I am scared to put another cam in her

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

rentascout

Well-known member
Joined
Mar 4, 2012
Messages
369
Reaction score
1
Location
Colorado Springs, Co
My Car
1973 Mustang Mach One
Alright brothers, I got it started early and I will leave you with a complete run down to ensure I don’t miss anything.

Went to parts store to get pcv valve to help pressure, went ahead and got my rebuild kit for my carb while I was there.

When I got home I pulled the plugs and checked, (Again this motor had less than 3 or 4 hrs running) they were nasty, a lot worse than they needed to be. I started to check pressure, and noticed a few where only hitting around 115, while the rest where 135-140. So I put them back in and fired it up and that is when it sounded like a bag of marbles was released. So I pulled the covers and noticed the 3rd cy (P side third back) rockers was way lose, but the rest where fine, or tight that is.

So I knew what needed to happen, and about an hour later you see what happened. That cam was brand new crane, I will leave specs below again, because I have want to ask for thoughts on hyd cam. I am not trying to go stock, but this car will never see a track, and of course street racing is illegal,lol.

I have seen them many times burn through one lobe but three, hey there is a first time for everything. I know my numbers where correct when I built it, but when it rains it pours,lol.

I am in need of some good parts, and need someone to throw me a bone on where to go too many places are good for some and horrible on others.

Cam int .280,/ valve int .485 /advdur 284*timdur int 208*/ open -3*BTC close int 31*/over lap 62*/ center 107*

I am scared of putting too big of a cam in there after this happened could use some help to ensure I can focus on the prize at hand.

Maybe I made the mistake by not changing my push rods, or I am overthinking this way beyond what I need too

IMG_0192[1].JPG

IMG_0193[1].JPG

 
Last edited by a moderator:
Congrats on keeping calm and diagnosing it properly!

Before installing any other cam, I'd strongly suggest tearing the engine down for a complete bath.

Sure, it'll run without cleaning. Actually, may not ever hurt a thing. I just know I wouldn't try it, cause my luck plain ol' sucks! :)

Most of those tiny, hard iron fragments are still in the engine and can cause nothing but heartache down the line.

Need to know what intake, carb, rear gear and converter is in the trans before thinking about other bumpstick specs...

If choosing a flat tappet cam, use specialty break in oil an/or GM "EOS" .

http://www.summitracing.com/parts/nal-88862586

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=476990

The web is filled with recommendations on break in sauces for the crankcase, and most seem to revolve around zinc content. And, everyone has an opinion on what is best.

The last junkyard 302 that Dad and I put together years ago ate its new FT hydro cam in under 1K miles. This was before we knew of the zinc free standard oils. Lesson learned.

 
Last edited by a moderator:
+1 to new camshaft failure due to low ZDDP zinc levels during break-in.

-Kurt

 
Last edited by a moderator:
it is a standard eldelbrock performer intake, with a 1406 carb (600), standard gear (2:75) for now 3:55 collecting dust in the garage. I will be using break in oil without a doubt, that stuff cost more than my kids birth together, but hey I don't remember trying to have to put my kids back in their mother. The trans is normal (FMX), and I am not wanting something that will rip out the rearend even with the new gears. Just like the extra, you know. I spent a lot of time reading numbers for cams but I think I overlooked an area which is the cause for taking it back out, Thank you

 
Cool, looks like excellent street component choices!

For that 302 that I mentioned, it was in a beater '68 Torino coupe with 2.80 gears and a C4 tranny.

Used a stock bottom end, added this cam kit (it was waaay cheaper at the time):

http://www.summitracing.com/parts/crn-130052/overview/make/ford

Lightly ported a set of early, stock 289 heads (slightly smaller chamber for more compression), stock replacement valves, and the STOCK 2 BARREL CARB with manifolds.

Yes, a budget build at its finest.

Chose the cam 'cause I wanted the slightly rumpity idle, and the 2-5000 RPM range.

It ran fine.

Car ran even with my friend's '68 Ranchero and its stock 5.0 HO roller engine with headers and Performer intake/carb. Ranchero was geared tall, too.

