BT7 Oneday!

[bbh]

Originally the tricarb would have put out about 132bhp, if I take the original figures.  I am hoping with the changes made plus upgrading to triple HS6's (more later on this) and a DWM tubular exhaust manifold and side exit pipes, I should get close to 150 - 170 bhp.  Time will tell !!

Re costings, I'll have a look and come back on this

[bbh]

Carbs

Once a Tri-carb, always a Tri-carb! Yep my intent was to keep with the triple arrangement.

Hopefully a bit tidier that the originals I took off the car …….






I briefly considered the conversion to Webers, but in the end decided that at this stage that was a step too far and meant that I didn’t need to do additional metal work on the engine bay panels.


However, I did want to open things up a bit. My thoughts being that the 1.5” HS4’s originally fitted, whilst Ok at low revs wouldn’t give the volume required with the revised engine mods, similarly I thought that for my use 2” HD8’s would be too much. So, I settled on going for 1.75”, either HS6’s or HD6’s.

Both had been used on Healeys, HD6’s on the 100-6 late BN4’s and BN6 and HS6’s on the 3000MkII BJ7.
I asked around for views and surprise surprise came up with a split opinion, some liked one, some the other. So, in the end I decided to keep with the link to the original and go with the HS6’s.

I had purchased the triple SU intake manifold from DWM and had it matched to the head when the porting was done. To this I bought 3 HS’s from Burlen and matched these up to the intake manifold. ……..






The black plastic tops are as original, but I prefer the brass ones, so these might change.


Still to be worked up are:

Getting the throttle arrangement sorted. Plan is to move away from the rods and levers arrangement and go cable, but minimising the number of cables which go over the top of the rocker cover as I think it can look untidy.

Modifying the heat shield to go with the 1.75” carbs, I have a pattern created in stainless but need to decide upon heat shield material.

Doing something with the overflow outlets from the fuel bowls. I have seen a piped system which feeds the three outlets into one small bore pipe and then to ground which looked very tidy, so potentially something to copy.

I’ll leave optimising the needle / jets till we get on the rolling road at some stage in the future, but the following is not a bad guide / starting point.
midwebsite.ahcmid.biz/technical/tri-carb-modification/

[josefeckert]

Bored to 2.9 is an increase of 7 HP!!! You do not realise that difference driving the car. And you risc to scrap your block when not being really careful. Port polishing brings perhaps marginal, but no real benefit. Only way to easily increase horsepower is to fit a BJ8 camshaft and distributer.

[bbh]

Josef,

I am not boring a 2.6 to 2.9, I started with a 2.9 (3000 MkII tricarb BT7).  I have only overbored by 30 Thou to clean up the cylinders, so don't expect any issues from that. 

I think that the porting and polishing of the head will liberate a few more hp than you suggest, especially when taken into account with the other engine mods made (esp. AH2 reprofiled cam and distributor).  

But I guess we won't know for definite till it gets on the rolling road, which won't be any-time soon!!

[josefeckert]

Sorry bbh,
My reply was to the posting of "bn6" of 14th August. I missed the latest replies from you, as I only opened page 1.
I appreciate your efforts bbh, only its not my piece of cake doing those kind of modifications.

[bbh]

Front Suspension


The intent was to keep to a relatively standard and recognisable layout, but with a few upgrades:

Thicker anti-roll bar; 19mm (3/4”)

Adjustable shock mounts (incorporated during the chassis works)

Black “touring” polybushes

Spax adjustable dampers

Top trunnion bearing kit


As the plan was to end up with some negative camber, I could have opted for the alternative / offset top trunnion pieces, but as work was being done to the chassis, it seemed simpler to put in adjustable shock mounts, which I can then play about with at a later date to get the appropriate camber.


Front shocks in good condition, cleaned and painted up



As I was fitting the Spax units the valve was removed, retaining the fluid. The shock will still act as the upper suspension arm


The king pins which were removed and on strip down had seen better days. A Quinton Hazell set was obtained


Interesting note with kit


Having read somewhere that many of the original stub axles were showing signs of cracking and not wanting to take the risk, a set of heavy duty stub axles (DWM) were bought and used. One advantage of these is that they have been pre-reamed for the kin pin.


