Bad news - the switchover times on this car are quite lengthy. This appears to be due to the common rail being thermally tied to the engine's head. With ambient temps at about 70*F, it takes me 11 miles / 20 minutes to get the returning diesel fuel temps up to 140*F. The coolant is at full temperature at about 4-5 minutes, but the entire engine takes much longer to heat up.
A block heater or some type of aux 120v coolant heater should help, and that's my plan of action going forward.
Wednesday, June 18, 2008
Monday, June 16, 2008
Valves replaced
I took out the experimental valve set I had installed that was leaking quite a bit (41ml/min on the return side) and replaced it with a set of boring old Hydraforce SV-10s. The leakage rate is much lower (5ml/min on the return side), thank goodness. This means I can finally run WVO with getting huge amounts of cross-contamination.
One thing I've noticed is it does take a *long* time for this car to get up to temperature, at least fuel wise. The coolant temp can be up around 165*F or so while the fuel coming out of the common rail is around 110*F. If I keep driving around the fuel coming out of the common rail eventually gets to around 175*F, but it takes a while. Switching to heated VO does NOT make the fuel temps coming out of the common rail increase faster.
The conclusion is that the common rail fuel temperatures depend mostly not upon the fuel input temperatures, but rather upon how heat-soaked the head and rail are. This, of course, does not negate the need for heating the fuel before it enters the high pressure common rail fuel pump, but it does mean a much longer wait before a safe switchover can be made. I imagine this is true with most or all common-rail based vehicles.
To counteract this I'm going to purchase and install a block heater and put it on a timer, even in the summer. This should (hopefully) shorten my switchover distances.
I'm also going to update the controller logic so it is more suitable for common rail based vehicles. This update will mean that the controller will only switch when coolant AND fuel temperatures reach certain points. I'll most more on the controller software update in the weeks to come.
One thing I've noticed is it does take a *long* time for this car to get up to temperature, at least fuel wise. The coolant temp can be up around 165*F or so while the fuel coming out of the common rail is around 110*F. If I keep driving around the fuel coming out of the common rail eventually gets to around 175*F, but it takes a while. Switching to heated VO does NOT make the fuel temps coming out of the common rail increase faster.
The conclusion is that the common rail fuel temperatures depend mostly not upon the fuel input temperatures, but rather upon how heat-soaked the head and rail are. This, of course, does not negate the need for heating the fuel before it enters the high pressure common rail fuel pump, but it does mean a much longer wait before a safe switchover can be made. I imagine this is true with most or all common-rail based vehicles.
To counteract this I'm going to purchase and install a block heater and put it on a timer, even in the summer. This should (hopefully) shorten my switchover distances.
I'm also going to update the controller logic so it is more suitable for common rail based vehicles. This update will mean that the controller will only switch when coolant AND fuel temperatures reach certain points. I'll most more on the controller software update in the weeks to come.
Friday, May 30, 2008
Moved fuel temp sensor, timed purge
Pictures are up - http://picasaweb.google.com/ray.ackley/2005MercedesE320CDIConversion
Some of these config pictures are a little out of date with the changes I made tonight (see below), but I'll update them soon.
I moved the fuel temp sensor out of where it was (after the valves, before entering the common rail FP) to the output side of the common rail. The temps are higher now, although they seem less dependent on the temperature of the VO as it enters the system than how heat soaked the engine itself is. The common rail is basically one big hunk of metal tubing that's directly mounted to the head, so that makes sense. I'll post more temp readings after I get a chance to actually drive it around.
I also put a glass filter in the return line just before the valves and discovered the purge time is surprisingly short. Purge time is only 20 seconds, and I set the Return Delay parameter (delaying the return valve on the switch to VO from diesel) to 15 seconds. I was kind of surprised at this because it looks like the common rail holds a large volume of fuel in it. So either it's moving fuel pretty darned fast or it doesn't have as much volume inside as it looks like it does.
Some of these config pictures are a little out of date with the changes I made tonight (see below), but I'll update them soon.
I moved the fuel temp sensor out of where it was (after the valves, before entering the common rail FP) to the output side of the common rail. The temps are higher now, although they seem less dependent on the temperature of the VO as it enters the system than how heat soaked the engine itself is. The common rail is basically one big hunk of metal tubing that's directly mounted to the head, so that makes sense. I'll post more temp readings after I get a chance to actually drive it around.
I also put a glass filter in the return line just before the valves and discovered the purge time is surprisingly short. Purge time is only 20 seconds, and I set the Return Delay parameter (delaying the return valve on the switch to VO from diesel) to 15 seconds. I was kind of surprised at this because it looks like the common rail holds a large volume of fuel in it. So either it's moving fuel pretty darned fast or it doesn't have as much volume inside as it looks like it does.
