Mivec Owners Group

It is currently 10 Apr 2020 18:22

All times are UTC + 12 hours [ DST ]




Post new topic Reply to topic  [ 15 posts ] 
Author Message
 Post subject: Degreeing cams
PostPosted: 23 Oct 2009 19:28 
Offline
Mivec Guru

Joined: 04 Jul 2005 13:25
Posts: 1216
Location: Lower Hutt
Country: NZ
Just wondering if anyone has actually done this.
I know several people have either aftermarket cams or camgears or both.

I've done a few searches, haven't found specs for the 6G72 mivec cams and have assumed either rightly or wrongly that they're pretty much the same specs as the 4 cylinder cams.

So anyway, I've made a start measuring mine and noticed that tappet clearance makes a huge difference to the opening and closing angles.

So, after setting no 1 tappet clearances to about .1mm intake and about .2mm exhaust, here's approximately what I've got.

Low cam

In opens 27 btdc
in closes 60 abdc
ex opens 60 bbdc
ex closes 24 atdc

So that gives an overlap of 51 deg
in duration 267 deg
ex duration 264 deg

High cam.

in opens 54 btdc
in closes 102 abdc
ex opens 85 bbdc
ex closes 39 atdc

So that gives an overlap of 93 deg
In duration 336 deg
ex duration 304 deg

Should be correct to +- 2 deg apart from error with tapet clearance.

Anyway, still working on this , going to mod the stock cam gears to change it a bit.

The real question is that the "big" cams have such long duration, how do the aftermarket cams measure up in comparison. No I'm not talking "theoretical" specs, only "real" measured specs, straight comparison.

Hey, If you're going to put a motor together you may as well do it properly and measure a few things first.

pics

Image
Image

So , now that I've got the modded cam sensor can basically throw these heads straight into the car with the existing block.

There's 117 teeth on the ring gear so that's pretty close to 3 deg per tooth.


Steve

_________________
6G72 mivec Twin TDO5 20Gs up and running.
6G72 mivec bored and stroked to 3.4 litres...Frankenmitsi build
6G74 mivec bored and stroked to 3.9 litres....Frankenmitsi build.
6G75 under construction....4.2 litres bored and stroked.Another Frankenmitsi.


Top
 Profile  
 
 Post subject: Re: Degreeing cams
PostPosted: 28 Oct 2009 01:26 
Offline

Joined: 02 Apr 2008 22:06
Posts: 6
magn1t wrote:
....
Low cam

In opens 27 btdc
in closes 60 abdc
ex opens 60 bbdc
ex closes 24 atdc

So that gives an overlap of 51 deg
in duration 167 deg
ex duration 164 deg
...

hmm?! Should this not result in 267deg and 264deg ?

But thanks for the measurement. I would love to know if the 4G92 Mivec has really the same/comparable specs. [EDIT: cleaned up my misspelling]


Top
 Profile  
 
 Post subject: Re: Degreeing cams
PostPosted: 28 Oct 2009 10:04 
Offline
Mivec Guru

Joined: 04 Jul 2005 13:25
Posts: 1216
Location: Lower Hutt
Country: NZ
Ah. caught out by one of the silent majority, yes you're 100% correct and I DO appreciate it, will put it right.


I've reset ALL the tappets to .2mm just to keep it easier. Cylinders 1 and 4 fire at 360 deg to each other so the opening and closing points should line up on the flywheel.
For the high lift cams the no 4 cam lags the no 1 cam at every opening and closing point by between 6 and 15 crank deg. Some of that will be due to tappet clearance not being exact but the rest is due to the error in gasket thickness.

No , adjustable cam gears aren't an option, this is part of an ultra low budget build.....because I can.

Back later.

Steve

_________________
6G72 mivec Twin TDO5 20Gs up and running.
6G72 mivec bored and stroked to 3.4 litres...Frankenmitsi build
6G74 mivec bored and stroked to 3.9 litres....Frankenmitsi build.
6G75 under construction....4.2 litres bored and stroked.Another Frankenmitsi.


Top
 Profile  
 
 Post subject: Re: Degreeing cams
PostPosted: 31 Oct 2009 02:07 
Offline

Joined: 02 Apr 2008 22:06
Posts: 6
My research goes more into 4G92Mivec vs 4G93 (So... 1.8 Mivec Turbo), but...

I don't see why your thicker head gasket will introduce and offset onto the cam timing? Isn't belt wear and tear introducing more discrepancy than your 0.5mm thick head gasked?

