Complete valve failure

Well Veeky Forums, I'm fucking pissed...

After spending 1200 bucks on a compete engine rebuild for my 302, I've had complete exhaust valve failure after 3000 miles.

It's a 68' block with a stock rebuilt carb with a fully rebuilt c4 with 2.73 gears in my 70' mustang.

I drove the car from Toronto too Vancouver on what was supposed too be my dream road trip and after I hit Yellowstone everything went down hill (pun intended).

What the hell could have happened?

I was running 75 miles an hour most of the trip, running like 2800 rpms and the engine never once overheated or had oil pressure problems or anything...

I'm taking the rebuilder to small claims but before I do has anyone experienced this before? Was it the atituted? I leaned the carb out slightly above 5000 feet and get it back too normal at around 2000.

Any ideas?

By the time I reached the border I actually broke down and barely got too my destination...

Lower rpms like that or any altitude difference shouldn't fuck with valves at all, it bent/broke, came apart, what?

It's a Ford.

So I tested everything from the coil to the plugs (which looked normal) the wires ect but I did the "paper in tailpipe test" and both exhaust tips sucked in air...

I have an appointment with a mechanic who can properly diagnose the problem and get it down on paper but I built the car and I'm 80% sure it's the valves

was the engine run in before this road trip and the run in oil changed?

I got the engine primed and my builder told me how to do the break in cycle. He said change the oil after 10,000 miles

nope, it needs run in to harden all the surfaces, especially the cam, on a different oil and changed after about 4 hours of running from build.

I suspect you have flattened a cam lobe, or thrown a rocker, worst case is that the metal particulate from break in has got into a lifter or blocked an oil galley and starved the engine of oil.

Drop the filter and pour out the contents, and check you sump for metal bits or a shiny reflection in it.

Also compression test it, but turn it by hand first to make sure valves aren't stuck open.

Holy fuck kill me now, by the time I got here it idled like shit and would even stall. It was vibrating like crazy at low rpms and lost a lot of power... So is that it? Was I just clueless and ill informed about how to deal with a new engine? What's this gonna run me to fix?

If you have spanked the cam, it would cause these issues by affecting the valve timing, a flat spot will not actuate the valve correctly.

If a rocker has moved or is way out of adjustment, it would do the same, if metal bits have got through the oilways, the engine is toast.

You are looking at at least a strip to the cam and a repair or any parts, you need to check for metal in the oil, im not talking big chunks of metal, fine bits, but as you can imagine, metal in oil is not good and the engine will need a full rebuild.

Check the oil and do a compression test.

>taking a 40+year old motor on a road trip
>driving an outdated piece of American trash

You brought this on yourself

Who doesn't dream of driving across county in a classic mustang man, I'm just a kid, I thought I had everything ready. This is probably one of the worst things that could have ever happened too me.

it's just an engine man, argue it out with the builder, come to some agreement with him.

That engine is a very easy engine to build, so if all else fails, it's a good one to learn on.

Good luck sir.

Well I'm stuck in Vancouver and school starts in three days so I figure I'll get a 302 of craiglists and drop it in. I can use my uncles garage and rent an engine hoist. Maybe I'll ship the old block too Ontario, I do have a year warranty....

Should've just bought an LS1

well you are sorted then if you have a warranty.

Pull the valve covers and make sure it hasn't dropped a rocker first. Then check the oil for metal.

An explorer 302 is what you need, pretty much the best and the last 302 ford ever had in mass production for new cars.

That or a cobra 302.

302's are bullet proof (my 1998 explorer has 230k miles) but honestly it sounds like a break in procedure was not followed.

Also. 2800 RPMs at 75mph sounds kind of high for 2.73 gears.

My explorer for sure does less than that at 75 and it's got 3.73 gears and pig fat AWD. Sounds like your engine was on the way out.

Cheers,

I have an appointment Tuesday at a local shop and I'll have them do that. They were originally just going too diagnose the issue but I'll tell them what I think happened. I don't have any tool of my own in this time zone.

I was just guessing to be honest it could be lower, i don't have a tach, but it's a c4 with 1:1 at the end so I calculated 2800. The engine and transmission were rebuilt so I wasn't expecting any problems

If it you stuck to the break-in procedure, go tell your engine builder to build a new one. Whatever the cause, it shouldn't fail this soon.

Your Explorer probably has a lot taller tires, and an overdrive trans.

>10,000 miles on break in oil
Niger are you fucking high

I definitely didn't. I didn't grow up wanting to drive old steel boxes across the country I swear I don't see the joy in that. All my friends are like that. My first car was American. Never again. I'd dream to drive an acura integra type R DC2 across country before I drive something as old as my mom. Classic cars bore me. Then again the Japanese bug bit me when I was 13. I'm 23 now and have been with the rising sun ever since.

>rising sun

Topkek

>10k miles on break in oil
Pretty sure he meant 1k miles there buddy.

A ITR is also an old steel box, and you won't have a good soundtrack unless you're letting the engine sing in a lower gear.

Not as old as a 45 year old car.
I'll enjoy my 8K redline banging through the gears before I drive a 5 thousand pound coffin thanks.
>an ITR is an old steel box
Don't make me laugh

>You won't have a good sound track unless your letting the engine sing in low gear
Nigger what are you on about.

This is about as cringe worthy as Ken-sama.

People have their preference
How is this cringe?

>I'll enjoy my 8K redline banging through the gears before I drive a 5 thousand pound coffin thanks.

>don't acknowledge the comfy feeling of driving a veeate @1500 rpm on a highway

busrider detected

Of course THIS guy derails the thread

2800 does sound a bit high, but only by a few hundred. OP, I'm looking ato dd a classic with the exact same set up (302/c4/2.73), what was your highway mpg?

...

Thread is now destroyed. Lasted longer than I thought desu.

About 20mpg with an all stock setup

>68' block

If the original cam was reused there's a good chance you round off a lobe.

Modern low zinc oils don't play nice with old valve train components, They need the zinc for anti wear, so if you run modern conventional or synthetic you'll round a lobe off in no time.

Old shit like that needs shell rotella or delovac, diesel oil is good for old motors.

Hugs! cutest kid I ever saw to date.

Dammit.

Options for next rebuild in order of what you should do

1 Go with a hydraulic roller cam
2 Go with a hydraulic flat tappet cam with a high quality lifter (i.e. hardened billet or ceramic coated) be sure to run ZDDP oil

Sounds like your builder used Chinese junk