Having custom cams made for an unfamiliar engine.

Has anyone here had a cam manufacturer make them a cam or multiple cams for an engine that they've never dealt with before? 

Before I go the route of having the base circle reduced, I thought I would call around about having custom cams made for the Mercedes M120 V12. Obviously, most camshaft manufacturers in the US haven't made custom camshafts for this engine, and there are no shelf options. The lobe design is familiar enough, it is basically the same as any DOHC engine that doesn't have rockers/cam followers and uses a bucket (tappet over the spring). The lobe design and firing order is the same as a lot of the more popular inline-6 engines like the 2JZ. 

I'm just wondering who here has had luck doing this, and what kind of cost can be expected. I'd be willing to send in my OEM camshafts for measurements. My first quote was $4500, which seemed absurd. Reducing the base circle was considerably cheaper but with the obvious limitations. 

It's a lot of work to do it properly, and the material alone is very expensive.

Hydraulic or mechanical? What is the current lift, duration and base circle, and what do you want to do, as far as lift and duration?

Billet material is expensive. I don't need billet. 8620/8660 cam cores are much cheaper. Any company that buys these cores in bulk can get them for a couple hundred bucks. I'm likely converting from hydraulic to mechanical tappets. This is for a toy, not a daily driver. 

Current cam specs at imperial measurements aren't known, but they're irrelevant unless I'm doing a regrind of the current lobes (without welding).

Desired cam specs would be in the ballpark of (imperial measurements):
234-240 degrees at .050"
.390-.410" lift.

Exact valve opening/closing numbers and desired peak lift will be determined by final head flow numbers and final compression ratio calculations once the larger valves are installed and the pistons are done (with deck clearance measured after milling). Desired compression ratio is ~12.5:1 to be used on E85 fuel. 

Here's some places I've heard of that can do custom cams, although I think they mainly do American V8 stuff - you could contact them to see if they can do Mercedes stuff too (it may be possible to regrind your existing cams, rather than manufacturing something totally new.)

https://www.bulletcams.com

http://jonescams.com

https://deltacam.com

https://www.howardscams.com

Web used to do custom cams and regrinds for DSMs, not sure if they still do custom work.  

Dbilas offers a regrind of the OEM camshafts- https://dbilas.com/en/Mercedes-6-0-V12-M120-Regrind-standard-camshaftsset/12.065.001U. I'm actually trying to get them to do custom camshafts for the M120 with more aggressive specs- still discussing with them.

I also got to wondering if there was a Facebook group for folks modifying the M120 or swapping it into other vehicles- I couldn’t find any, so I created one- don’t be shy if you want to join

https://www.facebook.com/share/g/iK4WSBAs19DhnLsb/?mibextid=K35XfP

You speak of buying cheap cam cores in bulk, but.... who makes them?  It's a nice idea in theory but if they aren't available to be had, you're stuck with billet.

Billet just means "we can't afford to cast/forge it for small production numbers so we whittled it from a solid bar", it's not magic.  If anything it's a sign of doing things on the cheap.  It's more expensive because "on the cheap" is different when talking about weird engines.

I think now most of the cam cores are made in Turkey , 

here is the USA office, 

Estas USA Camshaft Industry | About Estas Camshaft

PS; This is the company that makes the blanks and sells them to the cam grinders ,  you may want to ask them if they make a blank for your engine type ,  and if they do hopefully they can give you the cam grinders name  that ordered them ,  or at least the part number of your cam blank .

If you wanted to make a special cam blank I think you need to order 100 pcs .

Can't you just get the stock cams reground to whatever new profiles you want?  If that involves changing the base circle you can get thicker shims to be able to set the clearances.  That is what I did when I took a DOHC MG engine from 1588cc to 1950 cc and mounted the head on a 5 main MGB block.   I used Cosworth Ford profiles and to get shims I went to Alfa cup style shims which are available in a wide range of thicknesses.  I also used oversize valves with stock stem diameters so I could cut them down to appropriate length.  Having custom cams made from billets can get pretty expensive. 

Oregon Camshaft is the go-to cam regrinding service in the slant six world.

Oregon Camshaft

They'll regrind cams for anything, from lawnmowers to locomotives, so they are a reasonable choice for an oddball engine. If you're concerned about not having enough adjustability to deal with a smaller base circle, you can have metal welded onto the lobes to thicken them (assuming that the Mercedes cam isn't slid in through a set of bearings that limit its overall height).

In reply to MadScientistMatt :

Ha.  I'm reminded of a Speedtalk thread that was an example of why I stopped reading/posting there.

Guy gets a new cam for a small block Chevy.  The cam manufacturer screwed up and ground the lobes such that they were larger than the cam journals.

The guy was insistent that they fix the problem, BUT he didn't want to have the cam ground smaller because he didn't want to lose any base circle, or lift.  He wouldn't listen to the reality of it, he wanted a high lift cam with a large base circle like he got, and it was the cam company's fault that this was impossible.

Lotta people there refused to apply reason or logic.

Pete. (l33t FS) said:

In reply to MadScientistMatt :

Ha.  I'm reminded of a Speedtalk thread that was one of the reasons why I stopped reading/posting there.

Guy gets a new cam for a small block Chevy.  The cam manufacturer screwed up and ground the lobes such that they were larger than the cam journals.

The guy was insistent that they fix the problem, BUT he didn't want to have the cam ground smaller because he didn't want to lose any base circle, or lift.  He wouldn't listen to the reality of it, he wanted a high lift cam with a large base circle like he got, and it was the cam company's fault that this was impossible.

Lotta people there refused to apply reason or logic.

Clearly he needs to have the cam bearings bored oversized.

Or a solid smack over the head with his freshly ground camshaft.

In reply to wspohn :

My primary experience with aftermarket cams acting directly on a shim/bucket is with the Toyota 4A-G twincam, so MGAs and Mercedes might be different, but with the Toyota, getting more lift and a hotter cam profile with a regrind that reduces the base circle and using thick shims increases the likelihood of the cam lobe flicking the shims out and causing carnage in the head. The better way to do it for the Toyota is a hardweld to add material and regrind of the stock cams (I believe Web cams does this, or at least did at one point) or else billet.

It might or might not be an issue in reality, but on an unproven application I would be cautious about a reduced base circle and thicker/heavier shim when going for more lift, longer duration, and presumably also more revs. The steepness of the ramp and valve springs play a role as well. On Toyotas, one work around is to convert to shim-under-bucket (rather than over) but that makes valve adjustments a lot more complicated. YMMV, but could be food for thought.

In reply to ae86andkp61 (Forum Supporter) :

For VWs, which had solid and hydraulic cams, you can get "solid HLAs" that fit in the cup of the hydraulic buckets, so you can use those instead of the OE solids' shim over bucket setup.

You have to grind them to size, which is fiddly, but they won't ever spit out.

The next issue is that they are only 33mm (I think) so you are limited for how aggressive the lift rate can be.