Unusual Symptoms???

[67 B-body]

I'll look into the heat tape. I haven't changed the fuel yet. Haven't ran out the first batch yet. It's 93 octane + 1 full bottle of octane boost to 10 gal of fuel. I'll swing by the airport this week and buy some high test stuff.

 

[67 B-body]

Was checking valve lash yesterday and found a couple that were open to far. I hope my cam and or lifters didn't go south!! I adjusted them with the hopes of it not being at the tottal base line during initial setup! I went over to the passanger side to have a look see on the head, and found a neet little pin lying up on the inside lip of the valve cover...??? "Whats that!" I said to myself..... After looking at it for a momnet I realized that it had to be one of the pins for the roller tip in a rocker arm! Sure enough,, number 6 cyl intake rocker has half of its roller pin missing! I called the parts guy up, and he said "NO PROBLEM, I'll get a complete rocker out to you right away"!
The lash on that rocker didn't seem to out of adjustment at all, so I have to chalk it up to a manufacturing defect. Now I have to wait for the new rocker to show up, and back at it I'll go.
I might pull the intake and valley cover to inspect the cam and lifters this weekend. I need to get the oil changed out too, so I have stuff to do if the rocker doesn't show up by Sat morning.

 

[moparpoor]

I had something similar happen to me.I had rocker adjuster lock nut back off and lay in the head.The adjuster backed all the way out.I didn't even hear it until I went to load it up on the trailer.Luckly no damage on parts,this motor has a lucky horse shoe up it ***.

 

[67 B-body]

Yep,, I just hate it when you buy all new stuff "not taking shortcuts" and the new stuff fails!

 

[moparpoor]

Unfortunately were all human and make mistakes!

 

[67 B-body]

Unfortunately were all human and make mistakes!

I've made my share of them,,, that's for sure!
Fortunatly the guy I get my stuff from is very generous and didn't even question me about it! I offered to send the old back and he said not to bother... he trusts me! GREAT GUY!!!!!!
I did find another item needing replaced though..
The camshaft didn't hold up! I used the new Huges oil through lifters and lost a couple lobes... I dont know the exact cause, but I will use standard flat tappet lifters that come with the cam as a kit this time! I checked the lash several times as I ran the engine, but this last time I noticed a lot of lash had developed. After pulling the intake and valley plate/cover I seen why.... Damn it anyhow! One thing after the next! Well here goes some more money to Summit racing! I cant afford a roller setup right now, and I would also need to have new pushrods made to make the switch... Very costly to do! I will stick with the solid flat tappet camshaft this time, and maybe next year I can look into a roller setup if I deem it neccesary at that time.

 

[moparpoor]

What oil did you use.You can't run standard oil with flat tappet cams.

 

[67 B-body]

What oil did you use.You can't run standard oil with flat tappet cams.

I've ran standard valvoline oil in MANY race engines "9,000 rpm circle track" up to this point with 0, ZERO,,, I'll say that again...... ZEEERRRROOOO camshaft failures.
I also added ZDDP to this oil. Two out of 16 lobes failed,,, I cant imagine oil having the ability to target only two lobes and leaving the rest alone. I believe it is lifter related. This lifter is a "special" design with a direct oil passage to the cam lobe through the face of the lifter. I think something went wrong in this area myself.
BTW, I ran Valvoline without any additives in my RR with a Mopar Performance camshaft for years with no signs of failure as well. I'm not going to say that it isn't possible for oil to have a role in this,,,, But I think it's a very outside chance.

 

[Gpuller]

I have seen other engines with those oil through lifters that the cams went bad in. I dont think its the lifters fault, I believe oil and huge spring pressures is what will take a cam out.
Last months Car Craft had a good article about cam break-in. They talked about removing the inner springs and what seat pressures are good and bad for cam break-in.

 

[daredevil]

Thats why I went solid roller.Too many cams going south nowadays. You may have ran standard valvoline in the day with no problems. Problem is it has been reformulated because modern engines are mostly roller motors.The zddp it used to have isnt in it anymore. Epa and others have cleaned things up. But its just a suggestion to run zinc on a flat tappet. Your motor do what you want.

 

[67 B-body]

Thats why I went solid roller.Too many cams going south nowadays. You may have ran standard valvoline in the day with no problems. Problem is it has been reformulated because modern engines are mostly roller motors.The zddp it used to have isnt in it anymore. Epa and others have cleaned things up. But its just a suggestion to run zinc on a flat tappet. Your motor do what you want.

Read from above,,,, zddp was added to replace the missing key. Thats why I dont think its a factor in this case.
As for "back in the day" it hasn't been so long ago that I as building two engines a year running all summer at the track two nights a week, hot laps, heat race, and A main each night. I think the additives have been missing for some time now "in most oils".
I would love to have a roller setup,,, but funds prevent that from happening right now. I hope to have that next year or the following summer. Then I too will have no worries.

 

[daredevil]

I know a while back there was a rash of bad blanks hit the market also. What rockers were you using that came apart?

 

[moparpoor]

I was thinking of some of the issues you had.At one time you had some loose valve adjustments.Some lifter bouncing on the cam profile may have put a flat spot on the profile not allowing them to spin properly.The end result some wiped out profiles.Maybe human error or rocker arm issue you had.Just food for thought.The next issue is if you didn't remove the inner springs you could have over loaded the lifters which didn't allow them to spin during break in.That will explain on a few profiles being wiped out.Also improper break in rpm will act this way also.One more idea check lifter bore diameter at those areas.They maybe a tad untrue and need to be burnished with a lifter ball/burnish ball.Just shooting ideas to check for during disassembly.

