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Re: atmo cams timing
[Re: kj16v]
#1252129
22/08/2011 13:17
22/08/2011 13:17
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group5lancia
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group5lancia
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Both cams stock positions: 280 bhp @ 5100 rpm, 333 lbs-ft @ 4000 rpm. Nice big wodge of mid-range torque, but drops of quickly and dies a death just over 5000 rpm. Well suited to a fast-spooling T3, but a poor match for a T34, which is capable of flowing well past 5000 rpm. Both cams retarded 1 tooth: 313 bhp @ 6300 rpm, 279 lbs-ft @ 5200 rpm. Engine now makes more power and further up the revs, but at the expense of a lot of torque. On the road the car feels like it takes ages for the turbo to spool and is sluggish to accelerate. Not good.Inlet retarded 1 tooth, exhaust stock: 296 bhp+, 323 lbs-ft @ 4200 rpm. Great torque at low revs. Still drops off sharply, but much better than the first result. We stopped the run before it reached peak bhp but it looks like it would have made similar power to the previous run. Only one problem. The idle was irritatingly lumpy, with a loss of performance just off-idle. Although this may have been partly down to the MAP sensor at that time, which turned out to be faulty.Inlet and exhaust retarded somewhere between result 2 and result 3: 321 bhp @ 6200 rpm, 296 lbs-ft @ 5600 rpm. The exact timing is, well that's my business! Besides, optimum timing will depend on each individual engine's setup. The engine feels like it picks up at 3500 rpm. Then there's a kick at 4500 when the turbo hits full boost and it keeps pulling right to the rev limit. Perfect match for this particular turbo Despite the big horsepower number from the fourth setup, comparing the torque curves I would bet money that setup 3 would be quicker on the road, 0-60 etc. Did you get to drive the car between dyno runs?
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Re: atmo cams timing
[Re: ]
#1252294
22/08/2011 22:31
22/08/2011 22:31
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Joined: Feb 2008
Posts: 1,728 London
kj16v
My life on the forum
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My life on the forum
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Posts: 1,728
London
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Despite the big horsepower number from the fourth setup, comparing the torque curves I would bet money that setup 3 would be quicker on the road, 0-60 etc.
Did you get to drive the car between dyno runs? I drove all three cam settings on the road. Setting No.1 felt rapid according to my butt-dyno . But on an a real dyno it shows that the car made lots of torque for overtaking but it wasn't really going to be that fast overall. Setting No.2 was terrible on the road. Like driving a Honda in 5th gear - ie. slooow! No.3 felt fast in-gear. Just as fast as No.1 between, say, 50-70 mph. Looking at the horsepower curve, I guess it would have made about 313 bhp too. I think that would have been a great setting if it wasn't for the terribly lumpy idle at the time. No.4 feels fine on the road. You can feel that it pulls hard up to the redline. It feels about as "torquey" as settings 1 and 3, but it just happens a bt higher up the revs. It's quite easy for me to swap between settings 3 and 4 would be really interesting to try these out on the dragstrip and see which one really is fastest. My bet is that; in gear-changing acceleration, like a drag where you'd be revving between 5000-6500, that settings 3 and 4 would yield quite similar times - Possibly no.4 winning. Whereas if you're Audi-baiting on the motorway, staying in one gear, I think No.3 would win.
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Re: atmo cams timing
[Re: Rudidudi]
#1252295
22/08/2011 22:33
22/08/2011 22:33
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Joined: Feb 2008
Posts: 1,728 London
kj16v
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My life on the forum
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Posts: 1,728
London
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i have got to get a mule engine to measure cam timings, this thread is a refreshing change from the regular missives.
did you measure lift on overlap on the various profiles? Not yet, I'd like to do that when I get the time. Would be good if somebody could do the stock 16VT overlap figures too.
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Re: atmo cams timing
[Re: ]
#1260110
14/09/2011 12:07
14/09/2011 12:07
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mpampis_
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mpampis_
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Tell me please if I understood right because of my bad english. 1.stock crankshaft timing 2. Fiat tipo inlet camshaft with it's own pulley. 3. Oem inlet camshaft with it's own pulley for replacing the exhaust camshaft
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Re: atmo cams timing
[Re: ]
#1260153
14/09/2011 14:30
14/09/2011 14:30
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mpampis_
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mpampis_
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So 1 teeth is 4,5 degrees I think. In the last option is about a half teeth? With adjustable pulleys we are talking about 2-2,5 degrees?
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Re: atmo cams timing
[Re: ]
#1260423
15/09/2011 08:48
15/09/2011 08:48
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Julien
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Julien
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So 1 teeth is 4,5 degrees I think. In the last option is about a half teeth? With adjustable pulleys we are talking about 2-2,5 degrees? "Real" adjustable pulleys allow you to adjust cam timing within 1 degree.
