YHGN7/38120 The Gremlin

The Gremlin

The Gremlin is in disgrace.

She (don't ask why it's a she) was born a Mk IIA Sprite in January 1964. In 1976, she was registered as a Production Sports car, owned by Nick Ledingham, now a Solicitor and CAMS Steward. At some time in her life, she was badged as a MG so that she could compete in "all MG" races.

Early in her racing life, she acquired a MOWOG alloy 8-port cross-flow head. In another Sprite, I had held the Production Sports Car (under 1300cc) record at Amaroo Park, with two consecutive laps of 56.00 seconds. In her first outing at Amaroo Park, the Gremlin dropped the record to 53.5 seconds. I decided I should buy her.

I bought The Gremlin in May 1999 and raced her on a few occasions during 1999 and 2000. In March 2001, at a race meeting at Eastern Creek, she broke a brake pipe as we entered turn 2 on lap one. In 6th place at the time, we managed to avoid all the traffic and I beached her in the "kitty litter". After the race finished, I slowly drove back to the pits. As soon as we started moving, the diff went CLANG CLANG CLANG. OK, so I had broken a tooth off when I hit the kitty litter. I drove her onto the trailer, tried to change into neutral, and the gearbox locked up in 1st gear. So now, apart from no brakes, a broken diff and a jammed gearbox — she runs beautifully.

I took her home and backed her with trailer into the shed, where she has lived since. Often covered in rags, boxes, tools etc.

As I said — the Gremlin is in disgrace.

30 September 2004

Well, it's time we fixed the Gremlin. My son Chris helped me remove the engine, gearbox and diff. Now we just have a large hole that needs tidying.
Gremlin engine bay

The engine has been moved back six inches, and an ugly hole hacked into the transmission tunnel. I will be cutting the gear change remote and welding it back together a bit shorter, so that we can get the tunnel looking a little neater. Of course this will also mean the gear stick is closer to the right spot.
Hole in transmission tunnel

We have some worn valve guides in the factory 8-port head, so we will service that while everything is apart.
8-port head

The sump was cracked and leaking, so off that came.
Cracked sump

The aluminium flywheel needs a skim and a new ring gear.
Aluminium flywheel

The gearbox isn't jammed in 1st any more! But it does need new first motion shaft, laygear, 3rd/4th speed synchro hub, baulk rings, bearings. Oh well, it's only money!
Gremlin's gearbox

Yes, the diff was broken. It was also a 3.7:1 diff, so will be putting back in a 3.9:1 with a Detroit Locker.
Broken diff   Detroit locker diff

While we're at it, the wheels are a bit grubby. They will be bead blasted and repainted in 2-pack white.
Old wheels

And the exhaust system looks untidy, so that will be ceramic coated.
Old exhaust system

That should keep us going for a few weeks!

21 October 2004

The flywheel has been skimmed and a new ring gear fitted. The steel insert in the aluminium flywheel isn't perfect, but it was much worse before and wasn't slipping then, so I doubt the few remaining imperfections will matter.
New ring gear

We cut up the gear change remote, but only managed to gain 4 1/2 inches. However I'm certain that will make gear changing a lot easier.
Cut gear remote   Shortened gear change remote

The gearbox is now rebuilt, with the new short remote.
rebuilt remote

The Detroit Locker is now fitted to the 3.9:1 gears, all lapped in and ready to fit.
The Detroit Locker fitted to the 3.9:1 gears

Since the engine was sitting upside down and going no-where, we thought we should have a look at the camshaft. Well that was a good idea - the hardening on every lobe has broken up badly and would not have lasted much longer. Normally you would regrind another camshaft, but cross-flow cams are unique in that the valve order is ex-in-ex-in-ex-in-ex-in. The standard cam is ex-in-in-ex-ex-in-in-ex. A blank billet cross-flow camshaft costs around $800, so we will weld, regrind and harden this one.
Broken hardening on lobe

The extractors look like new in their ceramic coating.
coated extractors

Amazing what a little paint and polish can achieve!
the new wheels

24 December 2004

Well the cylinder head is back at last, with K-lined valve guides, re-cut seats, and a light skim.
Head inlets   Gremlin head face   Gremlin engine serial number

And since the engine has been lying around all that time doing nothing, and it was going to take just another half hour to totally dismantle it......
Gremlin block and head   Gremlin engine dismantled

While it was apart, I thought I should measure the engine capacity. We have 74mm Omega pistons, which would normally give 1400cc, except that the crankshaft is from a Morris Marina with big end journals offset ground down to 1.625", giving total stroke of 3.350". Engine capacity is 1465cc. Not a lot of cylinder wall left!
74mm Omega pistons   Engine capacity is 1465cc.  Not a lot of cylinder wall left!