And if the non factory setup is introducing an offset, it will get doubled on the second bank (in case of an V-Engine).

So I think the 4G93Mivec's will not suffer as much as an V6.

Are you going to Turbo that thing?


Top
 Profile  
 
 Post subject: Re: Degreeing cams
PostPosted: 31 Oct 2009 17:38 
Offline
Mivec Guru

Joined: 04 Jul 2005 13:25
Posts: 1216
Location: Lower Hutt
Country: NZ
stei.f wrote:
My research goes more into 4G92Mivec vs 4G93 (So... 1.8 Mivec Turbo), but...

I don't see why your thicker head gasket will introduce and offset onto the cam timing? Isn't belt wear and tear introducing more discrepancy than your 0.5mm thick head gasked?



It's a 1mm diff because the mivec gasket is .5 mm and the TT is 1.5. Yes I agree with you about the small difference it will make but the other bank will be 3 times that so I just want to get it as close as realisticly possible without making it too hard for myself.

Steve

_________________
6G72 mivec Twin TDO5 20Gs up and running.
6G72 mivec bored and stroked to 3.4 litres...Frankenmitsi build
6G74 mivec bored and stroked to 3.9 litres....Frankenmitsi build.
6G75 under construction....4.2 litres bored and stroked.Another Frankenmitsi.


Top
 Profile  
 
 Post subject: Re: Degreeing cams
PostPosted: 31 Oct 2009 17:40 
Offline
Mivec Guru

Joined: 04 Jul 2005 13:25
Posts: 1216
Location: Lower Hutt
Country: NZ
stei.f wrote:

So I think the 4G93Mivec's will not suffer as much as an V6.

Are you going to Turbo that thing?


Sure a 4G93 will be a lot closer but I'm sure it's worth checking. Then someone could report back and say everything lines up perfectly.

Turbo for sure. I just got bored with welding on the 74 so decided to play with another motor.
Once I get the car going (again, drags soon), it would be handy to have another 72 block to go in if it blows up, or if it doesn't blow up I could just swap these heads onto the 72 block in the car , now that I've got a cam sensor to make mivec a bolt on fit.

Steve

_________________
6G72 mivec Twin TDO5 20Gs up and running.
6G72 mivec bored and stroked to 3.4 litres...Frankenmitsi build
6G74 mivec bored and stroked to 3.9 litres....Frankenmitsi build.
6G75 under construction....4.2 litres bored and stroked.Another Frankenmitsi.


Top
 Profile  
 
 Post subject: Re: Degreeing cams
PostPosted: 31 Oct 2009 18:01 
Offline
Mivec Guru

Joined: 04 Jul 2005 13:25
Posts: 1216
Location: Lower Hutt
Country: NZ
Some numbers at .2mm clearance
for the big cam
in op 1=60* btdc 4=45*btdc
in cl 1=96*abdc 4=102*abdc
ex op 1=85*bbdc 4=75*bbdc
ex cl 1=39*atdc 4=45*atdc.

Should be +- 2 deg if I haven't messed it up too much.

Pretty long cams?

So that's in dur 1=304 4=300
ex dur 1=336 4=327

overlap 1=99 4=90

looks like I'll have to recheck the tappets.

Steve

_________________
6G72 mivec Twin TDO5 20Gs up and running.
6G72 mivec bored and stroked to 3.4 litres...Frankenmitsi build
6G74 mivec bored and stroked to 3.9 litres....Frankenmitsi build.
6G75 under construction....4.2 litres bored and stroked.Another Frankenmitsi.


Top
 Profile  
 
 Post subject: Re: Degreeing cams
PostPosted: 20 Nov 2009 10:37 
Offline
Mivec Guru

Joined: 04 Jul 2005 13:25
Posts: 1216
Location: Lower Hutt
Country: NZ
Just thought I'd dig this one up again.

Right, well the tappet clearances make a huge difference to the opening and closing angles, Tappet clearances seem to make a far bigger difference than anything else so if they're not done properly, well go figure?
BTW I've spent ages on this going around and around.


Anyway I had to modify my feeler gauges a bit and now here's what I've got just incase someone out there might be just remotely interested.

This is with both intake and exhaust set to .2mm which I know isn't the correct spec.

