Cam clean-up?
 

I went up into my attic over the shop last night and retrieved this 8CM cam. I was given a merc engine that had been rebuilt many years ago and overheated badly on the initial drive. 3 or 4 cracks. I used the crank back in the 90s, but the cam was still where I left it. I have since found a std merc 4"er and got it turned. Question: Can I clean this cam up at home with scotchbrite or something? The journals look like they will clean easily, but lobes not so much. I continue to collect parts for a 255 to replace the 221 in my truck based woodie, a Heavy car for sure.

Re: Cam clean-up?
 

That is too much rust for my liking - as you'll have a lot of pitting on the lobes. Maybe have Pete1 regrind it for you . . . maybe even a bit more performance into it.

Re: Cam clean-up?
 

Hard to say now. Give it a brisk rub on a wire wheel and then show us the extent of pitting. Could go either way .....

Re: Cam clean-up?
 

I would think to be usable it would need to be reground. Probably could be done to 8CM specs. Cam Grinders is in Seattle, Delta in Tacoma. Might be cheaper to find a better one.
Good Luck!

Re: Cam clean-up?
 

Pete is in Washington and does an awesome job .
It will look almost new when he gets done

In my opinion,,,,those lobes look pretty darn rough,,,,,and will in turn be very rough on the lifters riding on them as well

Tommy

Re: Cam clean-up?
 

To use a phrase that I got from Joe Mac (long ago owner of Ford Obsolete, on Signal Hill, and also trans rebuilder during retirement years), thems pits are good for holding extra oil, for better lubrication. lol

Re: Cam clean-up?
 

Greetings Everyone. GB it does look a little weary in the current condition. But maybe this helps...

Option 1 - It's Junk - Whatever you do can't make it worse.

Option 2 - It's gonna need regrinding - You probably can't remove enough if you don't get medieval.

Option 3 - It's ugly now, but wait - Hit it with something? You can always go back to 2 and 1.

Would you guys use Evaporust/Rust911? Would the 'blackening' be a problem?

Then something to see where the pitting ends? Scotch-Brite is pretty gentle, and you can step up/down in 'grit.' A wire wheel sounded like an okay suggestion, but carefully.

https://www.3m.com/3M/en_US/company-...94857497&rt=r3

Re: Cam clean-up?
 

As my grandpa would say... "now it's a pry- bar"

Re: Cam clean-up?
 

...

Re: Cam clean-up?
 

chuck it in a lathe and hold the steel wool to it with penetrating oil.

Re: Cam clean-up?
 

Only have a wood lathe.... No pits on pump lobe or any I can see on the journals, ran it hard onto my wire wheel. Still some deep pits, so looks like a regrind. The woodie is no hotrod, but it's home turf is hill country. No interest in a 'lopey idle'. I don't even get why that is supposed to be cool. My engine experience comes from the one lung engine and antique tractor world. I would tow all my machinery to the yearly meet behind my 38 tonner with the 59ab and merc crank. SOOOO many old timers at the show only wanted to listen to the flathead V8 idle. I had to warn the newbies that that silent engine was actually running and stop putting your fingers so near the fan blade. In review, I love the added torque/hill climbing of the merc crank, but no interest in extra HP and no interest in hard to adjust lifters from the small base circle, special wrenches, shorter lifter bore etc. I will take some pics of the wire wheeled cam, but as usual my 10 year old phone is dead on my truck seat......

Re: Cam clean-up?
 

Brother from another mother from another seashore?

P.S. I'm so delighted that my 8 year old phone just got a NEW BATTERY this past week and it perked it up so well. Anybody's 3 year old phone got that option? I think I'm buying another battery so I can use it a few years from now?!?

Re: Cam clean-up?
 

Brother from another mother? Duh.

Re: Cam clean-up?
 

We have similar opinions about people who put their fingers near fan blades? And who doesn't love fire-miss-miss-miss-fire?

Re: Cam clean-up?
 

My 6" bore, 12" stroke goes miss, miss, miss for 30 seconds before it hits like a cannon and coasts for another 30 seconds. I reground the cam (one lobe) with my belt sander. The intake valve has no cam. It is atmospheric. Has a light spring and when the piston is on intake it just sort of chatters and draws in what it needs. It is a simple check valve..

Re: Cam clean-up?
 

OK, my phone charged up but it's way past bedtime.... Some pics of the good, the bad and the ugly. Once it's reground is an 8cm cam any different than any other?

Re: Cam clean-up?
 

GB...you are my hero. I'll bet you clean it up and run it until you are toes up

Re: Cam clean-up?
 

I believe the 8cm has the better low end torque required when mercs were heavy, and the new trend was automatic trannys. good cam for the woody on the hilly island

Re: Cam clean-up?
 

I don't think even I would try and run that one, GB. Do you not have any other potential cores to hand?

Mart.

Re: Cam clean-up?
 

There was an article in Hot Rod a while back that explained (and I don't know if this applies to OHV's only or all engines) that the lobes on the cam have a very slight taper when viewed from the side and lifters have a slightly spherical shape on the ends. This allows the lifter to contact the cam somewhere off center, causing the lifter to rotate, a bit like a ring and pinion. Thus there is really no sliding contact. If both surfaces were flat, they would both be wiped out fairly quickly, especially with the higher spring forces found in OHV engines.

