Overcome with Frustration!

[savatreatabvr]

My truck originally came with a 350 but somewhere down the road somebody dropped in the 454! I think it's a 1977 or 1978 block, I haven't checked the head casting numbers yet but that's next on the agenda! I know I'm wrong for calling it a 1973 454, I just assumed the 70's big blocks were basically all the same but you guys cleared up my confusion! Now, how common is it for big block Chevy camshaft to go flat?

[Firebirdjones]

BBC's from 73 on didn't really chance much. After 74 you didn't see them in passenger cars anymore and were soley used in trucks and went unchanged for many years. HP numbers may have joggled around slightly from year to year, but they all shared the same compression, cylinder heads, intakes, camshafts, for the most part up until the Gen V next generation came out in 1996 (I think was the first year).

Camshafts going flat really isn't a big block chevy thing, as it has happened just as frequently in the small blocks. There was rumor that in the late 70's GM had a run of soft camshaft material with flat lobe problems, but personally having several vehicles from the 70's (big and small block) I have never experienced that issue.

What is more common now in the last few years with any engine manufacture is the ZDDP being removed in the oil causing flat camshaft lobes. It's been a debate for a few years now among camshaft manufactures that the oil companies started lowering ZDDP in the oils for emissions reasons (clogging cat converters etc... was part of the explanation) but left us classic car guys that don't need to worry about cats with a subpar oil.

There are oils out there now that carry the Zinc/Phosphorous levels needed for flat tappet cams. All your 20W/50 weight oils will have enough as they don't have to comply with the new ZDDP regulations I'm told. To be certain you can also buy oils that advertise more ZDDP from Brad Penn, Amsoil, etc..
Valvoline Racing oils also have higher ZDDP content. