found Brown Rover travelling at a GPS-confirmed 100kph with just 2100rpm indicated on the tachometer. Very relaxed cruising compared to the 3000+ that I used to put up with.

All done! With a transmission cooler installed and the torque converter locking up, I can now call the project COMPLETE!

I will shoot a video, promise, but I want to try and sort the wobbly tacho first.
 
Congratulations! Where did you take the seperate cooler from? A 75? This also should improve fuel consumption as with the lock, there will less energy losses in the transmission
Regards
Peter
 
roverp5Bcoupe said:
Congratulations! Where did you take the seperate cooler from? A 75? This also should improve fuel consumption as with the lock, there will less energy losses in the transmission
Regards
Peter
Click to expand...

Hi Peter. I attempted to fit the Rover 75 cooler I have in the garage but it was too wide. The only spot that it showed any hope of squeezing into was halfway down the radiator, behind the number plate plinth/bumper, where it was mostly blocked from good airflow and beyond help from the fan, and it would have required some surgery on the inlet pipes at the very least. In the end I bit the bullet and bought an appropriately sized unit from my local independent motor factors. It's American made (can't remember the brand off the top of my head) and cost a bit, but I couldn't see the point in messing about with anything cheap and nasty. I mounted it on the front of the radiator, directly in front of the fan (as per the instructions) and it made an immediate noticeable difference to the transmission. Smoother shifts, etc. I was told that the existing cooler was the bottom three rows of the radiator, but on closer inspection it turned out to be a pig's tail in the starboard side tank. Bugger all cooling from that, I'll bet! However I have noticed the temperature gauge sitting slightly lower on a steady run than before the piggy tail was disconnected, so there must have been a certain amount of heat transfer going on. Just not enough to keep the ZF happy. This isn't a very good pic, but it shows the installed cooler before it got hidden away behind the grille:

DSC09779_zps853eea90.jpg~original


And thankyou, Richard. I have to admit, the project fought me to the end. Lack of experience, lack of precedent to follow, and a few unexpected problems (principally the previously messed with LR valve body). Nice to have nailed the last problem, I can tell you. At one point I was frustrated enough to almost be prepared to forget about lockup and just enjoy the extra gear (a grand improvement by itself), but tonight's experience of lockup as it should be has proved a further revelation and made me very pleased to have kept going right to the end.

All I need now is a new fuel pump and I can forget about working on the car for a while. Time to just drive it and enjoy it.
 
Hi Warren,

Glad to hear that you have the problem sorted. I do find it strange though that Brown Rover would run at 3000 or so rpm at 100kph with your old BW. Mine runs at less than 2600rpm at 100kph, which isn't high by any stretch of the imagination. The transmission oil cooler will make a huge difference to the longevity of your transmission, well that is the theory at least. You'll notice in addition to a cooler and more stable coolant temp during highway running, an even more noticable stability during suburban driving, especially if the traffic is anything but light.

Look forward to seeing some proper fuel consumption figures once you have the new electric fuel pump up and running.

Ron.
 
WarrenL said:
Good news! The latest round of frigging with valve bodies has nailed my final outstanding problem - lack of torque converter lockup using the Land Rover valve body. It is now present and correct, and makes its presence felt as a very noticeable drop in revs at 50mph...
Click to expand...

Superb news Warren!

Torque converter 'lock up' at 50mph seems pretty much spot on, and where it would be much needed for better economy and quieter cruising etc., as you say. It is strange though, how some Borg-Warner autos fitted to P6 V8s have different gearing somehow. I'm sure it's more of a final drive gearing rather than different gear ratios that could be the issue?
 
I do find it strange though that Brown Rover would run at 3000 or so rpm at 100kph with your old BW
Click to expand...
isnt that what the ratios say it should do Ron? Sleipnir has no rev counter being a series one, but i'm pretty sure it's somewhere around that figure...

Rich
 
I will have a look at revs at 100kph next time I'm out - I know 70 mph is very close to 3,500. So I'm fairly sure my car corresponds with Warren's figure rather than Ron's. A likely cause is that somewhere along the way, Ron has acquired an "upgrade" in his torque convertor and it now doesn't slip as much as our standard ones. That is evidenced by a different "stall speed" figure being quoted. That would certainly match with Ron's instruction to his tranny builder that he wanted a nice sharp change.

Chris
 
All bets are off until that fuel pump problem is sorted, Chris. I'm enquiring about the Huco pump as we speak.
 
WarrenL said:
All bets are off until that fuel pump problem is sorted, Chris. I'm enquiring about the Huco pump as we speak.
Click to expand...
I dont think the thread is the sealing portion of the fuel line terminating into the pump body but rather the olive or flare, unless your olive is some how entering the receptical off square it should still seal regardless of thread damage. Personally I would not go back to the electric pump but would sort out another mechanical from a wrecker or see if Chris has one handy with a good thread, you can always chuck your good bits in a duff one.

Graeme
 
It's blowing back out the thread, Graeme. You can see where it's spraying onto the engine block. I'd say there's not enough tension left to seal the olive properly against the seat. And I got another pump off Chris, but the thread on that was knackered too. Looked OK to the casual eye, just dirty, but I cleaned it and wound in an olive on the bench and it immediately stripped. I think a lot of them are stuffed because of the mild difficulty of getting the inlet pipe lined up properly during reinsertion if the pump has been out. A caring Rover owner will take the time to get it right before tightening up, but a garage monkey would be likely to neanderthalise it without giving a shit. This is what happened to mine, I think. It was then OK for an unknown number of years until I took it out and tried to put it back...

I could see this going on and on, so an electric pump it is.
 
Oh, and I've been driving about and savouring the newly unearthed torque converter lockup. It's like having yet another gear! A gentle acceleration down the road from rest produces an upshift sequence that seems just like 1-2-3-4-5, remembering that with the old gearbox you only got to 3 (which is the same ratio in each box). It's really cool! Unless you're accelerating hard lockup happens at 80kph, and a GPS-checked 100kph is achieved with just 2100rpm on the tachometer.

In terms of power, my bog standard 10.5:1 3528cc donk adequately handles the much reduced cruising revs. At 2100rpm in lockup there isn't a great deal of overtaking power, but a bit more pressure on the go pedal breaks it out of lockup (feels just like a down change), boosting the revs to 2500 or so and sitting high enough on the torque curve for things to start happening. And if you really need to go, just stab the pedal and kickdown into 3rd (as I said, same as the old BW top), and the old girl bursts into life with a lovely V8 growl. Oh, it's lovely!
 
Nice to hear you got it sorted Warren.
Picking my newly painted wings (fenders ? ) up next Friday, only the doors to sort, exhaust, interior and of course the MOT before I can explore the ZF..

Jim.
 
Thanks Jim. I'm pleased it's all over. There were a few problems to overcome, not related directly to the conversion, but more to do with a misbehaving valve body. Just the luck of the draw. Anyway, it's really sweet now, although I think there will be at least a couple more tweaks of the TV cable before it's shifting exactly how I want it to. Take note, you will need a transmission cooler. The pig tail in the P6 radiator just isn't enough.
 
You must log in or register to reply here.
Back
Top