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MG MGB GT V8 Factory Originals Technical - Fitting my LT77 in the MGB

I have tried to fit the Engine and new box yesterday.

What a pig, working outside too.

I need a few pointers please.

Engine has a new block and new LT77 box “kit” from the MGOC.
I was led to believe it would be a straight swap for the old 4syncro unit I have been using. It seems not so.

With the engine sitting in the same location as before I have found that:-

1) Box hits the top of the tunnel at the front. ( I have a Rubber bumper shell).

2) Gear lever is about 1" too far forward. (It has a modified remote linkage)

3) The Modified cross member does not match either of the pairs of mounting holes.

The engine cannot go back any further without some bulkhead bashing, and cannot go any lower as it will hit he power steering rack.
Is the front of the tunnel structural? Can I cut a portion out and rivet a new plate in or should it be welded??
What sort of clearance should I have. I was imagining 1/2" would be OK?

Should the bottom of the box be parallel to the ground when fitted correctly? If the rear end will have to go up a hell of a lot.

I assume I will have to drill new cross member mounting holes and bash the tunnel up a bit and re-cut the hole for the gearlever, or have I missed something!!!

Any recommendations would be appreciated.

Regards

Dave
D M Tetlow

Dave,

there are some pis on www.britishV8.org that show the mods to the tunnel. BMH offers a fabricated panel as used on the RV8 that should be weldet into place but can also be revetted as there is no structural load in this area. The panel can also be fabricated very easyly.
As far a i know the RV9 and SD1 fly are not the same as used on the BGTV8. If your engine is an Abington version, check out to have the right fly for the LT 77 or R 380.
With the modifications done to the tunnel, the cross member should fit your aplication. If the gear lever does not exactly meet the hole, cut it above the extension and weld on a short piece of thick sheet metall with the rest of the lever in the right position.

Hope this helps

Ralph
Ralph

If you have Roger Williams book on converting your car, you will see how to make the piece that needs to go into the top of the tunnel. The attached photo shows it welded in on my car. (It was the first thing I did - the car now has all new floors and looks a lot better underneath!).

I'm amazed that your gear lever is too far forward. On every LT77 conversion I've seen, including my own, it is too far back. The RV8 has a dog-leg in the gear lever for this reason.

As for the gearbox crossmember, again I used Roger Williams book for the mods and they were spot on. I'll post a picture in the next thread.


Mike Howlett

Gearbox crossmember before final welding. The slots for the cotton reels are right at the rear edge of the crossmember. It bolts through the original holes as used for the 1800 engine/gearbox.


Mike Howlett

Cheers Mike
I have the MGOC modified crossmember but it fits only the last hole. I will have to drill another.
The gear lever is forward and to the right. I was hoping to bend the gear lever but as I have one that has a thick anti vibration lower part I may have to think again.
I have cut the tunnel to give me 1/4" clearance at the moment, but I am not sure this is enough.
Your plate looks good. It seems to give the same height from the gear lever hole to the front, so I will try this tomorrow.
Is the bottom of your box parallel to the ground? It looks as if mine won't be.
Dave

D M Tetlow

Mike what is the full name of Rogers book and where can I get it? RIC
RIC LLOYD

Ric,
Here is the link to the publisher. http://www.veloce.co.uk/shop/products/productDetail.php?prod_id=V393&prod_group=Performance%20Tuning%20&%20Modification&

The book is sold by other outlets - any book store should be able to get it using the ISBN number.

Dave,
I don't know if my gearbox is level. I've never really looked. I'll have a dekko tonight when I get home. I'll also try to post a picture of the inserted piece from inside the car, and also how I modified the Rover gear lever.
Mike Howlett

Sorry Ric. I thought the link was going to show you the book. Its called "How to give your MGB V8 power" by Roger Williams. If you go into the publisher's search box and type MGB V8 you will find it.
Mike Howlett

Thanks Mike
I was wondering how I would mod the lever.
Dave
D M Tetlow

Ric Lloyd,

Here is a direct link to the book:

http://www.amazon.com/gp/product/1904788939/ref=sr_11_1/002-8191208-6004845?ie=UTF8

Cheers

Pete
Pete Mantell

Pete,

I shortened my remote by an inch and had it rewelded. You will also need to shorten the internals of the remote housing aswell as rebending of the pianowire spring. Hope you see what I mean. I happen to have my engine and garbox out of the car, so I could send you pictures, including the modified x-member.

