Is it feasible to metal spray a cam?
 

You cannot buy a roller cam for a Mopar slant 6 because there are NO blanks for a roller in that engine. Nobody seems to have one.

You CAN get a blank made for $1,000.00, but it won't include the gear for the oil pump drive and distributor drive on it, requiring you to have to employ an aftermarket, accessory-drive oil pump (gilmer belt?) and a crank trigger ignition.... a lot of extra trouble and expense.

I was curious if any cam grinders were able to metal spray a new steel flat tappet cam with enough material to make a roller profile from that original flat tappet cam. I know it will take extra material for the "fatter" roller lobe profile.

Years ago, stroker cranks were created by metal sprayng to build up crankpins to larger diameters, which were then ground "offest" to increase the stroke. I don't think they use that method any more.... but I don't know.

Is metal spraying ever used on camshafts?

Is a roller-lifter cam subject to less damaging unit-loading than a flat tappet cam, since the lifter wheel just rolls over the surface, and doesn't abraid (abrade?) the surface, like a flat-tappet cam would? Or, does the roller's small contact area pose similar unit loading pressures, commensurate with a flat-tappet cam?

Is this just a terrible idea, and totally unworkable? I don't know where else to go to ask for reliable information.

Any ideas and information will be much appreciated!

Thanks...
Bill

Re: Is it feasible to metal spray a cam?
 

Someone grinds a cam for a 6 , what about the stockers like Bushmaker and I cant remember the other one. Look them up
Bill,s cell# 206 793 -1276

Re: Is it feasible to metal spray a cam?
 

Just an idea here, I have a iron roller cam from comp in one of the bracket cars. I was concerned it wasn't a billet steel like all the other rollers I had bought from them when it arrived but after a phone call I was informed that they do make iron roller cams also, It seem to be the same material as a flat tappet cam just ground without the crown on the lobe. You should be able to have them grind a cam like this for the slant also. Have you figured out the lifters yet? How much lift are you trying to get?

Re: Is it feasible to metal spray a cam?
 

Bob, Bushmaker's car runs a 360 V8, and his daughter's Valiant runs a 273 V8.... I don't know of any slant 6 cars he ever had anything to do with.

Thanks for the response.

Re: Is it feasible to metal spray a cam?
 

I'll call Comp again, but the last time I talked to them they had NO rollers for the /6 motor.
That was about a year ago...

I only need .500" lift. This is a race-only app, so I am not much concerned about longivity.

I'll let you know what they say.

Thanks for the info!!!

Re: Is it feasible to metal spray a cam?
 

Well, Phillip, I called Comp Cams and talked to a tech there named "Buggy."

Here's what he said: " I don't know where Phillip got a roller cam for a /6, but we don't grind one. We have NO blanks for a /6 roller motor. If you send us a blank, maybe we could grind you one, but we have no source for a roller blank for that motor."

So, maybe somebody ELSE ground that iron roller cam for you????

Curious minds want to know....

Re: Is it feasible to metal spray a cam?
 

Philip/Bill
I cannot tell you if you can metal spray a cam and make it live, but I can tell you what I tried. A few years back I wanted to make my on grind, so I metal sprayed a cast cam just to try. Man I CNC "grinded" this cam and it looked awesome. Put a set of rollers on it and seemed to be ok. Well I lost control of the rpm and every thing in the engine was wearing metal spray. Bearings and pistons looked awesome. i got some picture some place but I hid them so no one would know how dumb I was. I think what happened was that I lost control of the roller lifter and it banged the shaft and just peeled the spray right off or it was the point contact of the roller. Dont know which cause I was afraid to talked to any body about it cause I was so dumb. But what I finally did was get a billet steel blank and had a guy with a lathe to make me a billet with all the knobs on it then I sent and had it ground. Might want to try that if you have some one handy on a lathe. CNC grinders make it pretty easy for people like Lunati or Comp to do that now. Was hard to do when you had to use masters

Re: Is it feasible to metal spray a cam?
 

Thanks for that info. Where did you get it sprayed?

Re: Is it feasible to metal spray a cam?
 

Bill,

This may be a long shot, but try contacting this company,
they specialize in all things 6 cylinder.

