Carobu Engineering - 560 Dyno Testing
- Thread starter c107
- Start date
With volumetric efficiency power will increase to a point . I already know this from extractors and exhaust. And having tried a larger throttle body. Now I have to fit my billet throttle and frankencis and tune once I have car back. Knowing my luck transmission will cry enough.
That’s not using radical cams either! Might even use LESS fuel depending on how they’re driven! Reliability is built into the stock engines & won’t be affected.
This one apparently made 600hp and that was years ago & prior to the tech now available:
This one apparently made 600hp and that was years ago & prior to the tech now available:
Well that sounds encouraging!
So I find it's always better to talk to the horse.... So after messaging Carobu directly they tell me their original figures were incorrectly corrected (they discovered this recently). Not sure why engine dyno figures need to be corrected, but anyways. So the correct figures are (still impressive):
350.9 hp and
395.1 lbft.
Doesn't quite beat the pre-merger AMG M117 DOHC Hammer at:
380 hp and
417 lbft.
Considering the Hammer was a 6L with 32v, the SOHC is closing the gap for FAR less coin!!!
So I find it's always better to talk to the horse.... So after messaging Carobu directly they tell me their original figures were incorrectly corrected (they discovered this recently). Not sure why engine dyno figures need to be corrected, but anyways. So the correct figures are (still impressive):
350.9 hp and
395.1 lbft.
Doesn't quite beat the pre-merger AMG M117 DOHC Hammer at:
380 hp and
417 lbft.
Considering the Hammer was a 6L with 32v, the SOHC is closing the gap for FAR less coin!!!
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- Thread Starter
- #35
That assumes AMG were honest with their figures. Back in those days, as a seller of parts, they probably didn’t have to be. We are used to MB being conservative about their figures, but in the 60s and 70s a lot of manufacturers were not. Take Jaguar and their claims of 265hp out of the triple carby 3.8/4.2 XK. Kind of bit them later when the v12 came out and they had to be honest and it didn’t look a lot more powerful when it actually was.
Well I’m hearing all sorts of things ATM. Firstly that the pic of the AMG M117 isn’t the original but sort of a mockup. Key indicators are the fuel rails not bolted down & a dizzy which wasn’t fitted to the original pinstripe race cars. I was assured the hp figures are correct since they apparently changed the manifold flange angle (???) along with bigger valves in the AMG heads, maybe porting & cams. The intake looks identical & I was told it featured slide throttles, which I can’t see in any pix. But that could explain why you can’t see the end of any throttle shafts either. The engine in the pic apparently had twin throttles & a plenum. Sounds all rather bogus to me…
I was also told by the same person that std M117 heads will only flow 330-350hp max on a flow bench. Bear in mind Carobu got 352hp from a 560 with stock heads. And the actual 500SEC had a very nasty habit of shredding the huge slicks & you can’t do that with the 300hp offered with the factory RUF & ECE engines or 350hp in a potential maxed out version.
Someone told me a while back the M100 heads are designed quite well & they are very similar to the M117. This was recently backed up by a dyno or airflow chart comparing M117 & M119. I’ve yet to get access to the clearer document so I can read it properly.
Certainly the M119 heads flow better than the M117. It could be the extra valves provide more surface area through which the charge can pass or it could be the straighter path of the intake air. It could be a combination of both. Early Indy race cars had very radical head designs with a very straight airflow path & they have been left behind by many modern engines so that’s not solely the answer.
I will say the designers made a big error & aligned the intake and exhaust valves together (along the cam centreline) and far closer to the exhaust outlet than the intake. This made the intake path far longer than is ideal and a tight bend just before the valve head for good measure. I wish they'd built their own version of a Hemi head….
I was also told by the same person that std M117 heads will only flow 330-350hp max on a flow bench. Bear in mind Carobu got 352hp from a 560 with stock heads. And the actual 500SEC had a very nasty habit of shredding the huge slicks & you can’t do that with the 300hp offered with the factory RUF & ECE engines or 350hp in a potential maxed out version.
Someone told me a while back the M100 heads are designed quite well & they are very similar to the M117. This was recently backed up by a dyno or airflow chart comparing M117 & M119. I’ve yet to get access to the clearer document so I can read it properly.
Certainly the M119 heads flow better than the M117. It could be the extra valves provide more surface area through which the charge can pass or it could be the straighter path of the intake air. It could be a combination of both. Early Indy race cars had very radical head designs with a very straight airflow path & they have been left behind by many modern engines so that’s not solely the answer.
I will say the designers made a big error & aligned the intake and exhaust valves together (along the cam centreline) and far closer to the exhaust outlet than the intake. This made the intake path far longer than is ideal and a tight bend just before the valve head for good measure. I wish they'd built their own version of a Hemi head….
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And this is the radical Ford Indy engine from 1964. Obviously intake & exhaust have been reversed.
So what is the answer to all this development when applied to our engines?? Straighten out the bends of course! I may have a partial solution….
So what is the answer to all this development when applied to our engines?? Straighten out the bends of course! I may have a partial solution….
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