BritishV8 Forum

Don't suppose you mentioned your professional status to ole "I got tons of six speeds" at the junkyard, did you?  He should know better than to stick it to a barrister.

Rover bell for a ZF 4hp22

I seem to remember theres a GM180 option for the RV8, would that be any better for a Bellhousing,

Jim B., sorry for the thread jack.

I did a search on ZF 5hpNN and 6hpNN and made some interesting discoveries.

The 6hpXX transmissions have integrated bellhousings.

The 5hpXX transmissions seem to be very similar to the ZF 4hp22 transmissions used on Rovers. I suspect that it is possible to bolt the Rover 4hp22 bellhousing on a ZF 5hp24 or 5hp30 to get a narrow case 5 speed auto that fits the MGB.

As in Jim's case, the challenge will be the electronic controller for the transmission.

Very interesting stuff guys, can we get some more detail shots maybe?

Finally got a reply from Michael today, after I mentioned I might be interested in an 8 speed. (Funny how dollar signs can affect a guy's attitude ;-) )  Actually he's not a bad guy and I didn't mean to be critical. To be fair it's a mistake that anyone could make. Lexus used both the 5 and 6 speed in the SC430 and changed over mid year, plus they both look exactly alike as far as I can tell so you have to cross reference the part numbers. Plus he gave me a killer deal on the 8 speed. It's more than I've ever paid for a tranny in my life, but it's less than half the going rate so I'm pretty psyched.

Anyway, the upshot of it is that we made a deal on an 8 speed out of a 2008 IF-S. This is the transmission that is second in speed only to the transmissions used in F1 cars, which shift in .05 seconds. This one is half as fast at .1 sec but that's still faster than you or me. They also keep the converter locked in the top 7 gears so it acts more like a standard transmission, and there are a few other tricks. But I don't plan to use the Lexus computer to run it, I want to use the Megashift add on to the Megasquirt controller I already have.

So now the dilemma. Do I put in the 5 speed first for the simple install in order to get the car on the road faster, or do I go for the whole tamale? Not a bad choice to have to make, everything considered.

JB

2008?,Man, it's probably just broke in. If you got an older one like me, you would have to decide when you rebuild it. Parts prices bring up the costs quite a bit on a "good deal".

8 speeds...how many overdrives?

8 speeds! We'll have to start calling you "shifty" with that one in the car. As for which to install, what's your estimate on development time? It sounds like the basic shifting controls will be pretty much the same for either, just have to add more levels for the 8 speed, I woundn't think it would take that much longer to get it programmed than the 5 speed. Either one will make the car very interesting to drive with great performance.

Probably granny low in first and top two Overdrive? Let us know when you find out the ratios,just curious.

1      
4.596:1    

2
2.724:1    

3
1.864:1    

4
1.464:1    

5
1.231:1    

6
1.000:1    

7
0.824:1    

8
0.685:1    

R
2.176:1

JB

1-granny-dozer, do you copy ?  Soo,  soon as you release the brakes, you grab second ?

Looks like it to me. Redline right under the redlight. THAT ought to be a wild ride.

JB

Good thing it is an auto.  Can you imagine all the paddling you'd have to do?  What are the ratios on the 5 speed?

S'pose,  if'n ur in ta "paddlin", LOL. Can you say... Wheelie Bars ? "Real Men Use A Stick".

Should make a real interesting ride in combination with the blown 340. Tell you what. I betcha it'll outrun the MGB-Roadmaster.

JB

A650E

5 Speed Automatic Transmission

Applications:

    * 1998-2005 Lexus GS 300 (2nd Generation)
    * 1998-2000 Lexus GS 400
    * 1998-2000 Lexus LS 400
    * 2001-2005 Lexus GS 430
    * 2001-2005 Lexus IS 300 (1st Generation)
    * 2001-2003 Lexus LS 430
    * 2001-2005 Lexus SC 430

Gear Ratios: 1st 3.357 2nd 2.180 3rd 1.424 4th 1.000 5th 0.753 Rev 3.266

Max Power Rating: 325 wheel horse power.

