101 replies to this topic

[Minigman]

Thanks, quite a useful website. I suppose in a realistic scenario do I really need to be splitting hairs for acceleration when running a 1380

If you do lots of motorway driving and want a quieter ride at 70/75mph then a 3.1 would be better. If you have a torquey cam rather than bhp cam then you could go 2.9 with a 1380. Me, I’m a fan of a 3.44 or 3.76 and build my engines to rev, but I do very few motorways. I live in rural Devon and most of my driving on country lanes and a few A roads so I want good acceleration up to 60 or 70 mph. Not worried after that. All noisy engines though.

Edited by Minigman, 10 March 2019 - 12:51 PM.

[Will96]

Just checked the 1st one of my gearboxes and it seems to have got a 3.44 in it. So unless one of my others have magically got a 3.1 in then I might as well save a bit of money and see how using the 3.44 goes. In other news I had a check of the carbs I've got laying around and as far as I'm able to tell I have a single hs4, a hif6 and a hif4 (bit more uncertain on that one) then one other hs carb on my car that I didn't identify before I ran it. No idea if any of them are useful to me

[Retroman]

Carb wise you need to be looking at a 1 3/4 inch and I would vizard it and the manifold

 

Post some photo's for ID on them

[Will96]

Yeah I was thinking of hif44 or twin hs4's, sorry I can't get photos right now but I have 1 hs type (with external float) and it measured about 38.1mm. Then I have 2 hif types, 1 measuring 38.16mm and the other about 44.46mm. Since I'm after reliability I'm lenient towards hif44, but I've had a look at what the hif6 (44.46mm one) is in relation to the hif44, and not been able to find much other than they shared some parts and the hif6 was usually ran twin on some 1800 jaguar's or something like that

[Will96]

Measuring the diameter of the butterfly chamber for those measurements

[Minigman]

Just checked the 1st one of my gearboxes and it seems to have got a 3.44 in it. So unless one of my others have magically got a 3.1 in then I might as well save a bit of money and see how using the 3.44 goes. In other news I had a check of the carbs I've got laying around and as far as I'm able to tell I have a single hs4, a hif6 and a hif4 (bit more uncertain on that one) then one other hs carb on my car that I didn't identify before I ran it. No idea if any of them are useful to me

A 3.44 on your 1380 will accelerate well and still be below the 4500rpm at 70bhp. I’d stick with it and see how you like it.

I’d go with a 1 3/4” carb on a 1380 or a nice pair of HS4s.

Edited by Minigman, 10 March 2019 - 06:56 PM.

[Will96]

I should be set then after reconditioning the carb and gearbox I have. Are there any benefits from fitting stiffer or double valve springs if I'm not going to thrashing it around at 6000rpm

[Minigman]

I should be set then after reconditioning the carb and gearbox I have. Are there any benefits from fitting stiffer or double valve springs if I'm not going to thrashing it around at 6000rpm

I’d say no but others may disagree. Double springs just ensure your valves close quickly at high revs. If you’ve no plans to rev it past 6000 then I wouldn’t fit them.

[Will96]

Taken that into account, thanks. While they get delivered next thing I'm thinking about is the dizzy. I've recently attempted to improve my current std dizzy on my 998 with a washing up glove, but I think I've done a poor job and it still begins dying on me after 20 minutes of driving in the rain. So for the shiny new engine I'm looking to try and eliminate this from happening as its limiting my road trip potential. Was looking at electronic ignition but I read somewhere that a handful of people were still having issues in the rain. So electronic or not is the main question? (I already have a custom made splash guard too)

[Cooperman]

You need to seal the distributor cap both around the plug-lead holes and around the joint with a non-conductive silicone grease. Coat the coil connection and plug caps with the same grease, then spray with an ignition sealer.

 

That's what I have used for over 50 years on rally Minis and they don't have any sort of splash shield. remember, thet drive through some deep water and heavy rain and slush. I also have to run points ignition in my historic spec Cooper 'S'.

[Will96]

Anything special or would vaseline do? And would electronic ignition actually be beneficial over points?

[cal844]

Electronic ignition has been very reliable IME. The only issue I've ever had was the cap and leads failing under load( slight misfire in the rain, cured with an ignition service)

[Will96]

Okay excellent. My current engine in even light rain misfires after about 10 minutes and then after about 15 is total failure. So anything would be a realistic improvement anyway. I assume the 123 will be the better end of the scale given their price. But anything budget (saw powerspark? On Ebay at like 70 quid) actually any good or am I better just saving my pennies up.

[imack]

I've only ever had the little plastic anti splash shield that fits behind the grille and screws to the slam panel, never had misfiring problems in any amount of rain with this fitted. I've cut mine down a bit to clear the oil cooler.

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Edited by imack, 15 March 2019 - 05:31 PM.

[Will96]

Yeah... I say custom made but what I really mean is a rubber/plastic sheet I've trimmed to the shape of the grill and then sandwiched it between the slam plate/front valance, goes from air intake on drivers side all the way across about 4 inches shy of the radiator side. I did see an improvement but as I said still got problems