1974 450 SLC performance - Page 3 - PeachParts Mercedes-Benz Forum

ja17 · #31 09-11-2009, 12:13 AM

Hello mercmad6.3,

I would definately like to return again someday. We enjoyed every minute, beautiful country and friendly people! Sounds like you have nearly as many years as me under the hoods of these MBs.

Since the majority of Mercedes SLs always came to the USA, we have may older ones for good prices, of course rust can be an issue in some parts of the country. Rusty but runningW107 parts cars are showing up for $400- $750on occasions.

I actually saw two six cylinder SLCs in Adelaide and a factory six cylinder 190SL prototype being restored at the dealer! Mercedes was the featured marque that year and there were over 20 300SLs and 190SLs there from all over the world!

Learning to drive on the other side of the road was quite un-nerving!

mercmad6.3 · #32 09-11-2009, 03:29 AM

I saw the '220SL' last year at BEA. Speaking with the partner at the dealership he told me he actaully sold the car as used car back in the late 50's and again during the 1960's but because Daimler had removed the six and fitted a four ,knowbody twigged to the odd heater and firewall in the car . it wasn't until one of the subsequent owners ,who raced it etc wondered why the ID plate had W127 on it that everyone suddenly got more excited.

.
It looks stunning now and it's W127 engine looks like it belonged there all the time.

mercmad6.3 · #33 09-11-2009, 04:55 AM

On the subject of Sl/SLC.s with a M110. How about this W123 as built and rallied by Famed Tuner Carlsson.
http://www.youtube.com/watch?v=RMA5cQwn3nI&feature=related

cgoodwin · #34 09-16-2009, 10:12 AM

I am searching for a 300CD for exactly that project, strip it, get a Myna pump, larger turbo, eibach springs, LSD, etc

Just found a 450slc 5.0 the body is stripped for paint, the 5.0 is a strong runner and the trans is good. It was stripped to replace the rocker panels which has been done. Looks like I am on my way! Now I need to find out where MB sourced the fender flares and track down some BBSs with the correct off set.

Tomguy · #35 09-16-2009, 10:19 AM

cgoodwin, it's an interesting project you're embarking on, I wonder what the end dyno results will be?

I would love to compare it to what my 4.5 would put down... I keep saying "Someday" but that seems further away all the time! The goal for me is to restore my 108 to my ideal specs. In other words, keep the 4.5 in it but do more to it for power, like maybe fitting a k-jet manifold since it's larger diameter AFAIK (or fabbing my own manifold), megasquirting it, etc. It's got 3.5 heads and cams, so I know it puts down more than stock - but no idea exactly how much more, because it's never been dynoed.

GGR · #36 09-16-2009, 10:33 AM

If that car is an early 3 speed you can fit a mercedes manual gearbox out of a 3.5 engine: flywheel etc is a direct bolt on, only the clutch bell requires a slight modification for the two top bolts. I just did it, see pictures below.

Also, if you want to get rid of the troublesome CIS and go for megasquirt, I would recommend the use of an early Djet 4.5 intake manifold: port and butterfly diameters are the same, only slight modification at the rear of the block to clear the plenum which has a different shape. Other than that it's a direct bolt on. I'm currently doing it, will take pictures later.

GGR · #37 09-16-2009, 10:42 AM

Tomguy, I compared the 5.0 CIS and 4.5 port and butterfly diameters and they are the same: 39ish mm and 64/65ish mm respectively. Later CIS manifolds have slightly larger ports, 40/41ish mm. 560 butterflies are 70mm. But your 3.5 head ports are 39/40 mm, so you wil need to enlarge them.

My 5.0 engine will go into a car currently equipped with a 3.5. I could swap the heads, or only the cams and solid lifters. Would that make it any good? How is your 4.5 doing with 3.5 heads?

cgoodwin · #38 09-16-2009, 08:38 PM

They say that MB did not race the manual box because it was too weak for the 5.0 which tore it to pieces. What is gained by using the 3.5 heads or cams?

I have also read that the 5.0 had a different bolt pattern than the iron blocks making trans swaps very difficult.

mercmad6.3 · #39 09-16-2009, 09:31 PM

There are several types of cams but the 280SE 3.5 that was delivered to Europe had cams which really lay down power. The 3.5 300SEL has milder cams which don't provide quite as much top end power but deliver more torque. If anything,I would try and find the cam specs for AMG stage one and get your cams reground to suit. They also need the mechanical tappet balls too,which the 3.5 heads came with. As for the heads,i have never seen 4.5 heads as used in the USA but the heads we have here are identical.
As gael said ,you need to alter the two top bolt locations,thats about all you have to do to fit the earlier style bell housing to the m117 style block . The M117 has a bolt pitch circle 10 mm smaller.

The mercedes 4 and 5 speeds are very robust and i've never seen one damaged by too much horsepower but the shift is balky and too slow for serious competition work. The Auto trans is vastly different to the sloppy Contemporary US auto matics and they can be driven manually which makes changing gears very quick and easy. In Rallys the only drive line failure was a back end in New Zealands heatway rally .I watched as they flew in a complete diff assembly by helicoptor.

sjefke · #40 09-16-2009, 10:24 PM

Quote:

Originally Posted by mercmad6.3

The mercedes 4 and 5 speeds are very robust and i've never seen one damaged by too much horsepower but the shift is balky and too slow for serious competition work.

