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If you look at the last pic of the guides you'll see a drop of oil laying on the side of the guide also every intake hole has been washed clean in two spots front and rear too much gas?.

Seems like it would have been smoking. Is the motor out of the car now? wouldn't be to much harder to re-ring it now as opposed to pulling it out and doing it over.

The machine shop I worked in had a banner over the door that read "It cost less to do it right the first time"
 
Read his posts, it was just re-rung (ringed?) 1000 Miles ago. That whole ordeal was well doc'd on this site.
 
Discussion starter · #43 ·
There oil all over cause when I flipped the head over oil ran everywhere.

The cylinders look oily cause I sprayed WD40 everywhere to prevent rust
 
Wouldn't the motor be running rich if he was down on compression? If so, would stand to reason that the oil would be diluted with the fuel and causing excess wear on the rings and or cyl walls? If it were mine it would get new rings. JMHO

Jeff
 
My take on this a little simpler. If anyone saw the clip on valve control as excessive RPM, the valves will actually wobble. Back in Sept or October this year when he fisrt put the TKO in, 69 had mis-shifted from 3rd to 2nd at 6000. This would have put the motor to upwards of 8000 RPM. Bad enough for a solid roller, disaster for a hyd roller. The shortblock obviously held up just fine. If the valves actually wobbled and floated, you would expect valve/piston contact. Have to be realistic, the valvetrain was designed for 6000 rpm, not 8000. Doesn't matter what he did, the fact is the motor got rev'd to an abnormal RPM, that even the most engineered solid roller would have had problems with.
 
Vince,BUMMER for sure,sorry to hear that,keep your chin up and at least were in the off season so you have the time to get it fixed.

Man ,i bet your very quick at tearing down the bbc in your 69 & could do it with your eye's closed (LOL!!!)

Good luck.

Scott
 
. This would have put the motor to upwards of 8000 RPM. Bad enough for a solid roller, disaster for a hyd roller.
Flippin' cake walk for a flat tappet solid with Isky lt weight triples on it ( 140/345).

Vince, bummer dude! But you know what, hey man, it aint like someone got cancer here. Its flippin' metal. You build 500+ hp rats and BEAT on them and you might have some issues like this once in a while - still a helluva lot of fun!

I installed an MSD 6Al a while back ( its hidden, they look like crap on firewalls in oem-style engine bays)imho), only for the rev chip. Ignition was a simple Pertronix timed small base, Accel coil and solid Taylor wires. MSd added NOTHING, as well it shouldn't with a top flite ignition, except the insurance of a rev limiter. On a bad shift though, the engine would still see some hard Rs.

Best go heavy on those springs. I use titanium retainers now. But a slightly heavier Manley Streetmaster valve. The Isky 8005 a are set up tall, but I was as much concerend with keeping seat pressures up as not going over 350 on the nose.
 
Discussion starter · #48 ·
Thanks for the encouragement fellas, but I'm not too bummed out. I'm actually kinda excited thinking the car is gonna be alot faster with valves that actually seal.

Taking the heads off only took an hour b/c I have the headers off to try 1.75" vs. the 2".

Winter project list:
-valve job
-spring upgrade to 'hives or dual with Ti.
-1.75" headers
-dyno tune

I was going to do the interior this winter, but I like HP better :D

PS - I'll do a rev limiter too, although in this case it wouldnt of done anything as the 3rd to 2nd shift mechanically forced the motor to over-rev.
 
I know you don't want to hear this but I don't think you have anything wrong with your valves or seats. Both pictures of the seats in the heads have very clear 45 degrees seats. If the valves were leaking one side of the seat would be smokey or black looking where the leak was. The seats on all of the valves except one(and that may be a shadow) had clear demarcation lines.

There is no way you could have 20-50% leakage in 6 cylinders and have a good idle and a smooth vacuum gauge. If you have not taken the other head off try this. Remove all rocker arms. Install the leakage tester and pressurize the cylinder. Let the piston go to the bottom. Put a 3/4 socket on the crank bolt and rock the crank around until you have the least leakage. If you are getting leakage you should be able to feel it coming out of the intake port or exhaust port. If the leakage does not go under 12% and we can feel the air coming out the head is removed to recut the seat.

I will give odds your 50% leakage will improve by rocking the piston. If you did not take the rocker arms off you are getting false leakage readings.

When you get your heads back from the machine ship and install them on the engine hook the leakage tester back up and see if it is improved. Spray some WD40 in the intake ports and see how much leakage you have. You can tell by the amount of bubbling that is going on. I will bet you have bubbles.
 
Pour some diesel in the ports and watch it run on the ground, continue lapping the new valves and valve job until there are no leaks then clean and install.

Your right 69 chvl it will run better, you'll see most of it out of the hole, it makes enough difference I never run a set of heads from a fresh valve job without leak checking them first.

Even from a good machine shop I normally find at least 2 valves that leak and if he put his trainee on them they might all leak.
 