I O 33* (27*) BTDC
I C 56* (60*) ABDC
E O 52* (40*) BBDC
E C 18* (18*) ATDC

That's for Cyl no 1 and the number in brackets is for cyl no 4 which is on the opposite bank 360 deg out of phase, both for the low cam.
So that gives intake duration 279* (277*)
exhaust.............................250* (238*)
overlap................................51* (45*)

And on the big cam

I O 51* (51*) BTDC
I C 94* (94*) ABDC
E O 77* (74*) BBDC
E C 30* (30*) ATDC

So intake dur 325* (325*)
Ex dur 287* (284*)
Overlap 81* (81*)

So as you can see the big cams are pretty close (1 and 4), the small cams aren't.There seems to be a bit of rocker wear too which I'll have to sort out.

Of course in a real life situation the motor gets hot, the tappet clearances close up , cam duration gets longer, the exhaust duration more so than the intake duration because the exhaust valves get hotter, that's why there's a tappet clearance.

So what about these aftermarket cams that people like to buy?
What's the advertised and what's their "real" duration?

Steve

_________________
6G72 mivec Twin TDO5 20Gs up and running.
6G72 mivec bored and stroked to 3.4 litres...Frankenmitsi build
6G74 mivec bored and stroked to 3.9 litres....Frankenmitsi build.
6G75 under construction....4.2 litres bored and stroked.Another Frankenmitsi.


Top
 Profile  
 
 Post subject: Re: Degreeing cams
PostPosted: 30 Nov 2014 22:57 
Offline
Mivec Guru

Joined: 04 Jul 2005 13:25
Posts: 1216
Location: Lower Hutt
Country: NZ
magn1t wrote:
Just wondering if anyone has actually done this.
I know several people have either aftermarket cams or camgears or both.


Low cam

In opens 27 btdc
in closes 60 abdc
ex opens 60 bbdc
ex closes 24 atdc

So that gives an overlap of 51 deg
in duration 267 deg
ex duration 264 deg

High cam.

in opens 54 btdc
in closes 102 abdc
ex opens 85 bbdc
ex closes 39 atdc

So that gives an overlap of 93 deg
In duration 336 deg
ex duration 304 deg

Should be correct to +- 2 deg apart from error with tapet clearance.


Steve


Just bringing this back up from the dead.
I've been thinking for ages that the best way to do this is with a standard unmolested engine that's never been pulled to bits.

So that's now what I've done .....numbers to follow.

So what I've actually done.......Diamante 30M engine, I've had it sitting complete for a few years, got the spun bigend mod. I've stripped it down to the cambelt, removed covers and brackets.....roughly confirmed that the tappet clearances are correct then measured several points with a dial gauge. I'm using the same flywheel and pointer setup at TDC and 3.076 deg per tooth.
Starting with the original numbers above of (IO,IC,EO,EC) 27, 60, 60 ,24.
Those numbers changed later with tappet clearance and modified camgears.
Ended up with 33, 56, 52, 18,for the small cams and 51,94,77,30, for the big cams.
I still wasn't happy with the numbers.That was all back in 2009.
The new numbers are for a proper 30M engine

Now we have, small cams 18.5(21.5), 67.5(63), 72(72), 38.5(38.5), the numbers in brackets are for cylinder no 4.
The big lobes 33.8(33.8 ), 93.8(96.9), 94(94), 57(54).
So adding up numbers the int duration is 266(264.5), ex 290(290) and int dur big cam 307.6(310.7), ex 307.6(310.7).
The overlap is 56 deg on the small lobes and 89 deg on the big ones.
The intake cam lift is, 3.6mm, valve lift 6.8mm small cam.
big int cam lift 5.8mm, valve lift 9.5mm.
Small ex cam lift 4.2mm, valve lift 7.5mm.
Big ex cam lift 5.6mm, valve lift 9.5mm.
Peak lift small int 103 BTDC, centreline 110 BTDC.
Peak lift small ex 106 ABDC, centreline 107.5 ABDC.
Peak lift big int ummmm, centreline 119 BTDC
peak lift big ex 109 ABDC, centreline 106.75.

So next step is to re adjust the tappets.
More measurements.

Going back to the original post on this subject. I don't know whether I mentioned it but I got my numbers to change when I modified the camgears. I'm not interested in adjustable camgears but I modified the originals by shifting the locating slots sideways....because I can.

edit, measured, adjusted tappets.......re measured valve opening/closing, changed the numbers.
A difference of .15mm valve lash can make a difference of 6 degrees at each end of the cycle.
The exhausts were at .25mm lash measured with the dial gauge, one intake was OK ish at .15 but the other was at .20. The proper spec is .10 intake and .20 exhaust.


