Welcome to our resource for MG Car Information.
MG MGB GT V8 Factory Originals Technical - Power steering
|Has anyone fitted PAS with a Rover V8 engine and a chrome bumper cross-member? If so, how was it done so that tie-rods remain horizontal etc.|
All comments gratefully received.
Seems nobody want to answer this one, Moss do a kit for the V8 but it is very expensive and you would have to work out and re align the rank mounts to avoid bump steer. I am wondering why you would want to do it unless you are always parking in tight places.
I have 6 x 15 wheels with 195/65 x 15 tyres and my steering was excessively heavy with the replacement Argentinian rack and the original castor angle. I had my original rack rebuilt and fitted the Brown and Gammons castor reduction kit £30.00 and the steering is now much lighter and even at parking speeds very acceptable.
The B&G kit is technically better than the frontline wedges which do not address the fact that when you move the front of the crossmember down the mounting studs no longer fit into the recesses in the chassis frame. The B&G kit has spacers which fit on the lower part of the stud which then allows it to still fit in the chassis with the correct pre-load on the crossmember poly or rubber pads and correctly controls the amount of castor, without these you cannot correctly tighten the nuts on the studs and can over compress the crossmember pads.
The downside is that you do have to disassemble the front suspension to gain access to the inside of the crossmember, or at least lower the spring pans and remove the springs but if you are rebuilding the front end it would not be a problem.
Pic of B&G kit.
|Thank you for replying Kevin. I drove an MGB 1800 for 12 years as my daily car, only selling it in 2005 when I replaced it with an MGF. Since then I have developed a painful right elbow and I find the MGF's PAS is superb, easy to use and giving plenty of feel. I am concerned that once the V8 GT is ready to use, I will not enjoy it because of the heavy (by comparison) steering. My V8 will have Hoyle front and rear suspension and, like yours, 195/65 x 15 tyres.|
I have been in touch with Roger Parker about the MGOC PAS kit using a LHD Peugeot rack turned upside-down, and he said that it wouldn't work with a chrome X-member as the hydraulic ram is on top of the rack, so there wouldn't be clearance for it under the front edge of the sump. He suggested I switch to a R/B X-member and use shortened springs, but I'm not prepared to compromise the ride in that way. As you say, these kits are very pricey.
I've not seen the B&G castor kit before and thought the wedges were the only kit available. The B&G kit looks much more professional. Do you know how many degrees reduction it gives? Reading through the instructions for the Hoyle front suspension, I see that the castor can be adjusted to a small degree. I must contact John Hoyle and find out how much of a change can be made.
It's interesting to note your comments on the Argentinian rack and think I will have my original restored. Where did you get it done? I have got some instructions for restoring the rack at home, although I'm not sure where I would get the parts from.
Once again, thanks for your input, - Mike.
I was so fed up with the steering after I fitted the Argentinian rack as the car was barely drivable. I had some serious health problems and my upper body strength was somewhat reduced so that in desperation I took my old rack which had failed the MOT to a power steering firm, and asked them to have a look at it. There are no rebuild kits currently available for original racks but they said they could probably fix it. They rang me the next day to say it was done and said they didn't know why it had failed as it only needed re shimming and a bit of adjustment. They had completely stripped it down, cleaned it internaly reshimmed, adjusted and filled it with Lithium grease which they claim is a lot better than gear oil, and less prone to leak, and then repainted it as new, for £50.00 + VAT which I thought was a bargain.
Re the reduced castor, the original is 7 degrees and was designed for cross ply tyres the kit reduces the castor to approx 3.5 degrees which is the norm for modern tyres.
If you are intending to use the hoyle suspension check how much you can reduce the castor to, as you may not need any additional reduction.
If you really feel you need power steering, and you are going to buy both the front and rear suspensions from John Hoyle why dont you see if you can talk him into an alternative power steering set up.
When I was at the power steering place I had a look at several power racks which would appear suitable and could be made to work with a bit of engineering.
The Mazda MX5 rack looked a possibility and has a short pinion shaft so you could add an additional uj and have shaft cut and splned to mate up with the steering column at the bulkhead NF development in Kent willdo that and they are well known to John Hoyle.
I did some costings and reckon you could do a kit for around £500 including a reasonable margin of profit.
What John would need to do is look at a chrome bumper crossmember and work out the position of the new rack and design some new mounts to be welded on, with power steering you do need the mounts to have additional lateral atiffening as the power rack will put more stress on the mountings.
