CAM lift and duration

Post by **smorison** » Mon Jul 26, 2004 1:04 pm

Hey guys,
before i go on an endless search for this... does anyone have the lift and duration configuration of 6a12 MIVEC CAMS???? ...

thanks

ruchi · Post by **ruchi** » Mon Jul 26, 2004 1:43 pm

hmmm..... do I detect some custom cams in the works?

Post by **smorison** » Mon Jul 26, 2004 1:55 pm

ruchi wrote:hmmm..... do I detect some custom cams in the works?

yeah....
RPW want 2650.00 for theres...

Unique have a CAM's builder in sydney who are currently supplying 4 billet cams for 300zx's for about 1100.00... i'm hoping to get some designed and built for around the same price.

oh and unlike RPW we will be supplying dyno results before we ask people to hand over even half what RPW want.

wildfaye · Post by **wildfaye** » Mon Jul 26, 2004 2:20 pm

Err...can someone explain what are 'cams'?

Thanks!

FTO338 · Post by **FTO338** » Mon Jul 26, 2004 2:35 pm

Well instead me go on & on, hereâ€™s a brilliant site that even got moving illusions to explain what cam is & why steve need the timing/duration.

http://auto.howstuffworks.com/engine4.htm

MADFTO · Post by **MADFTO** » Mon Jul 26, 2004 3:04 pm

*smiles* I'll be wanting this info sometime in the future as well =)

It's got to be in the Workshop manual somewhere.
Otherwise we should ask Black_FTOGPX to ask his japanese contacts =)

We'd want the duration and lift for both Cams and the MIVEC lobes on the intake cam.

*grins* mind you I still have to save money for an ECU =)

Black_FTOGPX · Post by **Black_FTOGPX** » Mon Jul 26, 2004 3:37 pm

Any one want to draft up something i can send Mitsubishi Japan, Cause i'm not 100% sure what to ask.

Try to be ask specific as possible.

This should be easy to get.

MADFTO · Post by **MADFTO** » Mon Jul 26, 2004 5:56 pm

Well, I think you'd be asking something like this.

---

What are the camshaft specifications for the 6A12 MIVEC Engine for both intake (both profiles) and exhaust camshaft?

---

They should get all the stats to us for the cams if we ask that.

At the moment, we'd be asking for duration, lift, opening angles, basic RPM range that the cams are tuned for, but we should try to get as much data as they can release as possible. There's other data there that I wouldn't know to ask =P

Steve will probably want to refine my question more =)

dannyboyau · Post by **dannyboyau** » Mon Jul 26, 2004 10:24 pm

i suggest you look in the workshop manual for engine and transmission on page 1-2 engine general information and 1-3 engine specifications

salacious · Post by **salacious** » Tue Jul 27, 2004 6:39 am

From the engine manual you get the following information
Intake valve
opens (BTDC) 15 deg (low-speed cam) 37.5 deg (high-speed cam)
closes (ABDC) 41 deg (low-speed cam) 82.5 deg (high-speed cam)
Exhaust valve
opens (BBDC) 41 deg (low-speed cam) 75 deg (high-speed cam)
closes (ATDC) 15 deg (low-speed cam) 30 deg (high-speed cam)

Camshaft cam height (mm)
Intake (low-speed cam) 34.34 (high-speed cam) 36.46
Exhaust (low-speed cam) 34.40 (high-speed cam) 35.86
Camshaft journal diameter 26mm
Valve clearance (mm)
Intake 0.10
Exhaust 0.13

MADFTO · Post by **MADFTO** » Tue Jul 27, 2004 9:58 am

Alright, redoing Figures to read in Opening and Duration.
I didn't realise that both exhaust and intake cams had extensions . . . that's gonna make things more expensive =)

Specs
Low Speed:
Intake: Opens - 15 degrees BTDC. Duration - 236 degrees
Exhaust: Opens - 41 degrees BBDC. Duration - 236 degrees

High Speed
Intake: Opens - 37.5 degrees BTDC. Duration - 300 degrees (Holy Crap)
Exhaust: Opens - 75 degrees BBDC. Duration - 285 degrees

Heights (mm)
Limits appear to be minimums

Low Speed:
Intake: 34.34 (Limit: 33.84)
Exhaust: 34.40 (33:90)

High Speed
Intake: 36.46 (35.96)
Exhaust: 35.86 (35.36)

Journal Diameter: 26 mm

Damn, that sounds like the Intake cam almost at the feasiable max limit, probably could only open up another 20 degrees . . .