Steve

_________________
6G72 mivec Twin TDO5 20Gs up and running.
6G72 mivec bored and stroked to 3.4 litres...Frankenmitsi build
6G74 mivec bored and stroked to 3.9 litres....Frankenmitsi build.
6G75 under construction....4.2 litres bored and stroked.Another Frankenmitsi.


Top
 Profile  
 
 Post subject: Re: Degreeing cams
PostPosted: 30 Dec 2014 22:13 
Offline
Mivec Guru

Joined: 04 Jul 2005 13:25
Posts: 1216
Location: Lower Hutt
Country: NZ
I'm still working on this on and off.
What I've done now is to set the tappet clearances to zero, or at least as close to it as I can. That's measuring the clearance with a dial gauge, moving the rocker up and down until there's only just zero movement.That's a lot easier than using a feeler gauge as it's tight for space and you need to bend the end to 90 deg without snapping the end off.I can't find the ones I used last time, I think they've rusted up?
I've measured the opening and closing points at both zero lash AND at 1mm of lift.

So far for no 1 exhaust valve
EO = 78.5 (BBDC)
EC = 44.5 (ATDC)
MEO = 97
MEC = 60

That gives durations of 303 for low lift cam and 337 for the high lift cam, both at zero lash.

At 1mm lift.

EO = 20
EC = -14
MEO = 48
MEC = 6

That gives durations of 186 for the low lift cam and 234 for the high lift cam at 1mm lift.
The low cam centreline is 107 deg at zero lash.
The high cam centreline is 108.5 deg at zero lash.

The low cam centreline is 107 deg at 1mm lift.
The high cam centreline is 111 deg at 1mm lift.

The difference in the high cam centreline measuring at both zero lash and 1mm is because the opening and closing ramps are not the same.

Now for the intake cam at zero lash
IO 55.5
IC 98.5
MIO 49
MIC 109

That gives durations of 334 deg for the low cam and 338 deg for the high cam.
Again, the unexpected long duration of the low cam will be to do with the gentle ramps at low lift.

At 1mm lift
IO -12
IC 23
MIO 9
MIC 60

That gives a duration of 191 for the low cam and 249 for the high cam at 1mm lift
The low cam centreline at zero lash is 111.5 deg
The high cam centreline at zero lash is 120.5 deg

The low cam centreline at 1mm lift is 107.5 deg
The high cam centreline at 1mm lift is 115.5 deg

Some of the numbers seem a bit strange. The intake cam is a bit longer than the exhaust cam.
The cams have different ramps on them. Measuring at 1mm lift seems to be more accurate for finding the centrelines.
Measuring at zero lash seems less accurate than measuring at working lash.
A hydraulic cam should be measured at zero lash.
A mechanical cam should be measured at working lash.
Measurements at 1mm are handy for finding the centreline, nothing else.


Mistakes?
Who knows?

It makes you wonder about the non mivec crowd who thing they're doing well upgrading their cams to 272s?...or splashing out for 280s.
Or even HAVING a mivec and buying JUN cams without knowing what they've already got?

Steve

_________________
6G72 mivec Twin TDO5 20Gs up and running.
6G72 mivec bored and stroked to 3.4 litres...Frankenmitsi build
6G74 mivec bored and stroked to 3.9 litres....Frankenmitsi build.
6G75 under construction....4.2 litres bored and stroked.Another Frankenmitsi.


Top
 Profile  
 
 Post subject: Re: Degreeing cams
PostPosted: 01 Jan 2015 14:51 
Offline
Mivec Guru

Joined: 04 Jul 2005 13:25
Posts: 1216
Location: Lower Hutt
Country: NZ
Right...so.....to get off at a bit of a tangent here. This has got me turning the clock back 20 or 30 years to the days of when pushrod V8s used to be the greatest thing ever.

There's different sorts of cams and if you get it all wrong, you'll end up with a major disaster.

First of all there's solid cams Vs hydraulic cams.
Then there's roller cams vs flat tappet cams.

Mivec is "solid"...it's also a "roller".
It's NOT hydraulic, it's NOT flat tappet.


What's that got to do with mivec?

Solid cams have a lash adjustment, that means there's always a clearance unless the valve has been lifted, that clearance has to be taken up gradually to avoid any "hammering" action.
Hydraulic cams, parts are always in contact, no hammering action.
The opening and closing ramps are different, you can go from fully closed to open a lot quicker..