I'm sure John would have a crossmember to hand and should have no problem working out what is required.
|I'm encouraged by your message Kevin, and think I will pursue the manual rack route as you did. Thanks for the heads-up about NF in Kent - looks like they could be useful, having had a look at their web site. One drawback of living up here is that there is are no specialist services anywhere within striking distance. Everything has to be done long distance. I'll drop John Hoyle a line and ask him about castor angles.|
|Kevin, John has told me that his kit isn't designed to alter the castor angle as the range of adjustment is very small. It's only made like it is to ensure that both kingpins can be set at exactly the same angle. One thing he did bring up was how does the B&G kit make allowance for the alteration in the angle of the steering shaft?|
The castor kit comes with a set of shims (see picture of kit) to go under the front rack mountings. You have to be very careful to get the alignment of the pinion shaft and steering column correct or you will have problems.
If I were to do it again I would cut the bottom of the pinion shaft and fit an additional U/J which is what my friend with a chrome bumper V8 conversion has and his steering is superb.
I understand that on some of the modern small cars with electric power steering all the power assistance mechanism is on the column and not on the rack. I guess this is due to packaging issues in the engine bay. Perhaps you could investigate that route as it may allow you to retain the current rack.
|Mike, Start with a small car - like a Fiesta, or Corsa?|
I dont find the steering on my V8 too hard - the 2nd UJ is a great help I think, but then again mine's a chrome bumper so I had to do that. I suppose even if yours were a rubber bumper there's no reason you couldn't fit a 2nd UJ.
Plus I use a smaller diameter steering wheel, and althoguht hat makes it harder to turn its fine at speed, you do need to 'move' it, but not force it. It is harder work doing e.g. a 3 point turn though.
|RE: David Withams comments...|
I have a rack from a 2006 Mazda3 which i intend to use. it is an electro hydraulic unit and initial measurements look pretty favourable. Will no doubt still have some clearance issues to negotiate but it's a pretty neat unit.
|Thanks all. One thing you have to consider is that almost all modern cars have the rack behind the axle line, whereas the rack on the MGB is in front of the axle. That means that if you fit a rack from a RHD car to an MGB the steering will work backwards - turn the wheel left and you go right. You have to use a LHD rack upside down to make it work. |
My MGF has electrically assisted steering, but looking at that, I think the motor makes the column pretty bulky under the dash. I'm not sure there's room on the B. I think I will investigate Kevin's idea of cutting off the pinion shaft and using an extra UJ. By the way, it is a chrome bumper car, Liam.
|Have you considered using the new front suspension setup offered by Fast Cars, Inc? http://www.fastcarsinc.com |
Not power steering, but the steering effort is significantly reduced, and the handling is greatly improved.
Somewhat costly, but you can't beat the ease of installation - one afternoon's work. In the long run, it might not cost any more than coverting a power steering unit from another car, and the results, I feel, would be much better.
These articles don't provide a direct comparison of the Hoyle front suspension (as Mike said he's planning to use) versus the Fast Cars front suspension (as Dan suggested instead), but they might help someone weigh the two options.
Don't know if you have seen this guys web site but you may find it interesting.
You can see how much work was involved fitting the power steering.
|Kevin, that's an amazing piece of engineering! I wanted to ask you where your pal got the parts he used for his two-jointed steering shaft, and what those parts are. I have been looking at the Car Builders Solutions web site and their intermediate shafts and UJs are a different diameter from the MGB's 3/4 inch components. I think I would like to use a short pinion shaft and an intermediate shaft with 2 UJs but have no idea where to source the parts from. Can you help?|
To Dan and Curtis, that Fast Cars suspension assembly is superb isn't it. I already have the Hoyle kit, but if I didn't that would be tempting.
Thanks again to all,
My friends car was already converted when he bought it so not certain where the previous owner got the parts from.
The steering is basically converted in line with the original Costello conversions, so he probably got the parts from Dave Vale at V8 conversions, Dave was part of the original Costello team Tel. 01689 858716
Are you using a rubber bumper shell? if so you could probably use the pinion shaft from the rubber bumper rack and have it cut down to the correct length to allow fitment of a small uj onto the cut down pinion shaft of a chrome bumper rack. If it's a chrome shell then you have obviusly got to do all the mods to allow fitment of the V8, and the steering position at the bulkhead will need modifying to rubber bumper spec to allow clearance for the exhaust manifold.
The V8 conversions web site may provide some additional useful information.
If you speak to NF I'm sure they would make or modify the pinion shaft to the required spec preferably with splined joints.
Neil Foreman was involved both with John Hoyle and Hawk Cars who make a nice 289 Cobra replica which utilises MGB supension parts in it's most basic form and the hoyle suspension was I believe originally designed as an upgrade for that car, so he is very familiar with MGB steering and suspension.
|Mike, for U-joints and steering intermediate shafts, try these guys: http://www.borgeson.com/|
You might also look at what I did with the steering on my TR6/V8 at http://www.britishv8.org/Triumph/DanMasters.htm Not the same as your problem, but maybe a good idea or two that you could use.
