BAD 300E project commenced - Page 2 - PeachParts Mercedes-Benz Forum

c280nz · #1 02-04-2010, 06:08 AM

yea convert to efi like turboe320 says,
am i correct looking at your pics that only a few of the cylinders look to have leaned out, (the middle one?)

welcome to the forum and tuning forced benz's, there arn't many that do it, but that makes it so much cooler

roman (pumpish) has a merc tuning website, and seems to have great success tuning the m103, maby he may sell a manifold or be able to help you in some way,

MAG58 · #2 02-04-2010, 02:33 PM

Quote:

Originally Posted by Turbo E320

Solution. Convert to EFI and run E85. 105 Octane (R+M/2) and cheaper than regular gas(at least here in the states). You'll have to update the lines and use a more current fuel pump like a Bosch 044(About $200 and flows enough gas to support 685bhp) but it's worth it.

Issue: We live in the cornbelt. E85 is cheap. I don't even think he lives in the country, much less Indiana. E85 not so cheap, perhaps not available.

400Eric · #3 02-04-2010, 06:57 AM

My vote is still for the LPG. Plus he has already indicated that he basically wants to finish and improve upon what has already been started. It would definitely be the least expensive way to go and he is the one after all, paying for the project.

Regards, Eric

Joreto · #4 02-04-2010, 07:32 AM

If you decide to stick with LPG, than I recommend you convert to liquid injected LPG. Years ago I tried LPG (old type) on my stock 2.5-16v and was not pleased so I basically threw it out. As to the exhaust header you could buy one from turbobanditen.se ( http://turbobandit.com/shop/show_cat.asp?cat_id=96&head_id=91 ) or you could build a custom one.

P.S. I don't think this LPG system will be able to coupe with the boost levels your aiming at 20-25 psi. Evaporators/mixers have e hp/kw rating, do you know the rating of yours, you might need to upgrade or even add another depending on the power your aiming at ?

BAD300 · #5 02-04-2010, 04:08 PM

WOW

thanks guys for all your feedback

Quote:

Originally Posted by Joreto

Yes LPG has higher octane and it's common to advance the timing a bit when running LPG. Currently a friend converted his turbo E36 328i to LPG, on petrol it runs @ 1 bar but on LPG it starts leaning out after 0.5, so now his waiting for bigger LPG injectors.

When engine is rebuilt, I will be putting in larger LPG jets prior to dyno! I believe the orig' owner retarded timing, as you do when boosting on petrol, & perhaps leaned out the 2 cylinders & caused detonation?

Quote:

Originally Posted by Joreto

If you decide to stick with LPG, than I recommend you convert to liquid injected LPG.

I know of people having huge success with the mixer fed LPG systems. It's just the AFR's, tuning that's appears difficult

Once I have the engine running again & have run it in, tuning will be my main priority. Thanks for tip on ext header btw!

Quote:

Originally Posted by 400Eric

LPG has an octane rating of 110 (R+M/2 method. This means you can run way more boost before detonation occurs (provided the AFR is correct). That's why I said this car is cool.
Regards, Eric

The higher octane & detonation resistant properties of LPG is what interests me most although, you do have to push through more LPG due to the gas having less energy, as mentioned prior by JayRash

This aspect along with difficulty in tuning, is the main trade off you need to consider I guess

Quote:

Originally Posted by c280nz

yea convert to efi like turboe320 says,
am i correct looking at your pics that only a few of the cylinders look to have leaned out, (the middle one?)

welcome to the forum and tuning forced benz's, there arn't many that do it, but that makes it so much cooler

Yes, 2 cylinders copped it good! Even the bores have suffered rust damage. You can see where water has flowed down the cylinders

There is also a very strange lip about 1 1/2 inches down 2 bores. Fug knows what the seller has done to this poor engine

Heard about Roman, will definately catch up with him soon

Quote:

Originally Posted by 400Eric

My vote is still for the LPG. Plus he has already indicated that he basically wants to finish and improve upon what has already been started. It would definitely be the least expensive way to go and he is the one after all, paying for the project.

Regards, Eric

Precisely! Hit the nail on the head

I'm sticking with LPG as car was already converted when I purchased it

The buggered engine was a bonus I wasn't expecting yeehar!

Quote:

Originally Posted by Joreto

P.S. I don't think this LPG system will be able to coupe with the boost levels your aiming at 20-25 psi. Evaporators/mixers have e hp/kw rating, do you know the rating of yours, you might need to upgrade or even add another depending on the power your aiming at ?

Concidering the work already done to car, I'd like to get @ least 18psi. Thanks for heads up!

I am probably needing new evaporator anyway due to rusted water inlet/outlet pipes.

Quote:

Originally Posted by MAG58

Issue: We live in the cornbelt. E85 is cheap. I don't even think he lives in the country, much less Indiana. E85 not so cheap, perhaps not available.

Yep! I live in Australia. E85 is not available here yet. We have E10 & it is alot more expensive than LPG (well over double). This was to support our sugar industry down here. In hindsight, I probably wouldn't bother with conversion myself although, our Gov' were offering 80%+ rebate if we did conversion

I've become interested since the purchase so, wth?

c280nz · #6 02-05-2010, 04:49 AM

my only concern if you stay with lpg is getting consistant mixes accross all cylinders to make the sort of power/ run the boost you want,
it is all about even cylinder conditions accross all 6 cylinders, for example you dont want all the lpg going to some cylinders and not to others, this may be why the current system leaned out on some cylinders and not others, just speculating,
as long as you can get even lpg and air mix to all cylinders it should be sweet tho!
i like the difference in your project, very cool!

