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MG Midget and Sprite Technical - Frogeye bonnet clearance

I am still trying to get the best fit I can for my bonnet. This involves checking all points of contact - or near contact.

I have the bonnet fitted to the hinges, and sitting nicely level with the centre of the scuttle at the rear. Closed, the two cone pins at the front settled snuggly into their angled receptors on the top of the front chassis extensions.
With it like this, the curved lower edges of the wing match reasonably well to the upsweep at the front part of the sills, but it could be better. Ideally the front of the bonnet should go maybe 1/8" lower which I think I can achieve with a bit of panel adjustment. That would get that curved panel gap properly uniform along its length.

However what is now troubling me is the clearance under the bonnet for the radiator. It seems extremely close with very little clearance betwen the top of the radiator and the underside of the bonnet - see photo of clearance to radiator cap. With the forward slope of the bonnet, the clearance at the front of the cap is even tighter than where my finger is.

Is the clearance really supposed to be that close!


GuyW

guy

Its very tight round there. I ended up spacing the radiator back about 1/2" to give provide more clearance. I think the problem is over time the bonnet curves a bit like a banana and the clearances get a bit tight
Bob Beaumont

I've got this pleasure to come. I've been wiring up the front lights, and trying to estimate how much room I've got, to deal with the great lengths of cable that have to be tucked away.

Of course, you won't have to do this, Guy, as your wiring is bespoke.
Nick and Cherry Scoop

At one stage today l was sitting in the engine bay (no engine in yet!), feet out the front, head bent forward with the bonnet shut so l could check the under bonnet clearance. Just a bit claustrophobic in there!

Nick, yes a bespoke wiring loom. I haven't made up the bonnet sub loom yet though.

Bob l don't think l can move the radiator back as there is little clearance with the steering rack. But l think l could angle it back by putting some spacers in at the top. I will just need to check the fan position when that goes in.
GuyW

Guy

Angleing should also have the effect of lowering the rad cap slightly.
Dave O'Neill 2

Guy

The steering rack/fan shroud just cleared on mine. There is plenty of space before the rad shroud gets near the fan. I have a 1275 with a plastic six bladed fan and there are no clearance problems. Angling the rad back at the top may be enough anyway.
Bob Beaumont

Bob, just been checking and for some reason there is no possibility of angling it back because of minimal clearance with the steering rack!

The only other thing might be to slot the mounting holes in the support stanchions and l could maybe lower it to gain about 3/8". But that may give problems with fitting the bottom rad hose. Beginning to wonder if l have the correct rad!

GuyW

I dropped mine to gain clearance. Also back filled the wings to the sills with lead and filed back to get uniform gapping.
f pollock

Fergus,
What width panel gaps did you aim for? I don't know what they are supposed to be on a Frogeye bonnet.

And, a lot of frogeyes you see around have some sort of securing mechanism - leather straps, rubber pull down or Deutz fasteners. I have even seen Triumph Herald type catches. But is this necessary for a rattle free fit?
GuyW

Have you got any rubber washers on your cones, Guy? I have, but only on one side. I'm reserving judgement on that until I try to fit the bonnet.
Nick and Cherry Scoop

No rubber washers Nick.

If I added them then the curved sill gap would widen towards the front and not look right. Though Fergus has introduced the thought that that gap could be corrected with lead loding.
GuyW

" . . . sitting nicely level with the centre of the scuttle at the rear"

How does it sit further out, on the curves? Don't I remember that you were suffering from flattened scuttle in respect of the windscreen?
Nick and Cherry Scoop

Yes the scuttle joint is fine and level with the bonnet across the full width.

The wings are reproduction aftermarket ones that I weld ed up to the centre section. I now find that they are slightly oversized. I have got the offside one to align neatly as it should, but the nearside one is wider than the scuttle/ A post unit at the rear. Some further work is needed, but I have a "cunning plan" which should get it right. Just more work, more delays.
GuyW

I have a slightly bigger cill/wing gap on the off side to the near side but its because the bonnet will not sit quite flush with the scuttle at the top on the offside by the screen. I can press it down but it pops up!The gap is constant however.

I can confirm the rubber washers on the cones help to stop rattles!
Bob Beaumont

The gapping tends to be driven by the door hinges - as 4mm is the tightest you can achieve as the door swings past the A post. So all my gapping is set to 4mm - but I have no idea what its meant to be. The Frog on display in the A H Spares showroom has much bigger gaps and not particularly consistent. I've never had bonnet rattles, but I did make sure all the buffers make full contact.
f pollock

Thanks Fergus.
I realised, after posting the question, that the gap should be set by the thickness of the shelf part of the buffers that go on the sill top. Except with aftermarket stuff like that you can never be sure that they are still made to the original specification. 4mm is about 3/16" which sounds about right, and probably as tight as one would want the gaps to be anyway.
GuyW

Guy - a thought: how many flutes are on your radiator's top tank?
Tom Coulthard

3 flutes Tom. Assuming you mean on the top angled, forward facing bit if the tank, offset away from the filler neck. The tank is made by Hardy's of Leeds.
GuyW

This thread was discussed between 13/07/2018 and 22/07/2018

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