The QH kit came with rubber ‘O’ rings, rather than the original felt rings for the stub axles, but these fitted well and I am sure will be a better option.


As part of the build-up of the stub axle, the bronze thrust washers in the top trunnions were replaced with the bearing kit, which is meant to lighten the steering effort – time will tell!


A small wooden cube 2” tall was made up to help keep the shock arms at the right height before everything was tightened up.


One thing to watch for, which I hadn't planned for!  I have had the wishbone anchor points on the chassis strengthened by adding webs either side, as per works design, but on doing this you need to take into account the odd shape of the "washer" and collar on the wishbone securing hardware.  I reused the originals as they were in good condition, just cleaned and re zinc plated.  Fortunately they just fitted - more luck than planning!!

With the bottom “A” arms in position, the camber was roughly set at -0.5 deg. Thanks to a Mr. F.H. suggestion, Ipad worked well in determining the angle.


The front springs looked in good condition and after a clean-up and paint were ready for fitting. I had purchased some threaded rod and tall nuts for the job and this worked out well



I’ll skip over the brakes till later, so now ready to fix the front hubs and associated parts….


and completed with Spax units in-place


Finally, the upgraded ARB was fitted complete with the rose joints.


The only thing to be resolved is the grease caps for the front hubs.

The new ones I bought are too small, so I cleaned up the originals only to find that they are too big!!

[healeyneil]

Looking great ! Personally I've never been a fan of one joints on a road car due to the possibility of crap getting into the joint, but that's just me. Well done

[bbh]

The thinking was that I would go with a slightly thicker ARB, but not too much, but tighten up the linkage a bit. I'll give the rose joints a go and see how they perform. If it doesn't work out, then it won't be too hard to replace as it is one of the easier things to reach.

[healeyneil]

Mine had a DWR thicker bar which used the same links as the standard ARB. What got me was the attachment to the wishbone. I've always thought that that daft wee triangle with turned up edges didn't look to be up to the job. Maybe it was a case of a designed in weak spot, so that would fail before the bar pulled out of the chassis, but I doubt that!
Talking of which, I've seen a couple of cars with doubled up chassis mounts - one beside the other.
Anyway, do you have a completion date in mind yet ? Must be getting close 😀

[bbh]

"Must be getting close" ......... Unfortunately after a double house move things have a long way to go!

The current plan was to get each corner ready to at least fit a wheel (so if it has to move some-where again it can at least be wheeled.

So front suspension, rear axle and rear suspension fitted, but that is all.

Next job is starting to get back to the more traditional approach of getting the brake and fuel lines and associated bits in-place, wiring loom installed and initial heat proofing put in-place. Talking of which in a lot of the pictures I have seen the heat shield boards fixed in the engine compartment on the left hand side footwell, don't align too well, is this just car to car variation or poor quality of the replacement panels?

Any-how long ways to go, but no rush - happy to keep plodding along

[bbh]

Brakes

As this is a pretty much total re-build, the initial plan was to incorporate dual circuit braking, for a bit of added safety, using twin servo's as per some of the later race cars.




The first idea I have kept with, incorporating a dual circuit pedal box and having an extra master cylinder 'hole' added to the bulkhead.



However, at the moment I have decided to keep things simple and stay with an un-boosted set-up. I may go back and add at a later date if I find things too heavy.

Braking at the rear is standard. New cylinders and springs were purchased but pretty much everything else cleaned up OK. The shoes have been re-soled in a Mintex material,



.. and everything reassembled as per normal.



The drums themselves were Ok and cleaned up fine, but as has been reported elsewhere (http://www.hendrixwirewheel.com/drums.html ), when they were originally machined the concentricity is off-centre to the casting - they had a thicker wall at one side than the other. A bit of laithe work on taking away some of the 'thick' shoulder should hopefully help with the balancing.



At the front I wanted to improve things a bit, but still keeping standard looking.

There have been a few articles written on upgrading front brakes:

www.healey6.com/Technical/big

www.acmefluid.com.au/larry/brakes.pdf

Each of them recommends upgrading from the thinner "early" disks to the thicker BJ8 discs as this allows the use of bigger calipers and manages heat build-up better.

