1986 190E 2.3-16 Chain Guide Rail Replacement - Page 3 - PeachParts Mercedes-Benz Forum

Racing · #31 05-22-2007, 03:00 AM

Yeah,Hockenheim was really fantastic.No two ways about it.
The sound of the guilliotine equipped more or less class1 engines as they go WFO...geez...gives me the creeps man..
Sounds like a chainsaw on crack for the lack of better words!

I was a very happy camper with that one of my customer installs was set to the test on a chassis dyno they had at the base camp.
I delivered the car with very conservative timing and very rich on fuel-for run in.
Owner,who is a really nice guy in every imaginable way,asked me if it would be to early to lean on it by putting it on the rollers,and i told him....go for it.

So...with boost backed out as much as we could(base setting of 0,7 bars at wastegate) we hit the dyno,and i expected something alone the lines of 240-260...
Judge my surprise...
300hp and 450Nm..

With a mere 19 deg and super rich...(lambda 0,83 approx)

Could say that the limiter on that little engine WILL be the conrods as times comes to lean it out and ad the timing needed for power...(approx 25 deg)
Hell,i dunno if i´ll feel comfortable with increasing boost anymore that the mentioned 0.7 bars..

JimSmith · #32 05-22-2007, 08:08 AM

Ok, no heat. Got that. I was thinking of heating the cover to loosen the fit between the cover and the crank seal ring, which seems to be what the cover is hanging up on at the moment.

We have the oil pump suction tube and strainer free from the bracket, which was also a bit of a chore.

The front cover is really only hung up on the seal ring. The ring is inside the bore of the cover and there is no way to grab it. It is maybe 15mm inside the bore, about on the other side of the Woodruff key slot. Your instructions suggest the seal ring should come out of the bore before the front cover comes off, and I am struggling with figuring out how that can be done.

I would photo copy the manual cross section view of this area and post it, but the quality of those kinds of photos at 65kb is not good. I will post the photos of the bounty of chunks and parts in the oil pan. Overall the oil pan was relatively free of small stuff; mostly just larger chunks that won't get removed with the pump. Seems most of the smaller stuff was flushed into the filter.

Jim

JimSmith · #33 05-22-2007, 08:52 AM

Were those numbers hp at the wheels on the dyno? That is a lot of hp from a little 4 cylinder engine! What do you expect for the final set up? How do they hold up at that kind of power level?

So far I am amazed at how well these engines hold up at their factory set up and tune. My first one now has 240,000 or so miles, and has only had the head off to repair a burned and cracked valve. We also had some rust problems and had to have the four fenders and rockers, as well as the floor pans up to the drive shaft hump replaced. Big job, but the car looks and runs great now.

There seems to a very strong following for these cars over in Europe. Here they are viewed more as just another Mercedes-Benz model and nothing that special. If you have some clips or you update your site with photos from this year's event, let us know. Thanks, Jim

JimSmith · #34 05-22-2007, 12:47 PM

Racing,

After carefully examining the cross section view of the end of the crankshaft, I believe I am hanging up on an interference between the spacer ring, part 107 (all part numbers are from Figure 03/1 in my manual, which I presume will be the same in other manuals because of the job numbering system MB uses, but that is likely incorrect on my part), which is also what the front seal bears or seals on at the OD, and the internal gear, part 301, of the oil pump. They are not a slight interference or inadvertent one. That ring, part 107, should just pop out, but it won't, and it is inside the front cover seal bore too far to grab with anything serious.

I know you guys must get these things off, I just wish I knew how. Jim

Well, patience was wearing thin and so I yanked on the cover itself and used it to tap the ring off the shaft and, after a few liberal applications of penetrating fluid, it came off quite easily. There are some very small optically apparent longitudinal score marks, but they have no perceptible depth, on the crank. The oil pump drive sleeve is loose for about 8mm, and then it gets tight. I can work it back and forth to get it off but I am not sure it has to come off, other than to make sure I haven't got any dirt in the space between the sleeve and the crank. Doesn't seem likely so I may just leave that part on there.

For the most part, Racing, the engine is quite clean. I will wipe down some areas and maybe photograph the paper towels and post them to see if you agree. But the frequent oil changes seem to have kept up with the rate of aluminum being ground up. There are some bits of plastic from the chain rails that were stuck here and there, including a large chunk that was hiding out near the distributor drive sprocket.

I have taken the main chain tensioning rail out and will photograph it and post the photos, just for fun. It is really torn up, to the point where the remaining plastic liner the chain normally rides on is almost completely loose. I am amazed the chain didn't fail. I will photograph it as well and try to post some detailed shots. It is surprisingly ok looking. But it, the rails, the relief valve and likely the oil pump parts will soon become a bit of art hanging on the wall here.

