valvetrain issues; cam/lifter replacement; 1978 454 truck motor

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Sep 7, 2006
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The exhaust valve lobe to the number 6 cylinder in the stock cam in my 1978 454 truck motor decided to do flat. The lifter collapsed, its indented at the bottom.
This happened two weeks after adding a quart of Rislone additive to the oil. Everything was running perfect before the Rislone. I never had any issues with Rislone, everybody swares by it to clean engines up.
The engine is and the magnets on the oil pan drain are also clean. The car started poping when I would try to get some power from it.

I decided on the Melling MTC-6 camshaft and lifter kit. It has more adv. duration then the stock cam with the roughly the same lift.

This also comes with a four ounce bottle of Mel-Lube to brush on the cam and lifters contact areas.
I normally use Mobil 1 5W30, I've successfully used it in quit a few flat tappet motors without any additives.
The lifters have the ring a half inch or so from the bottom, so they must have the stronger base metal.

What oil and additives should I use?

Back in the seventies, we used to use straight 30 Pennzoil and poured a can of STP over the cam and lifter contace areas. Then started it up and drove it. Changed oil after 20 miles still straight 30 then changed oil after 500 miles with the regular 10W40 Penzoil.

Thank you.
 
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This is the most critical part of camshaft life: Use a proper break in oil and follow this (or manuf recommended procedure)... https://help.summitracing.com/app/answers/detail/a_id/4707/~/how-do-i-break-in-my flat-tappet-camshaft-and-lifters?

That is the proper way to break in a new cam and lifters, and you'll risk having a really bad day if you don't do it. Not worth the risk, imo, to take a chance with any other procedure for something that's such an ordeal to replace. Never had an issue after doing it this way.
 
I would use a higher zinc oil like the Castrol stuff with a bottle of breakin additive. Make sure the enging fires immeadiately ane bring the idle up to 2000 RPM for a good 20 minutes. I put a window fan in front of the radiator to aid in cooling.
Good luck and have fun with it.
 
The exhaust lifter is usually the first to go as it sees the highest load. It's possible it wasn't even the cam/lifter's fault. Something like a weak pushrod or rocker stud can induce flex in the valvetrain that shocks the lifter. However, it could just be straight up load.

Say you have a 1.72" exhaust valve with a stock cam that opens the exhaust valve at say 70° BBDC with ~100 psi cylinder pressure. That pressure is multiplied by the valve square area. (2.32 in^2 for 1.72" exhaust valve)

2.32 in^2 x 100 psi = 232 lbs resisting the valve opening

Then tack on the valve spring rate which a stock spring probably only has ~80 lbs on the seat.

232 + 80 = 312 lbs at the rocker tip

Then that's multiplied across the rocker ratio as it's acting like a lever arm in this case. (1.7:1 for BBC)

312 x 1.7 = 530 lbs on the lifter that must be overcome just to lift the valve off the seat.

Now apply it to the Melling MTC-6 camshaft that you have. It's 288/298 duration @ .006" and 204/208 @ .050" which is really weak. It's on a 112 LSA. (straight up)

The exhaust valve on that cam opens at 86° BBDC. At that point, the cylinder pressure is about 160-180 psi. Let's assume you're upgrading the valve springs as well, as you should, and the seat pressure is now 120 lbs.

2.32 x 160 = 371 lbs on valve face
371 + 120 = 491 lbs at rocker tip
491 x 1.7 = 835 lbs on the lifter

So that cam, despite being on the weak side, induces +57% more load on the lifter. That must be considered with that long duration, weak lobe. I recommend putting in new pushrods, beefier ones, and better rocker studs to keep flex out of the valvetrain with that load. A stock pushrod can flex really easily, especially on a tall deck BBC.

On to the oil choice and break-in...

I never recommend oil supplements. The way I see it, if you have to add something to your oil, then you're using the wrong oil. Forget that supplements exist and just run a proper oil.

For break-in, I'm partial to Driven BR30 break-in oil though Amsoil's SAE 30 break-in oil and HPL's break-in oil are great choices as well. They contain a proper additive package for the break-in.

Before starting the engine, I preheat the oil in the pan with a pan heater. You can use a turkey fryer or something and pour it in after warming, doesn't really matter how you get it warm. This makes priming the system much easier as the oil thins out a good bit with the heat. It also benefits ZDDP since it becomes more reactive with heat so you're giving your anti-wear a kickstart to start protecting as soon as possible.

This part is important... make sure you have everything good to go before you try to start the engine. Make sure the carb is somewhat tuned okay enough for it run through the initial break-in. Make sure your spark timing is correct, not 180 out or something of that sort. Make sure the balancer isn't faulty and giving false timing mark readings. Make sure you have fuel flow and pressure. The reason for all of this is because you can wipe the cam lobe just trying to start the engine. I've seen it happen quite a few times where someone is sitting there cranking the engine over and over and over trying to dianose why it won't start. Meanwhile, that cam is grinding itself down with no oil splash. You don't want to do that. If it doesn't fire within say 3 seconds, let off the starter.

Once fired up, go to 2500 rpm for about 30 minutes. There's several reasons for this. 1) It puts more heat in the oil faster to get ZDDP working better. 2) It ensures good oil splash in the valvetrain and on the cylinder walls for the break-in. 3) It gives more piston speed to get the rings into EHD and HD lubrication so they don't glaze the hone while you're breaking in the cam. (this only applies if you rebuilt the engine with new rings and hone) I ensure the coolant and oil both reach 200°F for a minimum of 15 minutes, usually using delayed spark timing to heat it up faster and then switching to manifold vacuum advance to maintain the temperature once warm and keep it from overheating.

I like to heat cycle the engine. Some don't. It's really not necessary in most cases, but I like to do it anyway. I shut it off to cool all the way down to ambient temperature naturally.

Then I preheat the oil again, start it back up, go back to 2500 rpm to get it heated up quickly, and then start making loaded pulls at WOT with varying rpm. (as tuning will allow) Never let it idle. The worst thing you can do to a fresh engine is let it idle. I make several WOT runs, showing it no mercy. This can mean driving it out on a desolate country road, putting in 2nd gear and flooring it from say 30-50 mph, and then coasting back down to do it again.

After that, let it cool all the way down again, and then remove the filter. Inspect the filter for anything unusual. I'll check rocker alignment and lifter preload and do a compression and leakdown check at this time. If all is good, put a new filter on, top off the break-in oil, and go 100-250 miles. Vary the rpm and load through this time. After that, the break-in is done.
 
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I got called a troll a few days ago, life goes on.

Rebuilt a couple back in the day, was involved in multiple rebuilds. With todays modern oils, I wouldn't know where to begin. My guru swore by a thin oil for the first start up then after the engine running for about a minute, minute and a half, draining it and filling it with 10w30. Ran that about 500 miles, then changed (10w30 again) and that was the break in process. Drove them fairly hard during the break in process to make sure everything seated and sealed correctly. Looks like some good recommendations above.
 
I didn’t know that was an actionable offense.

If I were the op I would ignore those that convicted and sentenced, lol
The "guardians of the sacred site" can be harsh with judgement. OP was judged on one of his other posts, for an honest mistake made by thousands of other people, wrongly IMO, but it obviously hurt his feelings. Some of us need to think before we type.
 
The reason for all of this is because you can wipe the cam lobe just trying to start the engine. I've seen it happen quite a few times where someone is sitting there cranking the engine over and over and over trying to dianose why it won't start. Meanwhile, that cam is grinding itself down with no oil splash.
Sounds like the engine builder didn't use any of that special lube that comes with most cams to avoid just that.
Then I preheat the oil again, start it back up, go back to 2500 rpm to get it heated up quickly, and then start making loaded pulls at WOT with varying rpm. (as tuning will allow) Never let it idle. The worst thing you can do to a fresh engine is let it idle. I make several WOT runs, showing it no mercy. This can mean driving it out on a desolate country road, putting in 2nd gear and flooring it from say 30-50 mph, and then coasting back down to do it again.
Every owners manual I've read says not to beat on an engine before it's broken in.
 
Sounds like the engine builder didn't use any of that special lube that comes with most cams to avoid just that.

Every owners manual I've read says not to beat on an engine before it's broken in.

If you sit there and crank it over for while, it'll wipe that gel off the lobe. Plus, the additives in that gel still need heat to work well. The gel may buy some time, but if you keep cranking it over and over, it'll only delay the inevitable.

Most owner's manuals also say 1 quart of oil consumption every 1,500 miles is "normal" so take that for what it's worth.
 