Cheers
Erik
Erik

Thanks Erik
I have the shortened remote as part of the MGOC Kit.
I hope to be able to modify the lear lever to get it in the middle of the hole.
I have modded the tunnel in the rain this afternoon.
I hope it will be enough.
If I can I will put spacers under the cotton reel rear mounts to raise the back of the box.
It seems the kit's crossmember assumed the engine was in a lower position than mine is, and I cannot drop it due to the power steering rack.
Regards
Dave

D M Tetlow

Dave here are the pics I promised. The first one shows the Williams tunnel mod from inside the car.

Mike Howlett

The second one shows the position of the gear lever on my car. As far as I can see the gearbox is just about parallel to the top of the tunnel.


Mike Howlett

And this one shows my modified gear lever. I cut off all the rubber bits, then cut the lever right above the thick part and welded the top bit on the front face as you can see. This has displaced the lever forwards enough and has also shortened it by about an inch and a half.


Mike Howlett

Thanks Mike

That's a hell of a modification to the tunnel. It puts your box in what I think is the perfect position.

My box must be at least 1" below the level of yours, which is why mine's not level!!

Your gear lever is nicely in the centre. Did you have an off-set cross-member to get it centred?

Regards
Dave

D M Tetlow

I made the gearbox mounts myself using Williams book again, and fitted them to the original cross member once I had got rid of the original MGB mounts. I actually tacked up the mounts and trial fitted the engine and box. I measured how far off centre the lever was and then worked out with simple geometry how much I would have to move the gearbox mounts. I then moved them until the lever sat dead in the middle of the hole.

Mine is a 1969 chrome bumper car, so I had to do a fair bit of cutting and shutting around the bulkheads to get the engine in at all. I had to change the main engine mounts and the radiator mounts. I also had to slit and beat out the left side of the tunnel to prevent the Rover bell-housing from fouling there, welding it back up after. The work on the gearbox mounts was a doddle by comparison.

If your box is lower, I would worry about the angle of the prop shaft. You really want it to be as close as possible to directly in line with the axle flange.
Mike Howlett

Dave

I did the same tunnel mod using the V8 power book, i have a rubber bumper car and also had to do a bit of "panel beating" to the rear engine bay gearbox tunnel to give me a bit of clearence for the gearbox, although it did not need a lot.

For the 5th gear i did a bit of a cut-out for allow for the gear stick movement and didn't modify the gear stick, i did this by cutting with a hacksaw blade and then finishing off with a rotary file, it is all hidden and you cannot notice when you rebuild the centre console. it does take away the right hand screw attachment nut but you can false fit it with an ordanary nut to the screw.

I still cannot get pictures to upload with vista but i can e-mail you some pictures if you want?

Graham

Graham Lavis

Graham

I think we must have had a similar experience although I did not do the tunnel mod.

I used TR8 kit with an RV8 crossmember (and bonnet).

Dave

.. don't understand why you are having to chock the gearbox. Is it possible your engine should be lower ?
You have the thinner mount on the port side ? Your shell doesn't have an earlier version of the mounting brackets / the engine brackets are the right way round ??

Roger
Roger

Morning Folks

Thanks for the help.

I bought the car with the V8 conversion so I do not know much of the history.

The engine mounts are fabricated but use what I think are rubber bumper blocks. (pic)

The Engine has been raised a bit to clear the power steering rack. I cannot go any further forward due to the Anti-Roll bar and can't go any further back as the rocker covers will hit the bulkhead.

The car has been running with the V8 for about 5 years but with a 4 syncro Std MGB box with the adapter plate. I bought a LT77 replacement box kit from the MGOC.

