SL55/63/65/R230 AMG: Heat exchanger options for the SL55...




I would consider fab'ing/adding 2 small 90° brackets to tie the (now hanging in air) rear oil cooler bracket holes to the back side of the bumper.
here are a few pictures of my modified undercover; you will likely want to modify yours similarly.
Cheers,
Chris




but you could also just do the whole job with the dremel (and 1/2" drum)
Cheers,
Chris
I ended up using one 90 degree fitting and one straight fitting for the hoses. The oil cooler had to be moved back considerably and I had to remove the plastic air flow shroud that enclosed it as there just wasn't any room for it. The passenger side fog light housing had to be trimmed in the rear so that it wouldn't obstruct the hose. Also, the front bumper had to be notched on the left/right for the HE end caps, and the left side front bumper support bracket had to be trimmed. The notches on the front bumper can't be seen with the mesh grill in place.
So to recap, it fits. However, it certainly required a lot of patience and time to make it do so. For the price, it's worth it if you have a free weekend. As afar as I know, there is not a direct fit heat exchanger for the SL55, so any one that you buy is going to need some work.
The Best of Mercedes & AMG
Also worth mentioning that I got exactly 10 quarts of coolant out of the approximate 14 quarts in the cooling system. This was done simply by draining from the radiator petcock. I couldn't locate the drain plugs on the engine block to get the remaining 4 quarts out unfortunately.



I ran a clear hose from the air bleeder nipple into the coolant reservoir tank, clamped the downstream coolant hose, and ran the pump for about 20 minutes. Whenever I was at the dealership, the tech had mentioned something about parking on a steep hill while the engine is running to help bleed the system?




I ran a clear hose from the air bleeder nipple into the coolant reservoir tank, clamped the downstream coolant hose, and ran the pump for about 20 minutes. Whenever I was at the dealership, the tech had mentioned something about parking on a steep hill while the engine is running to help bleed the system?
If you look at any (and every) Mercedes factory configuration for Heat Exchangers (and for most radiators for that matter) ... the output is at the bottom (because heat rises presumably).
Getting the air out can be tricky but your hoses are configured correctly and should remain that way
Cheers,
Chris
The reason the factory has the outlet is on the bottom is to ensure the pump does not run dry on the first startup after install. But with two radiators that no longer is possible.




The reason the factory has the outlet is on the bottom is to ensure the pump does not run dry on the first startup after install. But with two radiators that no longer is possible.
Every Renntech second heat exchanger kit I see has a crossflow HE, but I have seen some BMW kits that do it backwards, so it would come as no surprise if Renntech has on occasion as well. I will admit that having the water flow in the opposite direction of heat is only a mildly compelling argument as compared to not being able to get all of the air out (if that is an issue). For my installs, to speed refilling, etc , I always add an air-bleed at the top of the new HE. But, in an install like Brian's here, I see no reason why the air would not come out eventually.
In the end, I'm sure either way will be effective enough.
Cheers,
Chris
There are lots of good rules about cooling systems that aren't obvious from a casual inspection, and that's one of them.
- The pump inlet pressure should be as high as possible.
- The pump should be located at the lowest point in the system.
- Locate the pump after the radiator, to keep it as cool as possible.
- Mount the pump horizontally, to minimise end loads on the bearings.
- To avoid air locks, the outlet should be at the top of the pump.
- The pump outlet pipe must always flow upwards.
- The pump's pressure/flow characteristics should be matched to the system resistance curve to achieve best performance.
- Don't run a pump into an excessively high resistance, or the impeller will be unbalanced, and wear the bearings.
- Don't run a pump into an excessively low resistance, or the fluid incidence angle will be wrong, and cavitation will wear the impeller.
- Always keep air and contaminants out of the system.
- Bleed the high points of the system to the reservoir.
- The bleed tubes should not run downwards at any point.
- Feed the pump from the bottom of the heat exchanger, to minimise air ingestion.
- Don't use more anti-freeze than necessary.
Last edited by Welwynnick; Apr 8, 2016 at 07:10 PM.
Nice!! I just purchased a sl55 and the same HE with the Eurocharged stage 1 kit. How are the results with the HE? Did you purchase anything else from them? If you have any photos that'd be great! Also I have the SL55, do Those come with a stock like the sl65 or is the HE an addition to the SL55?
What's the final verdict on the Weistec heat exchanger?
Do you know what the thickness of it is? Did you have to trim the bumper at all? Did you find the angled inlet/outlet ports beneficial when routing the hoses?
From your posts, it appears that the only modification that you had to do was to move the oil cooler back a peg on the stock mounts.