Well, I will let you know what the bore of the relief valve looks like once my son gets home. He wants to take the rest of the stuff out of the front cover himself. Jim

JimSmith · #35 05-22-2007, 04:03 PM

Well, upon further examination of the front of the engine after removing the front cover, we noticed the two pins the intermediate or middle chain guide rail mounts on are either sheared/ground off entirely, or about to be. See the attached photos.

I presume this is a shrink fitted pin and I will have to drill the old ones out, then shrink fit new ones in the bores. If there is another way, please let me know. Jim

The first photo is of the entirely ground or sheared off pin, which is the lower one, more toward the center of the engine and closer to the crankshaft. The second is another view of that same sheared off pin.

The third photo is a view from the driver's (left) side of the engine, showing the chain wear grooves that have nearly ground their way through the pin.

The fourth and last shot is a view of the mutilated main chain guide rail.

Racing · #36 05-22-2007, 05:40 PM

We expect around the shy end of the 400 mark when tuned all in.
Point being that running it any further is pushing it on the stock bottom end.

Pics of your chain guide gives me nightmares Jim!!!
Good thing though is that all of those pins can be ordered through MB as single spares one by one,and what´s more is that they´re inexpensive.

Just yank them out of there and knock the new ones in.
Do so with a drift and a BFH though.

As for getting the front cover off...whatever makes it come off i guess..

Cleaning out...don´t fret using the petroleum based engine degreaser...just do,and then let it dry out while you´re occupied putting the rest of the bits back..When working on engines in general..one can´t be to clean,that much is for sure.

JimSmith · #37 05-22-2007, 07:10 PM

Racing,

So a good pair of pliers, get a grip and yank? I'll give it a try.

400 hp is a lot of hp from that engine! Do they last or do they throw rods and other stuff at those power levels?

Thanks for the advice, Jim

Racing · #38 05-23-2007, 04:24 AM

Vise grips should work.Expect to tighten it hard though.

There´s a bunch of us that have turbocharged these engines over here with good results.
Seem the general notion is that you shouldn´t use the stock late rods passed 8 grand or 400hp,as they are notorius for breaking at that point.
Apart from that tho...the engine will take more or less anything you throw at it.

My old engine is all mercedes.
Ie;there´s not a bolt in there apart from the head bolts and camshafts that are not merc.(See my advice on headbolts further up)
This engine has propelled the car into the low 11s,and it is indeed used for daily transport as well as a trial and error "mule" for what can be done.
So far inxs of 25 000 km and counting.
A fair conservative estimate is that we´re putting approx 450+ to the ground with that one,but then on the other hand it holds the early version conrods-which as noted are much beefier.

Block is extremely sturdy.We stress bore them sine a while back,when we put them on the boring machine.
Have had blocks decked...but honestly...not because the deck has been warped but the give the gasket a new surface to grip into.
To clean the deck up we usualy get away with a cut of 3/100mm(divide by 25,4 to get fractions)

Crank is of finest forged swedish steel....by bofors..
Slugs are forged Mahles...even stock...

Only thing we´ve found is that the valves are to soft for revs much passed 8 grand,and the same goes for the rest of the innards of the cyl head.
Another soft spot....as you´ve discovered,is the camchain.
We exchange these for hardened one from japanese Tsubaki at a fraction of the cost of an OEM,and the price we pay is that the motor gets a bit more noisy under operation.
Something at least i can live with...seing the amount of power involved.
That apart..motor is built like a friggin tank.

JimSmith · #39 05-23-2007, 07:24 PM

Racing,

I clamped down good with a vice grips and pulled until my hands ached and got nothing. I ordered new pins and will measure them and then get a threading die and try to thread the stub sticking out with a fine thread. Then I will put a few washers on it and try screwing down a nut to pull it out. If that doesn't work well I may want to heat the small boss the pin is set into with a torch (heat again) so let me know if that will be really bad or not.

The machine shop called and told me the valve guides are shot, so we got them all out and things look good. All came out pretty cleanly (the through bore was enlarged to reduce the grip between the head and the guides), so the "first stage of repair" guides were ordered for intake and exhaust. Also the machine shop agreed to use their cleaning tank to clean out the front cover and the oil pan. The intake manifold has too much non-aluminum stuff on it to clean in a tank so we will clean that by hand with brushes and degreasers.

I actually found the early 190E 2.3-16's use the dampner arrangement I described. I got an exploded view printout of the front end of "early" model engines and it shows the same part numbers and arrangement we have, so that made me feel better.

