1974 450 SLC performance

[mercmad6.3]

One of my neighbors has used a toyota Supra steel case 5 speed behind a m189 in a 300SE . Almost perfect conversion with overdrive. When using these japanese 5 speeders you have to be aware that the 5th gear is actually the 3rd gear set and not too much strength either which is why the steel case unit is a good choice . I've seen a few alloy case trans grenaded behind some ordinary engines.

If real Merc performance on a limited budget is what you want then I agree with a M-100 car like a 6.3 or 6.9 or a swap into a smaller car. A 500 or 560 is drop in fit into a W123 as an example. I had a spare W123 and I was toying with the idea of a M-100 swap. The frame rails are the same as the W116 .
And..the same width etc etc ,only the the thinner fenders make the car narrower. I lined up a spare 6.9 engine and it's also a drop in deal.
The best part of this is the enormous torque and the bolt together deal. Same back end,trans mount,linkages,and if you use a W123 with Kjet as a victim car you have all the pump and so on already in place.
A friend is putting a M-100 into a W126,A 6.3 too,not a 6.9 .

Then there is the M119 engine with quad cams. An easy 650 horsepower with a piston change and a wide open style intake is not too hard.
Emerald in the UK and the ubiquitous megasquirt make the M119's cam control easy .

[mercmad6.3]

heres a German effort for this years race.
http://www.LCP-Mex.de/Home.html

[Tomguy]

See, the work that's going into the 4.5 will mostly be done by me, except if I decide to go bigger valves. The porting/polishing etc. Hoping to pick up the cams I want on the cheap, local shops can do a set for me last I checked for under $500. Again, it's the "Because I can" part of having a 500RWHP 4.5! If I wanted to "Start bigger" I'd modify the frame rails to force a 6.1 hemi to fit They're cheaper than 6.3's or 6.9's used in many cases, and have MUCH easier parts supply!

[GGR]

500 RWHP!!! Only turbocharging will give you that kind of power on a 4.5 for a reasonable cost... Why not using a 5.6 block? very similar in design to the 4.5, lighter, bigger displacement, better auto trans choices... You could use a US version: low compression would become an advantage if you go the turbo way. You could keep your 4.5 Djet manifold and injectors and use Megasquirt fuel and spark which would allow you proper tuning for the turbo set up. You may have the camshafts reground because the profile for turbo engines is different I believe. I believe this would be simpler and cheaper than twicking a heavy 4.5 with archaic transmission...

[mercmad6.3]

Originally Posted by Tomguy

See, the work that's going into the 4.5 will mostly be done by me, except if I decide to go bigger valves. The porting/polishing etc. Hoping to pick up the cams I want on the cheap, local shops can do a set for me last I checked for under $500. Again, it's the "Because I can" part of having a 500RWHP 4.5! If I wanted to "Start bigger" I'd modify the frame rails to force a 6.1 hemi to fit They're cheaper than 6.3's or 6.9's used in many cases, and have MUCH easier parts supply!

maybe cheaper and more common in the USA but no where else. 6.3 and 6.9 parts are a simple email away with delivery direct to my door. i have never had a problem with parts supply ever,where as any Chrysler built after Nov.2008 is going to be an orphan by this time next year.
No need to modify most Pre W126 mercs to fit an M-100,they bolt in . A hemi is only wide at the heads as far as i can see,but the M-100 may not be an attractive engine,the hemi is just plain ugly. with some of the most complex ECU setups going .Good luck sorting out the wiring on one of those.

[cgoodwin]

If I was after cheap speed I would go Japanese! I am limited in the modifications I can make, one step too far and you get bumped into unlimited classes where competition is no longer possible without huge budgets. The 450slc 5.0s with 3 spd autos won the18,000-mile Argentine rally, and came second in the East African Safari Rally as well as taking the 3500 mile Bandama 1-2-3&4 and won the Ivory Coast rally in both 1979 (Mikkola) and 1980 (Björn Waldegård) as well as many other rallys so they were clearly tough and fast enough. The 500slc was the same car except that it came with a 4 spd auto. Mods need to be "period" so head swaps, headers, cams, etc are Ok but not swapping later motors. My 89 560sel M117 lays down only 240 hp which is exactly what the 450slc 5.0 was rated at stock while the racers were quoted at 300hp.

I read that the helicopter delivery was a mistake as the dropped the part smashing it to bits, one car smashed in the nose, another rolled, the 500slc at the Acropolis rally turned it's tires to dust with all that torque in the rocks, and during one breakdown the team manager jumped in a parts truck, drove it through the baracades and down the raceway to assist his stranded car, unfortunately he hit another competitor head on and made amends by giving him one of the MB team cars to drive.

