well today i just found out one of the cylinders in my 390 (rebuilt in 3/07), is deader than a door nail.

now have to tear it all apart and re-do it.

but ill find out more after i do a compression test. hopefully its only rings and not the head(s). i just need to get meself a good compression tester.

neighbor suggested i get a set of 352 heads, 427 cam w/lifters, and a set of 331 rocker shaft assy. and new push rods.

the engine is already bored .030, and crank turned .010under. the heads were done also with new springs for the .484 lift cam im already running.

or just have the heads re-done with larger valves?

neighbor also suggested if it is the rings that could explain why im going thru rear main seals. leaking oil out in large puddles.

any and all suggestions are appreciated.

 

I dunno Frank...think I'd find a new neighbor

I can't see where bad rings would affect the Rear Main, and personally if it were me, I'd rather it be in the heads than the block...but don't rule out something in the ignition either.

Give a holler if you want to bring it over, be happy to assist in figuring it out.

 

well mike,

neighbor was saying if the rings are bad and putting excessive pressure thru the crankcase, thus causing the rear main seal going out.

he also said if the crank was turned too much, the rubber seals wont seal properly on the proper area.

plus he been working on ford/chevy/dodge....etc for past 20+ yrs. he was the first ford master mechanic on the west coast.

if you are available on monday, i can bring it by then, im off on this monday and tuesday, but i think tuesday would not be real good, since it is hangover recover day.

 

Frank, if the rings were that bad, I'd think you'd be blowng blue smoke on acceleration, plus have a lot of blowby coming out of the oil fill on the valve cover.

I'll be available this afternoon, anytime after about 2pm.

Mike

 

mike,

it does smoke some out of the exhaust. i noticed this after i replaced the rocker shaft assy.

eariler i was doing the compression test, but my battery died. it is at kragens getting re-charged. so far cylinder #3 and 4 are at 170lbs.

if you want give me a call on my cell phone 676-1408 or 595-1740

 

finished the compression tests. cyl 7 & 8 were at 160.

cyl 1 at 155

cyl 2 at 170

cyl 5 & 6 at 140

did wet test on cyl 5 & 6

# 5 went up to 150, and cyl #6 stayed the same 140

looks like i have bad rings and possibly valves or hopefully head gasket.

ill just run her until it dies.

 

Hey Frank,

Your numbers are not too too bad, but shuold be a bit tighter across the board for a new-ish engine. Most use the "10%" rule, i/e all cylinders within 10% of each other...so you're not too far off...and definitely nothing in the test shows a "dead" cylinder.

Just one question, did you hold the throttle blades at Wide Open during the tests?

 

in the engine you can defintently hear a miss, getting fire to all plugs.

had a weight on the pedel and return spring disconnected at throttle linkage.

and if you look at the highest comp of 170, and the lowest being 140 thats is a 30lb difference, and past the 10%.

and ive been thinking from the re-build i did in march, when i checked the rings none of them needed to filed down for proper gap, but a few of them actually did have a larger gap then what was specified. at the time i did call the machine shop about this, but they said it is ok, as long as the gap was not way beyond the spec's.

i think im going to say *^%$*@!#@%$##@$%&*&^%$#@%&&^$#@@%%^&^*&%#@#@!%$E$& ^*&*%%##@!@%$^&&$#%$,

and just pull the engine and just re-do the entire engine. who know i might do some better performance upgrades, bigger cam, totally re-do the heads. as tim allen would say uggh uggh uggh more power.

of course neighbor and i was teasing my wife, about putting together his bb chevy motor and put it into our ford, boy did i get some dirty looks from my wife for even suggesting that.

man that was a cold new years eve nite. lol

 

I luuuuv BBC's

I wonder about something...is your valve train non-adjustable, like the 460 was? I/e you just torque down the rockers or the shaft, and you get what you get?
If so, could be the push rods are a scooch too long holding a valve(s) open? Oil won't seal an opening like that on a compression test...just something to think about, depending on what work was done to the heads when they were rebuilt.

 

Wet test? Put a little oil in the cylinder and spin the engine? If your compression does not go up, then you do not have a ring problem. And don't lose any sleep over ring gap - just make sure the rings do not line up - all have the gap at the same place.

I am with Mike - time to get a new neighbor. He is all wet and telling you wrong things. GM people are queer and worry about the damndest things!!!

Your compression is fine - likely you used moly rings or SS valves and need some more miles for everything to wear in. My guess is that you have an ignition problem - a plug can fire just fine, but if it occurs at the wrong time it will still cause a miss.

Oh, btw, blowby (smoke in the crankcase that causes oil leaks) went away with the PVC upgrade - one of the first pollution controls!!!! So much for the Ford Master Mechanic.

"looks like i have bad rings and possibly valves or hopefully head gasket."

Na - don't think it is any of these. It is possible you have a lifter/push rod mismatch, but I still bet it is something simple like a bad spark pug wire.

The only real problem is that you keep letting GM people work on your Ford!

 

Ah, the dark side ......

Luke, I'm your father .... BBC ain't so bad:

 

If it does not have a Ford engine, it is not a Ford!

 

I agree there .... It would kind be like a Frankenstein abomination imo. He, he, he....

As much as I like the LSX motors especially the new LS3. I just couldn't bring myself to drop one in a FORD ..... Well then, j/k.

 

That's a good looking workshop you have there AJ and the engine is pretty impressive.

 

That engnie is impressive...you know you're making serious power on a BBC when you run a stud girdle...them things can spin 6500 w/issue and make 700HP...if the girdle is needed to keep things inline...ya gotta be making some real power