Still waiting on that 8 speed, so I have gone ahead with modifications to the bell of the 5 speed. With some minor trimming of one bump and removal of the pan, the whole transmission fit nicely between centers in my old LeBlond lathe, well actually between the collet chuck and a live center in the tailstock. This wouldn't work with most domestic transmissions but this one had no wobble in the shafts and the park pawl locks up solidly so I decided to give it a try. I cut a counterbore 1/2" deep and 13-1/2" in diameter to accommodate the larger flex plate and ring gear of the 340 (and/or BOPR) and then cut a 1/8" deep by 14-1/2" step on the outside to register concentric and square with the input shaft. So now all I need is a plate with a like sized bore centered on the 340's crank (or BOPR) and the matching bolt and pilot pin pattern. Chances are pretty good it can simply bolt to the bellhousing.

JB

Jim,

You are a very brave, but sick puppy.  That's got to be a scary amount of mass spinning about.  Did you at least drain out the tranny fluid?? And all the floppy bits held together with masking tape.  Oy!    

What rpm did you do the cutting at?

MR

45 rpm. And the scariest part? Lifting the handle to turn it on the first time.

JB

Ya could've at least got out the 200MPH tape.  

Ive done some crazy turning before, but thats got to be the best!!!!,
Personally, I think I would have unbolted the bellhousing and either mounted it on External jaws or made a custom spigot to mount it from,
But thats because I only have a Colchester/Clausing Student Gap Bed

Can you say..."rotary table" ?  Novel approach. I've seen alot This is a first ! Any balls fall out, trans or elsewhere ? Did it, at least, upshift to second ?  Was the "govnor" nervous ?  roverman.

The Guvnor was a wee bit nervous, indeed. But nothing fell out other than a small bit of oil and all went well. However, on further inspection back on the bench it was learned that originally the torque converter had not seated fully so my 1/2" clearance cut was shallow by about 3/8". That works out OK though because I'll use a 3/8" ring to match the converter to the flex plate and a 5/8" ring to match the  bell to the engine and all should be well. After additional measurements to be absolutely certain of course.

On the 8 speed, we are now checking to see if a LS460 8 speed is the same as an IS-F 8 speed, apparently there was some confusion as to which one the yard has. More on that later. For that adapter I may go with thicker ring sections and may eliminate the bellhousing machining operation entirely by using the first plate as a pattern. Yet more measuring of course.

JB

Jim, considered using a B.O.P., B.H. , stick or auto ?(less work at the motor).

Art, I'd like to make something that works with the entire line of transmissions, which would mean everything from the 4 speed through the 8 speed. Since the 8 speed uses an integral bellhousing that means no bellhousing swap. Also, the flexplate is not an easy bolt-on affair as the Lexus 6 bolt converter has a bolt circle that sits well inside the GM bolt pattern, with 3 bolts hitting the thin point of the spider and 2 hitting open areas. Simplest way to deal with that is with a ring or plate to match them up and that means a plate is required between the bell and the engine. A 1" thick plate there will give adequate flexplate clearance and good thread depth, in fact I could perhaps get by with 7/8". That makes the flexplate adapter about 3/4" thick which also gives good thread depth, and both pieces can be aluminum to reduce weight. Cost of materials is an issue, as a chunk of 1" plate nearly 20" square doesn't come cheap, but the flexplate ring can be cut from the drop cut out of the center of the bellhousing adapter, which helps.

Has anyone had experience cutting aluminum with a plasma cutter? Especially aluminum plate. I just wonder how well that works, although ultimately I expect I'll enlist the aid of my good friend Ken Steidle who owns a waterjet machine. That way we can pretty much produce them on demand without running minimum quantities.

This will be my third commercial offering of a transmission/engine adapter and other than materials it is surprisingly similar to the others, which I had manufactured and stocked by Advance Adapters in California after I developed the prototypes. They still carry that line which mated a GM auto to an International Harvester V8.

JB