Morris Minor Twin Cam

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MinorTC
Posts: 83
Joined: April 28th, 2009, 9:30 pm

Morris Minor Twin Cam

Post by MinorTC »

Greetings all,
I recently purchased a 1965 Morris Minor 2-door saloon fitted with a Fiat 2.0-litre twin cam and five-speed 'box, MGB rear axle, Marina pedal box and front disc brakes, and Mini steering column.

The car had sat unused for years, after the owner 95% completed it, including practically a complete new underside, inner wings and sills. The main things left to do are the wiring, and fitting an interior.

Since buying her, I have fitted a Mini heater, and jury-rigged the engine wiring to get it up and running, though it needs some tweaks to get it properly on song; problems I currently have are that the block-mounted mechanical fuel pump doesn't appear to work (I tried swapping it for one off a Fiat 1800TC block and that was the same) so I've had to use a Moprod electronic one which tends to cause flooding. Also the 4-2-1 exhaust manifold gets red hot after only a few minutes running where the collectors meet 8-[] so I may have to refabricate it to avoid spontaneous combustion!

Does anyone know what may be causing the fuel pump problem? When I took it off, it appeared to suck OK when operated by hand, and I could feel the cam on the auxiliary shaft. Would a Facet type pump be best, and would it need a pressure regulator?

Thanks for any pointers,
Maurice (Kent, UK).
Last edited by MinorTC on April 30th, 2009, 8:44 pm, edited 1 time in total.
Maurice,
East Kent.
dp
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Re: Morris Minor Twin Cam

Post by dp »

I've run a facet solid state pump on a 2.0 T/C (also in a Morris Minor) with no problem with a Weber DGV carb. No pressure regulator. The Facet needs to be fitted near the petrol tank. It's a bit noisy if that is a concern.

I can't offer more specific advice but would suggest that if you haven't already, you go through the standard service items to make sure all the basics are as they should be. I.e. are plugs the right type, are the points clean, is ignition timing correct, does it advance, air filter clean or new? Are the cams timed correctly (wondering if the cam might be a tooth out)?

What carbs are you running, what jets? Are the cams standard or something else? Actually I'm assuming carburettors, if you have fuel injection then the solid state Facet would not be suitable.

If the exhaust is literally red hot, something sounds very wrong. I'm not an expert so can't suggest anything more but more specific details will help experts to help you.
Guy Croft
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Re: Morris Minor Twin Cam

Post by Guy Croft »

Hot exhaust can mean ignition is retarded. Get a strobe and set it to 10 deg advance at 850 rpm.

GC
MinorTC
Posts: 83
Joined: April 28th, 2009, 9:30 pm

Re: Morris Minor Twin Cam

Post by MinorTC »

Many thanks for the advice guys - much appreciated :D Will check it all out...

The carb is a 34ADF54/250. Not sure on the cams, but the jets are as follows:

Idle Jet: 90
Main Jets: 130, 122
Air Correctors: 170, 175
Last edited by MinorTC on June 1st, 2012, 9:04 pm, edited 1 time in total.
Maurice,
East Kent.
MinorTC
Posts: 83
Joined: April 28th, 2009, 9:30 pm

Re: Morris Minor Twin Cam

Post by MinorTC »

I have since fitted a Facet 'Road Kit' solid-state fuel pump just in front of the rear-mounted fuel tank, and it pumps very effectively, if somewhat noisily!

Following advice from my local Weber specialist, I have now got the carb to operate more or less as it should (some fine adjustment probably still required to optimise it). I also cut off the previous tubular exhaust manifold 2-into-1 collector as its squashed tube design was creating a hot spot, and welded in a collector from a Fiat Mirafiori Sport front downpipe instead, which has noticeably improved the sound of the exhaust and allows the engine to exhale easier, the result of the work being that now it starts easily and runs respectably smoothly with pretty good throttle response.

I am somewhat concerned at how hot the engine seems to get during standing test sessions of a few minutes at a time despite having a Kenlowe electric fan, though maybe these Fiat twin cams run rather hotter than the Minor's standard A-series engine?

I shall be inspecting the thermostat and would like to fit a suitable water temperature gauge - does anyone know of one that works with the standard Fiat head sensor?

Thanks,
Maurice (Kent, UK).
Maurice,
East Kent.
tcmoggy
Posts: 18
Joined: July 19th, 2010, 9:53 pm

Re: Morris Minor Twin Cam

Post by tcmoggy »

Hi,

Reading your posts with interest as I have just bought a twin cam traveller (after sadly selling my part built Viper powered split screen minor and my twin turbo'd V8 minor) although the engine is creamed, the ends ratlle and the bloke that I got it from didn't know what the noise was so drove it every day for about 8 weeks so there's no hope of saving the bottom end.
Mine runs hot on stand still, about 2 mins before you can push the choke in and the kenlowe cuts in after about 5 mins, however, the car has never overheated and as the engine is shot, I hqave driven hard as well and again, no overheating.
Mine runs quad bike varbs which is rather interesting and the throttle is all or nothing. Any pics of your cars?
MinorTC
Posts: 83
Joined: April 28th, 2009, 9:30 pm

Re: Morris Minor Twin Cam

Post by MinorTC »

Hi TC!
Good on you for getting a Traveller with a Fiat Twin Cam - should make for a great wolf in sheep's clothing! I think I have now licked the cooling problem, by following Guy Croft's advice and ditching the original Fiat inline/external thermostat and instead fitting a Mini 74 degree C one in the cylinder head outlet elbow, and blanking off the end of the T-piece that came from the external thermostat: I had to get it aluminium welded, after an unsuccessful attempt at plugging it using Chemical Metal, which leaked like a sieve under hot water pressure! I have also used a 1/8" domestic radiator bleed valve in the T-piece to bleed the system.

