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Camshaft and Valve spring advice neded


estately

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Hi all,

I am currently rebuilding a 2500TC/S motor to drop into my MK1 estate with j type od manual box and 3.45 diff.
I will (and am) use the car as a daily driver and to tow my mgb racecar on its single axle braked trailer.
Car has mk2 rear suspension arms and front and rear brakes.

Spec so far is very standard;
- 030" over county pistons
- reground crank
- all new bearings
- 219016 head - TC and S - 30.3mm exhaust valves with hardened seats.

The engine was probably a TC I think because it had a 311399 3 ring cam and double valve springs.
I am wondering what sort of grind to go with, and then which springs to use, to give me good midrange power.

My thinking thus far has been based on what little info Chris Witor has on his site. A grind based on the 308778 1 ring cam but with increased inlet lift and compression raised to 9:1.

Any thoughts/ experiences?

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There are so many horror stories with cam regrinds at the moment that I would seriously look at a new blank and followers from Newman with his mild PH1 cam - Newman seem to use a better quality chill cast blank that have a very good reputation for NOT wearing lobes

http://www.newman-cams.com/pdf/triumph.pdf

For springs - try Jag Heritage parts - EBC4871 - cost pennies literally and are the same rate as Triumph single springs - search for that part number here - 20p each!!! They come in bags of 5  ??)

http://www.jaguarclassicparts.com/html/JCPFrames.html?languageId=0&Country=UnitedKingdom&applicationType=JCP

Also if towing a lot i would suggest a 3.7 diff is better (if you have one handy)

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lagerzok wrote:
There are so many horror stories with cam regrinds at the moment that I would seriously look at a new blank and followers from Newman with his mild PH1 cam - Newman seem to use a better quality chill cast blank that have a very good reputation for NOT wearing lobes

http://www.newman-cams.com/pdf/triumph.pdf

For springs - try Jag Heritage parts - EBC4871 - cost pennies literally and are the same rate as Triumph single springs - search for that part number here - 20p each!!! They come in bags of 5  ??)

http://www.jaguarclassicparts.com/html/JCPFrames.html?languageId=0&Country=UnitedKingdom&applicationType=JCP

Also if towing a lot i would suggest a 3.7 diff is better (if you have one handy)


That sounds good.
On the diff front, I was looking at using all 2.5 mk2 running gear and then grafting a mk2 speedo into my spare mk1 housing to get correct callibration. But if i use a 3.7 diff - from an auto whats the best way to get it reading right?

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lagerzok wrote:
Stag or late 2000 J Type will have the right drive pinion - you need a 1000rev / mile speedo

http://www.rimmerbros.co.uk/Item--i-NKC49

18 tooth red one - best find a S/H one at that price!


Ok cool, Thanks this all sounds very do-able.

Cheers all for your advice, this is a great forum!

Ill graft a 1000rpm speedo in the with a plate - thanks Piman.

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I removed the rims from the Mk1 and Mk2 instruments and built up a speedo and tacho from a late Mk2 with Mk1 rims. They fit perfect and look great, especially with 5 smiths instruments in the centre console.

Just a thought.

Steve

piman wrote:
Hello Estately,


The MK2 instruments are slightly smaller in diameter so you'll need to make an adapter plate

Alec


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759 wrote:
I removed the rims from the Mk1 and Mk2 instruments and built up a speedo and tacho from a late Mk2 with Mk1 rims. They fit perfect and look great, especially with 5 smiths instruments in the centre console.

Just a thought.

Steve





Nice, I was thinking along the same lines- I have my eye on an auction for a mk2 PI dash with speedo and Tacho but according to chris witor's page I think the speedo is a 840 rpm one so not what i need, sadly.

I'm running a pertonix points replacement kit - do the tacho's go ok with these?

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lagerzok wrote:
Stag or late 2000 J Type will have the right drive pinion - you need a 1000rev / mile speedo

http://www.rimmerbros.co.uk/Item--i-NKC49

18 tooth red one - best find a S/H one at that price!


Acording to Witor's website red is 19t for j type od with 3.7:1 diff and 1000rpm speedo. I have 18T Blue/Green Nylon for 3.45:1 with 840rpm speedo or 4.1 diff and 1000rpm speedo.
And according to Witor the 2000 which has the 3.7 diff uses a 6 tooth drive gear not the 5 tooth that the 2500's use (and I have).
Is that correct?

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thescrapman wrote:
You can fit a pre-facelift Mk2 PI tacho with a Mk1 deep rim and an orange needle pinched from a Mk1 GT6 and it fits in nicely.

Still on teh bench mind, as is the new centre console.

I'll put up pictures later when I get home.

Cheers

Colin


Cheers Colin - keen to see that.

Ken

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3826 wrote:


Acording to Witor's website red is 19t for j type od with 3.7:1 diff and 1000rpm speedo. I have 18T Blue/Green Nylon for 3.45:1 with 840rpm speedo or 4.1 diff and 1000rpm speedo.
And according to Witor the 2000 which has the 3.7 diff uses a 6 tooth drive gear not the 5 tooth that the 2500's use (and I have).
Is that correct?


Bugger - I'm confused now !! -   a stag speedo is 1000rev/ per mile AND 140mph whereas - the 2000 is only 120mph speedo - we need a definitive matrix orf combinations
Maybe just go with the 3.45 diff for the moment!!! LOL

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thescrapman wrote:
Here they are.

Cheers

Colin


Nice. Thats looks great. I'd like to do the same with a tacho too.
I have a very long list for this car. It has a lot of potential - which is another way of saying its a tad rough. I think I'll focus on the mechanicals before the ine interior - other than the speedo I guess- as I'm trying to use it as my primary 4 wheel transport at the same time as rebuilding and swapping new bits into it.

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lagerzok wrote:


Bugger - I'm confused now !! -   a stag speedo is 1000rev/ per mile AND 140mph whereas - the 2000 is only 120mph speedo - we need a definitive matrix orf combinations
Maybe just go with the 3.45 diff for the moment!!! LOL


Under the technical section on Witors site he lists speedo specs, but only for saloon/estates not stag etc.

http://www.chriswitor.com/cw_technical/speedo_data.pdf


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lagerzok wrote:
http://www.rimmerbros.co.uk/Item--i-NKC45

Looks like the Stag has a 6 tooth drive on the overdrive  - and probably a 18 tooth pinion? because of 14 inch wheels?



Yeh according to witor the setup would be 6T drive, 19T pinion and 1000 rpm speedo with 3.45 diff and 175/13 tyres. I have 195/65x14 tyres which are about 1% out from std.

I'm really keen to leave the drive geaar alone at the moment - its a 5T.
So the easiest route for me is to use the 3.45 diff with my 5T,18T combination and a 840 rpM speedo.

But having never towed with a 2.5 I don't know what to expect. Will it have enough poke with the 3.45 diff? might suck it and see. Cammy has offered me a 3.7 diff which I might put under the bench for if i need it and start with the 3.45, which will make the every-day driving nicer anyway.

Ken

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