Overheating Roadster

[Ye Ol Ripper]

Re: Overheating Roadster

Stephen , As you are running trumpets on the carbs , that will definitely improve the already very good low end torque.
what Carb needles are you running ?
Was moving up from the standard to usual listed richer needle sufficient?

As you have no air filters and a nice large free flowing exhaust, is the cam standard ?

[HairyDave]

Re: Overheating Roadster

Shame about the overlong clevis pin on the throttle cable. Jealous, Moi? Damn right I am! Beautiful!

[stephenlilley]

Re: Overheating Roadster

Its a length of 2" plastic pipe covering some grotty wiring. One of my next jobs to do is sort the wiring out.

[Ye Ol Ripper]

Re: Overheating Roadster

Stephen, what is the white item to the left of your RHS bonnett hinge?

[stephenlilley]

Re: Overheating Roadster

Yep, I get asked that all the time. When I fitted the carbs, the spacers made them protrude too much so I thought I would try without.
Fearing the worst, I bought some new spacers ready to fit when it all went pear shaped but, 8 years later it runs great, in all weathers. Some more pics.

[wiggiesworld]

Re: Overheating Roadster

Very neat engine bay there Stephen, do you actually get to drive the car?

I thought that but didn't want to be the first to say it Definitely looks like a show car, some serious polishing been going on there.

[HairyDave]

Re: Overheating Roadster

If my engine looked that good, no way would I take it on the road, it would be in a display cabinet! Who made your exhaust manifold? It looks as if you have not fitted the insulating spacers between the manifold and carbs and no heat shield either, the insulation must be very effective. Lovely job, how abut more engine room pics just to rub it in!

[stephenlilley]

Re: Overheating Roadster

I do yes, perhaps a four or five times a month. A mate of mine has a Moggie Traveller and once a month we take a trip to a Café somewhere in Yorkshire, Changes every time. We sometimes go to Thornton le Dale to visit Matthewsons (Bangers for cash). If ever you up this way, its well worth a visit.

[Ye Ol Ripper]

Re: Overheating Roadster

Morning. Its a home made steel manifold and I have a 2" big bore exhaust. The throttle is a Shimano gear cable with a slow bend, really smooth action. The linkage is simplified with two springs attached to brackets on the manifold bolts.I made up a S/S bracket fixed to each carb inner bolt. It works well and does look quite neat, I think !!.I have done lots of other mods including a Sprung hood frame, rear hinged bonnet, Rear MGF discs. etc I seem to be always at it, especially these days.

Very neat engine bay there Stephen, do you actually get to drive the car?

Any noticeable gains from your manifold & 2" exhaust combination?

[stevejgreen]

Re: Overheating Roadster

My Roadster used to get really hot when stuck in traffic in the 30 degrees plus we had recently. So I have fitted a 3 bladed metal fan blade in conjunction with the remote one. It cured the problem straight away. it now never gets above 90 degrees. The metal blade also gives plenty of clearance to the rack. so there is no chance of hitting it under heavy breaking.. I am not saying this would be right for all situations, but it works for me.

A word of caution on MGB style plastic fans. They have a tendency to flex forwards, more than a metal fan, and can make contact with the steering rack mounting bolts, especially at higher revs.

You can of course reduce the diameter of the fan, but check that it is still balanced and does no shake itself apart.

[stephenlilley]

Re: Overheating Roadster

Morning. Its a home made steel manifold and I have a 2" big bore exhaust. The throttle is a Shimano gear cable with a slow bend, really smooth action. The linkage is simplified with two springs attached to brackets on the manifold bolts.I made up a S/S bracket fixed to each carb inner bolt. It works well and does look quite neat, I think !!.I have done lots of other mods including a Sprung hood frame, rear hinged bonnet, Rear MGF discs. etc I seem to be always at it, especially these days.

[Ye Ol Ripper]

Re: Overheating Roadster

My Roadster used to get really hot when stuck in traffic in the 30 degrees plus we had recently. So I have fitted a 3 bladed metal fan blade in conjunction with the remote one. It cured the problem straight away. it now never gets above 90 degrees. The metal blade also gives plenty of clearance to the rack. so there is no chance of hitting it under heavy breaking.. I am not saying this would be right for all situations, but it works for me.

Hi Stephen
What exhaust manifold are you using as I note that it is wrapped ?

I also note that your throttle cable is affixed differently to the norm, what is the advantage of that, although it does look a neater way of doing things?

[stephenlilley]

Re: Overheating Roadster

My Roadster used to get really hot when stuck in traffic in the 30 degrees plus we had recently. So I have fitted a 3 bladed metal fan blade in conjunction with the remote one. It cured the problem straight away. it now never gets above 90 degrees. The metal blade also gives plenty of clearance to the rack. so there is no chance of hitting it under heavy breaking.. I am not saying this would be right for all situations, but it works for me.

[milliemarlin]

Re: Overheating Roadster

I still wonder if mixture is the problem. Does the overheating occur idling in traffic or under load such as on a motorway?

If it overheats when idling it is most probably the cooling system.

If it gets hot on the motorway it is almost certainly running lean. Even at fairly slow speeds there is enough air movement to keep the radiator in constant contact with ambient temperature air. The water pump should be propelling the water round with sufficient oomph to ensure a constant replacement of the coolant.

I would try to convince myself that mixture is not the problem, before going to the time trouble and expense of measuring the cooling system, most of which seems to have been recently refurbished.
Paul

[duncan]

Re: Overheating Roadster

It should be easy, but it isn’t, that’s why the same conversation has been had many times since the first 1800 roadsters were built.

But it IS easy
And the difference in temperature between a system that is working and one that is not is HUGE
You are not interested in a degree or so - answers accurate to 10 degrees will show you what you need to know

You do need to know what is happening under full load - which is why I advocated fitting some gauges and not simply using a temperature probe

Incidentally those non contact probes cost bugger all these days - $15 NZ - less than eight pounds

I should mention that I spent decades testing engines - I was the Quality Manager of the Darlington Engine Plant for seven years before going to the USA as a corporate trouble shooter