Since I have entered for a race meeting at the end of January, looks like I will be busy during the Christmas break!

1 January 2005

While the engine was being rebuilt, I thought we should take a few pictures of the other modifications carried out on the car, such as:

Ford Cortina front brake discs and calipers
Ford Cortina front brake discs and calipers

adjustable Armstrong rear absorbers
adjustable Armstrong rear absorbers

Panhard rod
Panhard rod

Front spring pans lowered by 2 inches!
Front spring spacers

Fuel tank with twin pumps
Fuel tank with twin pumps

10 January 2005

The engine is back together and we ran it in on the engine dyno.
Maximum torque was 130 ft lbs at 4,000 4,500 and 5,000 rpm. Maximum power was 155 bhp at 6,500 rpm
Maximum torque was 130 ft lbs at 4,000 4,500 and 5,000 rpm. Maximum power was 155 bhp at 6,500 rpm. With such high mid range torque, and having a long stroke crankshaft, we didn't bother revving it above 6,500 - that's territory that I don't need to explore!

18 January 2005

We encountered a small obstacle as we inserted the engine and gearbox. The shortened gearbox remote will not fit in the transmission tunnel. Previously, the remote change would lift up through the gearstick hole BEFORE the gearbox mount entered the transmission tunnel. Now that the remote is shorter, it is still underneath the metal top of the tunnel and will not allow the gearbox to lift up to position the mount. Did you follow that? Solution: remove the remote and studs, fit the gearbox without them, then attach the remote with long bolts.

Gearbox inserted without remote   Remote fitted

20 January 2005

The Gremlin is all back together and sparkling.
Highslide JS

Front 3/4
Highslide JS

Rear 3/4
Highslide JS

Highslide JS

A cleaned Gremlin!
Highslide JS

Engine bay
Highslide JS

Engine bay
Highslide JS

Engine bay

That's the muffler under that stainless steel cover. There's no room under the car for it. The exhaust exits through the left side sill panel.
Muffler cover   Exhaust exit

And she looks a little tidier inside too, thanks to Gary's skills fabricating aluminium.
Transmission tunnel

30 January 2005

The long awaited All MG race meeting at Winton, just North of Benalla in North-East Victoria. There were 88 cars entered for the two day meeting, with timed sprints on Saturday and four 10-lap races on Sunday. Just three cars, all MGB V8s, were faster than the Gremlin. One of them had a 5 ltr engine, I think that helps. But that's OK, there were another handful of MGB V8s behind us too!
So what's next?

Well we have a massive oil leak from the rear of the gearbox. I have a suspicion that the rear oil seal has actually fallen off the box and is sitting idle in the dust shroud at the front of the tailshaft. Hopefully we can get the tailshaft out of the way, and refit the seal, with the engine and gearbox still in the car. If not - it's engine out time again!

The car overheated a little at Winton, but that's not surprising given the extreme 35+ C days. Anyway, as a precaution, the radiator is out having a new heavy duty core fitted.

The "sports" seat was far too high for me, and I felt very exposed. It will be replaced by a standard Sprite seat back and base frame, and a lowered foam cushion sitting directly on the floor.
Race vs standard seats

13 March 2005

We entered for a Production Sports Car race at Wakefield Park, just outside Goulburn and approx 4 hours South of Sydney. The Gremlin ran beautifully, gearbox oil leak fixed, good lap times - but we battled for last place.
Production Sports Car race at Wakefield Park
The poor thing is 42 years old, and ProdSports has in the meantime become Formula Porsche. The top 10 cars included 7 Porsche GT3s ($180,000+), 1 GT3rs ($250,000) and 2 Cobra Replicas (that shouldn't be in ProdSports anyway). Well, at least we managed to out-drag a Lotus Exige and a 2 ltr Mazda MX5 (Miata) down the main straight!
Production Sports Car race at Wakefield Park
Nice photo - but not another car in sight. Such was most of the racing.

Work needed for the next race meeting? Wash it.