1973 F-250 - Turbo BBF - It's off to a new home!

[squirrel]

probably lost a guide and has a bad valve and/or seat.

Or a busted piston or ring or something.

They usually don't heal themselves...

[Russell]

You are more than likely right, but what about a bent push rod?

[BBR]

I didn't have much time to fiddle with it today, but I did manage to get the compression tester screwed into #4. Bumped it over and it only had 25 psi. Bummer. I went ahead and retested the others and they were all 110-115.

While I was messing with it I decided to pull the vc and make dead nuts sure the valves were opening and closing properly and fully. Spun the motor over and everything looked great. Grabbed the phone and took some random pics of the #4 rockers, etc.

Later I was standing in the kitchen looking at the random pics I took and there it was plain as day.... #4 has a broken exhaust valve spring! Next move is to replace the spring and see if that brings #4 back to life. Hopefully I just caught a break (pun intended) if the valve is not all gunked up.

[BBR]

I just couldn't help it, wish I didn't live in the rust belt http://amarillo.craigslist.org/cto/4244956046.html

Holy crap!!!!!!!!!!!!!!!

[cantvalve16]

That would be great if it was just that valve spring. Sure save you a heap of trouble and the inevitable project creep. Not to mention having to explain it to the wife.

[andy30thz]

WaaaHooo!! Great news!! If you do the rope in the cylinder trick to change the spring, think you might have enough wiggle room to move the valve around and kind of lap it back in?

I'd love to hear that you get some seat time by this weekend!

[BBR]

Why could it not have been cylinder #1 instead of #4! It *would* have to be the last valve on the head way back next to the fire wall! haha

I am hoping I can rotate it back and forth to maybe grind any goo off that might have accumulated on the seat and valve head. Changing the spring MAY not fix it, but like the gaskets, it's certainly worth a shot.

I just want to reiterate just how lucky I was to take a pic of that. I just randomly took some pics back there and the pic showing the broken spring was the last one I took. It shows up in the other pics, but you'd be hard pressed to identify it in any of the others. Not to mention the fact that the break was not on the opposite side of the spring!

No dice on seat time this weekend. We are probably going to go do a little skiing and I don't think this is something I want to tackle during lunches this week.

[ford141]

I'm having similar issues with the 460 in my '79 F350 (brown truck in my profile picture). It picked up a bad miss just before Christmas and I found it had zero compression in #7. I finally pulled the head off over the weekend and found the exhaust valve on #7 stuck open. The spring looks good but the valve must have seized in the guide. Hopefully you don't have pull the head off of yours.

[BBR]

Me too. I think if I pull the heater box out first, I can get the passenger head out of there ok. I was almost resolved to just pulling the engine, but I'm not sure my engine hoist will lift high enough to get it out of there!

[Russell]

Take the wheels off if you pull the engine. Or remove the radiator and cut the core support off and weld tabs on so it can be removeable. Have my fingers crossed for just a valve spring! how about one of those inspection cameras that you can stick in the spark plug hole. If you can not borrow one now is a good time to justify buying one.

[NewEnglandRaceFan]

I'm thinking junked up valve causing poor sealing. Can you get E-85 there? Maybe jet up the carb a bunch and run a tank or two of E-85 through the system (new fuel filters all around! and maybe hoses?) and run it hard a few times to break some crap loose on the valve? I'm agreeing with you here, inside looks clean, I'm betting it's a head/valve issue.

and/or like I posted pages ago, so much carbon on the valve that the mix can't get into the cyl.. enough to fire.. mopar turbo 2.2's where known for this, when a turbo was going, but hadn't let go, when they did the car smoked like a plastic fire.. out the exhaust

[STINEY]

I'd run some water through the engine after you get that spring fixed. Yep, straight water.

Drizzle a quart into the carb as you run the throttle to keep it at 1/2 throttle or more. If there are any big crap deposits on the backside of that valve (or others as well) that will effectively "steam-clean" them right off.

Might want to do this BEFORE the new mufflers go on. Lots of crud comes out of some engines, wouldn't want to plug those new muffs!

[TheSilverBuick]

I'd run some water through the engine after you get that spring fixed. Yep, straight water.

Drizzle a quart into the carb as you run the throttle to keep it at 1/2 throttle or more. If there are any big crap deposits on the backside of that valve (or others as well) that will effectively "steam-clean" them right off.

Might want to do this BEFORE the new mufflers go on. Lots of crud comes out of some engines, wouldn't want to plug those new muffs!

Agreed. Warm the engine up good before the water on slaught. Heck I'd use every trick in the book. Water, then Sea Foam then I'd even try a tank or two of E-85 if available.

[BBR]

I've never done sea foam or water. Anything to know or procedures to follow?

E85 is available, but I would have that as a last ditch effort because it might unleash a onslaught of goo removal!

[TheSilverBuick]

I've done both, for right or wrong.

Get the engine to operating temperature and start pouring in the carb! A spray bottle with a good high flow/volume nozzle works well for the water, or simply have a water bottle and start pouring some in at 1/4 to 3/4 throttle. Listen to the engine to control the water flow or throttle. It'll stumble a bit but shouldn't be too bad. I'd run a gallon through, but a quart or two would probably do fine.

Sea Foam I swear is just diesel fuel in a quart can.... It'll smoke BIG time! I usually find an empty country road or industrial area to run the sea foam through. A very windy day would probably do fine without annoying the neighbors.