Now some reports suggest that this is a straight forward swap with the later "thicker" discs fitting all cars.

However other articles (correctly) suggest that on some cars the BJ8 disc interferes with the caliper mounting bracket.

www.fossewayperformance.co.uk/big-healey-brake-caliper-upgrade/

From some research for those who wish to upgrade (and keep with the earlier type of stub axle) I can see three options:

a. Change the original caliper brackets to one sold by the "performance outlets" which has been designed to take the later disc and Type 16 caliper. However at over £200 for the pair - not exactly a budget change.

b. Again, shopping at one of the "performance parts outlets" you can pick up a "Works Homologated" disk at 11.25" diameter (286mm), which are stated to fit all models (apart from those later BJ8's). Beware though at first glance the price looks comparative with a pair of EBC slotted & drilled disks, but on closer look it is for only 1 disk!, So some-what north of £300 for a pair., ouch!

c. The original caliper brackets are quite meaty and will stand a bit of judicious thinning. Each may be a bit different, but I found that thinning down the area around the caliper mounting hole and along the top and bottom of the bracket - where there is quite a thick protruding ridge (see picture), enough to clear the thicker disc worked fine, and certainly quite a bit cheaper than the other options. The only down-side is that there can be quite a bit of trial fitting to check if enough clearance has been achieved.

Now about discs ….

I bought a set of "standard" front discs from one of the usual suspects for the rebuild some time ago. The arrived in a pretty non-descript plain cardboard box in which I left them (apart from a bit of painting) till the time came to require their presence.

Now having uncovered them and looked in more detail the overall finish of the central casting is a bit rough - fair enough it doesn't do much work. However, running a straight edge over the surface shows it up as not entirely flat, further the finishing at the rear where the skimmed surface blends into the internal of the dome is a bit disappointing.

I did a bit of searching of available discs.

Brembo would have been my first choice but every-one I spoke to had them on at least 6 - 8 weeks special delivery from Italy.

EBC have a choice of three different styles, all readily available and now pre-coated, so if it is going to take some time to get "on the road" they won't rust!

Most of the usual supplier appear to buy from the same source with cast bell, as above.

However Moss do a disc for the MGC / BJ8 (BTC371) which is fully machined and comes in a bit cheaper than the Healey ones ......



Moss disc on the left, original "Healey Suppliers" on the right

So this is what I have used.

Before, I stated to remove some of the shoulder from the mounting bracket.



After a bit of work and many trial fittings!!



The original Girling Type 14 calipers have been replaced by a set of Girling Type 16M calipers (the Type 16 on the BJ8 had wider gap between mounting holes, however the Type 16M had the dame gap as the Type 14, the only issue being that they take a metric pipe fitting for the brake line. However, as the plan was to upgrade the rubber flexible lines to stainless, then DWM sells a set of stainless braided lines with a metric fitting on the caliper end and normal on the other - so easy solution. The pads are Ferodo (fast road / low dust)




Kunifer tubing has been used for the manufacture of the brake pipes.

[bn6]

Are you not going to have the rear drums painted silver instead of black ?

[bbh]

I know that silver would be 'original', however I quite like the dark look behind the wires..... or even Minilites.

[bbh]

Having checked that the "extended" (dual circuit) pedal box fitted into the bulkhead (note to any-one also doing this - double check the alignment of the captive nuts on top with the holes in the top of the bulkhead pedal box.  Don't ask!!) any how I decided to add another for security so have three equally spaced rather than the original two).

I did a trial fit on the bench to check every-thing matched up, to check that the balance bar was centered and to roughly set the lock nuts such that each brake cylinder was at the same distance from the balance bar.







I looked at various options for the master cylinders, the originals were way past their best, and in the end opted for AP racing cylinders which are available in a wide range of bore sizes.



To start with I am going with 5/8" (0.625) for both front and back brakes (same as clutch), on the basis that, that is what was there originally, albeit only one of them. If I need more adjustment than I can get from the balance bar I can move up to the next size.



Then in it all went.







