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Cam timing

12142 Views 21 Replies 9 Participants Last post by  jupe
G
________2002 Daytona ________ 2002 Speed Triple _____________ 1050 Speed Triple
IN: open - 25* BTDC --------------------- 26* BTDC --------------------------- 11.25* BTDC
-- -Close - 53 ABDC ---------------------- 38* ABDC --------------------------- 41.25* ABDC
Duration - 258* ---------------------------- 244* --------------------------------- 232.5*

EX: open - 39.5* BBDC ------------------ 43* BBDC --------------------------- 34* BBDC
---- close - 29* ATDC --------------------- 5* ATDC ---------------------------- 4* ATDC
Duration - 249* ---------------------------- 228* ---------------------------------- 228*

The 1050 engines look to use the same exhaust cams as the 2002+ Triples, but the intake cam is even more mild - even with greater stroke. This leads me to believe that the 1050 head flows better than previous heads.
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All that info lost!!!!!!!! Now my brain hurts.......... No info on the head yet I've been otherwise occupied......
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Post what you can, when you can. Your posts make me THINK. Do you know the specs on the valvesprings? Are they all the same?

I am thinking about ordering a set of Daytona cams to measure on my Cam Doctor. It would give me the max lift and duration for grinding a custom cam from them once I get the head on the flowbench.

Comp Cams seems willing to grind me a custom billet cam or regrind the Daytona cams. What is the best (cheapest) source for a new set of Daytona cams? Comp Cams have some impressive new CNC grinding machines that can alter the cam profile throughout its lobe and for each cylinder. This allows agressive profiles without making the valves bounce on the seats.

The more I look into the 1050 engine, the more I am convinced that the stock cams are a compromise based on cost and availability - not performance. Looking at the engine's geometry and (eventually) the head flow numbers should help design a profile that will much better match what the engine wants with a custom header.

Based on a max piston speed of 4825 ft/min - at 10300 rpm, this would put peak power at 9900-10,000 with 300-400 rpm of overrev. I feel that the stock rods can handle this with a bit of work - maybe even in stock form. I want to take a close look at them first.

Brain hurts..... must stop thinking...
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What kind of gains would you expect with custom cams? What's the cost?

I was thinking of starting to look for daytona cams. You could propably get them very cheap from a salvage yard. There's A LOT of crashed daytonas out there. The daytona cams aren't straight swap? What other parts would I need for this mod?

PS. Sorry for the questions, but I'm kinda clueless with these things. Yet for some reason I am drawn to it :D
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Beware P, you are dealing with a _very_ Devious man. ;D

He will drag you in and soon you will have a large bill for tools......... :eek:

Devs the man!

Mark
I talked with a Comp cams rep a couple weeks back at a motorcycle supply open house.......was impressed. Usually they send some stuffed shirt or salesman type to the functions, but this guy definately knew what he was talking about.

(Had asked about a reverse grind cam, in order to swap fwd and rear heads on an HD big twin.....I think that pipes exiting in the center with carbs on the outside would be wicked cool). He started rattling off pushrod angles, durations and overlap figures and had a sketch and figures all over it in minutes. I love it when somebody enjoys their work like that!

Not only did he say they had the capability, but were more than willing to do it. Of course, he could not comment on price........we'll see.
Devious said:
________2002 Daytona ________ 2002 Speed Triple _____________ 1050 Speed Triple
IN: open - 25* BTDC --------------------- 26* BTDC --------------------------- 11.25* BTDC
-- -Close - 53 ABDC ---------------------- 38* ABDC --------------------------- 41.25* ABDC
Duration - 258* ---------------------------- 244* --------------------------------- 232.5*

EX: open - 39.5* BBDC ------------------ 43* BBDC --------------------------- 34* BBDC
---- close - 29* ATDC --------------------- 5* ATDC ---------------------------- 4* ATDC
Duration - 249* ---------------------------- 228* ---------------------------------- 228*

The 1050 engines look to use the same exhaust cams as the 2002+ Triples, but the intake cam is even more mild - even with greater stroke. This leads me to believe that the 1050 head flows better than previous heads.
Devi,

Is there a misprint in the 1050 exhaust opening? Shouldn't the opening be 44 degrees BBDC given that you said the duration is the same as the 2002 S3? How about lift numbers? I think the intake cam timing has a lot to do with the fantastic low end torque these motors have. Of course the stroker crank helps too. Why do you say the cams are a compromise based on cost? It doesn't cost any more to grind a long duration cam than a short duration cam. The trick to getting good power and wide powerband is getting the valves open and closed quickly without pounding out the seats or floating the valves at high RPM.
Traditionally the secret behind the notoriously wide powerband in modern motorcycle engines is the cam design. They use pretty conservative duration but very steep ramps aka quick valve opening and closing rate. This way the valve/time area can be quite big without "leaking" the cylinder pressure at low revs.