I ordered a slimline one from flamingriver.com - about £60 with import tax. I still had to do a bit of work on the engine mount for clearance and shim the rack a tad, but its a beautiful bit of kit, plus it solves a lot of alignment problems.
I just took my pinion shaft to machine shop here told them where to cut, and got them to machine two flat sides so they'd slip into the UJ. Cost £10.
I got quite a bit of advice here about it - it'll be in the archives.
If weather permits Harrogate you can have a go on mine.
|I'll hold you to that Liam old man!|
|Liam, I would appreciate it if you could let me know exactly which part(s) you bought from Flaming River. I've had a look at their web site - it looks good stuff.|
|Mike, It's at :|
Its a Low Profile Chromemoly Racing U-Joint.
You can also buy more or less any combination of ends/length pinion shafts, but they can't help with the pinion gear and of it. I just set mine up so the UJ was a mm from the steering rack and told my people to go from there, they did more of the shaft DD than I needed so I could cut it down to length myself. The closer to the rack the better for clearance.
My problem was that I set up the clearance with the engine out, then when it went in, it flexed the mounts down just a touch, but it was enough to foul the UJ, but as I say a few washers under the front of the rack sorted it. 2 minute fix.
I was out last night in it, and paid particular attention to the steering, it's really quite light.
I am probably too late, havn't been in this area for ages.
I fitted a PAS from the MGOC some time ago. Some trouble fitting but I bought it with a modded crossmember, not cheap though!!
|D M Tetlow|
The MGOC say PAS cannot be fitted to a CB crossmember with a V8 conversion. I guess you have a RB crossmember but Mike and myself would be very interested to hear if you have PAS fitted to a CB crossmember in your V8.
|Hi Geoff / Mike|
I do have the rubber bumper MGB. Sorry if I mis-led you.
Do the MGOC not recommend the power steering that they sell for the Chrome Bumper 1800? It is an electrical pump but surely it does not matter which engine you have? In fact the V8 is not any heavier than the 1800. ( Unless you have twin turbo's or a Supercharger!!!)
I have looked at the blurb for the chrome version and the pump is fitted infront of the radiator. Would this mean there would be no room in your modded version?
I was told the mechanical pump was better than the electrical version but surely it would still work.
|D M Tetlow|
I definitely wouldn’t want a PAS pump in front of the radiator, that’s about the worst bit of packaging I have seen – beaten by those that mount the battery there mind you. But that’s not the problem, with a CB crossmember the PAS rack to engine clearance and the position of the column is.
I posted a message here last night, but for some reason it hasn't appeared. If you look at the recommendation for the RV8 PAS system, they use the electrical pump squeezed in on the RH side of the engine between the brake servo and the radiator - it's a horrible thing.
But, as Geoff says, the problem is the cross-member, which on the chrome car is about 1.5 inches closer to the sump than on the R/B car. This means that the power rack with it's ram just won't fit. If you lower the rack mountings to get it to fit, you throw the geometry out and will suffer from the dreaded bump-steer. Roger Parker from the MGOC reckoned that the only route was to replace the cross-member with a R/B one and then use shorter springs to regain the correct ride height. I don't want to do that, so it looks as though PAS is out.
The picture shows how little clearance there is between the original rack and the V8 sump with the chrome cross-member.
The only way round this problem is to use a pair of dropped spindles/stub axles in combination with a rubber bumper crossmember to retain suspension geometry.
The dropped spindles are available in the states from Dave Headley a well known MGB racer who runs a company called Fab Tech in Colorado, they cost $325.00 which is not too bad at current rates of exchange.
Link to his web site with some very interesting information on MGB suspension for road or track.
Don't Know if you've been away and might have missed my last post so I've just stopped it dropping off into the archives.
|Thanks Kevin for your thoughts and the link. I have seen the dropped stub axles on the web before, but it seems unnecessary complication. I haven't had much time lately to do any more, but I suspect I'll stick with my chrome x-member and forgo the PAS.|
|I wonder if you could mount it in a similar way to what I've done on the Roadmaster, and swap the steering arms?|
If necessary the arms can be bent to position the ends higher or lower.
Does the PAS rack have the same length of arms at the end, or when they were upgrading did they make the arms longer and the rack shorter to get better geometry?
I am not fully conversant with all the details but I understand the PAS from Subaru can be fitted with minimum complications.
I know there is at least one here in Australia with a Subaru steering system fitted mainly to help with the huge tyres also fitted. This is as you may have guessed a track car only.
Cheers , Pete.
This thread was discussed between 06/07/2007 and 15/08/2007
This thread is from the archive. The Live MG MGB GT V8 Factory Originals Technical BBS is active now.