mg cams
Turbo Mini Forums

For my 998 turbo build im gonna go with the mg cam,
but which one am i looking for again? is it the turbo metro cam or the bog standard one? or is there no difference!

Thanks martin

the NA cam would be better.
look for a 1/4 inch grove in the cam that will tell you its a mg cam

always looking for them bigger bunches of bannanas

Edited by Brocky on 12th Mar, 2006.

BTW - I took my buddy VTEC Pete out for a spin this weekend, and even though I am running her in, he gave it a name, the "Brocket"...cause I'm a brocket maaannn, nah nah nah nah nah nah nah nah nah nah nah....

Build thread - http://www.turbominis.co.uk/forums/index.php?p=vt&tid=7483

Katy Mini Owners Club Thread - http://www.turbominis.co.uk/forums/index.php?p=vt&tid=505552

Let's make sure you embarrass at least one VTEC MINI today !

https://www.facebook.com/groups/17557298589...096464253807802

if you cant get the mg N/A cam IMO

the kent 266 is shade better than this in the timing figures

i would chose this! cam

here is some timing figures for you to study paul.

the MG Metro cam, as fitted to MK2 metro VDP's, RSP Mini coopers, Metro Gta'a and 1275 Metro Sports.
It Has a 1/4" groove machined into the cam after the number one lobe.
Checking height: 0.017" @ lobe

Timing: (Intake): 16/56 (Exhaust): 59/29

Nominal lobe lift: (Intake): 0.263" (Exhaust): 0.263"

Duration (Intake): 252 (Exhaust): 268

Lobe centre angle (Intake): 110 (Exhaust): 105

Lobe separation angle: 107.5

Lift on overlap: 0.054"



NEXT is the Kent 266 a nice all round road cam, these figures are based on kents own specs, plus with my own additions.

Checking height: 0.016" @ lobe

Timing: (Intake): 24/56 (Exhaust): 61/29

Nominal lobe lift: (Intake): 0.263" (Exhaust): 0.268"

Duration (Intake): 260 (Exhaust): 270

Lobe centre angle (Intake): 106 (Exhaust): 106

Lobe separation angle: 106

Lift on overlap: 0.054"



& last is the Swift tune SW5 road cam,

Checking height: 0.016" @ lobe

Timing: (Intake): 15/49 (Exhaust): 52/12

Nominal lobe lift: (Intake): 0.281" (Exhaust): 0.281"

Duration (Intake): 244 (Exhaust): 244

Lobe centre angle (Intake): 107 (Exhaust): 110

Lobe separation angle: 108.5

Lift on overlap: 0.036"

you can see pete how Swift Tune has given their cam a shade more lift and sacrificed the duration!

in an attempt to make a cam for emission purposes,
i believe!

its well overated for a PERFORMANCE! cam IMO!

the cam in my next engine build is going to be a KENT 266

i honestly believe its just perfect for our turbo motors. & will make massive! torque & totall drivability.

the Kent 266 cam needs to be investigated further!
ANYONE!

Edited by BENROSS on 12th Mar, 2006.

did the mk1 metty vdp have the mg cam or normal?

And on the 7th day........... God created turbochargers!

for a turbo specific cam am i wrong in saying that we should be looking for more LCA being around the 110 to 112 mark so we are not pushing all our airfuel out the zorst before its even been burnt?

i might be wrong though

179hp on 12psi 1293cc of pure A series
14.0et @101 mph

when it comes to cams i always say try and see how it goes.
red 850 i recon that a bit waisted out the zorst is good and not bad as long as you can get it through the mot.

reason being turbos have a bigger dead area to clear than a high CR NA motor so you will get a cleaner burn.

thats why some of these cams with a slightly longer overlap periods are helping to produce big hp figs for the same boost, just like t3tones and hopefully mine this year so watch this space.

always looking for them bigger bunches of bannanas

been designing cams since '94, on a professional basis ,including engine induction and cam design on the fastest vintage bentley in the world,511 bhp 720 lbs ft .
ok trumpet blowing over ,
most of this using software on design and cam dynamics .and then building the engines.
my point of view is ,hey guess what ,theres no perfect cam .
shock horror.
let me explain .
as the pressure differential between inlet and exhaust changes, so the overlap , timing,, lsa et all ,change..so for a na motor ,where these pressures vary a little ,its not to hard to get a cam to operate in a predictable way .but in a turbo engine ,where the inet pressure can vary from 14 psi absolute ,to say 35 psi abs, and the exhaust can vary from 16 to 55 abs ,the balance of pressures varies a lot as we go up the rpm range . example ,a small turbine housing engine with a low rpm boost occurence,this will hit parity between inlet pressure and exhaust pressure at say 3200 then the ep will increase and our engine will have a need for less duration and overlap ,but only from this point on ..below 3200 it would be better with a closer lsa and earlier more advanced timing.so the situation is that ,in a street turbo engine ,the cam requirements vary ,and will be right for a set series of circumstances but not all
.which incidentaly ,is pretty true of all engines .a competition turbo engine ,with a narrow power band ,and a big turbine ,may achieve a similar overall pressure balance to a na motor ,and this is where a na cam tends to works well .i could spout on ad infenitum but i can see eyes glazing !! hope this makes sense ,regards robert.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Pete, just a thought, if you are increasing the valve train acceleration somewhat, have you considered doing some work to lighten the valve train somewhat, to reduce inertia? Maybe CF pushrods could be an easy starting point? Or maybe some Ti lash caps from Mr Austin??

