Spitfire Help Required Please!

[integraleSte]

I am in the process of rebuilding my mk4 Spitfire after a long time off the road and am hoping the PH Triumph faithful can answer a couple of questions for me.

I built the car as a hillclimb/sprint car about 13 years ago and am now looking to turn it back into a road car.

A fairly minor issue but what is the best size steering wheel to fit to the car as my original is worn out and I want to put a more modern suede wheel on?

When I rebuilt the brakes, I used Automec silicone fluid and I have recently fitted new (re furbed) front calipers and replaced some of the brake pipes from braided to copper and after bleeding the brakes the pedal goes almost to the floor before I get a good pressure. Is this just air in the system or something else? Would I be better using conventional mineral fluid?

I also have yet to get an unleaded head so what is the recomended additve to use in these engines?

From memory (although it was a long time ago) I think I have a 4.11:1 diff fitted ( the number starts with a GF or GE I can't quite tell). I also currently have 175/55r13 racing tyres fitted  which I believe are quite a bit smaller than standard. This set up was fine when going up the hills but has anyone any experience of this set up on a long journey and how wearing/tiresome do you think it will be (I have got O/D fitted which used to work....)? Basically do I need to go to the extent of fitting another diff?

Thats all I can think of at the moment so any help/advice will be much appreciated.

Many thanks in advance.

Stephen.

[//j17]

integraleSte said:

A fairly minor issue but what is the best size steering wheel to fit to the car as my original is worn out and I want to put a more modern suede wheel on?

13" or 14". I've always used 13" wheels (used to have a Mountney, currently have a Momo) and not had any issues with steering weight, etc.

integraleSte said:

When I rebuilt the brakes, I used Automec silicone fluid and I have recently fitted new (re furbed) front calipers and replaced some of the brake pipes from braided to copper and after bleeding the brakes the pedal goes almost to the floor before I get a good pressure. Is this just air in the system or something else? Would I be better using conventional mineral fluid?

Silicon will give you a SLIGHTLY spongy pedal but that doesn't sound like the pedal feel you have. I'd say there is something else wrong and switching to mineral fluid will just mean throwing £30 worth of silicon fluid down the drain for nothing.

My gut feel would be dead seals in the master cylinder. The main seal could be shagged and most of the pedal travel has fluid getting around the seal rather then being pushed down the pipe.

integraleSte said:

I also have yet to get an unleaded head so what is the recomended additve to use in these engines?

The recommended additive - nothing.

What's going to happen if you run your leaded head sans-plom? Well the Triumph valve seats are NOT very prone to receding without lead, especially with a good build-up of lead from running on 4-star in the past (in fact one of the fuel companies took a new engine off the line and ran it on unleaded as a test and saw no regression of the valves).

The worst that will happen if you have to adjust the valve clearances a little more often for the next 10 years as the valves eat in to the seats...the very same seats that the machine shop will drill out to fit unleaded inserts.

Just run it on unleaded, retarding the ignition slightly if it pinks until the valves have started to regress, THEN get an unleaded head.

integraleSte said:

From memory (although it was a long time ago) I think I have a 4.11:1 diff fitted ( the number starts with a GF or GE I can't quite tell).

Probably GE - Triumph Herald 13/60, 4.11:1 ratio. Don't think there is a GF diff. code.

integraleSte said:

I also currently have 175/55r13 racing tyres fitted  which I believe are quite a bit smaller than standard. This set up was fine when going up the hills but has anyone any experience of this set up on a long journey and how wearing/tiresome do you think it will be (I have got O/D fitted which used to work....)? Basically do I need to go to the extent of fitting another diff?

Standard tyres are actually 155/80/13.

Depending on gearbox/type of overdrive your diff+tyres won't have you far off standard RPM at 70MPH:
Yours: 3890
Stock Mk IV: 3217
Stick 1500: 3002

Check out www.mintylamb.co.uk for loads of useful tools for the impact of diff/gearbox swaps and wheel/tyre/rolling radius.

[integraleSte]

Thanks for the info, that's a massive help. My reason for asking is that I'm planning on taking it to the Le Mans classic in July and just trying to cover as many things that might give me issues as possible. The head was decoked about 500 miles ago so there isn't a build up of lead so I might just tun additive through every other tank full.

I have a D type over drive and what I believe to be a GT6 gearbox with lower ratios in 1st, 2nd (and 3rd?) but I thought that 4th gear was 1:1 in both gearboxes and with the overdrive it droppped to 0.8:1.

Another quick question, I have heard conflicting advice regarding the greasing of the starter moter engagement screw. What is the correct way, dry, grease or DFL?

Thanks again.

[caziques]

You're correct on the gearing, with the overdrive you'll have 20mph per 1000 in top, don't go for a long drive without it.