 

[Endangered Species]

67 B Body,

I'm not saying this is what caused the cam failure. But in the last few years our friends at the EPA forced the oil manufactures to pull the zinc out of the oil. This according to the cam manufactures has caused a tremendous amount of cam failures especially with solid flat tappet cams. The cam manufactures are selling a zinc additive to use for break in. Also I would try going with Brad Penn racing oil. It's the best on the market right now.

Mopar Poor also has a good point. If you had a rocker back off then the lifter bounce could have done it.
Spring pressure is very critical with flat tappet cams. Too much and you wipe the cam, not enough and the valves float (which I know didn't happen since you haven't run the motor hard yet) but it will take a cam out or break a valve because of the bounce.

Man I'm sorry to hear about all the problems you're running into!!!

Good luck!

 

[67 B-body]

yep, it sucks!
I'm looking into the oil I want to run from here on out. I have been eye balling Brad Penn stuff and Gibbs too. I also looked into the different additives as well. I can say that the three inspections of valve lash prior to the failure point showed no wear in cam lobe / increased lash. Not untill this last inspection did I find any signs of camshaft issues. It happened well after the cam / lifter break in period required. Your correct in that I haven't had a chance to realy wind it up yet,,,, just short revs during the tunning process checking for throttle responce and timing advance. There is no reason for this camshaft failure on two of 16 lobes short of "I believe" lifter issues. I was sceptical of having a hole in the face of a lifter running around a camshaft to begin with.... This cam was used in the engine prior to all the new fancy parts just added. I only added new lifters because I wasn't sure if a couple got switched on me, so I didn't want to take chances on wiping out my cam. That is why I bought the new oil through design lifters. I bet I wouldn't have had a failure keeping with the original lifters I removed prior to rebuild. Just my thoughts..... Once again, additives put back into the oil, new lifters, correct lash, heads purchased with correct spring pressures and coil bind not an issue with setup rated for .600" lift.
I will get the oild dumped out / replaced with new filter, camshaft removed and used as a reminder, Hughes lifters thrown into the trash can. Then I'll put a new cam and lifters back in. During installation I'll put the new rocker onto the shaft and install. It's getting started and wound right up to 2500 for 30 minutes with the garden hose shoved into the neck of the radiator and petcock half open.
If no signs of wear are evident / excess lash, then I'll take it out and run the **** out of it!
I'm tired of replacing new parts!

 

[67 B-body]

Engine bearings are fine..Rinsed it all out, re-assembled the engine with the Mopar .590" lift camshaft and solid lifters. I used the entire bottle of Mopar assy lube on the cam and lifters, and used fresh Brad Penn oil this time. Engine ran terrible at first, but I found some bad plug boots arking to the headers. I ran it at high speed right away for several heat cycles to break in the cam, without ever letting it idle down except when I shut it off to cool down. Each cycle lasted 3 to 5 minutes and I did this 6 times.
Now I have to dump the oil and replace with a new filter, then I'll get her ready for the road! I'm replacing U-Joints, bleeding the brakes, and still have to install an electric fan, and mount my switches beneeth the dash.
Off to the airport for some fuel now....

 

[moparpoor]

I see things are on the way to positive progress.I hope to see some time slips maybe soon.

 

[fastfish1967]

Maybe I missed something while reading through this thread. Are you still using the same carb? If so what number power valve is in it, as I recall you said it still had one in the front. You need to check how much vacuum your engine has and use the correct PV. Usually about 1.5 numbers lower than vacuum reading. If you have too high a PV number the carb is always in power circuit and will never get back down to the idle circuit of the carb. I would lose (block off) the PV and set timing at 36 to 38 degrees total advance with locked out distributor. Just my 2 cents worth.

 

[67 B-body]

I just looked at the power valve the other day, and couldn't find the markings on it to even tell what was installed... Bummer! It's tuff to get a correct vac reading before final timing and idle circuit is established, because they affect vacuum readings. Catch 22!!
I dont plan on locking out the dist though. I plan on a street strip application, so the advance doesn't need to be full in when starting or in town driving. 20deg base timing seems to work OK now, and full advance at anything above 2000-2200rpm.
thanks,

 

[67 B-body]

Mystery solved

OK,,, Here's some interesting news for you to ponder!:happy1:
I ran through the comp test and found two cyl's at 0, "ZERO"! Numbers 1 and 7...
I did a leak test and heard it all going out the exhaust on these two. The other cyl's dry were at around 190psi, maybe a bit more... Hard to tell with the overlap on the cam, but a solid 190!
So, I pull the head and found both 1 and 7 had bent exh valves??? I can see where they touched the piston, but can't imagine how? I wonder if reving the engine with a bad cam made the lifters bounce off the lobe causing valve strike??? Not all the lobes that were bad on the old cam had bent valves,, so the valve strike didn't cause the cam failure.
Anyhow, the pistons appear to be fine, just a light mark from the valve on the thick part of the dome... I don't believe I have to worry... The valves bent at the under-cut area "weakest point". I removed them and inspected the seat,,, Doesn't appear to have any damage either!!! I think I realy lucked out on this one!!!!! I'm going to buy two new valves and set them in place then do a leak test with solvent. I might just lap them in to inspect the seal if they pass the leak test. We'll see once I get everything in hand. Worse case scenario is I have to grind the seats.
This is why the new cam hasn't sounded the best,, I had two dead cyl's!
Good news though,,, I got a chance to inspect the lifters and cam after breakin, and everything looks GREAT!
I should have everything Tuesday and begin putting it back together after work... AGAIN!