Right ok , well i think i got all of that ...

You guys ,,,you just crack me up.
Good info but deep we`re` going deep,deep .....

Soooo, should he use a mg N/A cam or spend his money on a K-266 or a k-276 or .....

I know , i know im sorry , it just makes me grin !!!

Intercooled 1293 cc Turbo +
March 06,4psi and counting .
Its now gone up to 8psi.
Nov 06,10psi +.
And now part of the Airbourne club.

I would use the SW5.

That now gives us 4 options.

LOL

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

ooo, about a ph2 cam. lol

Theres now 5 options...

this is great....

I know , i know im sorry , it just makes me grin !!!

Intercooled 1293 cc Turbo +
March 06,4psi and counting .
Its now gone up to 8psi.
Nov 06,10psi +.
And now part of the Airbourne club.

so is the std 998A+ cam not worth bothering with?
(6 options??)

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

Ah good question.
Come on tech ies , tell us , go on....

We need more info ,,,more .....

Don`t leave us now .
My brain is a sponge ......ivanhoe where are you.
Put the Bentley pictures down , leave the TVR alone and tell us oh wise and all knowing cam profiler,shed some light on this dark tunnel of questions and theory.
This is a dark hour ....LOL...

I know , i know im sorry , it just makes me grin !!!

Intercooled 1293 cc Turbo +
March 06,4psi and counting .
Its now gone up to 8psi.
Nov 06,10psi +.
And now part of the Airbourne club.

I have tried CF pushrods in the past, and had no problem with them, of course making sure that the seat pressures on the valve springs were set correctly. I also know of a few other people having used them with no problems, so maybe it is worth trying them out as a budget (well, compared to other solutions) option first of all? Before I had tried them, I was also worried along similar lines as you are, about failure at high engine speeds, however Mr Vizard who has done far more engine testing than I am ever likely to do mentions in his book that if a CF pushrod is going to fail, it seems to do so very early on in life, with no damage to anything else (other than an engine dropping onto 3 cyls.) The other thing that must be considered by using CF pushrods is the valve clearances that can be used, obviously the thermal coefficient of expansion is much less than steel, giving valve clearances down into single figures of thous I would imagine. With lift off the seat giving useful valve curtain area quickly being the prime objective, this will go a long way to contributing to what you are trying to achieve.
The roller follower idea sounds interesting, I am guessing this is being done to cope with the high acceleration rate desired off the base circle, that would otherwise side-load the standard lifters excessively.

mart ..id go for the mg cam nat asp . for bhp per pound spent .
pete ,some points that occur , to my micro pea brian..and they may help,are ..
roller followers need a fair bit of lubrication ,with their small needle rollers under a substantial load ,the bigger the roller the better ,but with the bore of the tappet gallery the limiting factor ,which i asume yuo have taken out to the max .so flow the lube system with it all installed and see wether thers enough ,i realize youv prob thought of this but better to appear patronising now ,than oops wish id told him that later !!lol.
next ,dont forget your 1.7 rocker ratio means you can drop your spring pressure ,as it obviously multiplies your pressure back the other side of the rocker ,alsowith ref area under the curve ,if yuo have the valve open too far ,with ref to the acceleration of the piston ,your gas speed can drop and this can become detrimental to the flow .best to fond the right valve position so the flow matches the speed of the piston as it accelerates from the head .generally ,a good point of max piston velocity is a starting point for yuor peak flow point ,which incidentaly,is not always the same as peak lift point . ok off for supper ,hope that was usefull .regards robert ps dont even get me started on duration ..lol

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

pete what are you looking for rpm bhp torque etc ,and what flow is the head ??also whats your gear ratios vehicle weight ,usage ,acceptable power band start/ end rpm's??

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

My head hurts!!!!!!! I think i just killed all my useful brain cells by just reading that! ITs amazing the depth of answer that is produced from my simple question!!!!

my mother would be so proud!!!!! :)

just a point 1071 if you are grinding a cam from scrtach wouldnt it be better to give it the extra lift on the lobe than using 1.7 ratio rockers this will then elliviate more pressure of the lobe surface and reducepower absobtion through the rockers.

just a thought

always looking for them bigger bunches of bannanas

i remember gary at mini speed saying somthing about the roller follower idea.

but all makes sense

keep us posted

always looking for them bigger bunches of bannanas

ok pete or we could keep it on here if theres enough interest? something else occured to me , ,have you investigated the option of a spring on top each of the r tappets up to the bottom of the pushrod shelf above? this would give you pre load where you need it without punishing the valve seat ,also make sure you actually have more flow at the lifts your talking about ,otherwize it isnt necessary to lift that high ,say 650 thou if the head flow stops at 500.it is said in varoius books that thers no point in lifting any higher than 500 in that situation ,, i dont adhere to this theory !!
i feel that lift over the pk flow port lift can up to a point gain you something if only a smoother over the nose profile ,but obvioulsy one can over do it to the point that one is compressing a valve spring much more than is worthwhile and also there is the sit where a port can flow more at a lower lift due to the valve actaully acting as a venturi wall and aiding laminar flow and cutting turbulence in a positive way .regards robert.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM