JC's mk2 MGB GT V8 conversion.

JC. · Post by **JC.** » Wed May 06, 2009 11:19 pm

Some of you will know I did a V8 conversion on an MGB GT about 2 years ago...
Phase 2 of that project was to strip it down, restore and paint the body and build it back up again. However, the scumbag bodyshop owner stole my shell and disapeared leaving me with all the parts I stripped off the car.

Since then, I've been quietly planning the best way to get back to where I was 2 years ago and I'm now ready to reveal my master plan.

Back in November, I picked up a new MGB GT to use as a base.
Here she is as bought in November:

A set of 15" Wolfrace Slotmag alloys on Firestones and a new front valance had the car looking like this:

I then decided that I needed to rebuild the front suspension. I stripped the suspension, resprayed the wishbones and springpans, fitted new pollybushes and and all new bolts. I also fitted new shorter stiffer 600lb springs to replace the original 300lb units along with new uprated lever arm dampers, brand new droplinks, rebushed the anti roll bar, a new steering column, new UJ's and a motolita steering wheel.
These modifications lowered the front end by about 3 inches. It also stiffened up the front end by 100%

The car only moves about 1/2 an inch if you try to bounce it on the front suspension. The only mods left to do on the front end are to uprate the brake disks, calipers and pads to V8 spec and maybe a thicker ARB.

I decided not to lower the rear end at this stage as the big tyres on the back would rub on the arches. When I fit my new axle (more on this later) I will be able to lower the rear as the new axle will be slightly narrower.

In the last month I've had the 4 cylinder engine out to do a clutch change, rebuilt the carbs and fitted them with solid butterflies and serviced the overdrive. It's a pity the whole lot is getting ripped out at Christmas to make way for the new engine, eh? I also found time to fit a towbar.

Specs of the car will be:

3.5 litre V8
Borg Warner 65. 3 speed automatic gearbox
MGC LSD rear axle

Ive been steadily aquiring parts to do this conversion since the last one was stolen.
I've recently aquired a genuine Factory MGB GT V8 block and a narrow case MGC axle fitted with a Quaiff LSD.
I've also managed to aquire a very rare MGC automatic shifter and a genuine MGC auto big brake pedal.

Realistically, all I need to complete the project is to build the engine, aquire a borg warner autobox, buy / make the inlet and exhaust system and propshaft.

There will be more updates in the near future covering the strip down and rebuild of the V8 engine along with the actual conversion process. Needless to say, this one is going to be a lot better than the last one and with the aid of nitrous oxide I hope to be putting down around 200bhp and around 220ftlbs of torque.

Watch this space for further updates...

-JC.

CastleMGBV8 · Post by **CastleMGBV8** » Wed May 06, 2009 11:54 pm

JC

Looks like a nice basis for the conversion.

Personally I would have thought 600lb for the front springs to be more than a little on the hard side for road use 475-500lb would give good Handling with suspension that still works!

For the rear can I recommend the reverse eye rear springs which you can get from Moss or MG Motorsport which are ideal to lower the car to chrome bumper ride height.

They lower the rear approx 2 1/2" and are well made with a spring rate of
110lb Part No. from Moss MGS40721

The springs totally tranformed both the ride and handling of my car and being much flatter they seem to resist lateral movement and axle tramp.

Dont be tempted by the Parabolics as they always seem to be set far too high, a friend with a chrome bumoer roadster fitted them and it's rear ride height is higher than a rubber bumper car! MGOC said it would settle, it didn't and he'e had them on for 4 years.

If you have a rear anti roll bar i would also recommend removing it as soon as possible as it creates snap oversteer, which will have you off the backwards before you know it.

Have fun,

Kevin.

JC. · Post by **JC.** » Thu May 07, 2009 12:26 am

If I'm honest, the front suspension is pretty good. It handles like a Go-Kart and corners really flat. The way to make an MGB handle is a stiff front and a soft rear. So, on that score, the car is quite well ballanced at the moment. The antiroll bar is standard but I am tempted to go up to a 3/4" ARB to make it corner even flatter.
I also want to fit the moss shortened bump stops in the near future too.