Having a 4 speed V8 I totally agree with mercmad6.3's assessment: it is way slower in shifting than my MG transmissions and would not work as well in competition. I've only raced a few times in my life (with my MGs), but it is so much fun that I wish I could do it more. Good luck with the build!

Bert

Tomguy · #41 09-16-2009, 10:34 PM

The 3.5 heads are higher compression than 4.5 heads. I have pics somewhere, but basically, let's say you're using one cylinder's head area as a "Stamp"... a circle in a square. Cover it in ink, stamp on paper.
- A 4.5 will have an empty area shaped like a circle. The diameter is the same as the piston's diameter. Not for piston clearance, just to keep compression down.
- A 3.5 will have an empty area shaped like a paper clip. The length is the same as the piston's diameter. The depth is the same as the 4.5's head - I'm pretty sure they used the same mold to form a 3.5 and 4.5 head - just less is cut out around the area. Higher compression by lower combustion chamber volume.

My IDEA for the 4.5 is to port the 3.5 heads to a larger intake manifold. Maybe bigger intake & exhaust valves - that's to be seen. Stronger valve springs. Actual headers (even the passenger's side style twin downpipe, with a larger diameter, in ceramic-coated steel not cast iron, would be pretty good). Feed the vacuum lock system off of a different vacuum source so it doesn't rob manifold vac at all. Find a way to adapt a better transmission, if at all possible... maybe a 560's unit, maybe better than that. At least 4 speeds though.

The goal of all this is to just do it "Because I can"... I know the 4.5 engine, built off the platform of the high-performing 3.5, can use that extra liter of displacement and easily make the same hp per liter as the 3.5 if done right, and then more if using modern technology and techniques to tune and so forth. AMG made cams for a 3.5? Something I didn't know. I was thinking of using AMG Hammer's 6.0 grind (not the 32 valve quad cam beast, just the 16 valve one) set up for mechanical studs vs hydraulic.

Bill Adkins · #42 09-16-2009, 10:37 PM

I did one for a guy in LA a number of years ago, it dyno'd near 700 hp but he did pay over 100000 US. The question if how much $, horsepower do you want?

GGR · #43 09-16-2009, 10:40 PM

Ron, I know the cam profile also take into consideration the engine displacement. This is why I'm a bit shy of trying these cams on the 5.0. My 3.5 really flies between 4000 and 6000 rpm. I wonder what would be the effect on the 5.0.

Re the manual trans, the mod I did is only possible on the earlier alloy M117, which had flange mated to the 3 speed auto with a separate clutchbell. The block design changed when they went for the 4 auto trans: no more flange, and a smaller bolt pitch circle. This is why I asked him if he had a three speed auto trans. If he's got a 4 auto trans he may well stay with it as this was recognised as being a real improvement over the 3 speed.

I have another question. I obviously want to stay with this block because of the manual trans. I have access to a 5.6 crankshaft, and the rods seem to be the same. I saw that 5.6 pistons were available with a repair 97 mm diameter which is the bore of my early 5.0. My question is about the wear of the nikasil lining: I know cast iron linings adopt an ovoid shape due to the movement of the piston. Obviously a change of stroke would need a rebore to get rid of that shape. Is that also the case with nikasil linings?

Tony H · #44 09-16-2009, 10:55 PM

This post refreshes a question I never had answered. Is there a difference in power between a European market and US market 111 3.5? My car still has the European market cams and ECU.

Quote:

Originally Posted by mercmad6.3

There are several types of cams but the 280SE 3.5 that was delivered to Europe had cams which really lay down power. The 3.5 300SEL has milder cams which don't provide quite as much top end power but deliver more torque. If anything,I would try and find the cam specs for AMG stage one and get your cams reground to suit. They also need the mechanical tappet balls too,which the 3.5 heads came with. As for the heads,i have never seen 4.5 heads as used in the USA but the heads we have here are identical.
As gael said ,you need to alter the two top bolt locations,thats about all you have to do to fit the earlier style bell housing to the m117 style block . The M117 has a bolt pitch circle 10 mm smaller.

The mercedes 4 and 5 speeds are very robust and i've never seen one damaged by too much horsepower but the shift is balky and too slow for serious competition work. The Auto trans is vastly different to the sloppy Contemporary US auto matics and they can be driven manually which makes changing gears very quick and easy. In Rallys the only drive line failure was a back end in New Zealands heatway rally .I watched as they flew in a complete diff assembly by helicoptor.

ja17 · #45 09-17-2009, 12:00 AM

Hello,

You may want to consider starting off with a W108 6.3 sedan to start with if you are going to spend a lot of money modifing your 4.5. You will be starting off with around 100 hp more to start.

There is a guy on the W108 site selling a standard trans and bell hoursing out of a 3.5 right now. Don't try using this in a 6.3

A fellow I know also used a modern Chevy Camaro 5 speed standard transmission in his W113 Mercedes 280SL. It was a nice conversion, very robust and an extra gear!