The rocker arms were off for the leak test. Pressurized air was pumped into the cylinders and definitely came out through the intake ports. Sound is unmistakeable. For those that don't know thw story, this was a 454HO crate that had oil burning issues. The motor was disassembled, cleaned and torque plate honed. Then reassesmbled with fresh rings and bearings and a new set of GMPP/EDE ovals ports. The shortblock was assembled correctly (I can personally guarantee it) and obviously has held up well to plenty of dragstrip action and street thrashing this past season as well as some mechanically induced excessive high RPM blasts.

JMHO, this is a classic case of what happens when you get past the practical limits of a vavletrain. Really wouldn't have mattered what cam design was in there. Unless the valvetrain was designed to rev to 7500-8000 RPM, it was going to take a hit.

PS - this is also why you don't go with the minimum piston/valve clearance. This motor had approx .030-.040 when first fit up. Valve reliefs were cut deeper to .080 (is this right Vince ?). My guess is the impact was minimal, but severe enough to cause a mild bend. Who knows. Another .020 cut might have been all that was needed.
 
Discussion starter · #52 ·
Have about .100 p/v clearance, but some of these d*mn valve sit lower than other others, so there may be around .080 of some of 'em.

Yes, all rockers were off during the test, as was the headers and carb. You could feel air blowing up through the intake manifold, some jugs worse than others obviously. Not really so much coming out of any exhaust port. I still have the other head on. I'm going to do a compression test on that side just for kicks before removing the head.

I do remember getting around 180 PSI before when doing the compression test. Be interesting to see what's there now. I mean, if I still have 180 PSI but also have leakdown, maybe it was leaking from day one???


BTW - would bent valves explain the rattle at 6000? Maybe it wasn't float I was chasing afterall?????
 
"Most" intake seats I see have a clear shiny ring all the way around where the valve seats against them. The exhausts almost never have this shiny ring, and mostly look to have a little rust or discoloration to them. I don't see a clear shiny ring on the intake seats or valves. I also see some carbon buildup on a couple of them that extends onto the 45* seat angle itself. Looks like they were not sealing properly to me, and that's backed up by your leakdown test. As you say, this could very well have been that way when you re-ringed it. A "good" performance valve job blended into the chambers and bowls would be money well spent. If you were closer to me I could cut you a very good deal on the work. Most shops are charging $225+ for a "performance" valve job these days. And that doesn't count assembly and setting spring pressures.

I wouldn't expect big gains from getting lower leakdown results though. In an engine spinning anywhere over 3000 rpm, the combustion mixture has very little time to escape from a leak that small anyway. JMHO.
 
On the valve job, I would suggest taking a close look at the cuts on the seats. If they are all still there and there is nothing visibly wrong I would buy new valves and lap them in. As long as the seats and valves show a nice thin line all the way around when you lap the valves you should not need a valve job in my opinion.

If the rings are good, then maybe there is a valve seal issue. I had a problem with Teflon seals last year and replaced them with Viton and resolved the problem. I'm not saying all Teflon seals are bad, only that I had issues with them -- when I researched the problem I found a few other people that had issues with them too. Noone seemed to had any issues with Viton. Maybe valve float and stems wobbling effected the valve seals????

I hope that helps!
 
Discussion starter · #55 ·
I noticed before all these issue that the intake valves were getting gummed up from day one (I changed lifters out a couple of hundred miles into this motor and was able to see the intake valves). I replaced Eddy seals which looked like a good quality seal, with these metal-clad viton jobs. But, the car burns no oil.

I'll pull the other head to today and see what we got.
 
Discussion starter · #56 ·
Just a quick update. Did a compression test on the remaining head, and I got around 170-180...which where it was from day one. But, some of these cylinders show 50-60% leak down. I put shop air (about 60 psi) into the cylinders and air escapes out of the intake ports - BAD! It will actually blow by hand off the ports!

I'm starting to think I have bum heads from the getgo. There really isnt any shiny distinctive lines around the valves. I think the valves may not be bent - my drill may be a bity lope-sided, cause I stuck some pushrods in there and they wobbled, even though they roll nice and true.

Bottom line I really need to get these evaluated by a competent shop. May get out of this with just a valve job (may not even need valves).
 
Vince, sorry to hear of your problems again with this motor. On the up side, when you get this thing figured out, you will know BBC inside and out!
 
Vince, has this motor ever seen starting fluid? Guaranteed to put a wobble in your valves.
Uh? :confused: and why would that^ be? Because of detonation? I've never used any fluid of that type to start an engine, but I'm just a bit confused as well as curious about the reason for your comment above. Please elaborate.
 
Discussion starter · #60 ·
Never used starting fluid in this motor, but I have used it extensively on just about everything else though.

Valves look the same on this head as the others...no real distintive sealing line on the valves..unbeleiveable. Maybe the compression should of been higher than this from day one.

Again, I'm thinking these heads were F'd up from the begining.
See anything here:



















 
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