Roller cams have rollers running on the lobes, the best and usual material for them is steel. It's got the best wear properties.
Flat tappet cams, the lobes slide across the tappets, the cams are often some sort of cast iron with surface treatment, often brittle and can snap easily........think of eg Nissan's version of VTEC, forgot the name? Cast iron is harder than steel and ....well it's the usual material.
Some engines like soobys make a solid bucket head and also make a hydraulic bucket head for a different model, the hydraulic buckets are usually found on the VVT models.The cams will have different ramps on them but you wouldn't know unless you spent a lot of time measuring everything.

Suppose you're the usual 4G63T ricer type that's thinking about upgrading the cam and maybe going to solid lash adjusters. You need the right grind. You can't get a common hydraulic cam and expect to fit solid lash adjusters and expect it to last long. The ramps are all wrong , the hammering action will end up mushrooming the tips of the valves.
Not just a 4G63 but the same applies to 6G72s which use the same ish valve gear.
But......there's nothing to stop you from keeping the hydraulic last adjusters and shimming them tight so that the last .2mm is hydraulic.
But why would you want to do that if it doesn't cost anything?
You always get what you pay for?
Think....... door to door vacuum cleaner salesmen?
That's the aftermarket auto industry.

Steve

_________________
6G72 mivec Twin TDO5 20Gs up and running.
6G72 mivec bored and stroked to 3.4 litres...Frankenmitsi build
6G74 mivec bored and stroked to 3.9 litres....Frankenmitsi build.
6G75 under construction....4.2 litres bored and stroked.Another Frankenmitsi.


Top
 Profile  
 
 Post subject: Re: Degreeing cams
PostPosted: 01 Jan 2015 20:16 
Offline
Mivec Guru

Joined: 04 Jul 2005 13:25
Posts: 1216
Location: Lower Hutt
Country: NZ
So I thought I may as well take a plot of crank degrees vs lift for the intake low cam, it's got the longest / gentlist opening ramp.
I've taken readings 1 tooth at a time from the flywheel ring gear.......far easier and far more accurate than using a degree wheel. 1 tooth = 3.076 deg.

Going from zero lift to a bit of lift is a bit tricky cos it's such a gentle ramp and the dial gauge will stick a bit.

Teeth no.....lift mm
0 .000
1 .03
2 .03
3 .03
4 .035
5 .04
6 .045
7 .05
8 .07
9 .09
10 .10.

So as you can see, in crank degrees, it takes 7 teeth or 21 crank degrees to lift the valve 0.05mm (half of the specified lash) when at zero lash. It takes another 3 teeth (9 deg) to lift the next 0.05mm.
So if the tappet clearance is set correctly (0.1mm), it'll take 31 crank degrees to close that gap and then start lifting the valve.

The next 4 teeth or 12 deg lift the valve another 0.1 or so mm.
11 .12
12 .14
13 .17
14 .19

15 .23
16 .26
17 .31
18 .38
19 .47
20 .62

21 .80
22 .97
23 1.16
24 1.41
25 1.64
26 1.92
27 2.23
28 2.56
29 2.87
30 3.19



Then I found something to back everything up.

http://my.prostreetonline.com/2014/12/0 ... 4g63-cams/


They even cocked that up too, they don't pump up, they bleed down and lose lift, the hydraulic ones that is. That's why people go solid when they'd be better off to go mivec....Go 4G94?

And this

http://www.kelford.co.nz/sole-purpose-o ... g-your-cam

Next step........
Lots of people talk lots of shit when it comes to cars. Nothing ever changes.

So, after a bit of a search, here's a few links for some new years amusements.
Think........vacuum cleaner salesmen?

http://www.lancerregister.com/showthrea ... lid+lifter

http://www.lancerregister.com/showthrea ... lid+lifter


http://www.lancerregister.com/showthrea ... lid+lifter

http://www.lancerregister.com/showthrea ... lid+lifter

http://www.lancerregister.com/showthrea ... lid+lifter

http://www.lancerregister.com/showthrea ... lid+lifter

http://www.lancerregister.com/showthrea ... lid+lifter

http://www.lancerregister.com/showthrea ... lid+lifter

http://www.lancerregister.com/showthrea ... lid+lifter

http://www.lancerregister.com/showthrea ... lid+lifter

Steve

_________________
6G72 mivec Twin TDO5 20Gs up and running.
6G72 mivec bored and stroked to 3.4 litres...Frankenmitsi build
6G74 mivec bored and stroked to 3.9 litres....Frankenmitsi build.
6G75 under construction....4.2 litres bored and stroked.Another Frankenmitsi.