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Re: atmo cams timing
[Re: ]
#1260446
15/09/2011 10:12
15/09/2011 10:12
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Joined: Feb 2008
Posts: 1,728 London
kj16v
My life on the forum
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My life on the forum
Joined: Feb 2008
Posts: 1,728
London
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So 1 teeth is 4,5 degrees I think. In the last option is about a half teeth? With adjustable pulleys we are talking about 2-2,5 degrees? "Real" adjustable pulleys allow you to adjust cam timing within 1 degree. ...And are also a lot less hassle to adjust. You only ever really need to adjust 2 degrees at a time, btw. I made cheap-skate adjustable pulleys by slotting out the key by the number of degrees I wanted! I've been thinking about how to modify the stock pulleys to them to make them into proper verniers. Haven't plucked up the courage to butcher my rare cam pulleys though!
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Re: atmo cams timing
[Re: ]
#1260451
15/09/2011 10:22
15/09/2011 10:22
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mpampis_
Unregistered
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mpampis_
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Have you think anything about exhaust camshaft? What about tipo's exhaust camshaft?
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Re: atmo cams timing
[Re: ]
#1260453
15/09/2011 10:30
15/09/2011 10:30
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Joined: Dec 2005
Posts: 12,296 Sandhurst
Begbie
ex El Presidente
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ex El Presidente
I AM a Coop
Joined: Dec 2005
Posts: 12,296
Sandhurst
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I've been thinking about how to modify the stock pulleys to them to make them into proper verniers. Haven't plucked up the courage to butcher my rare cam pulleys though! I've got a set of 16vt cam pulleys that I'm selling
Your car is Usain Bolt with wellies
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Re: atmo cams timing
[Re: ]
#1260480
15/09/2011 12:25
15/09/2011 12:25
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Julien
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Julien
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Have you think anything about exhaust camshaft? What about tipo's exhaust camshaft? It would be awfull : too much overlap and too much lift as it is an NA engine, the exhaust and the intake cam have the same cam profile.
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Re: atmo cams timing
[Re: ]
#1260554
15/09/2011 17:16
15/09/2011 17:16
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Joined: Feb 2008
Posts: 1,728 London
kj16v
My life on the forum
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My life on the forum
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Posts: 1,728
London
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Have you think anything about exhaust camshaft? What about tipo's exhaust camshaft? It would be awfull : too much overlap and too much lift as it is an NA engine, the exhaust and the intake cam have the same cam profile. Do you know that for sure? That's not meant to be rude, by the way! I just mean have you tried it and tried different timing settings?
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Re: atmo cams timing
[Re: kj16v]
#1260561
15/09/2011 17:58
15/09/2011 17:58
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Julien
Unregistered
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Julien
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Have you think anything about exhaust camshaft? What about tipo's exhaust camshaft? It would be awfull : too much overlap and too much lift as it is an NA engine, the exhaust and the intake cam have the same cam profile. Do you know that for sure? That's not meant to be rude, by the way! I just mean have you tried it and tried different timing settings? I've checked both intake and exhaust cam from tipo and they are the same but I haven't tried it. On turbo engine you should not run the same overlap and cam lift on both intake and exhaust side. The fiat tipo cam should be fitted at the exhaust only If you have an aggressive intake cam like Gr.A or even C&B race cam, not less.
Last edited by Julien; 15/09/2011 17:59.
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Re: atmo cams timing
[Re: ]
#1260616
15/09/2011 21:09
15/09/2011 21:09
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Daeron
Unregistered
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Daeron
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sorry to burst into thread..
does anyone have info about stilo 2.4L 20v cams? timing, lift, etc...
where can it be found?
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Re: atmo cams timing
[Re: ]
#1260631
15/09/2011 21:51
15/09/2011 21:51
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tricky
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tricky
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On turbo engine you should not run the same overlap and cam lift on both intake and exhaust side.
When you say overlap I take it you mean as a function of duration ie; degrees ?
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Re: atmo cams timing
[Re: ]
#1260651
15/09/2011 22:33
15/09/2011 22:33
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johnnybravoturbo
Unregistered
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johnnybravoturbo
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Just to add my piece,i have messed about with a few sets of cams now and i find the inlet works best as standard as it can be altered by the displacement of the variator,and i go more aggressive with the Exhaust timing. Dont notice any difference in power but drivability is much improved,and it stops the ''on/off switch''power associated with the aftermarket cams.
I havent seen these cams but just make sure they offer duration on the cam lobe rather than lift only as this engine doesnt respond well to high lift but poor duration.