BAD300 · #7 02-05-2010, 06:36 AM

Quote:

Originally Posted by c280nz

my only concern if you stay with lpg is getting consistant mixes accross all cylinders to make the sort of power/ run the boost you want,
it is all about even cylinder conditions accross all 6 cylinders, for example you dont want all the lpg going to some cylinders and not to others, this may be why the current system leaned out on some cylinders and not others, just speculating,
as long as you can get even lpg and air mix to all cylinders it should be sweet tho!
i like the difference in your project, very cool!

This is the kind of feedback I need. Thanks! I see what your saying now. I am used to EFI turbos running ECU's as in Jap cars like Mazda for instance. I never considered the Merc being mechanical injection. These don't have an ECU do they?

I just read that people are having great success with LPG mixers? Who knows?

I just don't know why all the rust & corrosion through everything? I wonder if the previous owner didn't run coolant & just used water?

400Eric · #8 02-05-2010, 07:24 AM

Your car did have an ECU and the injection system was both mechanical and electronic but my guess is none of this is at play now because you have a mechanical LPG system providing the fuel now.

Maybe what 280 is referring to is the fact that a manifold that was designed to be a dry flow only manifold is now being forced to be a wet flow manifold. An intake charge with fuel in it is heavier and not able to make sharp turns as easily as air alone is. I'm assuming that the fuel and air are entering at the stock throttle body location. If that is the case, you have a horrible, very sharp, very sudden turn from that location into the center two cylinders. Probably not much of an issue in a dry flow scenario but a bad deal for a wet flow scenario. This might explain why those center two cylinders got in trouble. The rest of the cylinders have a little more room and time for the intake charge to make the turn into their runners. I'm not saying this problem can't be overcome, I'm just saying you may need to be aware of it so you can do something about it.

If you can afford it, the LPG injection would do a better job, but I'm sure the current set up could be made to work decently as well.
Regards, Eric

400Eric · #9 02-06-2010, 02:20 AM

Quote:

Originally Posted by 400Eric

Maybe what 280 is referring to is the fact that a manifold that was designed to be a dry flow only manifold is now being forced to be a wet flow manifold. An intake charge with fuel in it is heavier and not able to make sharp turns as easily as air alone is. I'm assuming that the fuel and air are entering at the stock throttle body location. If that is the case, you have a horrible, very sharp, very sudden turn from that location into the center two cylinders. Probably not much of an issue in a dry flow scenario but a bad deal for a wet flow scenario. This might explain why those center two cylinders got in trouble. The rest of the cylinders have a little more room and time for the intake charge to make the turn into their runners. I'm not saying this problem can't be overcome, I'm just saying you may need to be aware of it so you can do something about it.

I made most of those same points in the above post.

Yes, LPG won't fall out of suspension but it is still heavier than air alone is and is thus unable to make sharp turns as quickly and easily as air alone can.

I still say that a person could smooth and radius the entries into those center two runners from the plenum area and not touch the rest of the runners so that maybe they could all be evened out somewhat by helping the center runners catch back up to the flow of the other runners. It's not a perfect solution but it's probably the best one short of doing the LPG injection thing.
Regards, Eric

JayRash · #10 02-05-2010, 06:51 AM

that and that it prolly sat for weeks on end with water in the bores due to blown hg. and prolly water was in the manifold as well.

BAD300 · #11 02-05-2010, 07:09 AM

makes me sick. What a waste of a great engine.........coulda been great

BAD300 · #12 02-05-2010, 02:29 PM

At tghis stage I wouldn't know where to turn for fixing this dilemma with mixer. I could have a chat to this installer/tuner down here & take along the head I guess Monday. May even be able to call him this morn.

All this info is helping me do what I have to. Thanks again

400Eric · #13 02-05-2010, 11:16 PM

The problem is in the intake manifold..... take that to him too.
My fix would be to smooth and radius the entries into those center two runners from the plenum area and not touch the rest so that maybe they could all be evened out somewhat by helping the center runners catch back up to the flow of the other runners.
Regards, Eric

MAG58 · #14 02-06-2010, 01:13 AM

Quote:

Originally Posted by 400Eric

The problem is in the intake manifold..... take that to him too.
My fix would be to smooth and radius the entries into those center two runners from the plenum area and not touch the rest so that maybe they could all be evened out somewhat by helping the center runners catch back up to the flow of the other runners.
Regards, Eric

As a wet flow mani, the CIS mani's suck. The plentum more or less requires the flow to make a sharp 90 degree angle after the TB and there really isn't much you can do to help it. However, being LPG should help as it is already gaseous and thus can't exactly fall out of suspension.

BAD300 · #15 02-07-2010, 03:52 PM

I think I get the point with the manifold now. I'd never looked into this prior.

I just read this article concerning wet/dry manifolds. Bit basic but that's sometimes the best way to learn

http://www.kennebell.net/techinfo/gm-tech/manifold-injection.pdf

Actually, this article made more sense:

http://en.wikipedia.org/wiki/Nitrous

edit:

spoke with LPG gut this morning, he doesn't think the manifold has anything much to do with prob @ this stage. It is the fact LPG delivery is via only 1 convertor (vaporiser). It would have leaned out by not enough fuel. He has had success with mixers & says the mixing is all done within mixer ahead of throttle body so, it can't unmix, so to speak once in the inlet manifold.

If he adds a 2nd convertor it should have plenty for 400rwhp. This is what I am chasing. The car will only be pushed hard occassionly but, due to all the bleedin' money/timer & bottom end parts used, it'd wanna make good figures for me to accept all this fun (not)

I am taking engine to my builder also today.

Cheers again guys!