Top
 Profile  
 
 Post subject: Re: Degreeing cams
PostPosted: 06 Jan 2015 19:49 
Offline
Mivec Guru

Joined: 04 Jul 2005 13:25
Posts: 1216
Location: Lower Hutt
Country: NZ
Right, well, so........I thought it might be a good idea to measure the opening ramp on the big cam too, just for comparison.
The cams don't actually swap over as such, the rockers lock together so that the lifting is done on which ever is higher at the time.
I've Cut and pasted the above numbers then added the high cam figures alongside.
This is lift at the head of the adjusting screw, so it's valve lift. At lower lift there's some minor errors 'cos the RH column shouldn't have lower numbers than the LH column.

Teeth no.....lift mm
0 .000 .00
1 .03 .005
2 .03 .005
3 .03 .025
4 .035 .06
5 .04 .095
6 .045 .125
7 .05 .155
8 .07 .185
9 .09 .235
10 .10 .285

11 .12 .345
12 .14 .435
13 .17 .565
14 .19 .685

15 .23 .885
16 .26 1.075
17 .31 1.285
18 .38 (TDC) 1.465 (TDC)
19 .47 1.715
20 .62 2.055

21 .80 2.305
22 .97 2.665
23 1.16 2.915

There you go , lots of useless info.There's a few errors in there but it's more right than wrong.
As you can see, at TDC there's .38mm lift on the low cam but on the high cam there's 1.465mm of lift.


I just read on some yank forum that you can't degree cams without a cam card.......WTF.


Lols.


Or maybe I just made the whole thing up.
Even if I did.........nobody out there would have an effing clue?

Steve

_________________
6G72 mivec Twin TDO5 20Gs up and running.
6G72 mivec bored and stroked to 3.4 litres...Frankenmitsi build
6G74 mivec bored and stroked to 3.9 litres....Frankenmitsi build.
6G75 under construction....4.2 litres bored and stroked.Another Frankenmitsi.


Top
 Profile  
 
 Post subject: Re: Degreeing cams
PostPosted: 14 Jan 2015 16:11 
Offline
User avatar

Joined: 13 Jun 2013 13:05
Posts: 18
Location: Auckland
Country: New Zealand
I for one am enjoying your rants.

I usually play with SR & RB motors.
There are plenty of muppets who don't understand the lifter design affects cam choice.
Moar boost = moar powa right? :lol:

On our wee 4g92 Mivec I don't see the point in a cam unless it's a race car. We're already cam'ed extremely well from factory, and above 100hp/l, so it's not going to improve much!

_________________
1996 Mirage Asti RS - M1V3C - http://mivec.co.nz/forums/viewtopic.php?f=28&t=11944


Top
 Profile  
 
 Post subject: Re: Degreeing cams
PostPosted: 16 Feb 2020 23:36 
Offline
Mivec Guru

Joined: 04 Jul 2005 13:25
Posts: 1216
Location: Lower Hutt
Country: NZ
I don't think there's anyone left on this forum anymore.
I'm quite pleased I left this data on here because I've been making use of it.

I've got a crankshaft grinding machine in my garage at home. I've got nearly 10 years experience with it now, I've done 3 different offset crank grinds with it to make 3 different Mitsubishi v6 strokers, 3.4 litre, 3.9 litres and 4.2 litres. All for myself, just playing around.
I've also figured out how to use the machine to make custom cams. The downside is that it's very time consuming. The plus side is you can make whatever you want within reason.

A camshaft grinding machine is different, plenty to see on ewetoob.

I've already done a set of diamante N/A cams, they're going into my GTO TT tow car, next is a set of mivec cams but I need the data to get the opening and closing ramps right.

Because I measure everything, I've just found out that there's more than one different sort of 6G mivec cam, I've got other sets that have more lift than these ones I measured.
So there you go, you can't assume anything.

_________________
6G72 mivec Twin TDO5 20Gs up and running.
6G72 mivec bored and stroked to 3.4 litres...Frankenmitsi build
6G74 mivec bored and stroked to 3.9 litres....Frankenmitsi build.
6G75 under construction....4.2 litres bored and stroked.Another Frankenmitsi.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 15 posts ] 

All times are UTC + 12 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group