So, I hope to have the dye tomorrow and to begin threading the stub and damaged chain tensioner mounting pins using the "puller" method I described above. I will keep you posted.

We have a lot of cleaning to do. At the bottom of the oil pan there was a slight sludge of aluminum "powder" and oil, and I noticed the pump outlet tube in the block had some as well. I am wondering if I should start the car on some kind of oil system flush when the time comes?

Thanks again for the help Racing,

Jim

Racing · #40 05-24-2007, 04:43 AM

Jim.
Let´s see if i get this right...
You´ve got the head off.
Got the pan off.
What´s left in the car is the basic shortblock,and even that taken apart to an extent,and even so you see evidence of the shortblock being partly sludged by residue?
Go get yourself an engine stand and lift the motor out of there to disassy completely and clean it out i say.
Easier to work on...saves time over the long run.

Hitting the block with the torch is ok.Just don´t overdo it.
Be aware of the fire hazard though.
When i get really stubborn pins i´ve got a special extractor for those...then again..when the vise grips don´t work i sometimes have good luck with a pair of "parrot jaws" and wiggle the pin back and forth to the best of my capacity.

Intake and such will turn out just fine if you start with petroluem based degreaser and follow up with some wheel cleaner for aluminium wheels.

JimSmith · #41 05-24-2007, 05:10 PM

Racing,

We got the pins out using my "pin puller." Cost me about $5.25 for a 6mm die and some washers and a few nuts. I have attached a photo below. I tried using the nuts to do the pulling and they were such horrible quality they stripped. So I used the threading die and they just came right out.

The exhaust valve seats are pushed quite a ways into the head, such that we are using valve adjustment shims at next to the last (smallest) thickness already. After refacing the seats and cleaning up and resurfacing the valves, I would expect the next smaller shim size won't be small enough. So, we can either begin to employ the local shop with a surface grinder and magnetic chuck making custom shims from our collection of old, thicker ones, or we can press in new valve seats, and hope the stack up is closer to a new set up and we can use the older, thicker shims as-is.

So, the question is, will the replacement valve seats reestablish a valve stem height near the "new" condition, or will the seats just go into the head the same distance as the ones we have now? Will we have to replace the exhaust valves to really achieve any benefit? Also, I will have to find a machine shop willing to take the job on, as the shop working the head now is not happy about pressing seats into aluminum heads without proven tooling. This head is something they don't want to experiment on, so they have declined the job.

We will look at what it takes to get the block out to disassemble and clean the whole engine, but I think you can see from the photos most of the engine is pretty clean, meaning there is no sludge to speak of, and the only aluminum particulate is in the areas of stagnant oil flow, like small depressions that are filled with oil. I am trying to talk myself out of expanding this job any further. Just the head, which was performing flawlessly before we removed it, is now looking like a complete rebuild. I don't want to take this any further than necessary.

Well, we will be busy cleaning while we struggle with what to do next with the head and whether or not to try to remove the engine entirely.

Thanks for the help, Jim

Racing · #42 05-27-2007, 06:30 AM

Jim.
Ther´s an old saying,power is always within the head.
Always.
Guess what i´m saying is get it right.

Cutting the old seat out to install new ones will usualy remedy the situation.
If not(measurements should be taken) you can always swap for seat for a different engine-that´s not really the issue.

IMO valves are.
Merc out of some reason has priced the OEM 16V valves to a degree it´s nothing but a joke.
After some looking around we settled for 7mm spindle stainless valves from american Ferrea for the hotter engines we build up.
In my book there are two mans of valves that can be counted on in the US.
Ferrea and DelWest.

Anyways.
What we settled on was 7mm spindle valves for bikes,and after cutting these to correct lenght and cutting keeper grooves we have both intake and exhaust valves that are vastly harder than the OEM and lighter at the same time.
I´ll look the numbers up for you if you wish.

For pure stockers it has turned out that you can install MUCH cheaper 7mm spindle valves from peugeot 207 i believe.
These also need to have the keeper recess recut,but no matter as that won´t be an arm and a leg in comparsion to the cost of the OEM pieces.
The Peugeot valves are approx 1/8 the cost of the merc ones.Only "mod" needed to be done is the install of intake valve guides in all 16 holes.
Prime reason for the 8mm shaft of the OEM exhaust is the material needed to have them sodium filled.
IOW,going the ferrea or peugeot route will work just fine...(Tried and tested long term)

It has been our findings that the OEM valves are WAY to soft really,and the only reason for the seats becoming "shrunk" is that the valve train has been out of control.
We´ve even seen valves come out of these engines cracked more than once due to abuse and lack of service.(Mainly overheat and fuelwash due to the POS KE being out of spec)
All in all merc put some effort into using fairly soft materials for the entire valve train and associated drive to make the engine more silent under operation.
To a point where,if you ask me,they went to far.