For pics, please visit Retrorides and search for username '1275Traveller'. There's a guy 'madmog' there who has used bike carbs on his Fiat twin-cam engined Minor.

Whereabouts are you? I have a spare 1.8-litre Fiat twin cam and five-speed gearbox if you are in need (I'm near Canterbury, Kent).
Last edited by MinorTC on August 2nd, 2010, 1:14 pm, edited 3 times in total.
Maurice,
East Kent.
dp
Posts: 28
Joined: September 11th, 2006, 9:07 pm
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Re: Morris Minor Twin Cam

Post by dp »

MinorTC wrote:Hi TC!
Good on you for getting a Traveller with a Fiat Twin Cam - should make for a great wolf in sheep's clothing! I think I have now licked the cooling problem, by following Guy Croft's advice and ditching the original Fiat inline/external thermostat and instead fitting a Mini 74 degree C one in the cylinder head outlet elbow, and blanking off the end of the T-piece that came from the external thermostat: I had to get it aluminium welded, after an unsuccessful attempt at plugging it using Chemical Metal, which leaked like a sieve under hot water pressure! I have also used a 1/8" domestic radiator bleed valve in the T-piece to bleed the system.

For pics, please visit Retrorides and search for username '1275Traveller'. There's a guy 'madmog' there who has used bike carbs on his Fiat twin-cam engined Minor.

Whereabouts are you? I have a spare 1.8-litre Fiat twin cam and five-speed gearbox if you are in need (I'm near Canterbury, Kent).
Wow fame! :) Probably a bit late to reply but I'm 'Madmog' on the Retrorides.org forum, (dp was already taken by somewhere else) but 'dp' here and on Morris Minor fora.

Knowing the requirement for facts rather than speculation I can only go as far as to note that bike carbs, GC3a inlet cam and crank fired ignition are a lot smoother and more powerful than the DGV carb, points and standard inlet. 'Measured' with seat of unacceptable. Rolling road will have to wait for another day.
MinorTC
Posts: 83
Joined: April 28th, 2009, 9:30 pm

Re: Morris Minor Twin Cam

Post by MinorTC »

Hi dp! Thought I recognised your car on the MMOC forum :)

I've now got my 2-litre Fiat TC Minor on the road, but naturally with such a project, there are teething problems. My main issue at the moment is to get the engine to run consistently. It has a tendency to sometimes abruptly loose power and backfire, usually following a run at some speed or while cruising, almost as if it has some sort of constipation problem and gets backed up! Once the backfire is over and done with, normal operation is resumed.

The carb is the standard Weber 34ADF54/250; I've tried altering the mixture screw and I've fitted a new set of Champion NY7CC spark plugs, but so far I've yet to eradicate the problem.

I'm wondering if maybe the carb is being overfed by the rear mounted Facet fuel pump, or maybe I should be using the fuel return back to the tank?
Last edited by MinorTC on June 1st, 2012, 9:04 pm, edited 1 time in total.
dp
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Re: Morris Minor Twin Cam

Post by dp »

Sorry, I don't know. If the carb originally had a fuel return I don't think you should just block it off. Perhaps you're overpressurizing the carb and fuel is being forced past the float valve - especially with the more powerful electric fuel pump.
MinorTC
Posts: 83
Joined: April 28th, 2009, 9:30 pm

Re: Morris Minor Twin Cam

Post by MinorTC »

Well, yesterday, I reverted back to the original engine block mounted mechanical fuel pump, and so far, so good - it definitely seems to make the engine a little smoother, and requiring less throttle input at low speeds. Starting seems unaffected. I don't know why it didn't work properly to begin with, but such is life with old cars!

I have been able to disconnect the Facet electric pump, although it is still in place as a spare. It's certainly quite pleasant not having to listen to the loud ticking, which somewhat marred the Fiat exhaust note!

Yet to test it out at dual carriageway speeds, so too early to say whether this will cure the backfiring...
Maurice,
East Kent.
MinorTC
Posts: 83
Joined: April 28th, 2009, 9:30 pm

Re: Morris Minor Twin Cam

Post by MinorTC »

The backfiring/kangarooing issue turned out to be down to an aftermarket fuel filter fitted between the fuel pump and the carb - once removed, the car ran like it should, almost; it can still be a right royal pain to get it to start, particularly after having either run out of fuel or been left standing for a few days.

I suspect this is because in its original Fiat 131/Mirafiori application, the fuel tank is mounted quite high up behind the back seat, whereas the fuel tank on a Minor is mounted low down and right at the back, so there is not as much gravity feed.

Someone suggested fitting a one-way non-return valve into the fuel line, which seems like a good idea that might be worth trying...
Maurice,
East Kent.
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