Monday, May 26, 2008
Parts List
Zip ties. LOTS of zip ties.
Valve system:
Fuel Filter: POP Diesel Filter Head + NAPA Filter
Brass:
Valve system:
- 1x POP Diesel Tri-Valve Manifold - 3 valves in a single body, pre-plumbed in a 3-valve config for loopback during VO operation and return to VO during purge. Note that fittings will be included with the valve manfold for customers (I was their guinea pig! Not always a bad thing..)
- 5x http://store.summitracing.com
/partdetail.asp?part=EAR -949006ERL - 1x http://store.summitracing.com/partdetail.asp?autofilter=1&part=AER-FBM1532&N=700+0&autoview=sku -This has a tighter bend.
- 2x http://store.summitracing.com/partdetail.asp?autofilter=1&part=AER-FBM1512&N=700+0&autoview=sku
- 1x http://store.summitracing.com/partdetail.asp?autofilter=1&part=AER-FBM1522&N=700+0&autoview=sku
- 1x http://store.summitracing.com/partdetail.asp?autofilter=1&part=AER-FBM1542&N=700+0&autoview=sku
- 1x http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM-220711&N=700+115&autoview=sku - This has a wider/longer bend
- Yes, this was though trial and error, ordering lots of parts that weren't needed and sending a lot of those parts back. Since the spot is so tight it's vital to get the right components though.
- 49 feet of SAE 30R9 rate fuel injection line (fluoroelastomer lined). Yes it's pricey, but I won't be reinstalling the whole system every 9-12 months. Get some extra. I found this available at every Murrays and NAPA location local to me. It's simply called "Fuel Injection Hose." Cool 30R9 document: http://www.gates.com/common/downloads/files/gates/brochure/techtipsform.pdf
- ~30 feet of 3/8" coolant line - To/from trunk (HotFox, POP Diesel Filter)
- ~10 feet of 1/2" coolant line - To/from FPHE (for better flow than 3/8" line)
- ~6 inches of 3/4" coolant line (stock heater hose hose is 3/4", so with a compact 3/4" plastic tee used to split it off near the firewall, a short section of 3/4" hose is needed)
Fuel Filter: POP Diesel Filter Head + NAPA Filter
Brass:
- Lots. Seriously. I went through a TON of brass fittings. Unless quantities are indicated, get 10 (or more) of each. Some of these are hard to find and you can't get them at your local hardware store. Freezing the conversion for a few days while a silly brass elbow is sent isn't worth the extra cost of having a few extra on-hand. I was short a few pieces I COULD get at the local hardware store (at Lowes, Home Depot was useless as usual) and it cost me several hours in trips back and forth a couple times.
- 3/8" NPT to 3/8" Hose Barbs Straight
- 3/8" NPT to 3/8" Hose Barbs Elbow
- 1/2" NPT to 3/8" Hose Barbs Straight
- 1/2" NPT to 3/8" Hose Barbs Elbow
- 1/2" NPT to 1/2" Hose Barbs Elbow
- 1/2" NPT to 1/2" Hose Barbs Straight
- 1/2" NPT to 3/4" Hose Barbs Straight (x1)
- 1/2" NPT Cross (4 ports) (x1)
- 1/2" NPT Tee (x3)
- 3/8" NPT Tee (x1) (fuel sensor assembly, temp sensor)
- 3/8" NPT to 1/4" NPT Bushing (x1) (fuel sensor assembly)
- 1/4" NPT Close Nipple (x1) (fuel sensor assembly)
- 1/4" NPT Tee (x1) (fuel sensor assembly, pressure sensor)
- 1/4" NPT to 5/16" Hose Barbs (all stock fuel lines are 5/16")
- 1/4" NPT to 3/8" Hose Barbs (all 30R9 fuel injection line we're adding is 3/8")
- Custom made tank, see picture for dimesions and layout.
- Manufactured by Luther's Welding, http://www.lutherswelding.com/
- Price excluding shipping, including flush mount fuel filler (they ordered from Summit) was $505.
- I highly recommend using them, they produced very high quality, CUSTOM work at a very reasonable price.
- Flush mount fuel filler: http://store.summitracing.com/partdetail.asp?autofilter=1&part=RCI-7030A&N=700+-119993+115&autoview=sku
- HotFox from Plantdrive.
- ISSPRO fuel level sender 7" from egauges.com.
Sunday, May 25, 2008
Overview
I'm creating this blog to document my E320 CDI Conversion. I hope this will help others in their conversion of this vehicle.
