RS vs RS500 Differences (56k beware)

turbofan · Post by **turbofan** » Tue May 09, 2006 10:19 am

what's different about the engine itself? i thought the internals were the same.

doug · Post by **doug** » Tue May 09, 2006 2:25 pm

I found this on the RS Cosworth....its a little hard to read, but manageable. Hope this inputs some info!

doug · Post by **doug** » Tue May 09, 2006 2:35 pm

ok, I came across this for the RS500...this ones a little harder to read

xrian · Post by **xrian** » Tue May 09, 2006 3:27 pm

"A much-modified engine, whose features included a stiffer cylinder block, larger turbocharger, twin fuel-rail/eight injector, modified and enlarged inlet passages, recalibrated electronics."
(this from the book; "The Sporting Fords Volume 4-Sierras"
Same info also found in the book; "The Cosworth Fords"

turbofan wrote:what's different about the engine itself? i thought the internals were the same.

turbofan · Post by **turbofan** » Tue May 09, 2006 3:49 pm

wow... they did all that for an extra 20 horsepower?

xrian · Post by **xrian** » Tue May 09, 2006 4:57 pm

NO! They did that so it had the potential to make well over 600 HP
Those were only done to the street car to get through Homologation to be alowed to race.

turbofan wrote:wow... they did all that for an extra 20 horsepower?

Post by **John Brennan** » Tue May 09, 2006 5:01 pm

I think they did it for more potential for racers, not just for 20 hp for the street version. Don't forget, the RS500 street car was only produced to meet the letter of the law for homologation. That's why, for example, the street cars had the second set of injectors, but they weren't activated.

I'd be very interested in hearing more about that block; for some reason, oil squirters come to mind as well, but those may also have been fitted to the original RS. Anyone know more?

Edit: Woops, see? Writing at the same time as Ian.

janvanv · Post by **janvanv** » Tue May 09, 2006 5:02 pm

turbofan wrote:wow... they did all that for an extra 20 horsepower?

No, they did that so when the car was prepared for ETTC or BTTC and the Weber-Marelli ECU got a different eprom which activated the second bank of injectors, injectors which were swapped for much larger than OEM, and the waste gate actuator swapped, and a herking huge 3 out to 4" exhaust, and a pair of cams that really would be OK on a hottish Normal apirated motor-
a couple of discs to the clutch, this gearbox--the identical box that BMW AND Volvo were using-

A 9" rear diff, and some big fat discs......
Then when the car had 500bhp, that's what they did it for.

The T4 cars were the slowest o-60 of all the production Cossies--stock.

Post by **John Brennan** » Tue May 09, 2006 5:04 pm

So it really is true, John-- you DO have everything in that garage!

janvanv · Post by **janvanv** » Tue May 09, 2006 5:43 pm

John Brennan wrote:So it really is true, John-- you DO have everything in that garage!

Dooooood, that's a bellhousing which really stretches the rules but malgrement its only for roadracing and you know all them pavement types are all limp-wristed nancy-boys, right? And i ain't a limp=wristed Nancy-boy so logically I can't be a roadrace pavement type.

As for Oil squirters:
All Cossies oil pumps were the basic internals of the old 2,0 Pinto: M86 in Melling speak, and all had under the crown piston spray bars coming out of either the pump or the pump cover.

Later WRC version of the 4x4 block were drilled and tapped into the main oil gallery and squiters from something were added, this being a real simple operation (I've done it on some non squirter blocks using Misterbitchy squirters).

The original 2wd block were just ordinary "T88" Pinto blocks which were "class 2" in bore size (a c hair bigger), but RS500 blocks were cast with MUCH more meat in the mainline, and really small freeze plugs which people still would drill a coupla small holes, tap it and screw down allens with the edge of a washer overhanging the freeze plug--all to keep the freeze plugs from popping out from thje inevitable block squirm.

Later, 1990 on "4x4" or "200" Blocks had the same material in the mainline and a few extra supports to mounting lugs (although I built one "205" 2wd block, that had the gusset to the alternator mounting lug---Ford is like that, nothing ever is exactly cut off).

You can feel the difference in weight just lifting the two blocks, so there IS something to this but the "205" blocks are good for 330-350bhp, and with liners and maybe main girdles even more.

The RS 500 waterpump was different and became a few years later the stock 4x4 pump. Thermostat outlets were different.

The second row of injectors were aimed right down the middle of the air horn inside the plenum, and when they wanted better drivabiility on the WRC Escort Cossies they once again went to 2 injectors per cylinder:
this time they were up on top where the ordinary injectors are, just two nestled all cutsie side by side Bosch 803 Greens.

fastmaul · Post by **fastmaul** » Tue May 09, 2006 11:50 pm

janvanv wrote:You can feel the difference in weight just lifting the two blocks, so there IS something to this but the "200" blocks are good for 330-350bhp, and with liners and maybe main girdles even more.

Just for the noobs, the other of the 2 blocks is the 205 from the 3dr early 2wd Saffs (if wondering about which cossie)
Sorry but the 200 blocks can hold more than 350bhp (I suggest you find out about Mark Shead, Martin Hadland, A1 rallying, PJ Motorsports, Motorsport Developments and Zoo Motorsports to name a few), in fact the 205 is good for 350-450BHP as long as it's not raced all day long.

Anyway, going back to the look of the cars those mentioned before are what to look for.
Underneath is also the same with the exception of the mounting locations like Ian wrote. Under the hood there was the bigger RS500 (duhh) IC, the air dam behind the grill was also removed for the IC (this was used to route air to the top of the opening where the IC sat), the bigger T4 turbo, the air box also had the bigger hose connectio, there was a pipe that went from the IC hose across to the other side,the extra 4 injectors that were wired up but NOT to the ECU, the battery tray that had to be cut to fit the extra row of injectors, the Water pump looks almost like the 4x4 one, The intake was a little different, the TB was also bigger, the Fog lights weren't installed instead there were grills there but the lights did come with the car if the owner wanted to put them in. Also, RS500's (the one's sold at the dealer) ONLY came RHD. The racing RS500's were just 3dr shells with full racing parts no "real" RS500's were used that's why some of them I.E Texaco Stars is LHD.

I think that's it...LOL