Starter motor bendix should only be lubricated with graphite, don't use grease.

[//j17]

And for the love of god oil your trunions with EP90 oil!

[integraleSte]

Thanks for the help again guys and yes, my trunions will be getting the EP90 treatment!

Anyone know where I can get some DFL for the starter motor from as Canley Classics want £12! I have read that the lead of a very soft pencil can be used instead......

Another question! Are the aluminium carb heat sheilds a worthwhile investment on a long journey?

Also, is it worth fitting an oil cooler? Is the standard oil pump man enough to cope with the extra volume?

On the subject of oil is it difficult to fit the (cvh?) valve stem seals as my car likes to smoke a bit with the top end oil feed pipe fitted?

Thanks again.

[//j17]

integraleSte said:

Another question! Are the aluminium carb heat sheilds a worthwhile investment on a long journey?

I've never had any issues with fuel vaporisation on a long journey - a long sit in a motorway traffic jam, yes but not on a journey.

integraleSte said:

Also, is it worth fitting an oil cooler? Is the standard oil pump man enough to cope with the extra volume?

Opinion is divided about oil coolers and it should only need to be track cars that need them. A lot of road cars can get over-cooling if a thermostatic switch isn't included in the system.

integraleSte said:

On the subject of oil is it difficult to fit the (cvh?) valve stem seals as my car likes to smoke a bit with the top end oil feed pipe fitted?

Unless you have roller rockers fitted or blocked the internal head feed take the dirty piece of the devils bum-fluff that is the external oil feed of the engine.

General opinion these days is that they cause more trouble then they solve - mainly because they don't solve anything. The standard Triumph head feed is more than up to the job (unless blocked, either intentionally or by gunk) and send the correct amount of oil to the head to lubricate the valve gear. An external feed just chucks too much oil up there, so it runs down the valve guides and in to the engine.

You will find that the only people selling valve guides for Triumph engines are the same people that sell rocker feed pipes... Their logic is that the Triumph feed isn't good enough, so you need to buy their pipe and that the triumph engineers got it wrong and should have fitted valve guides. Actually the Triumph engineers got it right and didn't NEED valve guides because they didn't pump too much oil in to the head.

These pipes only do two things.
1) Pump too much oil in to the rocker cover.
2) Rob oil pressure from the main bearings (to critical levels in the 6-cylinder engines).


I'll get off the fence now

[integraleSte]

I'm guessing your not a fan of the rocker feed then! I think I will definitely be removing it at the weekend.

Today I bought new master cylinder seal kit, new rear slave cylinders and some more slicone fluid today to try and solve my brake issue.

I also bought some valve stem seals that I will hopefully fit before Le Mans but by the sound of it removing the oil feed pipe will help a lot.

I don't think I will bother with an oil cooler or carb heat shield on your expert advice.

If I can get the brakes sorted then it should go for a carb tune up and an MOT next Tuesday weather depending. I will keep you posted.

Thanks for all your help.

[//j17]

The real Le Mans (24hr) or Classic?

[integraleSte]

//j17 said:

The real Le Mans (24hr) or Classic?

We are giving the Classic a go this year as fancy a change after several years of firework competitions at 4 in the morning on Houx Annexe at the real one. Although I would have quite liked to have seen the Mansell's and Jag this year.

I feel it's more appropriate to take the Spitfire for the first time.

There are 2 Spitfires and a TVR Griffith going down in our convoy so should be a good trip as long as the weather is good!

[itiejim]

Wouldn't bother with an oil cooler for road use, but I'd definitely fit some carb shields. There's no down side to having them and they can certainly help. I've suffered fuel evaporation numerous times when stopping for fuel after a good run, especially on the continent. I've only had it once when actually moving, that was when doing a steady 40mph through the St Gothenburg tunnel (18kms) - it was late August and very hot inside! Some heat shielding material around the fuel pipe (and well thought out routing) can also help.

I've never run oil stem seals, they might help, but if you feel you need them then I suspect you have a problem. If the top end isn't over oiled and the valve guides are in good order they really aren't necessary. That's why Triumph never fitted them.

integraleSte said:

I'm guessing your not a fan of the rocker feed then! I think I will definitely be removing it at the weekend.

Today I bought new master cylinder seal kit, new rear slave cylinders and some more slicone fluid today to try and solve my brake issue.

I also bought some valve stem seals that I will hopefully fit before Le Mans but by the sound of it removing the oil feed pipe will help a lot.

I don't think I will bother with an oil cooler or carb heat shield on your expert advice.

If I can get the brakes sorted then it should go for a carb tune up and an MOT next Tuesday weather depending. I will keep you posted.

Thanks for all your help.