Some of the posts may be random now but I'll go back and edit/organize them later as I have time.
I've pretty much finished the conversion at this point (with the exception of testing and a valve leak problem). This is a brain dump right now before I forget everything:
Overall the 2005 E320 CDI is a very easy vehicle the convert. The reasons for this are numerous:
1) The E320 CDI has a series of plastic underpans that bolt to the bottom of the car - these basically shield the entire underbody of the car except the exhaust and drive axle. The result of this is that running hoses (3/8" I recommend) is pretty easy and completely concealed/protected/insulated simply by bolting the underbody panels back up.
2) The bottom part of the trunk that holds the spare tire is entirely plastic. This means it is EXTREMELY easy to cut/drill/patch/etc. Running hoses into/out of the trunk and sealing them up afterwards through this plastic body is exceptionally easy since it is easy to drill individual holes for each hose.
3) The spare tire well is a perfect spot for a tank. Unfortunately it has to be custom made because there is no commercially available tank on the market, but I had one made for $500. This was a 15 gallon tank and fit the spot exactly. $500 included the flush-mount fill port that they special ordered from Summit Racing. The reason you need a flush-mount fill port is so that you can maximize the height of the tank (maximizing the amount of fuel it can hold) without hitting the trunk base panel (more on this later).
4) The fuel pluming at the engine is very simple, unlike the 96-99 E300s. It consists of a diesel supply line which feeds the diesel fuel filter. From the diesel fuel filter it goes into a mechanical fuel pump (big black metal thing bolted to the head, looks like it's part of the engine almost). From there it is pressurized to common-rail pressure (very high) and distributed to the common rail system. There is a return from the mechanical fuel pump as well as the end of the common rail. These tee together and run right back to the tank in a return to tank system. There is no fuel fed back into the diesel filter, there are no crazy loops or random places the fuel is routed. Tank -> Filter -> High pressure pump -> Common rail -> Tank. SIMPLE.
5) The coolant system is relatively easy to tap into (I'll post pictures showing you where to do it).
6) With the simple relocation of a bracket (and not so simple griding off of the bracket's bolting spot) you have a nice flat easy to use spot to mount valves that is in an ideal location. It's very close to the diesel filter, common rail, and diesel supply/return hose locations.
7) Wiring up the controller is also relatively straightforward.
Some of the posts may be random now but I'll go back and edit/organize them later as I have time.
I've pretty much finished the conversion at this point (with the exception of testing and a valve leak problem). This is a brain dump right now before I forget everything:
Overall the 2005 E320 CDI is a very easy vehicle the convert. The reasons for this are numerous:
1) The E320 CDI has a series of plastic underpans that bolt to the bottom of the car - these basically shield the entire underbody of the car except the exhaust and drive axle. The result of this is that running hoses (3/8" I recommend) is pretty easy and completely concealed/protected/insulated simply by bolting the underbody panels back up.
2) The bottom part of the trunk that holds the spare tire is entirely plastic. This means it is EXTREMELY easy to cut/drill/patch/etc. Running hoses into/out of the trunk and sealing them up afterwards through this plastic body is exceptionally easy since it is easy to drill individual holes for each hose.
3) The spare tire well is a perfect spot for a tank. Unfortunately it has to be custom made because there is no commercially available tank on the market, but I had one made for $500. This was a 15 gallon tank and fit the spot exactly. $500 included the flush-mount fill port that they special ordered from Summit Racing. The reason you need a flush-mount fill port is so that you can maximize the height of the tank (maximizing the amount of fuel it can hold) without hitting the trunk base panel (more on this later).
4) The fuel pluming at the engine is very simple, unlike the 96-99 E300s. It consists of a diesel supply line which feeds the diesel fuel filter. From the diesel fuel filter it goes into a mechanical fuel pump (big black metal thing bolted to the head, looks like it's part of the engine almost). From there it is pressurized to common-rail pressure (very high) and distributed to the common rail system. There is a return from the mechanical fuel pump as well as the end of the common rail. These tee together and run right back to the tank in a return to tank system. There is no fuel fed back into the diesel filter, there are no crazy loops or random places the fuel is routed. Tank -> Filter -> High pressure pump -> Common rail -> Tank. SIMPLE.
5) The coolant system is relatively easy to tap into (I'll post pictures showing you where to do it).
6) With the simple relocation of a bracket (and not so simple griding off of the bracket's bolting spot) you have a nice flat easy to use spot to mount valves that is in an ideal location. It's very close to the diesel filter, common rail, and diesel supply/return hose locations.
7) Wiring up the controller is also relatively straightforward.
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