Lines were mocked up with some fencing wire and then copied to the Kunifer and followed broadly the original route, except for;



.. the line to the rear which came directly to the master cylinder.

.. the clutch line M/c to flexi, which now comes directly down, rather than going over the top of the pedal box.



I did try those hairpin style grips, but I wasn't convinced that they were secure enough - perhaps it is because the kunifer is a bit softer than the original steel lines, so in the end I resorted to using rubber cushioned stainless "P" clips.



There were a number of options for the reservoirs, I could have kept the Girling dual type (as original) supplemented by a single, but in the end decided on three separate reservoirs, each linked to a single master cylinder.



Positioning, I looked to keep with the approach of the Sebring cars which used a "T" bracket in the original position….






So, using the original pedal box bracket adapted with a cross bar and spacer the three mini reservoirs were equally spaced. All that remains is to check whether a support bracket will be needed. Braided lines will feed from the reservoirs to the master cylinders.

[bbh]

Fuel Pump

Having heard many stories of fuel pump failure (although I must admit that on the MGA, the SU has performed admirably since the early 1990's rebuild) I decided that on the Healey I would err on the side of caution / redundancy by installing two pumps from the start. Some of the race / rally cars had this (twin SU) set-up, I believe.

The initial plan was to use dual Facets, but whilst they are undoubtedly less prone to failure and the set-up can look very nice …



However, there is something satisfying to turn on the ignition and hear that familiar clicking sound - if for no other reason to confirm that the pump is working / and or you haven't a problem with a float valve in the SU and leaking fuel!!

Hence, I decided to go with, not twin SU's but a double ended SU as this would simplify the piping with one common in and out for both pumps. The AZX1405's are dual polarity so no problem with either positive or negative earth setups.



I had read the article by Simon Lachlan (http://www.healey6.com/Technical/Double.pdf ) on such an installation as a starting point, specifically about mounting the pump.

The one issue I had (which in the end proved to be a red herring) was that having installed a Spax shock kit, it came with a new fuel pump mounting bracket, to replace the original.



Whilst the Spax bracket is a nice solid affair, the mounting holes are not drilled properly, and it would still need additional bracketry to fit the double ended pump.

I "wasted" quite a bit of time figuring out an appropriate bracket design which would keep the pump away from the Spax hardware at one end and prop tunnel at the other.

I tried to find the Jaguar mounting bracket as used by Simon, but with little success, so I reverted to getting two ABF916, SU Fuel Pump Mounting Brackets from Burlen. These are tapered to fit the body of the SU pump, with the double ended pump needing one for either side.

Having trial fitted the mounting brackets to the pump, the eureka moment came when the hole set-up on the SU mounting brackets, looked close to that on the original Healey bracket, and on measuring, they were pretty spot on with the SU brackets snuggled up tight on the pump body. Note I did put some additional rubber strip inside the SU bracket to "fill it out a little"



The only potential issue being that the screw head on the back of the pump sticks out past the end of the mounting bracket. Some of this fortunately is managed by the indented strengthening rib on the rear bulkhead between the bracket mounting holes, but I wanted a little more clearance, so made up a couple of spacers to give a little more clearance.



A couple of earth leads were made up to link each pump with the mounting bracket and the whole assembly fitted to the bulkhead.



Again, Kunifer lines were used from both tank to pump and then pump to engine bay, following broadly original routes, but as per the brake lines, secured by stainless "P" clips.

At least using SU's meant that the pipe fittings were standard.

The wiring will allow for each pump to be operated separately or together, if required.


Whilst on the subject of fuel, should have mentioned that a new aluminium fuel tank was installed.  I never had the old one in the bits I received with the car.

I could have kept it plain aluminium, but decided to paint it black.



I bought one of the self adhesive rubber pads for below the tank from one of the usual suppliers, but perhaps it was the metal work on my car (it has had a new boot floor) but the pre-cut pad just wasn't the right size.  So do-it-yourself.  Flat bit of the appropriate material purchased from EB and cut to size.  Fits like a glove.



Sender unit next, fitted as planned and some hylomar used on the gasket to give a good seal.  An each lead attached just in-case the earthing through the tank/straps/ etc isn't enough



and finally, in-place and tied down