Going 'Potty'

[Mr Cerbera]

Wotcha Team

Firstly - a BIG Happy New Year to everyone !

I wish you a Happy, Propserous and, above all, HEALTHY 2022

Life with BlackBeauty© continues from a Big Service to a complete change of identity
BUT
As some wag once said, "Never trust a programmer with a screwdrived in their hand !"

Some of you may have heard that I am attempting to replace my standard single-row 4.5 Injector Rail with e 4.2 Twin Rail.

I am only just beginning to realise how involved this idea is and have met my next problem.

Last year Joolz was kind enough to order some Throttle Pots for those interested and I took full advantage of it

Now I have discovered that the 4.2 Throttle Pots rotate in the opposite direction (They are White, I believe)

and I want to fit new ones to my set-up.

Obviously, when I made my order, I over-ordered the Blue ones so I cast my question to any who did the same with the White ones.

Is there anyone who could be interested is swapping a brand new pair of Blues (still in delivery pack) for a pair of White ones ?

As usual, your replies, humorous, scathing or even helpful would be most appreciated.

Meanwhile for all those who are lucky enough to be in that position.

PJ

[Jimm218]

The white ones are really common. They are on all Rover cars with the K-series engine so can be found easily on ebay and the likes. If you miss being charged extra for a common part then you should be able to pay more at a Lotus parts place

[spitfire4v8]

I bought some cheap white ones from the MG owners club, hoping they would be a quality part. They don't even have a return spring in them. Not a problem on the tvrs are they are a really close fit on the spindle end, but on throttle angle based systems you want to make sure you always eliminate any play in the system, or if you do have play at least make sure the sensor is spring biased one way.

Paul .. if you want to send your black pots back I can send you some of the proper spring biased white pots in exchange?

[Byker28i]

If you struggle I have extras as I ordered spares

[Mr Cerbera]

Jimm218 said:

The white ones are really common. They are on all Rover cars with the K-series engine so can be found easily on ebay and the likes. If you miss being charged extra for a common part then you should be able to pay more at a Lotus parts place

Thanks for that info Jimmy
Already used to being charged TVR TVA from certain suppliers

spitfire4v8 said:

I bought some cheap white ones from the MG owners club, hoping they would be a quality part. They don't even have a return spring in them. Not a problem on the tvrs are they are a really close fit on the spindle end, but on throttle angle based systems you want to make sure you always eliminate any play in the system, or if you do have play at least make sure the sensor is spring biased one way.

Paul .. if you want to send your black pots back I can send you some of the proper spring biased white pots in exchange?

I'm crying.

Have a little problem with the new duties and VAT being imposed on goods inported, J
BUT
I'll sort out an address in the UK for us to do the deal through.

Send you a mail later in the week
and
THANKS !!

Byker28i said:

If you struggle I have extras as I ordered spares

Dave, you're a STAR but I'll try and follow Joolz' kind offer for the moment, ta !

[Mr Cerbera]

.... and done, smoothly, simply and stress-free.

What a Star that boy is

[Imran999]

Paul, what’s the reasoning behind changing the fuel rail?
I believe that the 4.2 induction is considered superior to the 4.5, but does the fuel rail make much of a difference?
Presumably you are changing the induction too?

[Mr Cerbera]

Hi Imran, and a very Happy Canadian New Year to You

I had been trying to sort out an occasional misfire on cylinders 4 & 6 some months ago when I decided to run it without any of the Airbox hoses on it.

I was gobsmakingly shocked to see the injectors' output hitting the throttle valves and splashing back, up the airflow.

I have been chatting to Al Melling over the last year and, when I pointed this out to him, he unleashed his fury at the changes that TVR's engineering team had made to his original design and asked me to look at the path that his twin-rail system took.

I feel that an efficient delivery of fuel/air mix is the key to smooth, strong power production so preferred the 4.2 Injector / Throttle Body set-up. I thought that acquiring the parts migt be a problem but, after the usual mix of cheating bds and Angels, I am getting close to setting it up.

I've talked to Joolz and he says that the set-up will run but could probably be improved with, guess what ? a remapping session . I had, as you can imagine, already planned to employ his services for that purpose
BUT
The next problem I'm thinking on is "Which injectors to make the initial set-up with??"