CLIFFORD PERFORMANCE PRODUCTS INC.
22850 Sheffield Crt
Wildomar, CA 92595

1-951-471-1161 or Fax 1-951-471-0993

www.cliffordperformance.net

email for tech: Larry@cliffordperformance.net

Re: Is it feasible to metal spray a cam?
 

Bill
The place that did mine is no longer in business but the best place too look is a industrial repair shop. The ones that use spray process is people that repair shafts for electric motors or conveyor repair. Many industrial repair shops use them every day. I really feel it will work if the point load contact is not too high. The process used to day is more stable than what I used then and I was really suprised how hard the surface was. Had too be ground as it was well into the Rockwell C scale. And it takes very little time to do it. You will need to have some high temp insulation to put between each journal as you spray.
charles

Re: Is it feasible to metal spray a cam?
 

Bill, i'd look into grinding on a cast core.
Years ago when I first started building AMC engines ,I bought a bunch of parts from a circle track racer who was going to a BBC engine .
Amongst the parts were several cast cams that were reground into rollers.
I never had any wear issues with them and one is still in use today, 39 years later!
Lunati ground them ,and they were nitrided. Most hydraulic cams have a base circle around 1.300" , these were ground to a 1.150" base circle ,which gave plenty of meat to grind the flanks.

One note about metal spraying. I used to metal spray when I worked for General Electric.
Metal spray works very well in applications such as main bearing surfaces where the loading is constant ,and when the area to be sprayed can be undercut ,sprayed and then ground to size. Other surfaces we sprayed usually were not as durable.

Re: Is it feasible to metal spray a cam?
 

When I was at Eaton and we wanted to do the same thing, we actually tig welded the lobes instead of spray welded then grinded on it. I'm not sure what the rod was or the cam material. This was not converting from flat tappet to rollers though.

The camshaft was an old Ducati (sp?) and parts were not available and it did run afterwards, but not in a racing enviroment.

I may be mistaken, but I'm not aware of a spray metal weld that has ever been used in an actual strenght application like a camshaft. Most time I've heard of it used is to repair seal areas on shafts or to reman a turbine shroud housing.

Re: Is it feasible to metal spray a cam?
 

Associated Electro Mechanics (AEM)
185 Rowland St.
Springfield MA. 01107
(800) 288-4276
Welding, Metal Spraying, Plating and more
www.aemservices.com
e-mail: info@aemservices.com

Re: Is it feasible to metal spray a cam?
 

Chris,thats similar to what the NASCAR Cup cars used to do to their cams.
They used welded inlays on the lobes to obtain a harder surface.

Re: Is it feasible to metal spray a cam?
 

The cam I have is for a 360 but it is a comp part#20-742-9, serial #ul1669-04, grind #crsxr274r-10. I talked to Tim Cole when I took it out of the box and saw it was not a billet core and he told me some of the street rollers were done this way. Based on this they should be able to grind you a cam from a standard iron blank. I know for a fact they have slant six cores because they have made me a couple for the stocker..

Re: Is it feasible to metal spray a cam?
 

Phillip, they have cores, but a roller requires a fatter lobr profile and apparently, there's just not sufficient material for the required lobe profile that would be needed for the roller.

At least, that's the way I understand it.

The slant six cores he has at Comp are for a flat tappet cam.

Am I wrong?

Re: Is it feasible to metal spray a cam?
 

Yes

Re: Is it feasible to metal spray a cam?
 

I want to thank ALL you guys for all that good information. I'm not very hopeful that this is a good avenue to pursue, but I will nevertheless, pursue some of these good leads.

Thanks!!!!

Re: Is it feasible to metal spray a cam?
 

Bill, not sure if it applies in your motor, but on flat lifter chev BB the center of the lobe is offset a certain amount from the center of the lifter bore. That offset as well as the .002" taper of the lobe is required to make the lifters spin. Schuman in Iowa make a special lifter with a centered pointer for chev. to check this with marking compound on an installed cam. On a roller cam the lobes are apparently centered on the lifter bores so that the roller wheel is located in the center of the lobe, and the lobes are not tapered. Maybe it's not far enough off to cause problems in your application, but possibly worth checking out? I had thought about having a roller cam billet custom ground to my flat tappet stocker profile for strength but was told it would not work because of the lobes being located differently. Just what I was told.....
Grant

Re: Is it feasible to metal spray a cam?
 

Can you elaborate?

I was told that by a tech at Comp whose name is "Buggy."

