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Camshaft tech thread!


BobbyBreeze

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the 205 were in a special head with 35mm buckets on both sides ,the cam seems to mark up about 10mm from the top

the other cams which were about 268 at 50 thou and 575 thou lift has 2 much velocity

we try to keep the cams to about .01000"

this new 1 the 263 is max vel is .01074"

the super tourer is .01084"

the 205 is .01135"

and the 178x is way over the last 1 close to 12 from memory and on the dyno lost power every where.

we wernt using vvti and had the cam fixed at 100 lobe center and we tried moving it either way from 105 to 95 to see how it would go

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Fuck Moreys, I use it in old steering boxes only.

We have a boat spec 400hp 454 ex Hamilton Jet. Built by some joker in Queenstown who apparently builds the engines for all the river boats down there, we have put in an old Chevy C10 and it goes fine. (if a little fucking scary)

Do you know if there would use a special cam grind for the boat engines?

If so what would be the best grind to replace it with?

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For camshaft run in I see you guys (Kelfords) say that you should not run synthetic oil. Should I be using proper engine run in oil or just a non - synthetic oil such as Castrol Modern engine?

 

I would personally use a break in oil as some mineral oil these days do not contain ZDDP. It is only once and generally pretty cheap. If you do want to use a normal mineral oil maybe run an engine break in additive and make sure the cam has good coating of cam lube (normally supplied with the cam) to aid the cam break in process. 

 

Fuck Moreys, I use it in old steering boxes only.

We have a boat spec 400hp 454 ex Hamilton Jet. Built by some joker in Queenstown who apparently builds the engines for all the river boats down there, we have put in an old Chevy C10 and it goes fine. (if a little fucking scary)

Do you know if there would use a special cam grind for the boat engines?

If so what would be the best grind to replace it with?

 

Boat stuff is normally ground on close lobe centers and fairly mild - for epic mid range torque. Plenty of people use our jetboat v8 grinds in road cars wanting great driveability so I wouldn't really worry about putting a new cam in the C10, unless you are missing the top end. If you do want more top end I'll need the rest of the specs of the motor/trans to suggest something that will work well. 

 

Was the motor built by Andy? 

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This thread still alive?

 

Have a mate with a BMW 850i which is basically a couple of m20s welded together. Anyway, apparently he's been told (by Kelfords if I remember right) that the cams in it are unable to be reground. To me that sounded a bit odd seeing as they are more or less a pair of I6 cams.

 

Any thoughts on whether this is correct chaps?

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This thread still alive?

 

Have a mate with a BMW 850i which is basically a couple of m20s welded together. Anyway, apparently he's been told (by Kelfords if I remember right) that the cams in it are unable to be reground. To me that sounded a bit odd seeing as they are more or less a pair of I6 cams.

 

Any thoughts on whether this is correct chaps?

maybe they meant it can't be reprofiled without building it up first

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if the base circle is really small and you grind more lift into it it fucks with the ramp profiles so they might be garbo in that sense. in which case the 6cyl would be in the same boat. but maybe with the 6cyl there are lots of aftermarket cams with the same base circle but larger nose. also possible two of the cams on the v12 might spin the opposite way if one cam is driven with a gear off the other.

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With those V12's it will possibly have really wimpy cams in it as it is - to keep it "coin balance" smooth while running, that was the highest priority for those engines, maybe its a case of not being able to grind whats there as there is not much there in the first place?

 

I am keen to know the actual reason for that though, im just repeating stuff I have heard from others, it could be total cobblers haha

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No idea on the 850i cams sorry. Most probable reason is that it isn't worth their time, really not a whole lot of profit in regrinds (especially when they have to put in a couple hours of work to find or make a profile that will do the job). Kelford don't do a lot of BMW cams so its not like Shrick who has done the development and can pick a master & setup and regrind quickly. 

 

It is possible to regrind though, I can't see reduced basecircle being an issue for a mild hot up - it doesn't 'fuck with ramp profiles', the only issue is nose radius & invert radius on flanks get smaller (which ain't an issue on a slipper pad rocker follower like the M20/M70) and you have to have enough free adjustment left on the lash adjusters to set lash to the required clearance. 

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It is possible to regrind though, I can't see reduced basecircle being an issue for a mild hot up - it doesn't 'fuck with ramp profiles', the only issue is nose radius & invert radius on flanks get smaller (which ain't an issue on a slipper pad rocker follower like the M20/M70) and you have to have enough free adjustment left on the lash adjusters to set lash to the required clearance. 

 

hah was waiting for you to correct the terminology 8)

 

what about on a bucket/shim direct actuation setup. some people wang on about it on the fiat twincams that regrinds are rubbish because of making the vase circle small or something. I remember you did tell me that it wasnt a real deal or something/cant remember exactly why.

 

I can kinda visulise that if you make the circle smaller the size of the bit dictating the acceleration part of the cam gets smaller and you would lose "resolution" in that section so it would make it would require more accuracy in the grinding process as the diameter/radius gets smaller since 0.1mm (or whatever yours +/- is)  difference becomes a bigger % of the total.

 

writing that just makes me think its rubbish full stop because that radius is going to be tiny anyway and the whole thing just goes whack whack valve you be open whack valve you be close.

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No idea on the 850i cams sorry. Most probable reason is that it isn't worth their time, really not a whole lot of profit in regrinds (especially when they have to put in a couple hours of work to find or make a profile that will do the job). Kelford don't do a lot of BMW cams so its not like Shrick who has done the development and can pick a master & setup and regrind quickly. 

 

It is possible to regrind though, I can't see reduced basecircle being an issue for a mild hot up - it doesn't 'fuck with ramp profiles', the only issue is nose radius & invert radius on flanks get smaller (which ain't an issue on a slipper pad rocker follower like the M20/M70) and you have to have enough free adjustment left on the lash adjusters to set lash to the required clearance. 

 

Thanks for the reply mate. So possible but not worth their time and/or effort? I can understand that.

Presumably the same for the M62?

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