Graham

I have seen a modified gear lever with the thicker lower section removed and a large offset kink in the rod. This is the way I hope to go if possible, if not I will have to mod the hole as you have done.

What is odd is that everybody talks about the gear lever being off center ( including me) but this must be due to engine mounting problems as the remote/lever is in the centre of the engine as far as I can tell!!
If I have to cut the hole then the pic's would be a great help.
How much clearance do you think you have at the worst point in your tunnel? is the bottom of your box level with the ground?

Mike

I noticed that the box when mounted on the MGOC modified crossmember with the cotton reel rubbers it was not level. I rough fitted the propshaft and noticed that it was very close to the ribbed rear lower coned crossmember. I expect the prop shaft would hit it as the axle drops when going over a bump.
When you say directly in line you mean meeting the axle at 90deg to the diff? i.e. parallel to the ground. I would assume this would mean I should have the box level too. I don’t know if I can go high enough to obtain this without major mods to the tunnel. If I don’t will it just put stress on the propshaft yokes or would it balls up the diff too. I would rather not damage the diff as I have a Quaife LSD.

Regards
Dave


D M Tetlow

Dave,
I'm no expert in this area, but have a look at http://www.4x4wire.com/toyota/tech/driveline/ where he explains how the angles taken by the UJs must not be more than 3 degrees, and that the face of the gearbox flange and the face of the diff flange must be dead parallel if you are to avoid vibration and premature wear.

You can shift the anti-roll bar forward and down by a small amount if it's in the way - again Roger Williams shows how to do this in his book. The RV8 uses an anti-roll bar with a kink in the middle to give the necessary clearance.

I am using Clive Wheatley's alloy engine mounts with RV8 rubber cotton reels, thin one on the left side. Check Clive's mounts out on his web site http://mgv8.homestead.com/

Mike
Mike Howlett

Thanks Mike
I had better look into this before I ship the car off to the USA for a 5 week tour!!
Dave
D M Tetlow

Dave,

I have a factory V8 and just installed a LT77 mine sits way back I remade the shifter I did away with the rubber and welded a MGB shifter to the top of the Lt77 it looks like you could do the same thing only turn the top MGB part around.

Bob
Bob Fisher

Hi

First - have you got your engine mounts the right way around ? - they are handed.

1) Box hits the top of the tunnel at the front. ( I have a Rubber bumper shell).

Most people need to dress up the radio console section to some degree, as Mike described. If you mean it's fouling the bulkhead under the heater - use a hammer.

2) Gear lever is about 1" too far forward. (It has a modified remote linkage)
Dont panic - your gearlever gaitor will hide a multude of sins. If you had a normal remote we could say exactly where the problem lay - do you have a spare you can temp fix?

3) The Modified cross member does not match either of the pairs of mounting holes.

How far off is it - to the front or rear, or in the middle?

It's a close run thing - options 1)fit it to gearbox and re do holes on chassis, 2)cut off turrets and reweld with different plates.


Although - I can't see how you are that far out. If you do the tunnel mods first (tip give yourself a good 1/4 inch around the heater bulkhead to account for engine movement under torque), so you know the bulkeah is not keeping the engine too fart forward, then loose fit the x-member and see where it wants to fit naturally, a bit of hole enlargement is often needed.

Liam
Liam H

Thanks Liam
I have opened up the front of the tunnel and fitted a cover plate.
The engine now clears by between 1/4" - 1/2".
The box crossmember mounts on the last but one hole, needing just the other hole drilling. I am going to try to move the internal threaded plate instead of a seperate internal nut.
I am fitting lowered leaf springs and will see where the axle ends up to see if I need to modify the box rubbers. The prop shaft looks pretty well in line though.
The actual gear lever position is forward and towards the driver, and I am trying to see if I can reposition the box mounts. The crossmember is off set to solve this problem but obviously not enough.
If not I will try to modify the gear lever.
Regards
Dave
D M Tetlow

This thread was discussed between 16/01/2008 and 24/01/2008

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