Standard MIVEC cams and RPW ones

spetz · Post by **spetz** » Thu Feb 02, 2006 3:43 pm

Does anyone know all the details to the standard cams?
ie, lift, duration, SLA, overlap etc for the standard cams, and then the RPW ones? Stage I, II, II??

barfy · Post by **barfy** » Fri Feb 03, 2006 12:52 pm

Im sure dave could fill you in on this at RPW ...

Post by **smorison** » Fri Feb 03, 2006 1:07 pm

RPW won't provide much information regarding the CAMS, i've tried when i was looking at doing a CAM upgrade project.

to my knowledge they have only sold a set to a "race" fto and no data was provided back on the results. There was also apparently a set sold to a guy in the UK however neither the results (good or bad) nor the purchase ever appeared on the forums so i don't know what happened there, my observation is that there was little or no change.

akuma3 · Post by **akuma3** » Fri Feb 03, 2006 1:18 pm

wonder what we'll get if we could polish the header, i like the idea of cams but ... doesn't sound like much different

Post by **smorison** » Wed Feb 08, 2006 7:29 pm

akuma3 wrote:wonder what we'll get if we could polish the header, i like the idea of cams but ... doesn't sound like much different

i dunno with the right setup i wouldn't be suprised to see 10+kW which on a FTO is a big thing, if you've modifed everything else and are left with cracking open the engine which is where i'm upto.

the problem i ran into is that there isn't anyon out there who's had real experience with variable timing cams and modifying them... i bought myself a second set so we could use as templates just no company has impressed me yet regarding whether or not they can do them and for how much...

i figure pretty soon one of the lcoal cam makers will be playing around with VVT / VTEC YO!!!!!... once they are i'll probably revisit this part of the project

spetz · Post by **spetz** » Thu Feb 09, 2006 4:42 am

Smorison, have you talked to any camshaft makers?

As there are a few out there (in Oz) that will do billet blank cams for a decent price. I guess it's all a matter of finding out what works and what doesn't

Post by **smorison** » Mon Feb 13, 2006 2:01 pm

spetz wrote:Smorison, have you talked to any camshaft makers?

As there are a few out there (in Oz) that will do billet blank cams for a decent price. I guess it's all a matter of finding out what works and what doesn't

umm... a lot look at the cams and go "woah that's a messy wobbly stick" ...

to grind a set of cams (4 in total 2 intake 2 exhaust) is about 700.00 they then have to be put on the car ... 6-8 hours labour... you then have to retune the piggy back on the dyno depending the changes could take 4 hours...

its roughly 1500.00 every "trial and error set"

doesn't take long to add up to a hell of a lot of money if you get it wrong....

i've spoken to crow and another mob the name escapes me right now...

spetz · Post by **spetz** » Mon Feb 13, 2006 4:06 pm

But, if you give very detailed specs of your engine, which would include cfm of all parts like heads, valves, intake manifold etc, and all other details of the engine including standard cam specs, peak power/torque, bore/stroke, exhaust and basically everything they "should" come up with some good specs for the engine.

Unfortunately... every engine is different and everyone has different mods on their engines

How about, posting a "fund raiser" type thread, and seeing who would be willing to donate some $$$ and how much of it, and maybe go from there?

Unfortunately it is an expensive exercise, especially if you consider other costs like valve springs, cam gears and so on

Post by **smorison** » Tue Feb 14, 2006 1:18 pm

spetz wrote:But, if you give very detailed specs of your engine, which would include cfm of all parts like heads, valves, intake manifold etc, and all other details of the engine including standard cam specs, peak power/torque, bore/stroke, exhaust and basically everything they "should" come up with some good specs for the engine.

Unfortunately... every engine is different and everyone has different mods on their engines

How about, posting a "fund raiser" type thread, and seeing who would be willing to donate some $$$ and how much of it, and maybe go from there?

Unfortunately it is an expensive exercise, especially if you consider other costs like valve springs, cam gears and so on

ah i went one better

i have a contact at MMC japan who was part of the design team for the 6a12

so we gave a full detailed report on the engine, lift, duration, etc, etc... Crow were still reluctant to commit to building a good solid improvement first go or even possibly second go... by the time i did the sums it was getting a bit difficult to fund it myself...

this is why i'm looking for a shop that has VVT/VTEC YO!!!!! etc experience as they will have already learnt (the hard way) what sort of changes to make...

spetz · Post by **spetz** » Wed Feb 15, 2006 5:01 am

Are you looking at a shop that will make billet cams or a shop that can try to figure out what specs would be of benefit?

The other problem I am thinking of however is how much power can be obtained from doing cams without doing internals and raising the rev limiter to closer to 9000rpm.

Considering in stock form the FTO makes peak power at 7500rpm, and cutout is around 8200rpm, if you put other modifications peak power will probably move closer to 8000rpm.
And how much power can be gained without having peak power outside of what a internally standard engine can go to.

I was reading somewhere a few weeks back, about camshaft profiles. It was quite technical and hard to understand but I came to the conclusion that it may be possible to leave the primary lobes untouched, and with correct profiling still get the secondaries to kick in at 5500 but give the engine a VTEC YO!!!!! type rush in the top end.

I am at the stage where I have literally done everything I possibly could do the engine, with only cams/internals left.
In fact if all goes to plan, with working cams and slicks I think my car MAY get into 12 second territory NA...

Post by **smorison** » Thu Feb 16, 2006 6:34 pm

spetz wrote:Are you looking at a shop that will make billet cams or a shop that can try to figure out what specs would be of benefit?

i don't have nor pretend to have the experience in designing cams i'm after for someone to make the designs happen.

Considering in stock form the FTO makes peak power at 7500rpm, and cutout is around 8200rpm, if you put other modifications peak power will probably move closer to 8000rpm.
And how much power can be gained without having peak power outside of what a internally standard engine can go to.

i'm happy to deliver more torque across the enitre range and loose it early, if this helps with acceleration... i'm not worried about the redline or where the peak power is... i'm after consistent torque across as much of the rev range as i can get.

I was reading somewhere a few weeks back, about camshaft profiles. It was quite technical and hard to understand but I came to the conclusion that it may be possible to leave the primary lobes untouched, and with correct profiling still get the secondaries to kick in at 5500 but give the engine a VTEC YO!!!!! type rush in the top end.

agreed ... considering i'm after mid to high end power and not worried about bottom end this is what i had as a design in mind... changing the low speed cams (what you've called primary) would have a big negative impact on driveability for day to day driving...

I am at the stage where I have literally done everything I possibly could do the engine, with only cams/internals left.

i've done (engine mods only):
intakes (on my 3rd design now if i can get it finished)
TB
intake runners
ecu
exhaust

work in progress:
CAMS
electric water pump
new intake forced air induction (without turbos)
better cooling

waiting on:
extractors

blown up:
1 engine
1 gearbox
1 torque converter
other small bits and pieces

if only the 6a12 was as strong as me