The rear suspension was rebuilt in 2003 so I'll be putting the C axle straight onto that with no mods at all in the meanwhile. I might fit the lowering blocks and leave the ARB off, though. The C axle is a wire wheel case axle, so is a bit narrower than the steel case. Hopefully It'll be sufficiently narrow to get my big 195 section tyres under the rear arches when lowered. There's no way they'd fit under the arches at the moment!

Rear suspension will eventually be the frontline costello 5 link coil over system, so I'm not worried about the bushes etc being 6 years old etc in the short term.

To be honest, I quite like the "raked" look with the arse end high in the air.
I'd like to accentuate it even more by replacing the front 15" wheels with a pair of 14" wheels on 195 / 65 tyres whilst at the same time replacing the rear 195 / 65 tyres with some 205 / 75 tyres if such a size exists.
I'll be getting the speedo recalibrated anyway for the V8 conversion, so it won't matter.

CastleMGBV8 · Post by **CastleMGBV8** » Thu May 07, 2009 8:32 am

JC

"Handles like a Go Kart" go karts do not have any suspension and you do not need 600LB springs on a road car, that is the spring rate used for a full race circuit car.

My car has 475lb springs on a fully adjustable Moss coil over conversion which I picked up unused off e- bay for £225 I also have a 7/8th front anti roll bar with no bar at the rear. The car is very well balanced and the amount of grip amazing, it is also much improved in the wet whereas before it would slide at the least provocation.

Fot the rear i would never use lowering blocks as they increase the torque reaction/leverage on the springs especially with the torque of the V8 and I have seen springs bent with a reverse arch on the front section due to this.

I am running 6 x 15 KN Minilite wheels with 195/65 x 15 Pirelli 6000 tyres and and had the rear arches de-lipped for clearance, and do not get any rubbing using the reversed spring eye rear springs I mentioned.

For coil over rear conversions it's hard to beat Bill Guzmans at Classic Coversions four link kit that does not require a Panhard rod which was about $900 from memory and is now available in the UK but with the usual Uk mark up.

If I had the time and energy, I would slot in a narrowed Jaguar IRS, it can be done for approx £1800 including buying a complete rear end for reconditioning for£250 so not much more than the Frontline kit.

Link to some pics of my car during it's development but before fitment of the new rear springs,

http://s41.photobucket.com/albums/e258/castletine/

Kevin.

chodjinn · Post by **chodjinn** » Thu May 07, 2009 9:04 am

CastleMGBV8 wrote:JC
For coil over rear conversions it's hard to beat Bill Guzmans at Classic Coversions four link kit that does not require a Panhard rod which was about $900 from memory and is now available in the UK but with the usual Uk mark up.

Kevin.

Really? Where is it available then? I was looking at importing one directly from Bill. IIRC the price was $1100 plus shipping around xmas time.

Have you thought about the castor correction blocks for the front crossmember? My MG has them fitted, and although I'm sure it's got a quick rack and some other unknown mod, the steering is the lightest out of any classic I've driven. Handles very well too, think I have the standard springs but with thicker oil in the dampers.

mgbv8 · Post by **mgbv8** » Thu May 07, 2009 8:12 pm

I use the 475lb front springs and 7/8th front ARB on mine too Kev.
Thats a pretty good setup on a road car eh? And its ok on the strip as well.

Jon!
I reckon the the 600lb springs will rattle your fillings loose and be uncomfortable on the road mate.

PS
Where the fook did you get that auto shifter from???
Great find mate

JC. · Post by **JC.** » Thu May 07, 2009 8:35 pm

Well, all I can say is that I think the 600lb springs are brilliant having done 1500 miles on them. I barely have to brake for bends now - turn it in hard and it just sticks. I had 475lb springs on the last car and always felt that it needed to be stiffer. In any case, they work for me, so will be staying for now. Sure the ride is a bit harsh, but I'm 23 and if I want to be cossetted I've got a Jag for that.

