Overheating in a Marina Roadster

[stevejgreen]

I was reading with interest the thread in the Sportster section.

http://www.marlinownersclub.com/forum/showthread.php?4716-Louvres

Marina Roadsters, particularly 1.8's historically have suffered from overheating issues, often discussed on this forum and in Pitstop.
Even now there are Roadsters that have yet to have louvres in their engine compartment side panels.

The same company that helped with a Sportster could also help with a Roadster.

There are several other things that can be done to help a Roadster, all detailed on this forum, but I have tried to collate them all at http://www.keepandshare.com/doc/4039...34-pm-48k?da=y

[petermarlin1798]

Re: Overheating in a Marina Roadster

As a follow-up to Steve's excellent summary of solutions to overheating problems, I can report that after some thorough investigative activities including ignition timing, carb settings and a rebuilt brake master cylinder (all of which were necessary) my 'overheating' has just been solved with a new temperature sender!

[stevejgreen]

Re: Overheating in a Marina Roadster

Does that mean I have to amend my document? I know its not listed.

[dogoncrazy]

Re: Overheating in a Marina Roadster

I had same problem with apparent overheating when I built my 1275 roadster. Turned out that the 'Marina' sender was incorrect match for the Smiths gauge I used at the time

[neiltechspec]

Re: Overheating in a Marina Roadster

Put a proper temperature gauge in - a mechanical capillary.

Mines a 1500 Triumph with a re-cored Toledo rad (1300) & 13" fan on the correct side (engine side) and no mechanical fan, it doesn't overheat.

Neil.

[cdow]

Re: Overheating in a Marina Roadster

Hmmm.. I remember reading about the sensor problem years ago and was encouraged at the prospect of an easy fix. It wasn't. It's the bodywork; even after all my endeavours the car is still tempted to get hot when pushed - I'm considering vents in the bonnet to finally sort it out.

[CompoSimmonite]

Re: Overheating in a Marina Roadster

One of the receipts that came with my 1800 powered Roadster is for a "special" radiator with larger core. I've not had the engine running so don't know if it made any difference by my car hasn't the louvres that others seem to need. Maybe all it takes is such a custom rad with 4 cores instead of normal 3 cores or whatever rad specialists do

Paul H

[cdow]

Re: Overheating in a Marina Roadster

One of the receipts that came with my 1800 powered Roadster is for a "special" radiator with larger core. I've not had the engine running so don't know if it made any difference by my car hasn't the louvres that others seem to need. Maybe all it takes is such a custom rad with 4 cores instead of normal 3 cores or whatever rad specialists do

Paul H

I've got a receipt for several hundred quid for a custom aluminium radiator ;-) Didn't make a fat lot of difference to the re-cored Viva rad I had previously.

[ggrum]

Re: Overheating in a Marina Roadster

Several years ago I replaced the 1.3 'A' series in my Roadster with a 2 litre Alfa DOHC and was mindful of the risk of overheating so I did two things a) had the original Vauxhall (Viva or Chevette, I can't recall which) radiator re-cored and b) fitted a thermostatically controlled electric fan with manual override in front of the rad. I fitted a low temperature switch in the rad so that the fan would come on early rather than late. The engine bay has louvres down the sides only. The car has never overheated and the fan only comes on when stuck in traffic in really hot weather. There are maybe two reasons for this. The engine is virtually all alloy rather than cast iron so probably gets the heat away more efficiently and it has a large finned alloy sump that takes 6 litres of oil. With the 'B' series you can't do anything about the metal it's made of but maybe the addition of an oil cooler would help. Just a thought

[CompoSimmonite]

Re: Overheating in a Marina Roadster

I wonder if an oil cooler would help ?
The Sprite 1275 I'm fitting, in place of the 1800TC, has a cooler so intend keeping it.

Paul h

[cameronfurnival]

Re: Overheating in a Marina Roadster

my marina TC roadster has an oil cooler fitted. I dont think they make a huge amount of difference until you get the oil really hot - so every bit of cooling will help. CBS used to do a finned clamp thing that fitted around the oil filter and gave a bit of extra cooling too.

[Gareth]

Re: Overheating in a Marina Roadster

Hi,
I found the main cause of the car running hot was the amount of air passing through the grill but under the radiator. There was cowling either side of the radiator but none top or bottom.
I've cured this by using two pieces of black plastic guttering and formed an 'S' shape and simply cable tied them to the chassis to deflect the air through the radiator.
I didn't bother with the top cowling as there's nowhere to fasten anything to and the cold air passing over the top of the engine helps keep things cool a bit.
Hope that helps!
Gareth.

[b_caswell]

Re: Overheating in a Marina Roadster

The problem is that without blanking the radiator surround is that the air will go the easiest route first pressurising the engine bay and reducing the flow through the radiator.

[greyV8pete]

Re: Overheating in a Marina Roadster

Hi,
I found the main cause of the car running hot was the amount of air passing through the grill but under the radiator. There was cowling either side of the radiator but none top or bottom.
I've cured this by using two pieces of black plastic guttering and formed an 'S' shape and simply cable tied them to the chassis to deflect the air through the radiator.
I didn't bother with the top cowling as there's nowhere to fasten anything to and the cold air passing over the top of the engine helps keep things cool a bit.
Hope that helps!
Gareth.

I made up a ram air duct for my Hunter from thin dural sheet. It's like a drawer with the bottom missing and fits inside the nose cone. The inner end matches the area of the rad core. any air that goes into this duct has to go through the rad. The top triangular space has a duct in it to take cold air to the injection air intake which is at the back of the engine bay. I also modified the front grill to enable it to be removed from the front, so fitting the ram air duct was easily accessible. If you have a "pusher" fan make sure there is a space between the motor and the rad core. Even 10mm will make a difference. Peter.

[stevejgreen]

Re: Overheating in a Marina Roadster

It appears that faulty senders may be more prevalent than I first thought, I will have to add a rider to my document, but in my defence, a faulty sender/gauge is not an overheating engine but possibly a feature of Marina Roadsters in the same way as the fuel gauge.
My document was prepared as a compilation of many sources within the MOC, it was an effort to present all the possible causes and potential solutions. Some worked for me, others not so well, but I would not rule any out without first investigating.
blocking the surrounds of the radiator seems to be sensible in an effort to get air to pass through the radiator, the major source of cooling.
i am in agreement with Jez, I can't see that there is a real benefit in installing an oil cooler, it will either block further airflow or at worst become vulnerable to damage with catastrophic effects. The actual engine cooling benefit is marginal.
Ultimately if the UK gets the predicted hot summer this year, ambient temperature will have the dominant impact.