Another MGB GT V8, work in progress

[3xpendable]

I've introduced myself in the general chat thread, and many thanks to those who have been so helpful so far. So I thought i'd add some more photos in and give you a run down on my project. Its going to be done as and when, but i'll update this whenever I make progress.

I have an 1800 MGB GT which will be the donor car, but have sourced a V8 spec shell. Its actually a low mileage 1976 R/B shell thats been converted to chrome.





Very solid, with virtually all new running gear (suspension etc).



The only welding that is required is a few small patches on the inner wings, you can also see in this photo some poor patching to the back of the outer wing on the floor, which will be repaired properly. Its strange that they have fitted a lot of new bits, but then bodged other repairs.



They've tried going for the 'de-seamed' look, which I dont like and shall be rectifying.



Previous owner has painted over even grease in the engine bay! This will all be blasted back to bare metal.



This is the P6 3.5l motor I got, but is only useful for short nose parts due to the bores being screwed




So thats my base. Upon advice of some guys here I am now going to go for a 3.9 motor, so i'm on the lookout for a complete or (decent) short motor as I already have SD1 heads. But I can sell these if a complete motor turns up. My budget is about £200 as i'll be rebuilding it anyway.

Regarding spec. I plan the build the car to a 'fast road' spec. So with the 3.9 running electronic ign and holley carb i;ve been told I can expect roughly 190-200hp which I think is more enough. It will be British Racing Green and i'm going for a 'clean' look. The interior will have period bucket seats with harnesses, and things like a push button starter etc.

Body:
As pictured, with tunnel modification for gearbox,
Webasto roof.
Floor & valence modified to fit twin exhausts.
Post 1972 front valence for improve airflow

Engine
Rover 3.9 fast road/std spec
Holley carbs
Digital ign
LT77 gearbox

Suspension
Ideas taken? I wont be fitting coilovers to start with, but ideas on spring rates (i've been told about 475lbs?) and ride height would be nice. If the new springs i've got are too high, can I get decambered ones? I dislike using lowering blocks. It will have Spax adjustable dampers in the rear, and i've also heard about removing the anto roll bar?

Brakes
Std to begin with, with cented discs.
Do i need to fit roadster 8 inch drums for better brake balance?

Thats about it so far people, I hope you enjoy. Also I'll be trying to do it on a budget so cannot afford everything new. With that in mind if people have any items available please let me know.
I hope to build the engine & gearbox, then get the shell prepped so I can slot them in, once this is done I can finish off trim and interior as and when.

[gelmonkey]

Hi Welshi
That is going to be a great project for you.
Just one question....
Why the Holley rather than a Webber?

If springs too high can you not lop a coil out of the ones you already have?

Keep us posted with progress.
Cheers
Paul

[CastleMGBV8]

Welshie,

For the front suspension 475-500lb lowered springs are fine and a 7/8" anti roll bar will further improve handling.

For the rear a pair of reverse spring eye springs from Moss. MGS40721
rated at 110lbs will transform the ride, handling and grip, these are 2" lower and bring the car down to chrome bumper ride height, do definately remove the rear anti roll bar and cut a min. of 1 1/2" off the bump stop rubbers otherwise sudden and dangerous oversteer will occur.

You will need the shorter(chrome Bumper) rubber axle travel limiters

Unless you are going to do race starts I would avoid the anti tramp bars as the standard versions cause binding in the suspension travel which affects handling.

With these mods the car will have much better traction especially in the wet.

Not sure if you have bought the spax dampers but most people report that they are far too stiff even on the softest settings, the Monroe telescopics are much better matched to the above mentioned springs.

Rear brakes, just swap the wheel cylinders for the roadster ones and the balance will be fine.

Kevin.

[CastleMGBV8]

Welshie,

For the front suspension 475-500lb lowered springs are fine and a 7/8" anti roll bar will further improve handling.

For the rear a pair of reverse spring eye springs from Moss. MGS40721
rated at 110lbs will transform the ride, handling and grip, these are 2" lower and bring the car down to chrome bumper ride height, do definately remove the rear anti roll bar and cut a min. of 1 1/2" off the bump stop rubbers otherwise sudden and dangerous oversteer will occur.

You will need the shorter(chrome Bumper) rubber axle travel limiters

Unless you are going to do race starts I would avoid the anti tramp bars as the standard versions cause binding in the suspension travel which affects handling.

With these mods the car will have much better traction especially in the wet.