Perry, the auto shifter came off Simon Wilkinsons car over on the MGOC BBS. He's converting his C roadster to manual and had the auto stuff kicking around. Only set me back 30 notes for the shifter and pedal. There's supposed to be a little chrome screw on piece of trim that is missing, but I'm going to make something instead. It's not like I can complain at that price, eh?

-JC.

Alley Kat · Post by **Alley Kat** » Thu May 07, 2009 10:17 pm

Excellent, good on yer for keeping going after a horrible set back like that too...

CastleMGBV8 · Post by **CastleMGBV8** » Thu May 07, 2009 11:47 pm

Ah, 23 years old so you are lot more compliant than this old codger, but don't forget the very stiff suspension will put quite a bit if stress into a 28 year old bodyshell.

That auto changer is a nice bit of original kit. Planning ahead I may when I get too ancient and feeble have to think about converting to automatic and was thinking a ZF4 HP22 would be a nice box, only recently found out that 3rd is direct top and 4th is actually an overdrive with the same ratio as the LT77 so cruise RPM can be maintined at a sensible level and of course economy

Kevin.

ChrisJC · Post by **ChrisJC** » Fri May 08, 2009 6:56 am

Go for a hybrid ZF4HP22 / 4HP24. The 24 is a bit stronger, and can be built up using 22 parts to give a 100% hydraulic box (i.e. no electronics anywhere).

They are good boxes, and top is about 0.7:1 which is certainly high enough in my van with a 4.9:1 diff!

Chris.

chodjinn · Post by **chodjinn** » Fri May 08, 2009 8:10 am

CastleMGBV8 wrote:For coil over rear conversions it's hard to beat Bill Guzmans at Classic Coversions four link kit that does not require a Panhard rod which was about $900 from memory and is now available in the UK but with the usual Uk mark up.
Kevin.

Kevin can you answer my previous question about the Bill Guzman kit please? Can you actually get it in the UK or not? If so, where?

CastleMGBV8 · Post by **CastleMGBV8** » Fri May 08, 2009 8:35 am

Olly,

I know I've seen it offered somewhere by a UK supplier but can't find it, suggest you drop Bill an e-mail and he will tell you.

Kevin

chodjinn · Post by **chodjinn** » Fri May 08, 2009 9:04 am

CastleMGBV8 wrote:Olly,

I know I've seen it offered somewhere by a UK supplier but can't find it, suggest you drop Bill an e-mail and he will tell you.

Kevin

unfortunately I'm still waiting for a response to two emails I sent him directly in feb/march so I'm not holding out much hope lol. It's almost like he doesn't want my money!

CastleMGBV8 · Post by **CastleMGBV8** » Fri May 08, 2009 10:01 am

Olly.

If I find it again I'll let you know.

Kevin.

CastleMGBV8 · Post by **CastleMGBV8** » Fri May 08, 2009 10:21 am

ChrisJC wrote:Go for a hybrid ZF4HP22 / 4HP24. The 24 is a bit stronger, and can be built up using 22 parts to give a 100% hydraulic box (i.e. no electronics anywhere).

They are good boxes, and top is about 0.7:1 which is certainly high enough in my van with a 4.9:1 diff!

Chris.

I read somewhere that a ZF4 HP22 has lock up on 3rd and o/d 4th would this only be with the later models which are electronically controlled.

I had a ZF 4 HP22 in an old 1986 BMW and it was a very nice box.

To put a kit together I think I would need the box out of a 2WD car BMW Jag ? and a bellhousing from a range Rover assuming that the bolt patterns are compatable. The R/R bellhousings I believe came in two sizes with probably corresponding torque converters, I dont think the large bellhousing would fit the late MGB tunnel but the smaller one looks about the same size as a LT77 bellhousing so may fit providing the box will fit the tunnel, I have a LT77 at the moment.

Whats the difference between the HP22 and HP24?

Any guidance would be appreciated.

Kevin.