He was very specific that none of Comp's cores would work for a roller profile in a slant 6.

If I'm wrong, then he's wrong.

Where do I go from here?

Re: Is it feasible to metal spray a cam?
 

Bill -

If you are working on the turbo slant 6 project, it might be that the effort ($$ & time) spent trying to put a roller cam and lifters into the motor would not have enough ROI to be worth it. I do not believe that there is enough power to be gained above 6000 rpm or so to warrant the roller setup. The slant 6 valve train is light enough to be controlled with available valve springs at that engine speed. Remember that a flat tappet arrangement has the design characteristic to have much faster off the ramp acceleration and faster ramp action under .150" lifter rise than a roller cam and that is a great benefit to the performance of a boosted engine. I would spend more energy on camshaft profile for a flat tappet cam than get anal about a roller lifter moving the valves. I bet there wouldn't be a 2% difference in power output after five years of thrashing between a flat tappet engine and a roller tappet engine. IMHO

The cylinder head flow is your biggest limitation on that combination.

Re: Is it feasible to metal spray a cam?
 

x'2

Very well stated too!

Re: Is it feasible to metal spray a cam?
 

Dwight,
Thanks for that good advice, and just FWIW, I agree with everything you said except...
My motivation toward putting a roller cam in this engine is not for increased power output, but rather, to avoid the jeopardy of cam/lifter failure... nothing else.

These turbo slant six motors (at least the ones I'm familiar with) never see the far side of 5,500 rpm. I am still ignorant about the reason why they don't make power up to 6,000 rpm, but I suspect it's the extremely poor flow characteristics of the head. Even a well-ported head that has the biggest valves available (1.74"/1.5") only flows about 200 intake cfm and 150 exhaust, and that is to feed a 39 cubic inch cylinder, so you can see the problem. They just run out of breath after 5,000 rpm, even with 25 pounds of boost.

Still, they manage to make well over 500 horsepower, even at that low rpm... one such engine I know of (a twin to ours) runs 127 mph in a 2,800-pound car.

That is with a cam with only .484" gross lift, and 220/220 degrees of duration @ .050". That motor runs 28 pounds of boost without incident, on race gas.

The Shell station on West Markham in Litttle Rock, now has an E85 pump, and we're considering using that blend for its anti-detonation properties... but we haven't fired the engine, yet... the jury is still out on that one. We'll have to get a different carb, or this one modified, of course.

Our plan, once the engine is broken in, is to raise the boost level (but, not the rpm) to a higher value (up to maybe 35 pounds?) and see what this infrastructure will accommodate without blowing itself into a basket of scrap iron. LOL!

Because Mopar slant 6s were originally intended to be cast in aluminum (a plan that was scrapped early on, due to casting problems) and their head is so poor (due to the small 3.4" bores, and the small valves it necessitates), forced induction seems to be unusually appropriate for this engine. When the factory abandoned the aluminum block in favor of the cast iron construction, they didn't change the robust-design infrastructure that had been part and parcel of the aluminum block and head design, and as a result, the thing is REALLY strong in terms of stiffness. The crank is forged, and although the 4-main bearing design, is short (and doesn't "whip" like a longer, 7-main bearing crank,) and uses main bearings that are the same size as the mains in a 426 Hemi... sizeable, for a 225 cubic inch engine.

One guy in Australia is making 638 horsepower with his, using a stock exhaust manifold with a turbo flange welded to it(!) His name is Cameron Tilley, and his car (a 4-speed) is on You Tube, if you want to watch...

So, we're just trying to avoid the flat-cam blues.... we don't run much valve spring pressure (125# closed/335# open at .500") so it may not be a problem with enough ZDDP.

Sorry for the long-winded diatribe, and thanks again for the good info/advice!!!

Re: Is it feasible to metal spray a cam?
 

If you want to eliminate worries about camshaft-lifter failure, send your cam and lifters to Bud Yancer at Mach Engine Development in Phoenix for treatment.

Re: Is it feasible to metal spray a cam?
 

Sounds like a plan! What does he do?

Re: Is it feasible to metal spray a cam?
 

Re: Is it feasible to metal spray a cam?
 

Well, I talked to them, and I think we can do some bidness; $250 to coat the cam and Lifters with their proprietary coating process. Sounds good!

Thanks a lot!

Appreciate the good info!!!