daimler 250 v8 1967 recomissioning

[suffolkpete]

the thermal characteristics are exactly the same as these of ethylene glycol at the same ratio.

According to a paper I read, the heat transfer of propylene glycol is better than that of ethylene glycol but the depression of the freezing point is inferior, therefore you should use it at a higher concentration to achieve the same protection and this should not affect the cooling properties. The figure of 50% is probably correct, although I agree with your comments as far as ethylene glycol is concerned.

[DaveB]

There seems to be a lot of info out there about propylene glycol; most of it making favourable comparisons with ethylene glycol for older engines. The main problems for classic cars, given the different materials used way back in engine construction, is getting the balance right between cooling, longevity and corrosion management (inhibition). Any owner of a Daimler V8 250 saloon or SP 250 Dart will be familiar with corrosion of the waterways in the aluminium heads.

In the past, one solution for these engines was to use a 50% mix of ethylene glycol of the IAT type (Inorganic Additive Technology). This blue anti freeze gave an appropriate balance of cooling and system protection for these engine without too much damage to gaskets, seals and the like. I have, in addition to the 1969 Daimler V8 250 saloon, a 1937 Daimler 15 Sports Saloon, and the mix of metals in such engines causes electrolysis which in turn causes corrosion. The use of IAT anti freeze has kept the system remarkably stable.

Recently however, antifreeze formulations have changed to OAT (Organic Acid Technology), HOAT (Hybrid OAT) and NOAT (Nitrated OAT). These inhibitor formulations work well with modern car engines (and some of them are blue in colour) giving improved cooling and longer inhibitor life. (So just because it's blue doesn't mean that it's IAT any more!). These modern anti freeze inhibitor formulations don't seem to work so well with older engines, they have been observed to attack silicone based compounds (gaskets, hoses, etc.) and lead based compounds (soldered joints in radiators, lead alloy bushes in water pumps, etc.).

Commonly held views suggest that propylene glycol is a more acceptable and "greener" alternative to ethylene glycol for older engines. Independent testing suggests that corrosion of aluminium is significantly reduced, cavitation in cast iron similarly reduced, and no measurable effect on lead based laterials. The inhibitors used in Fernox Alphi 11 (a brand of propylene glycol) also lasted longer in use than propylene glycol based coolants. Apparently protection with propylene glycol doesn't take effect until there is a 25% concentration, so many car clubs that cater for pre-war cars suggest a 50% mix for those old engines.

Sorry to go on a bit! Anything we can do to protect our older engines is important and a topic close to my heart!

Best wishes, Dave B

[lhubbard]

hi there Dave

well I sorted out the lamination, bad earth and got a nice spark. however still no luck starting. Following the timing entry in the manual I set up tdc and then looks at the distributor. I could not alight in with l1 and it appeared to be 180 degrees out. I then investigated the distributor that came out the donor engine and discovered it has an additional gear piece on the end which changed the phase of the distributor back to the correct setting. I moved the ignition sensor over this evening and will use the donor distributor and see if that corrects the starting problem.

cheers

lee

[JPB]

got a nice spark. however still no luck starting

3: Have you made sure that both modules have a sound connection to the amplifier?

[lhubbard]

yep I done that I think its more a timing issue

[DaveB]

Lee, I've just noticed that you live in Bedfordshire. I live on the Beds / Cambs border, so presumably not too far away. Whereabouts are you based? If not too far I could bring my old girl across for you to take a look at to see if you can mirror the setup.

The extra gearpiece sounds odd to me. I have a known working points distributor from my spare engine, you could try that if it might help?

Best wishes, Dave B

[lhubbard]

I am pretty confident that the ignition system is now up to spec as its producing a huge spark at the plugs. I have decided not to use water in the system and ahve opted to use a specilist coolant wish is not based on water.

Having rebult the second distributor I have noticed a change in the gear at the bottom where the additional gear clips in in. I have never seen an arrangement like this before and when you slot the addtional gear onto the end it changes the position of the distributor rotor arm by 180 degrees.

I will fit this today and see if this makes any difference.

One point I found strange is that with the engine fully fluided up it is hard to turn the engine. This is even the case with the plugs out. Interesting enough that the starter motor turns the engine easy.

cheers

lee