Do you have any thoughts on the choice ?

Thanks,

PJ

Edited by Mr Cerbera on Monday 28th February 11:34

[Byker28i]

On the 4.2 Joolz also worked his magic on the throttle bodies, I think thining the spindles...

This thread from 2006 might be interesting...
https://www.pistonheads.com/gassing/topic.asp?h=0&...

or this one from the work Joolz did
https://www.pistonheads.com/gassing/topic.asp?h=0&...

From this:
The 4.2 inlets have a few area which need addressing to improve flow, mainly centred around the butterfly spindles, the area just immediately after the butterflies and the waisted section at the manifold to head face. The inlets need stripping down off the car in order to do it and refitting/balancing when back on the car, plus one slip in the butterfly area and it's an expensive mistake so time/patience/care are the order of the day .. hence the cost is quite high.

[Mr Cerbera]

Thanks for that mahoosive amount of information, Dave

When you say "cost is quite high" could you PM me an idea so that I can see if I have to cancel Mrs Cerbera's Wedding Anniversary present ?

Ta !

[Byker28i]

That was from the original thread. I think it was £750-800 to do at the time, around 2008/2009

[CerbWill]

Mr Cerbera said:

The next problem I'm thinking on is "Which injectors to make the initial set-up with??"

The spray pattern of the 4.2 injectors is different to the 4.5. I think the angle is narrower so it's more cone shaped to fire in a straight line down the throttle/intake port. 4.2 injectors flow enough for 400BHP so if your 4.5 made more than that with the 4.5 system on it you might want to find some bigger injectors, if not then the standard 4.2s will be fine.

How are you overcoming the throttle pot differences? Does your ECU need a different map chip to work with the white TPs?

The difference in flow rate of the 4.5 injectors is 350cc/min vs 215cc/min for the 4.2s. I'd expect it to run lean if you used the 4.2 injectors without changing the map. Not sure if the lambda feedback would be able to trim enough before hitting the adjustment limit (somewhere around 30%).

Overall assuming you're using a standard 4.5 map I'd put the 4.5 injectors in to get it to Jools.

[notaping]

Powersperformance can supply a chip for 4.5 running a 4.2 induction. I'm in the process of doing exactly that - although it started as a 4.2 and now has 4.5 liners etc. Same thing.

[Byker28i]

notaping said:

Powersperformance can supply a chip for 4.5 running a 4.2 induction. I'm in the process of doing exactly that - although it started as a 4.2 and now has 4.5 liners etc. Same thing.

Is this a Dom 4.2 upgrade to 4.5?

[notaping]

Only the liners were installed at Powers. Out of necessity. The original 4.2 liners needed replacing and are no longer available. Only option was to upgrade.

EPROM upgrade - Part No M3377 - £150 ex vat.

[Byker28i]

notaping said:

Only the liners were installed at Powers. Out of necessity. The original 4.2 liners needed replacing and are no longer available. Only option was to upgrade.

EPROM upgrade - Part No M3377 - £150 ex vat.

Strange as when I thought I might need them for my engine in 2017 then at the time was told Westwood liners make the AJP liners for TVR Power and only to their design, so they are only available through Dom.

Doesn't he get them made anymore?

[notaping]

Had none on the shelf. Westwood would only make a batch of (I think) 100. Too much stock to leave sitting on a shelf just to fix one engine. 4.5 liners were plentiful.

[Jhonno]

notaping said:

Had none on the shelf. Westwood would only make a batch of (I think) 100. Too much stock to leave sitting on a shelf just to fix one engine. 4.5 liners were plentiful.

4.5 liners are just bored out 4.2 liners..

[spitfire4v8]

When my 4.2 was converted to 4.5 I had to have the block machined as I was told by the parts supplier / machinist that 4.5 liners don't fit where a 4.2 liner once was... make of that what you will, but it was several hundred pounds I seem to recall ..

[notaping]

spitfire4v8 said:

When my 4.2 was converted to 4.5 I had to have the block machined as I was told by the parts supplier / machinist that 4.5 liners don't fit where a 4.2 liner once was... make of that what you will, but it was several hundred pounds I seem to recall ..

Which is what Powers did for me. Removed the old 4.2 liners, machined the block and fitted the larger 4.5's. Nice job.