Judging a cam by degrees and lift only does not tell everything.

http://koti.mbnet.fi/b12/cam.gif

These are Stock Bandit 1200 cams vs gsxr 750 cams. Look at the intake. Same duration seat to seat, same lift but much bigger area under the curve with the gixxer cams
G
Dr_Gallup - It is no misprint. I believe the same exhaust cam is used, but timed to open and close later - even though the specs for exhaut lift are slightly different.

It costs more to have a new cam designed, tested, and ground for production than to simply use one off the shelf. In fact the costs for the old cam should go down due to numbers produced.

Valve Lift:

1050 Speed Triple
In - 8.75 mm
Ex - 7.45 mm

955 Speed Triple
In - 9.15
Ex - 8.00

955 Daytona
In - 10.15
Ex - 9.65

RPM, valvetrain weight, and spring design/pressure determine valve float point. With the lower rpm of the 1050 Speed Triple engine, it would be very possible to have a high lift, fast opening rate camshaft lobe that still has relatively low duration.

The head flow and velocity (with engine geometry) at various lift points is used to determine the camshaft specs that are required for a given power band.

If you change head flow, you can change the engine's charicteristics nearly as greatly as changing cam specs.

As a side note, as much as I have been against using Daytona cams in the 1050 engine. I think that matching the correct cams friom prior engines with less overlap (wider centerline spacing) might be a possibility with less cost than a custom set of cams. I am looking into this now.
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2002 exhaust 43+180+5=228
2005 exhaust 34+180+4=218
218 does not equal 228

Plus, if the lift is different, it's a different cam.

Other than the R&D cost, there is only the changeover time cost between one part & another. They probably all come from the same raw material so economies of scale are still achieved.
G
Good point.

Better contact Triumph - the 2002+ shop manual is wrong!

Teach me to trust Triumph. I should have done the math. :violent1:
WOW! myhead hurts and my eyes are blurry-does all this make it go faster??
HiVel said:
WOW! myhead hurts and my eyes are blurry-does all this make it go faster??
Speculation no, actions maybe ;)
G
HiVel - At this point all of this is just mental exercises to determine potential power.

I do not have flow numbers for the 1050 head (yet, but soon), but the numbers below are a good indication of what is possible.

Daytona head flow at 10" H2O:

Lift" 0.05 0.01 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60
flow 20.9 43.1 65.4 85 101.8 111.2 116.8 120.3 122.4 123.8 113.8 113.2

Notice that flow is pretty much maxed at 0.40" - just where the Daytona cams have max lift. 1mm more lift may gain 3 hp, but at the expense of valvetrain stability.

Multiply flow number by 1.67 to get flow at 28" H2O.

Flow at 28" X 0.257 X number of cylinders = potential hp (at crank).

For the 1050 cam with 0.344 inches of lift (8.75mm lift):
116.8 X 1.67 = 194.889 CFM X 0.257 = 50.086 hp X 3 = 150.25 hp at crank.

For the Daytona cams, the max potential is 154.9 (3.26% higher). However the duration of these cams allow more flow at higher rpm.

With a longer stroke and shorter rod ratio, the 1050 engine sucks the air harder into the engine as the piston moves from TDC to BDC.

Thus, the cam duration is responsible for how much air enters the cylinder, and at what rpm the engine maxes out the airflow of the head/intake - making peak torque. If you add duration to move the peak torque point higher, you make more hp.

However, if you port the head to increase flow, all of this changes.

My brain hurts.
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150hp :eek:

Yes, please ;D

So if you change the cam, what else needs to be modded? How extensive change is this?
G
Just the cam needs to be replaced.

The 150 hp figure above is at the crank - multiply times 0.875 for approximate rear wheel numbers. On a Dynojet dyno, light wheels and chain/sprockets will show less loss - especially in lower gears.
So Gentlemaen,
What are the figures for the Daytona 1050 are they the same cams as the 1050 speed triple ????
Or are they the best cams or the Daytona 995i
George
subseageorge said:
What are the figures for the Daytona 1050 are they the same cams as the 1050 speed triple
???
No such thing as a Daytona 1050.
When Truimph increased the size of engine in the Sprint and speed triple they didnt increase the engine in the Daytona 955i ???
I assumed they would have??
George
Nope. Big Daytona was dropped from the lineup for good. Final year model had some parts from the 1050, but it was already on it's way out.
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