Every owners manual I've read says not to beat on an engine before it's broken in.
With today's machining accuracy and finish profile and roughness specifications, along with the run tests performed by the manufacturer, probably 98% of all break-in is done by the time the consumer puts their first mile on their new vehicle. Sure, there are always the special cases to this rule, but there's plenty of evidence this is not required for the engine's sake alone. If done correctly, today's cylinder wall finishes and piston ring preps will seal almost immediately to the highest level that they ever will during their entire life cycles.

If anything, "break-in" periods these days are to keep people from doing really stupid things in a car that's brand new (sights/sounds/feels/HP) to them, and also to give the brakes time to bed-in before they're really wailing on them. The drivetrain part is ready to go upon delivery...
 
Pitts, one thing to be aware of. You want to make sure that the cam you pick for your big block does not reduce the stock manifold vacuum level. Most of the BB Chevys have generous tolerances on the valve guides to let oil to be vacuumed into the cylinders to keep the valves cool. The truck engine variants might have even larger clearances just for such a purpose.
 
Sounds like the engine builder didn't use any of that special lube that comes with most cams to avoid just that.

Every owners manual I've read says not to beat on an engine before it's broken in.
The WOT open runs after cam break in is to seat the piston rings. Does nothing for the cam.
Basically I used to keep it in a low gear, run it up to near redline and let it coast down. 2 times generally.
 
The exhaust valve lobe to the number 6 cylinder in the stock cam in my 1978 454 truck motor decided to do flat. The lifter collapsed, its indented at the bottom.
This happened two weeks after adding a quart of Rislone additive to the oil. Everything was running perfect before the Rislone. I never had any issues with Rislone, everybody swares by it to clean engines up.
The engine is and the magnets on the oil pan drain are also clean. The car started poping when I would try to get some power from it.

I decided on the Melling MTC-6 camshaft and lifter kit. It has more adv. duration then the stock cam with the roughly the same lift.

This also comes with a four ounce bottle of Mel-Lube to brush on the cam and lifters contact areas.
I normally use Mobil 1 5W30, I've successfully used it in quit a few flat tappet motors without any additives.
The lifters have the ring a half inch or so from the bottom, so they must have the stronger base metal.

What oil and additives should I use?

Back in the seventies, we used to use straight 30 Pennzoil and poured a can of STP over the cam and lifter contace areas. Then started it up and drove it. Changed oil after 20 miles still straight 30 then changed oil after 500 miles with the regular 10W40 Penzoil.

Thank you.
Use a moly cam lube coating the lifters and lobes. Crane cams (99004-1) used to be the best. The Castrol Classic 10w40 will be fine. 20 minutes of 1500 to 2200 RPM the entire time. With a flat tappet cam stick with the high zinc oil.
No. The pushrod or rocker stud doesn’t flex with a stock cam. Yes, pushrods can bend if the engine was pushed to valve float and the valves made contact with the pistons. Doubtful with the low compression and stock cam. A 45 year old anything wears out… As mentioned already you will have lower vacuum at idle with that cam so be aware if you have less brake booster assist.
 
Hello guys. Thank you all for your help.

I installed a Melling hyd. 22216 cam (marine). With a set of GM spec lifters. I bought everything at Summit Racing in Ohio. It really woke up my 454 and the idle vacuum is around 18-20".. The mid range has brute torque and it revs past 5500 without issue.
I am so happy with this cam lifter combo! Cliff the Quadrajet builder suggest this cam and he was 100% spot on!

I used Lucas brake in oil, then after about 10 hours of run time, I changed the oil to 15W50 Mobil One without any additives. Everything was perfect.
At first I used K&N 3002 Oil filter with the Mobil 1 15w50, then changed the oil after 1000 miles to the same thing. Then at around 1500 miles the oil light started to flicker at idle (550 rpm) with the TH-400 engauged. I raised the idle to 650 and all was well.
I changed the oil to the same thing but this time used the trusty old Wix 1060 filter. Now the light stays off, even at 400 rpm with the transmission engauged. It also runs better.

I wonder if the bypass was sticking from the extreamily hi levels of zinc in the brake in oil and steel from the new lifters and cam..

In any case it all runs well now.

I wonder if my 454 big block likes oil filters to have the anti drain back and filter bypass systems working?
 
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