Not sure if you have bought the spax dampers but most people report that they are far too stiff even on the softest settings, the Monroe telescopics are much better matched to the above mentioned springs.

Rear brakes, just swap the wheel cylinders for the roadster ones and the balance will be fine.

Kevin.

[3xpendable]

Just one question....
Why the Holley rather than a Webber?

If springs too high can you not lop a coil out of the ones you already have?

Keep us posted with progress.
Cheers
Paul

I read ina guide that its better to use the Holley (390cfm?) carb, though that is for a 3.5 motor

Welshie,

For the front suspension 475-500lb lowered springs are fine and a 7/8" anti roll bar will further improve handling.

For the rear a pair of reverse spring eye springs from Moss. MGS40721
rated at 110lbs will transform the ride, handling and grip, these are 2" lower and bring the car down to chrome bumper ride height, do definately remove the rear anti roll bar and cut a min. of 1 1/2" off the bump stop rubbers otherwise sudden and dangerous oversteer will occur.

You will need the shorter(chrome Bumper) rubber axle travel limiters

Unless you are going to do race starts I would avoid the anti tramp bars as the standard versions cause binding in the suspension travel which affects handling.

With these mods the car will have much better traction especially in the wet.

Not sure if you have bought the spax dampers but most people report that they are far too stiff even on the softest settings, the Monroe telescopics are much better matched to the above mentioned springs.

Rear brakes, just swap the wheel cylinders for the roadster ones and the balance will be fine.

Kevin.

Great Kevin, such a help! I have spax dampers that came with my oroginal car, but if they arent suitable I will sell them and get Monroe versions.
Interesting what you said about the anti tramp bars...but with a 200hp 3.9 motor wont this then twist the springs?!

[mgbv8]

If you are only running 200hp you wont twist the springs too much to be worried really. I ran my old 3.5 up to 287hp on stock V8 springs and suspension. It was only when I hit the 400hp mark that the whole rear end became a can of worms. I made up my own old skool slapper bars and the problem went away.

You should be concentratrating on LSD for the rear axle though? You loose way too much fun by not having some sort of diff locker

You pull out of a turning onto a main road and boot it. You can either keep the stock diff and spend time sitting still with the inside rear wheel lighting up. Or you can spend several seconds of joy while you try to control a nice drift onto the main road

I have the uprated front coils and the 7/8 front ARB. Well worth the money IMO.

Advance warning! These are slo mo vids. So be patient

Here is 400hp with no anti tramp bars.


And



And with home made tramp bars

[CastleMGBV8]

Welshie,

I have around 260+ BHP from a specially built 4.35 engine and have no problem running without tramp bars with the springs I mentioned as they seem to resist tramp and are also more laterally stiff because of being flatter

The standard anti tramp bars because they are a fixed length but as the spring moves upwards it effectively gets longer causing a conflict between the the spring and tramp bar and this causes bind in the suspension and a tendency for the brackets holding the front of the bar to pull out of the mounting.

This can be overcome with some triangular brackets and fitting adjustable rod ends which allow the two items to work properly together.

Kevin.

[mgbv8]

Kev!!
Will those rear springs be ok for me??
I could do with dropping the back end a bit now I've cut the arches away.

[3xpendable]

If you are only running 200hp you wont twist the springs too much to be worried really. I ran my old 3.5 up to 287hp on stock V8 springs and suspension. It was only when I hit the 400hp mark that the whole rear end became a can of worms. I made up my own old skool slapper bars and the problem went away.

You should be concentratrating on LSD for the rear axle though? You loose way too much fun by not having some sort of diff locker

You pull out of a turning onto a main road and boot it. You can either keep the stock diff and spend time sitting still with the inside rear wheel lighting up. Or you can spend several seconds of joy while you try to control a nice drift onto the main road

I have the uprated front coils and the 7/8 front ARB. Well worth the money IMO.

Advance warning! These are slo mo vids. So be patient

Here is 400hp with no anti tramp bars.


And



And with home made tramp bars

Very interesting Peter, thank you! Wow you can really see the difference the tramp bars make (in a 400bhp car of course). I was definately looking at an LSD, and now on your advice I shall put the money saved from tramp bars into the LSD.
I must admit, reading the Roger Smith book a few times, has inclined me to think (from an engineering point of view) that some of the suggestions he makes are overkill...i will only occasionally be doing 'standing' starts etc so its night like its going to be a drag monster.