Have in mind that the motor per se couldnt care less of what it says on the package that carries the spares for it..Some intelligent use of know how goes a long way,and money is ALWAYS an issue...those that claim different are just full of it.

So,in essence...for a hotroded engine or one "leaned upon" regulary(like weekend track days,autobahn aso) i´d opt for the ferreas.Altho these are of nemonic quality(and thereby stronger than the OEM ones by approx a mile or so)they´re STILL approx half the cost of OEM.

For a pure stocker...there are alternatives as well as noted.

Make sure to measure the valve springs for seat pressure.
If in doubt...just order new ones,and again...merc has a pricing that´s redicolous.
Look into the hotrod VW scene.
Gene berg comes to mind in the US.

Seats are to be installed press fit.
If you want me to i´ll check the OEM merc manual.
Seats are something swapped everyday,and much like guides these can be had oversize as well.
We normally end up with a press fit of approx 4-5/100 of a mm,and we ALWAYS install the new ones by hand-to be certain of when the seat bottoms out(head is cast after all).

It is EXTREMELY common for the exhaust valves of these engines to be either shrunk,burned or warped out of control meaning you will HAVE to pick new ones up.
Spindle wear is also common.
If "mushroom" of valve checks out,i still toss the valve in the bin if spindle wear exceeds 1/100 of a mm.Always.

Shims in turn can be picked up way cheaper at any Citroen or Peugeot dealer.
Indeed,they are the same measurements as kawasaki bikes,but then again...spares for bikes ain´t exactly known to be cheap.

Is this overhaul just to bring engine back to specs?

Tinker · #43 05-29-2007, 01:12 AM

This all looks terribly familiar, even the broken pin exercise. I ended up clamping mine with the old vice grips and used a 'wonder bar' against the block and pushed on the jaws of the vice grips. They pulled right out. I believe you will need to cut the replacement pins to the correct length. I installed mine and cut them with a dremel.

Racing is absolutely right about just pulling the block at this point. You WILL save time reassembling it out of the car as opposed to trying to monkey around with the limited space under that hood. BTDT.

Tinker

JimSmith · #44 05-29-2007, 10:28 AM

Racing,

Sorry about the delay responding, my family visited relatives in the boonies, and we had no internet service. We got home last night late and I didn't think I could write a coherent response.

We are going to replace the seats that are pounded too far into the head, as suggested. It is presently expected that we will use MB seats. I have not priced the valves or the seats so that could change and I may need some help sourcing and preparing another maker's seats and/or valves.

It seems to me the aluminum is the weak link. Harder seats and harder valves may make the contact line more robust, but I would expect they would just pass the load more efficiently into the head casting. Which is why I was a little concerned that the replacement seats may not be a lasting solution. I had not noticed the valves being deformed, it seems to me the reduction in clearance at the camshaft lobe to tappet is a result of the seat actually being pounded into the head. If that is wrong, and it is the hardfacing of the valve and seat that are being worn away, or deformed, I would like to know that is the problem.

I may take you up on the offer for dimensional data. I have a shop with no experience with this job on this head, and no easy access to the necesary dimensional data. So, if you have the seat dimensions, and the dimensions of the "hole" the seat gets pressed into, please let me know what it is.

Thanks again, Jim

JimSmith · #45 05-29-2007, 12:06 PM

Racing,

This "project" started merely to replace the chain, chain guides, tensioner and address any collateral damage. Once the head was off, we figured we should check it and address any normal wear before putting it back on the block. We had already noticed, while adjusting the valve clearances, that the number one cylinder exhaust valves were at the 2.550 mm, and 2.750 mm thicknesses. and the next smallest available stock shim was 2.500 mm. It seems there are no stock, MB available shims smaller than the 2.500 value, and we figured we would be adjusting the clearances in the future by having those shims custom ground. I have done this before and it is not easy without a surface grinder.

Cylinder #3 has two shims at 2.650 mm. The rest of the shims are in a 2.800 to 2.900 mm range. All those shim thickness values resulted in operating clearances at or near the nominal value (~0.300 mm), before the head rework. Cleaning the valves and seats up, and reestablishing the design geometry is expected to close the clearance a bit. How much is not known at the moment, however, we would like to try to get all the valves back into a position where a reasonable range of adjustment remains. Another question is, is there a performance penalty if the clearance is achieved by using custom ground shims that are less than 2.500 mm thick?

Thanks for all your help, and I look forward to your response. Jim