Chamshafts

[Mark]

I'm looking into getting a performance camshaft for my ma12 engine. i've noticed that the ma10 and ma12 use differant cams. having spoken to slim about this and he thinks the ma10 use's a more aggresive cam which would beneifit the ma12 which has a less aggresive cam. anyone wanna share some information on camshafts which would put my theory into practice as i have a ma10 cam in my garage which if it offers more performance than the ma12 cam i'll stick in it my ma12.

specifications of both cams are:

MA10
Outer diameter of journal 39.95 to 39.97 mm
camshaft bearing inner diameter 40.00 to 40.03 mm
journal to bearing clearance 0.03 to 0.07mm
endfloat 0.03 to 0.31mm

cam lobe height:
inlet 33.77 to 34.02mm
exhaust 33.73 to 33.98mm

MA12

cam lobe height:
inlet 33.98 to 34.23mm
exhaust 33.94 to 34.19mm

 

[Ed]

Interesting topic mark. I made an assumption a while ago that the 1.2 cams would be less agressive due to the fact that the 1.2 makes its peak power 400 rpm less than the 1.0. However looking at those cam measurments there the 1.2 have a higher lift, but this on its own does not help since we need to know the duration which is quite hard to get hold of. I can say this however I have tried a 1.0 head on a 1.2 engine (1.0 head is higher compression) the result was not really worth the hassle. Its unclear really weather it made any difference or not.

Ed

 

[quickdraw]

ditto i was gonna do this a while ago if you remember ED
and was also advised that the results were not benificial unfortunatly.

but every point counts in the end.

go for it mark. keep trying. try boost the extra points u can get

 

[Mark]

The thing is when you have a re profiled cam they take material off the cam dont they? cause they dont add metal on which would make the lobe height smaller? and the ma10 cam has a smaller height?

i'm not really in the know about cams but i'm gonna get some more details on them.

 

[Ed]

Mark that is kind of right, they make the lower bits lower, then you ajust the tappets and it opens them more, etc. It could work well on a K10 but you would really need the inlet and exhaust changed to something better.

Ed

 

[Mark]

i'm not going to go down the normal route of what is thought the best way to get power out of the ma engine with custom inlet and exhaust manifolds as there are far too expensive. i'm going for a piper cam and maybe porting the cylinder head,

 

[quickdraw]

i'm not going to go down the normal route of what is thought the best way to get power out of the ma engine with custom inlet and exhaust manifolds as there are far too expensive. i'm going for a piper cam and maybe porting the cylinder head,

trust me i know a very (edited for swear filter grr) easy way of doing the inlet manifold and is cheap as can be
just not had time or effort to do it yet

 

[Ed]

Mark head porting (when done to and advantage) is expensive. I still tell you now that inlet and exhaust are still the most effective ways to get power.

 

[quickdraw]

^^^ very true

but at least your looking at other options. reminds me back to what i was like :S about 6 months ago

 

[Mark]

theres a guy who i know who quoted me about couple of hundred quid for a exhaust manifold, i could get the inlet manifold ported slightly but i'm gonna stick with a cam to start with and then maybe with the exhaust manifold

 

[quickdraw]

inlet manifold is the major one you need to think about trying to get better. as this is the most restrictive.
also regarding the exhaust you could modify an existing one to fit such as (damn memery) sorry who ever it was) modified a metro turbo one. i myself made a flange plate to convert the janspeed k11 manifold to fit. (never got chance to fit this though so cant verify it worked :S)

but this is a good way to sort this issue. obviously a custom one for the job will be better but these can be very inexpensive indeed.
i will most prob some time or another get round to fitting a janspeed to a k10. and if the benifits are good then i shall knock up a few of the flanges for others aswell

 

[Mark]

I thought you cant weld the manifold as it is cast? thats what i was told anyway? the guy who made my full stainless exhaust said he'd make me a new manifold but i think i'm gonna go for a cam and lighten and balance the flywheel first before that, main thing it all will help produce a few more bhp, just hope the clutch/gearbox/bottom end wont break lol!

 

[quickdraw]

i didnt weld the manifold.
the janspeed is mild steel but you dont touch that at all.
all i did was to offer a k10 manifold up to a sheet of steel stencil around it and cut it out.
then stencilled around the k11 manifold an cut that out. i then stencilled around these onto a piece of cm thick steel. and did the same again to the k11 one. so that i had 2 pieces of steel cut to the manifold ends.
i then took this to a mate (the mate i may be going into businesss with) and he basically cut them out then profiled the internals so that the k10 one flowedinto the k11, thus transfering the k10 outlet to the k11 outlet through a flange.
simply and cost nothing . you may be charged though for the fabrication company to flow them together but this should cost next to nothing to do

hope this helps

 

[quickdraw]

oh jut to add. you may require longer manifold bolts. this is nothing also. but since your gonna be basically adding a flange between the block and manifold you will need the bolts to be able to stretch right through them all and be able to bolt on.

 

[Mark]

It was actually the guy from powerflow who made my current exhaust system, who said he would make me the manifold, he has made stainless intercooler pipes for people i know and is up for the challenge of making a manifold.

dont think anyone on the forum has added a performance camshaft to the ma series so I cant ask them to find out how much of a difference it made but i'm willing to try it as its only gonna improve performance but by how much is the important part.

quickdraw i'm currently using a weber carb and aint changed the jets, it comes for a 1000cc, works ok-ish at the moment (fine when warmed up) but will the jets need changing if i change the manifold/Cam?

 

[quickdraw]

would be a good idea.
but as of yet i aint tested it fully. i am also in the middle of testing the webber through a non modified (exceot air filter) ma10 series engine. as i want to test performance stats.
but then that is because i wan to run it again the ma12 which i believe will eba weaker block. and something were i may be required to use the stronger ma10 block to be able to achieve whta i have planned. as i feel the stronger block may benifit me more than the weaker ma12.

though i was also intersted in your personaly experiances also and requirding the power steering you had on 1 of your k10's i belive i read about. i was interested in finding some information from yourself regarding this as i have a use for the PS pump.

if your on msn im on [email protected]
be good to have a chat about a few things.

speak to tommo he has me on there also

wayne

 

[quickdraw]

can i also just add into this thread one thing.

a thank you.
to mark

because i have been longing for someone else to also look into engine tuning of the ma series engine. someone i can bounce ideas from and get ideas from also.

slim has some but isnt looking into new stuff. ED is stuck through the ST at the mo. and nobody else seems to want to bother.

glad someone else is starting to instigate things.

oh and MARK
can i say

have a look, inuire about the golf pistons and cams mate.

 

[quickdraw]

can i also just add into this thread one thing.

a thank you.
to mark

because i have been longing for someone else to also look into engine tuning of the ma series engine. someone i can bounce ideas from and get ideas from also.

slim has some but isnt looking into new stuff. ED is stuck through the ST at the mo. and nobody else seems to want to bother.

glad someone else is starting to instigate things.

oh and MARK
can i say

have a look, inquire about the golf pistons and cams mate.

 

[quickdraw]

can i also just add into this thread one thing.

a thank you.
to mark

because i have been longing for someone else to also look into engine tuning of the ma series engine. someone i can bounce ideas from and get ideas from also.

slim has some but isnt looking into new stuff. ED is stuck through the ST at the mo. and nobody else seems to want to bother.

glad someone else is starting to instigate things.

oh and MARK
can i say

have a look, inquire about the golf pistons and cams mate.

 

[quickdraw]

and to also add to it

i will be back doing the ma series engine mods as soon as the ga16 is complete to my specs. hopefully JAE. will be a turning point ;p

 

[Slim]

the problem with tuning the MA is you need to alot to make it worthwhile

and the other problem is that they're so delicate.

 

[Ed]

I wouldnt say they are delicate, far from it. However as soon as you do onething you are faced by massive restriction from other areas i.e. exhaust alone wont help not will carbs - but both will be good.

 

[Slim]

i'd say they're delicate, as they're all getting on.

If you want to do some serious work, you want a full rebuild, grind the crank, rebore etc, and then the price for this bcomes ridiculous before you've even started to implement mods

i mean, your looking at a good 500+ for a propper rebuild. not cheap.

 

[Ed]

just as they are getting on doesnt make them delicate! Just means that will have wear. I have those bike carbs on a 90,000 mile 88' K10! I have tested them as much as I can and the engine still goes!

 

[Mark]

its pretty easy to say that the ma series realisticly are not the best engines out there.

i've been quoted 200 on a 4-2-1 manifold and am unsure wether to shell out or keep the money for a cg13 transplant.