The Overfinch Discovery legend is true

The Overfinch Discovery legend is true

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Discussion

eliot

7,912 posts

183 months

Friday 29th June 2012
quotequote all
C Lee Farquar said:
Here's my box with Schuler transfer box.



VJJ, a friend of mine has fitted a big block Chevy to a 110 and it's currently at Allisport having a rad fabricated. May be worth speaking to them if you don't have anything organised.
Definately a 700R4 there. They are pretty weak boxes as standard - but there's plenty of upgrade parts for them to make them last.
The crucial thing when fitting them is to ensure the TV cable works correctly. Its not a kickdown cable - more of a pressure regulating valve. Get it wrong and you will burn the box up very quickly.
At idle you want about 90-100psi pressure, slightest movement of the throttle should give an instant increase in pressure. You want around 150 psi at WOT (or "full pull" on the cable)

Edited by eliot on Friday 29th June 22:59

C Lee Farquar

2,090 posts

145 months

Sunday 1st July 2012
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Sorry we're getting a bit off topic.

I use a manual shift TH350, mainly as it fitted. I originally bought it from the States as a competition prepared gearbox and rebuilt it with pedantic engineer friend of mine last year. Your experiences with builders who should know better convinced me we could do a better job. I bought a book, made the tools and bushing drivers, ordered the bits from the States and it works great. A very satisfying job. We were convinced that some parts in the previous rebuild should have been replaced at that time, the wear seemed totally inconsistent with the wear to other parts. It definitely works better now and runs cooler.

vjj

Original Poster:

590 posts

168 months

Sunday 1st July 2012
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Hi Fellas

here is a pic of my Overfinch Disco with the top-end rebuild done - ali heads, inlet and new 650 carb.

I have the 14-inch black Edelbrock Air filter cover to match the rocker covers but it won't fit under the disco bonnet - will be putting a Puma bonnet on the defender when the engine goes in so it will be fitted then. I have fitted a 10-inch for now

Also, you can see the headers are a bit of a mess - these were designed by Ovefinch to fit in with the TPI injection system - I have sourced a set of ceramic-coated K5 Blazer headers to go in the defender.

The leads i got were too long as well so they are all over the place

All in all I am quite pleased so far.

vjj

Original Poster:

590 posts

168 months

Sunday 1st July 2012
quotequote all
here is a better pictureYou can see the dog's breakfast that is the headers

Edited by vjj on Sunday 1st July 12:45

vjj

Original Poster:

590 posts

168 months

Tuesday 14th August 2012
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Hello Guys

Thought I would update you on my build, which is to commence shortly.

To recap - currently have 1984 Cabrio Defender with TVR lump, 3 -speed auto box and a dodgy chassis in need of replacement.

Also have Overfinch Discovery 5.7 which I bought with 4-speed auto, uprated brakes, suspension etc, but crack in cylinder head, fuel injection replaced with carb etc - see earlier posts on this thread.

At my last post on 1 July I had rebuilt the top end of the chevy with Edelbrock Ali heads, new carb, roller rockers, performer camshaft etc and was running it in - well the work on the top end has exposed a few weaknesses in the bottom end - namely rattling shells - which I thought might happen.

So I am just completing a bottom-end rebuild - I decided to go the whole hog and stroke it to 6.3 litres with Eagle crank, new pistons etc.

In the interim I have also sourced all of the remainder of the bits to turn the old girl back into a station wagon.

The defender is now out of MOT and SORNed so the build starts soon.

here is the schedule.

1. Strip down Discovery and transfer all running gear to new Richards V8 Chassis(axles, gearbox, suspension, steering rack, anti-roll bars etc. - Send carcass to scrapyard

2. Strip down defender, and send panels away to paint(I am having a new bulkhead and 3 new doors)

3. Finish off rolling chassis using defender bits and then send off the remainder to the knackers yard.

4. fit new painted bulkhead and wiring loom.

5. Refit all new painted body, wings, Puma Bonnet, rear station wagon/ roof section,doors etc including Safety devices rollcage (as per 50th Anniversary Defender).

6. fit ceramic sports headers from chevy K5 Blazer and install stainless exhaust.

7. Install internal Auto console as per 50th(from Ashcroft Transmissions)

8. Full interior re-trim including forward-facing rear seats as per 2007 XS station wagon.

9. Finish off exterior trim, MOT , Tax , drive.

I have decided on Keswick Green, a modern soft solid colour, with black chequer plate and anthracite alloys - should look nice.

Although the car is a 1984 and should have a white roof I think it would look sharper with the modern look so the roof will be Keswick as well and I am going to paint the grille/ headlamp surrounds in body colour, and keep the external bit of the rollcage matt black.

So far I have spent 10k on parts(new and secondhand) and work on the engine - I expect the final total to be around the 16k mark.

I have sold my TVR engine and roof/rollcage in advance and I should get a bit more back from parts(bonnet etc)

I shall endeavour to give monthly updates with Photos for those interested.

Wish me luck!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!



Edited by vjj on Tuesday 14th August 19:12

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100SRV

1,359 posts

171 months

Wednesday 15th August 2012
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What do you plan to do to beef up the differentials and halfshafts?

budrover

294 posts

133 months

Thursday 16th August 2012
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More interesting question will be "how do you intend keeping facing the right way in a 93" wheel base"

Having driven a few high powered 90 ish wheel base vehicles they can swop ends quite quickly on wet tarmac !


Sounds a great project !!!

vjj

Original Poster:

590 posts

168 months

Thursday 16th August 2012
quotequote all
100SRV said:
What do you plan to do to beef up the differentials and halfshafts?
I am using the beefed-up items from the Overfinch Discovery - plus the huge great torque convertor - and I am having the defender propshafts and UJ's re-inforced.

eliot

7,912 posts

183 months

Thursday 16th August 2012
quotequote all
vjj said:
I am using the beefed-up items from the Overfinch Discovery - plus the huge great torque convertor - and I am having the defender propshafts and UJ's re-inforced.
Never had any problems with UJ's or props. I run 4 pin diffs and HD half shafts, but even that was a throwback to the days of heavy off-roading with the 33" tyres. My main issue was the autobox (th350 and later the 700r4) which took a few tries to get strong.

vjj

Original Poster:

590 posts

168 months

Friday 17th August 2012
quotequote all
thanks as ever for the advice Eliot - I don't ned to be spendin' money I don't have to - the gearbox in the Disco is the beefed up ZF22 4-speed from Ashcroft - rebuilt about 2000 miles ago, and it has the big torque converter so I should be okay.

Nobody will be doing any offroading in it - unlike your Chevy Dakar - I will purely be hooning around scaring old ladies and boy racers, and maybe the odd drag race!!!!!!!!!!!!!!!!!!

dubbs

1,558 posts

213 months

Friday 17th August 2012
quotequote all
Keswick green - nice choice, saw a G4'd D3 in that colour the other day - looks great.

Everyone will now think you're zooming around in some kind of a special force grab vehicle :-)

May as well fit nitrous whilst you're there!!

vjj

Original Poster:

590 posts

168 months

Saturday 18th August 2012
quotequote all
I don't know about nitrous, but Edelbrock do a retro-look bolt-on supercharger with Eaton internals for the L98 small block(and others besides) which is a temptation.

I will not do it straight away though - should be quick enough to begin with - crate motors to the same spec are 450lbs/ft of torque and over 400 bhp anyway so that should keep me intrested for the interim.


DonkeyApple

29,586 posts

98 months

Saturday 15th September 2012
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vjj said:
I am using the beefed-up items from the Overfinch Discovery - plus the huge great torque convertor - and I am having the defender propshafts and UJ's re-inforced.
Have you checked yet that these aren't standard parts? Very, very few Overfinches had any beefed up drive train beyond the HD ZF box.

It was one long options list and most people simply specced the engine and dash trim and badges to save money.

Most didn't even have the HD box let alone diffs or brakes.

eliot

7,912 posts

183 months

Saturday 15th September 2012
quotequote all
DonkeyApple said:
Have you checked yet that these aren't standard parts? Very, very few Overfinches had any beefed up drive train beyond the HD ZF box.

It was one long options list and most people simply specced the engine and dash trim and badges to save money.

Most didn't even have the HD box let alone diffs or brakes.
I've read that too. I suspect there's little you can do to beef the ZF box up anyway. Probably slightly better aftermarket clutch plates (if you are lucky) and increased line pressures (likely).
That's the benefit of using yank boxes such as the GM hydramatic's - there's always someone who has put far more power and abuse through one long before us brits have to mess around. Although it took several iterations to get a 700R4 to last behind my engine, but it works fine now.

DonkeyApple

29,586 posts

98 months

Saturday 15th September 2012
quotequote all
eliot said:
I've read that too. I suspect there's little you can do to beef the ZF box up anyway. Probably slightly better aftermarket clutch plates (if you are lucky) and increased line pressures (likely).
That's the benefit of using yank boxes such as the GM hydramatic's - there's always someone who has put far more power and abuse through one long before us brits have to mess around. Although it took several iterations to get a 700R4 to last behind my engine, but it works fine now.
Ashcroft boxes will do the trick. It's also their quick rack in the Overfinches.

I never had issues with the uprated ZF auto in mine but left as standard and tey were munched quite quickly.

If I go down the US route for my two door then I'll use an LS3 and the ZF 6 speed manual used in the Corvette.

JE Engineering will supply the rest of the drive train, pinned front diff, Quaife rear, shafts, Dakar spec suspension and lowered by 25mm.

Overfinches ran with standard RRC brakes by the late 90s and while these were fine for the LSE they were borderline and you'd find cracks in the drilled discs eventually. Fitting the larger brakes and pads from the Defender (110 I think) will be a basic solution.

The trouble with the two doors is that they ran 16 inch RoStyles so you can't fit larger brakes. But these wheels were a licensed copy of AR500s from the US and you can have 17 inch modern alloy versions made from billet in the US that will look perfect and accept larger brakes as well as allowing V rated tyres to be fitted, something not possible with 16s.

eliot

7,912 posts

183 months

Sunday 16th September 2012
quotequote all
A quick google around found a thread saying you put many of the internals from the hp24 into a 22, including the tc.
Im suprised the boxes live behind the chevy, but i suspect the engines dont put out as much power as you think and also the smaller wheels must help considerbly.

DonkeyApple

29,586 posts

98 months

Sunday 16th September 2012
quotequote all
eliot said:
A quick google around found a thread saying you put many of the internals from the hp24 into a 22, including the tc.
Im suprised the boxes live behind the chevy, but i suspect the engines dont put out as much power as you think and also the smaller wheels must help considerbly.
Yup. I believe the ZF from the P38 was tougher than the version in the Classic. I believe Ashcroft still do additional work beyond that.

The engines Overfinch used were the SBC 350 but I'm pretty sure they sourced them from wherever they were cheapest and so there is a wide range of differing LT model engines out there in Overfinches delivering different outputs. The management systems they used were also cheap and nasty so you wouldn't be getting the best performance anyway.

That's why many have switched to carbs as owners had nothing to lose in terms of economy and while gaining better performance would probably also get better MPG.

vjj

Original Poster:

590 posts

168 months

Tuesday 18th September 2012
quotequote all
The gearbox in my Overfinch Discovery 1 has proved to be a STANDARD ZF HP22 with the medium torque converter - seems my HD Ashcroft unit - as per service history - had been removed and replaced with an old crudder from a 1991 RR Classic!

Never mind - one buys old cars from seemingly genuine blokes at ones peril! But we all know that anyway!

This unit is in Luton as we speak(or type!) having the Ashcroft Stage 2 upgrades - see their website - which includes the front end from a HP24 with a large converter - appears that many, including Donkey, have used these with no problems.

In case you are interested the torque from the 383 is phenomenal - spun all four wheels on dry tarmac with only 1/3 throttle!!!!!!!!!!!!!!!!!!

As for my brakes etc - decided to put the disco 2 axles on the defender so I can have decent calipers and also going with 18-inch Hurricane alloys for big cross-drilled discs.

will put some photos on as the strip-down continues




Edited by vjj on Tuesday 18th September 18:24


Edited by vjj on Wednesday 19th September 22:38


Edited by vjj on Wednesday 19th September 22:40


Edited by vjj on Wednesday 19th September 22:44

vjj

Original Poster:

590 posts

168 months

Wednesday 19th September 2012
quotequote all
DonkeyApple said:
eliot said:
A quick google around found a thread saying you put many of the internals from the hp24 into a 22, including the tc.
Im suprised the boxes live behind the chevy, but i suspect the engines dont put out as much power as you think and also the smaller wheels must help considerbly.
Yup. I believe the ZF from the P38 was tougher than the version in the Classic. I believe Ashcroft still do additional work beyond that.

The engines Overfinch used were the SBC 350 but I'm pretty sure they sourced them from wherever they were cheapest and so there is a wide range of differing LT model engines out there in Overfinches delivering different outputs. The management systems they used were also cheap and nasty so you wouldn't be getting the best performance anyway.

That's why many have switched to carbs as owners had nothing to lose in terms of economy and while gaining better performance would probably also get better MPG.
Mr Donkey

What has happened to your lovely LSE 5.7 - has it been in an accident by any chance?

As for your 2-door RR, I know Damon O in Witney is doing a couple of conversions with crate LS3 engines and Ashcroft Auto gearboxes - is yours one of those?

Not prying or anything - just keen to chew tha fat with other Overfinch Enthusiast

DonkeyApple

29,586 posts

98 months

Wednesday 19th September 2012
quotequote all
vjj said:
DonkeyApple said:
eliot said:
A quick google around found a thread saying you put many of the internals from the hp24 into a 22, including the tc.
Im suprised the boxes live behind the chevy, but i suspect the engines dont put out as much power as you think and also the smaller wheels must help considerbly.
Yup. I believe the ZF from the P38 was tougher than the version in the Classic. I believe Ashcroft still do additional work beyond that.

The engines Overfinch used were the SBC 350 but I'm pretty sure they sourced them from wherever they were cheapest and so there is a wide range of differing LT model engines out there in Overfinches delivering different outputs. The management systems they used were also cheap and nasty so you wouldn't be getting the best performance anyway.

That's why many have switched to carbs as owners had nothing to lose in terms of economy and while gaining better performance would probably also get better MPG.
Mr Donkey

What has happened to your lovely LSE 5.7 - has it been in an accident by any chance?

As for your 2-door RR, I know Damon O in Witney is doing a couple of conversions with crate LS3 engines and Ashcroft Auto gearboxes - is yours one of those?

Not prying or anything - just keen to chew tha fat with other Overfinch Enthusiast
Hi, I sold the LSE last year. Prices had gone a bit mad and I'd stopped driving to the office while at the same time I found the 2 door I'd been searching for for a few years.

The 2 door should have been done by now but I'm still working on the Typhon project and need to get that all finished before starting on the Rangie.

It's currently out in the Cotswolds and I've been sourcing and restoring all the external trim parts to revert it '72 spec.

If someone is already sticking LS engines into them then I wouldn't mind having a chat with them as I'm still researching where to get the engine work done and finalising the various engine options.