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Re: atmo cams timing
[Re: ]
#1260766
16/09/2011 10:47
16/09/2011 10:47
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Julien
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Julien
Unregistered
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On turbo engine you should not run the same overlap and cam lift on both intake and exhaust side.
When you say overlap I take it you mean as a function of duration ie; degrees ? Yes that's what I mean
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Re: atmo cams timing
[Re: ]
#1261076
17/09/2011 10:40
17/09/2011 10:40
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tricky
Unregistered
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tricky
Unregistered
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I don't think that rule is as 'set in stone' as tradition would have you belive, many cam manufactures sell symetrical cam pairs for turbo cars. It's all a question of pressure differnces, the type of engine and what it will be used for that might lead you to use such a comination. I don't know everything about the subject, but I do know it works in the right combination of manifolding and turbo choice.
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Re: atmo cams timing
[Re: kj16v]
#1263865
26/09/2011 11:46
26/09/2011 11:46
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group5lancia
Unregistered
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group5lancia
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Just a quick question or two.
I believe the stock Tipo inlet timing gives max lift at 110 degrees ATDC. Can you confirm that?
Retarding one tooth would make that 117.2 degrees and half a tooth 113.6 degrees. Before your latest 'tweak', do those settings represent what you were doing in your earlier experiments?
Last edited by group5lancia; 26/09/2011 13:17.
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Re: atmo cams timing
[Re: ]
#1405133
20/01/2013 13:51
20/01/2013 13:51
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group5lancia
Unregistered
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group5lancia
Unregistered
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Re: atmo cams timing
[Re: kj16v]
#1405147
20/01/2013 15:17
20/01/2013 15:17
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group5lancia
Unregistered
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group5lancia
Unregistered
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Old Thread RISE!! I still haven't measured the lift or timing because I'm still enjoying having a leak-free rocker cover gasket! lol You guessed why I had revived it anyway! Your reason for not measuring is good enough, I guess What was the final setup and final dyno figures?
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Re: atmo cams timing
[Re: ]
#1405149
20/01/2013 15:20
20/01/2013 15:20
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group5lancia
Unregistered
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group5lancia
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Fiat 16v NA (9.57mm) cam : the lift at 0.8mm is only 198° (fiat gives 226°). I have checked many cams from the camshaft (only 2000km) and it gives the same results... I am sure this cam with published 226 degrees is the Fiat 7625939 cam. There is another - the 7727838 - which has longer duration I believe. http://www.turbo124.com/forum/viewtopic.php?f=2&t=435
Last edited by group5lancia; 20/01/2013 15:25.
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Re: atmo cams timing
[Re: ]
#1405360
21/01/2013 10:45
21/01/2013 10:45
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Joined: Feb 2008
Posts: 1,728 London
kj16v
My life on the forum
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My life on the forum
Joined: Feb 2008
Posts: 1,728
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You guessed why I had revived it anyway! Your reason for not measuring is good enough, I guess What was the final setup and final dyno figures? The final setup is my current setup: 5-Door Tipo inlet 16VT inlet (on exhaust) timed in using adjustable pulleys Result was 403 bhp @ 6200 rpm / 385 lbsft @ 5200 rpm, 1.55 bar I didn't post up the results on this thread because they're not really directly comparable with my others; new engine build, new turbo, more boost, different dyno. But all the results together still show the strong effects that cam timing has on a turbocharged engine. One thing that doesn't show so well on dyno graphs is how important it is to adjust timing for a balance of torque and power; Sometimes losing a few bhp at the top-end, in return for more torque -or a wider spread of torque- can make the car genuinely faster on the road.
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Re: atmo cams timing
[Re: ]
#1405468
21/01/2013 18:38
21/01/2013 18:38
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sediciRich
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sediciRich
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'16VT inlet (on exhaust)'
Are the cams diffent duration on the 16vt inlet to exhaust? Pretty sure they were the same??
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Re: atmo cams timing
[Re: kj16v]
#1405505
21/01/2013 21:12
21/01/2013 21:12
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group5lancia
Unregistered
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group5lancia
Unregistered
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[quote=group5lancia]Result was 403 bhp @ 6200 rpm / 385 lbsft @ 5200 rpm, 1.55 bar Well, at that boost I have to say I don't think anyone would beat your torque figure with any cams, any build... so well done! From the graph you also have 95% of peak torque between 4400 RPM and 5500 RPM - which is fantastic. A higher peak power at 1.55 bar might be achieved with a different cam/head combination that allowed for higher revs, but apart from that I would say you have 'maxed' it. Brilliant.
Last edited by group5lancia; 21/01/2013 21:17.
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