No idea about lift measurements, don't think you'd be able to figure them out from the cam heights, we don't know the base circle radius for the cam lobes.

So we might need to get the lift measurements from mitsubishi still.

Post by **smorison** » Tue Jul 27, 2004 11:07 am

yeah they are pretty impressive aren't they

we don't actually know if we can make them much better for a reasonable price... the specifications are going off to a company that make race cams to see what they think...

i keep being told "cams are an artform more than a science" which as a nerd i don't believe but i'm sure there is definately some sort of art in building them....

i actually spent an hour last night getting all this info out of the manuals as well.. .but thanks guys

i was hoping someone had it handy...

BLACK_FTO: can you confirm the above specifications please and also ask for the 6a12 non mivec specs...

also if they can advise what if any data they have for max modifications (without taking emissions into consideration)...

thanks

MADFTO · Post by **MADFTO** » Tue Jul 27, 2004 11:30 am

*smiles* it's only an artform as the human brain can't keep track of all the variables and different design types of cylinders, valves angles, intake and exhaust flow dynamics =)

Also the factors of load, and fuel makes engines perform differently.

What I'm thinking of doing, but I'm not going to do this until I'm financially settled, so this will probably happen around 2010 =)

Increase compression to at least 11:1 (12:1) if possible.
Replace Rocker arms to have high ratios and retool cams to suit
Titanium Conrods and rebalanced, knife-edged crankshaft.
Replace all small cast iron components to billet steel.
Raise rev limit to 12k rpm with the appropriate cams =)

*smiles* I'm gonna be annoyed if anyone copies this and pulls it off before I do =)
Mind you, they'd have to be rich to blow this sort of money when they can just turbo it =)

Black_FTOGPX · Post by **Black_FTOGPX** » Tue Jul 27, 2004 11:33 am

Email sent!.

Hopefully they can help with this.

Post by **smorison** » Tue Jul 27, 2004 11:37 am

MADFTO wrote:*smiles* it's only an artform as the human brain can't keep track of all the variables and different design types of cylinders, valves angles, intake and exhaust flow dynamics =)

Also the factors of load, and fuel makes engines perform differently.

What I'm thinking of doing, but I'm not going to do this until I'm financially settled, so this will probably happen around 2010 =)

Increase compression to at least 11:1 (12:1) if possible.
Replace Rocker arms to have high ratios and retool cams to suit
Titanium Conrods and rebalanced, knife-edged crankshaft.
Replace all small cast iron components to billet steel.
Raise rev limit to 12k rpm with the appropriate cams =)

*smiles* I'm gonna be annoyed if anyone copies this and pulls it off before I do =)
Mind you, they'd have to be rich to blow this sort of money when they can just turbo it =)

er raising the compression is already on my shopping list...

its either that or put a hairdryer on it.........

haven't decided which way to go yet still trying to do NA mods that don't cost a fortune but problem is i'm running out of options....

MADFTO · Post by **MADFTO** » Tue Jul 27, 2004 11:56 am

*smiles* I'm more after throttle response /control at higher RPM.

Hence the NA route for me =) Besides, I'd still be able to street it if I keep it out of MIVEC *laughs*

Though it would be interesting to see turbo setup with a 320 degree duration intake cam with increased lift, with an exhaust cam to compensate.

Though you'd be wanting to change the oil in that sucker pretty frequently =)

*laughs* endless possibilities =)

salacious · Post by **salacious** » Tue Jul 27, 2004 11:58 am

I do have a spare set of cams but unfortuately I'm on the other side of the planet

FTO338 · Post by **FTO338** » Tue Jul 27, 2004 12:00 pm

MADFTO wrote:*smiles* I'm gonna be annoyed if anyone copies this and pulls it off before I do =)
Mind you, they'd have to be rich to blow this sort of money when they can just turbo it =)

heehehe by the time anyone had save that kind of money for the mod, he/she would most likely change their mind, & use it for something else. So if u stick 2 it Eric, you might be the first, that if u don't spend it on someone else.

Post by **smorison** » Tue Jul 27, 2004 12:51 pm

salacious wrote:I do have a spare set of cams but unfortuately I'm on the other side of the planet

i think i've got a set at a wreckers here i can "use" if necessary... how much do they weigh and what would the shipping be just curious...

salacious · Post by **salacious** » Tue Jul 27, 2004 10:16 pm

smorison wrote:
salacious wrote:I do have a spare set of cams but unfortuately I'm on the other side of the planet

i think i've got a set at a wreckers here i can "use" if necessary... how much do they weigh and what would the shipping be just curious...

They are sitting in a friends garage, I'll check the next time I see him