can i swap back to the old radiator? - PeachParts Mercedes-Benz Forum

bricktron · #1 03-02-2013, 02:10 PM

hi folks,

i have the slightly larger radiator with overflow bottle now that there is a 617 in my 240D. i hate the overflow bottle though. can i swap back to the old radiator?

the one liter less of coolant that the old system holds seems like a minimal difference in a cool climate. i would keep the later fan and shroud.

Phillytwotank · #2 03-02-2013, 02:14 PM

Do you have an older style radiator?

qwerty · #3 03-02-2013, 02:52 PM

Quote:

Originally Posted by bricktron

i hate the overflow bottle though.

Is it actually an overflow bottle? Or is it an expansion tank?

Either way, what's the point of getting emotional about it?

Fattyman · #4 03-02-2013, 03:11 PM

I'll take your "big" radiator from you

t walgamuth · #5 03-02-2013, 03:34 PM

I'd suggest if you do to at least use the larger radiator with the old style cap and no expansion tank of the 300D na.

The reason the expansion tank is there though is to provide for the additional heat and its accompanying expansioni generated on a hot day when the turbo is kicking in big time on a long hill. I like the looks of the old style radiators where you can look in and see the tops of the rad cores too but on a turbo motor i'd keep the expansion tank probably.

sleepstar · #6 03-02-2013, 03:38 PM

he may be talking about a NA 300D radiator with the overflow hose routed to a bottle. theres a setup like that on mine. i dont know why you'd want to switch back to a 240D radiator though? is the larger oil cooler for the 300D mountable to the 240D radiator? you could always ditch the bottle and route the hose to the ground like it is stock...

Orv · #7 03-02-2013, 04:54 PM

I used to have a '90 Ford van like that, with no overflow bottle and the hose going to the ground. I actually went the other way and swapped in an overflow tank, because I got tired of it piddling on the ground every time it got hot. I figured having less air in the system couldn't help but reduce corrosion, too.

vstech · #8 03-02-2013, 06:10 PM

What engine do you have in the car? turbo or NA? if it's the turbo, I'd keep the larger radiator with the expansion tank... for sure. I actually think it's too small... long hills, and such will overtax the cooling system in the summer...

Quote:

Originally Posted by bricktron

hi folks,

i have the slightly larger radiator with overflow bottle now that there is a 617 in my 240D. i hate the overflow bottle though. can i swap back to the old radiator?

the one liter less of coolant that the old system holds seems like a minimal difference in a cool climate. i would keep the later fan and shroud.

charmalu · #9 03-02-2013, 08:52 PM

As I remember you are using a engine from a 85 300SD. Going back to using the 240D Radiator would give you less cooling, and as mentioned, would the Oil Cooler mount to the 240 Radiator?

As I remember the W116 300SD used a Radiator w/o the Expantion Tank, also think the tank on the Radiator is brass instead of plastic. Don`t know if one will fit into the 123 body.

Ya never know if some day you might venture away from the cold foggy weather of SF, and need the cooling of the larger radiator the 617 eng uses.

Charlie

pawoSD · #10 03-02-2013, 10:28 PM

I would leave the proper radiator and expansion tank for the turbo engine in place. Anything else will be too small capacity.

Why do you hate the expansion tank setup?, its not exactly a "high issue" item generally....

bricktron · #11 03-04-2013, 12:05 AM

OK, as to your questions.... it's a turbo engine with an expansion tank. i don't know about the mounting implications yet. i care because unlike those of you with late-model cars and A/C, i have a real empty engine bay and i think the extra tank is hideous. i would much prefer to have the open space there.

i understand that the second tank helps to avoid overflow in overheating situations, fine. i'm happy to use less toxic coolant and refill if i do boil over. however, a small increase in the amount of water in the system, i don't see how that increases cooling capacity. there is more water to heat, but the same heat to dissipate through radiators of similar or equal surface area. if the internal design of the radiators also changed, it could mean more heat transfer, sure (was that the case?).

cho · #12 03-04-2013, 04:10 AM

Quote:

Originally Posted by bricktron

.... a small increase in the amount of water in the system, i don't see how that increases cooling capacity.

water cools better than coolant (antifreeze) but you should not go
over 60 water/40 coolant in due water boiling point and possible winter lock.

some do experiment with water wetter but I have no data for those...

cheers

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t walgamuth · #13 03-04-2013, 06:18 AM

its not the extra water that matters, it is the increased expansion area. The turbo motor increases heat in the combustion chamber and its accompanying charge of heat into the cooling system. The extra expansion area allows expansion of the coolant without pushing any out on the ground.

In the old style radiators you are supposed to keep the level high enough to cover the top of the core but leave expansion space on top of that. If you fill it to the top of the neck as soon as the engine is loaded on a long hill or a high speed highway run it will push out coolant onto the ground.

vstech · #14 03-04-2013, 06:44 AM

the 240 radiator has fewer cores, and less heat transfer area. it is slightly wider, but it's thinner and the upper and lower tanks are thinner. that heat transfer area is increased on the turbo radiator system. also, the HIGH mounted expansion tank allows faster movement of steam out of the engine and a long transfer area for the steam to reintegrate to coolant before exiting into the tank. the tank is pressurized with the system, not an overflow system.

cho · #15 03-04-2013, 07:20 AM

Quote:

Originally Posted by t walgamuth

its not the extra water that matters, it is the increased expansion area.

true, very true, I was just "chemical"

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