If I were you, I'd look at similar specs for the 351. You're limited by its compression ratio and rear gears. I wouldn't exceed 270ish duration, stay under .500 lift and stay above 110* lobe separation (112-114* is probably better), max RPM only a little past 5K. Remember, what you gain on top is what you give up off the bottom.

Again, there's a zillion choices, and everybody will have an opinion on which is "best".

There are no "perfect" cams as far as I'm concerned. It's less critical in a street machine, too, so don't beat yourself up too bad with numbers ;)

 
Last edited by a moderator:
I love those Torinos, I have the break in oil and a few bottle of additive I will continue to run in there. I should not have to change my rods if I keep with the specs you gave me correct. I think I will need to get some new pivots the one that was lose looks rough.

 
Last edited by a moderator:
Are the pushrods and rocker arms the original ones to the engine?

If so, I'd probably replace them with new (pushrods, rockers and sleds, they work together as a team).

I don't recall seeing many OE valvetrain components that I would reuse, even on the cheapest of rebuilds.

Stock replacements are better than worn originals, and they are (were) fairly inexpensive.

 
If it were my brand new engine and I smoked the cam on break-in, I would pull the whole motor out. All those grindings from the cam and from the lifters is now all through that motor. You could chance it and try to just flush the motor and get lucky. It could run for 10 years or 10 min before it spun a bearing or eats cam bearing out....ect. I know its a pain in the arse but definitely pull the motor, tear it all down, check your main and rod bearings for any scratches, check or replace cam bearings. clean and flush every nook and cranny of the motor and put it back together. That's a lot of metal floating around in a brand new motor. The filter will catch a lot but not all of it. That's just my opinion for what its worth. I have seen guys flush the motor several times with diesel fuel and slide a new cam in and be fine, but I also seen a motor not last 500 miles after that.

I had my valve guides go out and put brass all through one of my brand new motors because the builder put too long of pushrods in and threw the geometry of they valvetrain off and side loaded the valves and ate the guides out. I pulled the heads and the builder rebuilt the guides and got the right length pushrods. I flushed motor well and reinstalled the heads. Ran good for almost 1000 miles. Then I heard a knock, then louder and louder. Spun a main bearing a toasted a few others. And that was mainly just brass in my motor not iron filings from a cam and lifter. You can try what you want but from personal experience I would pull it and clean it all from top to bottom.

Whatever you decide good luck!! And keep us posted on your progress!

 
Do NOT overlook another very common mistake: running an aftermarket cam with stock style press-fit rocker studs. High lift cams will pull the studs right out of the head and cause all kinds of problems.

My friend once brought his '67 Coupe with a 289 to my garage to swap in a Comp Cams 280 Magnum hydraulic flat tappet cam I was selling in order to upgrade to a roller. We swapped it in and it didn't even make it home... rocker studs pulled out.

 
Yeah the shavings are pretty bad, but you know what I could care less. I am probably going to flush it throw a cam in it and sell it, might just leave it as it lays, I have onwed this car for 8 years, and I have put 12K into it and only driven it 1 mile. I am sure there are some that will get on their soap box and try to tell me about hot rodding, but at some point you have to understand to walk away. This blows like none other but hey it happens, and I cannot see myself spending anymore time with something that has drug me the whole way. I know car guys it happens but it wont stop you from getting on here and telling me again.

 
Yeah the shavings are pretty bad, but you know what I could care less. I am probably going to flush it throw a cam in it and sell it, might just leave it as it lays, I have onwed this car for 8 years, and I have put 12K into it and only driven it 1 mile. I am sure there are some that will get on their soap box and try to tell me about hot rodding, but at some point you have to understand to walk away. This blows like none other but hey it happens, and I cannot see myself spending anymore time with something that has drug me the whole way. I know car guys it happens but it wont stop you from getting on here and telling me again.
Wow, Brother. I hate to see ya give up on it now, but you gotta do what you gotta do.

No soap box, I promise. I can certainly understand the frustration - I had an '85 Nissan 4x4 that went south on me, tried to fix it for almost a year before I gave up on it and traded it in on a much bigger POS '78 K-5 Blazer, which 8 short months later was sold to buy my Jeep (which I still have).