Welshie,

I have around 260+ BHP from a specially built 4.35 engine and have no problem running without tramp bars with the springs I mentioned as they seem to resist tramp and are also more laterally stiff because of being flatter

The standard anti tramp bars because they are a fixed length but as the spring moves upwards it effectively gets longer causing a conflict between the the spring and tramp bar and this causes bind in the suspension and a tendency for the brackets holding the front of the bar to pull out of the mounting.

This can be overcome with some triangular brackets and fitting adjustable rod ends which allow the two items to work properly together.

Having studied automotive and motorsport engineering at university I always thought that the geometry was wrong for the anti-tramp system, but seeing as I dont need it then it wont be a worry.

Many thanks again both

[CastleMGBV8]

Perry,

Don't see why not, they are a little softer than the standard V8 springs which I think were 130Lb, but as your "slapper bars" prevent wind up that should be ok. Don't forget to trim the bump stop rubbers as the back will sit down more on launch.

I find they improve traction which is very noticeable in the wet and Pete Mantell who builds MGB V8 conversions in the US was amazed at how much grip there was when I took him for a ride in the wet on his visit back to the UK, his family live round the corner from me.

Doug Smith of MG Motorsport recommended them and uses them on all his race cars, get them from Doug or Moss.

Hope you get the carb sorted and have a good season racing.

Kevin.

[mgbv8]

Thanks Kev !
I know Doug so I'll give him a shout. He's only down the road from me

[3xpendable]

Hi everyone,

I want a bit of advice regarding where to go with my project as i have a bit of a dilemma. I haven't done much (if anything) to it lately due to needing money for my superkart and my brother hogging the shed space.

Anyway at the moment I have a bodyshell, along with the short nosed engine components and cylinder heads. I have so far been unable to source a 3.9 Rover V8 but am still looking and hope something comes up a bit later in the year when funds are better. With all the best intentions I have been prepping various engine parts and other things but don't feel like i'm making any progress. The main issue is that the bodyshell is at my parents farm, 100 miles from where I live. Now my dad is happy to do stuff so that isn't a problem but the original plan was the get an engine sourced, rebuilt and ready, then prepare the body so that I could drop it straight in once done.
I'm now thinking, to give me some encouragement, to start preparing the body & suspension as on now but my main concern with this is if I paint the shell and its sitting for say a year, I don't want the paint getting damaged or having the paint the darn thing again. My plan for the shell is the fit a webasto roof, carry out the gearbox tunnel mod and then properly seal the underside etc while repainting and cleaning all the suspension etc and fitting shiny new bits.....would this be a better way forward?

Thanks in advance.

[topcatcustom]

Hi, why dont you just use the knackered engine as a template to get all the fabrication work done in the shell, all RV8 dimensions are the same so you can use it without worrying about getting weld splatter etc over it, then once all the engine bay & tunnel mods are done take it out and get the body done. It's better to do it that way round as then you can finish the body nicely without having to work round the engine, pipes, exhausts etc, then once the car looks beautiful you just carefully drop the new engine straight in and it's ready to go! That way you dont have to spend a penny on your engine until the body is finished and ready for it.

[3xpendable]

FINALLY GOT IT UNDERWAY!!!

I only had a few hours on Friday afternoon to work on it but decided to get tucked in with the full stripdown as I am putting it on a roller.

This is how it looks now, all thats left to do is to remove the boot, front crossmember and rear axle which, as it was all fitted with new bilts a while ago will be a doddle, in fact i've already loosened all the bolts.



This is whats left of the wiring loom, after a number of presumably bodged attempts to remove it, due to this it took me about 30mins to get it off. I'll be fitting a replacement.



Two issues of concern is by the scuttle. When I removed the wings they pulled some rusty metal off with them. Not ideal but you can get access from behind so we can carry out a proper repair





The o/s/f wing took ages to get off, I undid all the bolts and it moved a bit but seemed stuck solid in the upper rail. I did want to damage the wing but couldnt see what was holding it. So in the end my dad and I just yanked it and it came off to discover to what was holding it. They had filled the top of the inner wing with a builders spray foam!! Why go to the effort of fitting brand new splash guards, then leaving the top of the inner wing like this?



Fortunately the rest of the wing is in good condition, and the plus side is the underneath has had all new channels and from initital inspection I can't see any welding that will need to be done underneath.



Alongside is our Hillman Imp project...

[chodjinn]

where will you be getting your wqiring loom from? CUstom, home amde or off the shelf? thanks