The car I have is a 500slc so it has the aluminum 5.0 and the 4spd auto, it is a euro car with small bumpers and better cam than us spec. What I need is to know the best cam grind or swap?? And where headers can be found??

[cgoodwin]

Bandama 1980 Cowan



Same race, fixing something .



Bandama



Bandama river

[GGR]

There is this firm in Europe building 107 rally replicas. I did not take the time to find the link but you may find it by browsing the thread dedicated to this 5.0 model on the mbca forum. Apparently they fit hotter cams and fender extentions etc. They may be able to sell you what you need or tell you where to get what you are looking for.

I guess you can reach higher compression ratios by fitting Euro 500 W126 pistons (10:1 instead of 8.8:1 if I'm not wrong). If still on your car, the original tri-Y headers set up is already a good one, quite sought after! I'm not aware of headers available for 107s, If you find some let me know, I will also be interested.

If you put aggressive camshafts that take your power curve beyond 6000 rpm you may shift to solid lifters, readily available out of 3.5 and 4.5 engines. You may look at the 3.5 camshafts, or go for the AMG profile if you find it, as Ron suggests. I you get the profile somewhere, let me know, I would also be interested.

If you need mor air with hotter cams, you could go for a 560 throttle body: 70 mm diameter instead of 65 for the one currently on your car. The plenum may need a bit of machining though. Or you could use 560 intake manifold. They look really similar, but have 41mm ducts instead of 39/40mm, and they have the larger throttle body already. I don't know if this would be an accepted mod. You may have to enlarge the intake port of your heads which are 39/40mm instead of 42 mm on later models.

10:1 cr, hotter cams and more air are easy and cheap mods out of readily available parts (apart from the cams if you don't use the 3.5 ones) and may well take you to the 300hp of the factory cars, while remaining acceptable mods for your category.

[cgoodwin]

Did the 500SLC come with tri-Y headers??? I have not picked up the car yet, it is a runner but was taken apart for rocker replacement and paint, the work done it has been in primer for 3 years stored in doors.

The company is http://www.slcracing.eu and I have contacted them but gotten no response. They claim 300HP and are using the 3 spd auto. A post I read said that they responded and said they were changing cams and doing porting and that was all. From the photos on their site they are well funded and selling cars for 135,000.00 EU making them quite spendy. It looks as though they are buying every scrapped 107 in Europe! I find it impossible to believe that there is a large enough market to support the scale of their shop.

It seems that the factory race cars got different cams and ported heads and that was about it. I will definitely find some solid lifters, do I need anything else to swap them in?

Most of the races I am interested in allow "Period" modifications and during the 70's and 80's everyone was porting, polishing, changing cams, and I am sure modifying the intake to breathe better.

How can new find the AMG cam info? If I can get it I have a shop that does cams for me and I could have a few sets machined.

The car I got came with 2 rear spoilers and 2 sets of Euro bumpers, I found that Performance Parts sells the rear spoiler, but can find no info anywhere on the fender flares. From the photos I have it is clear that they cut the rear wheel arch as well as the front to the body line above the arches. The flares were used on the 450SLC 5.0 cars for only one season, then were standard on the 500SLC cars. I would hate to have to change a rear tire on the side of the road with the stock rear arch configuration.

Also looking for info on the wheels they ran, they look like BBS Basket weaves but I have no idea if they were 15" or 16" and can't find much on the tire size...

[GGR]

I found this web page about a Group-2 SLC 500 raced by MB in Argentina in 1980: http://www.rallye-info.com/carspecs.asp?car=207
They’re talking of 340 hp and 10:1 cr. Euro 500 W126 pistons will help you there.

Yes, the 500 SLC originally comes with tri-Y exhaust manifolds. From what I read, That's not as good as headers, but they give you up to 15 additional hp compared to the standard manifolds.

For solid lifters and reground camshafts I found this: http://www.benzworld.org/forums/w126-s-se-sec-sel-sd/1335237-560-sec-mechanical-lifter-agressive-cam.html Jonathan may not unveil the profile of the AMG camshafts he has, but he will sell you a reground pair for one grand. From what I understand solid lifters out of 4.5s are a direct fit and they will tap the oil lines of the hydraulic lifters in the process with no modification. But you cannot use camshafts designed for hydraulic lifters with solid lifters, hence the interest for the 3.5 camshafts. I heard that cam design technology had much improved now and I believe any good camshaft builder will come with a good profile as far as you give him the engine specs and what you expect.

[cgoodwin]

What was the cr of the 1980 Euro 500 slc, looks like 9:1

[GGR]

Here they say 8.8:1 http://www.carfolio.com/specifications/models/car/?car=84997

I think they were no US spec 500 SLCs, even if majority of them found their way to the US via the grey market.