FWIW: I bought my '71 H-Code Mach 1 the first day of August 2010, have sunk over $22K into it, and still haven't driven it even an inch yet.

I'd say you're probably in the home stretch, and getting past this engine set-back would have you where you want to be, but again: you gotta do what you gotta do.

Step away, take a breath, and good luck with whatever you decide to do. We're all here for ya. :)

 
The shavings will be trapped by the filter anyway, I wouldn't be too concerned about that. If you really want to drop the pan and clean it out, it's not that big a deal. A friend and a few hours will have it sorted out.

 
I sympathize with you, fer sure. Seems what ever I'm working on is possesed by demons. Sometimes I have to walk away for a while. However the dream keeps me coming back.

You still have a chance at happiness with your Stang and that flat tappet engine. Though not as a flat tappet. Do a roller lifter conversion (after flushing the block o'course), and all the problems modern oils cause by making flat tappet lifters obsolete, will be gone. For a cam you can then use something like a Comp Cams XE272 HR112. The hard work and money you've invested in the rest of the engine, and your Stang will be saved.

Yeah I could throughly see talking the Holidays off, from the Mustang hobby. Then come back and look at the problem fresh. Ther are a few tricks to the roller conversion so let us know when your ready.

Be sure an tell your Buddies, "No matter how good an idea it seems, never use a flat tappet engine in your street driven car." as it aint worth the heartache when they wipe a lobe.

Tubo

 
Fortunately never have had a problem with a flat tappet cam but I always put extra zinc additive in the oil at every oil change so maybe I've been lucky so far. Do you think the valve spring pressure might be to high causing the lobe failure on the cam:huh:

 
So I took her all down and over to the machine shop to be washed. If there are any hints to throwing her back together please let me know. I don't want to sell this car and failed to build it correctly. I have built over 30 engines in my short time and first time I have ever been worried about building one. I use to enjoy this like none other.



Fortunately never have had a problem with a flat tappet cam but I always put extra zinc additive in the oil at every oil change so maybe I've been lucky so far. Do you think the valve spring pressure might be to high causing the lobe failure on the cam:huh:
I have them checking the springs to make sure but almost positive they were factory it has been so long I wont know until shops give me the warno.

 
Last edited by a moderator:
I hate to say it, but stuff happens. If you let a failure scare you into thinking you aren't up to the task, you will be beaten every time. Take a few days weeks or even months and then go fix it using your existing knowledge along with whatever additional knowledge you need to gather from elsewhere. Maybe it was something that failed in spite of you doing things correctly (it happens)

 
rentascout,

I am with Tubo! A roller cam setup would eliminate the need for ZDDP oil additive. Here is a an Crane Cam Retro for non -roller cam Ford Engines.

http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Store_Code=CC&Product_Code=31-1000&Category_Code=HRLKits

Hot Rod Magazine: http://www.hotrod.com/techarticles/113_9604_choosing_the_right_camshaft/

By the way, I dropped the air cleaner stud down my running 351C engine and crunch, took out the first cylinder piston. Man, what a bad day that was!

mustang7173 :D

 
I run a flat tappet cam in the 400M in my Bronco and don't use any ZDDP additive. It's been running fine like this for over 10 years. I think the additive is only necessary when breaking the engine in, when the lifters mate to the cam during the initial break-in.

 
Mesozoic,

I believe you are right. I had to go back and look up the zddp and found this zddp additive article.

http://www.zddplus.com/TechBrief2%20-%20ZDDP%20and%20Cam%20Wear%20-%20Just%20Another%20Engine%20Oil%20Myth.pdf

Excerpt: Because ZDP was an inexpensive and effective antioxidant, it was used to place the phosphorus level in the 0.10% range. However,phosphorus is a poison for exhaust catalysts. So, ZDP levels have been reduced over the last 10-15 years. It's now down to a maximum of 0.08% for Starburst oils. This was supported by the introduction of modern ash less

antioxidants that contain no phosphorus.

I would state that one should follow the manufactures break in process and procedures for successful running engine.

mustang7173

 
Back
Top