Having said this, I'd say give it a go! There might be enough taper to get the required action.

Re: Cam clean-up?
 

Most shops have crank polishers, I'd try that on several lpbes just to see what the lobe looked like, I don't think pitting would hurt the lifter just hold alittle more oil. I sue 45 LB spring pressure on all my street engines, including the L100. Most street engines never see 4k revs. JMO
Gramps

Re: Cam clean-up?
 

No chance that I would run it "as is" - have it reground and know that the lobes are right and that you're putting a part in your engine that won't wear out . . . or wear things out that rub against it - the lifters.

I'd contact Pete and see what his thoughts are as far as a good profile . . .

Re: Cam clean-up?
 

I wouldn't want to try that in an engine I was rebuilding. There must be someone that has an 8CM left over from when they wanted a lumpy idle.

Re: Cam clean-up?
 

I get it and don't want to risk using it as is.... I bought the std 4" crank over in Friday Harbor for 300 bucks. I think it was like 250.00 to have it ground. I think it's worth sending the cam out for a pro job. I will contact Pete. Just a side note with Ol Ron's comment and my old hit n miss. This one lunger was stuck solid when it was given to me in '87. Heat, diesel, heat, rinse, repeat I eventually got it free. I bought a 6" hone and started honing it, but there were some pretty bad pits in the cyl wall. I called a guy I had met through Hemmings Motor News to discuss this matter. He said as long as the pits don't connect, just randomly occurring, they didn't hurt a thing, just a bunch of little oil resevoirs. He recounted that years back when racing air cooled VWs they would dimple the cylinder walls with a dremel tool for just that reason. I run this engine for four days in August at about 75 rpm and no load. Different story than what I hope to do with the woodie. My wife has never been to Yellowstone!

Re: Cam clean-up?
 

Great lookin truck GB, take the wife to Yellowstone in it, remember life is short, grab it while you can

Re: Cam clean-up?
 

make sure you get the actual 8CM grind and not some generic flathead grind. There are differences!

Re: Cam clean-up?
 

Re: Cam clean-up?
 

cas3, you said a mouthful there! ;)

Re: Cam clean-up?
 

Photo #1 tells me...... no go! Way beyond garbage.

Re: Cam clean-up?
 

You mean this one with all the little oil reservoirs that GB pointed out? Like PeteVS, I'd give it a go anyway. :) Jack E/NJ


https://www.fordbarn.com/forum/attac...9&d=1617164357

Re: Cam clean-up?
 

I like the "oil reservoirs" on the lobes.

Re: Cam clean-up?
 

Dang it you guys really know how to confuse a guy. Are these cams hardened on the surface, like maybe I'm past the hard outer shell? This photo depicts a quick pass on a pretty coarse wire wheel on a bench grinder. I have 2 sets of adj lifters, one from a swap-meet, the other from an 8ba I tore down. They look old and hollow and 'johnson-like'. I did my 5 lb-lbs flour sack test (60 inch lbs) and about half need a squeeze in the vice. A sharp file on the bottom says they are very hard on that surface...My jailbars have fat fenders and going back 'in' if original parts fail is miserable. My McGuyver side says run the pits, but my 67 year old aching back and shoulder side says use some covid check to do this part right. My current project has enough McGuyver to make the TV version break out in a cold sweat.

Re: Cam clean-up?
 

Hi G.B.
My 2cents....listen to your aching back and shoulders. You'll be glad you did.

Re: Cam clean-up?
 

Best lubricated cam on the market, last forever.
Gramps
PS Polish it first!!

Re: Cam clean-up?
 

So you CAN polish a turd?

Re: Cam clean-up?
 

If you're havering towards giving it a go, the base circles are not loaded at all so can have pits, the opening side of the lobe is most heavily loaded, so ideally you'd like any pitting there to be minimal. the closing side of the lobe is loaded, but not so heavily so may tolerate heavier pitting.
So how does it stand up to a close inspection of just the lobes, with an emphasis on the opening side?

Mart.

Re: Cam clean-up?
 

I except your criticism, However, I think it's based on aesthetics, not mechanical facts. The declivities offer no impairment to the lifters. Aesthetics is the most expensive part of this hobby and offers little or no improvement to power or economy. I just like to help people.
Gramps

Re: Cam clean-up?
 

When pitting is so extreme as to cross the contact surface, your not talking oil carrying any longer, your talking running a rasp on your lifters. It's crazy!

Re: Cam clean-up?
 

It's obvious to the amount of pitting you can except. I also do this to rustry crankshafts as well. I suppose it's a judgment call, which is based on experience.
Gramps
Send me the cam,I;ll clean it uo and we canconsider if it good enough to run, or just a turd??
No Charge.
G

Re: Cam clean-up?
 

Way to go, Ron.... My experience (though not as much as yours), agrees with yours. My only caveat is that I would never used it on a customer job. But, for myself, what the heck. I've had REALLY good luck using sub-standard, pitted parts, as long as they were genuine, original, Ford-script parts.