Same source says 10:1 cr for 500 SEC: http://www.carfolio.com/specifications/models/car/?car=64537

You will note that both engines have the same bore and stroke. So I think it's a straight swap. According tpo EPC, reference for 500 SLC engine bloc has been replaced by a reference also found on the 500 SECs. So there must be a lot of interchangeability. I would even consider them as different versions of the same engine. If you want to go for higher comp ratio pistons, you can just trace a good euro 5.0 out of a grey market 500 SEC and swap the engines. Given the engine block cross references, I don't think this would be a problem for your racing regulations. They come regularly on the web for reasonably cheap.

[cgoodwin]

From a site I found on the w107 history:

1.) 107.026 Series - 2,769 FIA Homologated Rally Racers made Street Legal and sold to the public. Most MB enthusiasts know there were two versions of the 5.0 SLC built between 1977 and 1981, but fewer know the engine change was not concurrent with the switch from 3 speed to 4 speed automatic transmissions.

Impetus for the engine change was to achieve compliance with a desired FIA Rally classification. The displacement of the original 5.0-liter, aluminum V8 used in the 450 SLC 5.0 was reduced slightly (from 5025 cc to 4973 cc). I always thought that that change in displacement, and corresponding lower bore (87 mm and later 86.5 mm), coincided with the change in designation of 450 SLC 5.0 to 500 SLC and with the change in transmission from 3-speed auto to 4-speed auto. This is certainly what one would conclude from Werner Oswald’s book. He has the 450 SLC 5.0 with the 5025 cc engine and 3-speed auto tranny and the 500 SLC with the 4973 cc engine and 4-speed auto tranny.

After further research, especially when I got the Engelen books on the SL models, I learned that the 3-speed to 4-speed auto tranny change is the real demarcation between the 450 SLC 5.0 and the 500 SLC, and not the lowered displacement. In fact the displacement was lowered in May 1979 in order to be able to homologate that 5-liter engine into a class that must be under 5000 cc. The change to the 4-speed auto tranny came later, in March 1980 when the 380 SLC and 500 SLC were introduced and the 450 SLC 5.0 ended.

Now as far as power is concerned, both the 450 SLC 5.0 and the 500 SLC were always rated at 240 PS DIN. The lower power rating of 231 PS DIN only came out later after production of the 500 SLC had ended. Thus there was never a 450 SLC 5.0 or 500 SLC with 231 PS DIN. The 500 SL started with the same 240 PS DIN that the 450 SLC 5.0, 500 SLC, and also the early 500 SE/SEL. Power was lowered to 231 PS DIN in October 1981. By that time, production of the 500 SLC had ceased. That's why there was never a 231-HP 500 SLC.

Still, it’s not surprising that even the 450 SLC 5.0 with the 3-speed auto tranny should feel faster than an ordinary 4.5-liter 450 SLC since the 5.0 was more powerful (240 PS vs 225 PS both in Euro version) and lighter (1515 kg vs 1630 kg of the Euro versions, respectively). This difference is even more pronounced when you compare the U.S. version 450 SLC (180 HP SAE Net) with the Euro 450 SLC 5.0 (240 PS DIN = 238 HP SAE Net). The horsepower difference is much greater (58 HP) and the weight is also greater for the U.S. model.

++++++++++++++++++

According to this the 500 SEC would have 231 rather than 240 HP and a displacement of 4973cc rather than 5025cc AND that all 500SLC's came with the 4 spd auto.

Here http://en.wikipedia.org/wiki/Mercedes-Benz_R107 they say 9:1

Here http://eng.motorsporlari.net/car/tech_spec.asp?specID=17827&make=Mercedes-Benz they say the displ. is 4973cc and the CR is 8.8:1

[GGR]

Info differs according to sources and versions. I've also seen the power of the 500 SEC rated at 250 hp din. Must depend on the versions. Anyway what I believe is interesting for you is the compression ratio of the 500 SEC pistons and interchangeability with yours. Power may have been reduced by anti pollution devices that you may not have to keep on your car. If you have a 4 speed trans then you have a 4973cc engine (reduction in displacement came before they switched to the 4 speed auto trans if I read the passage you quoted correctly) You therefore have the same bore and stroke as on the 500 SEC (and the bore is 96.5 mm, not 86.5).

[cgoodwin]

Paragraph 3
"I learned that the 3-speed to 4-speed auto tranny change is the real demarcation between the 450 SLC 5.0 and the 500 SLC"

since the vehicle I have is a 500SLC it therefore has the 4 spd, this being the demarcation from 450SLC 5.0 to 500SLC

"In fact the displacement was lowered in May 1979 "

Since my car is a 1980 it would have the 4973cc

" I always thought that that change in displacement, and corresponding lower bore (87 mm and later 86.5 mm"

If this is correct the 4973cc has a bore of 87mm not the 96.5mm used in the 500SEC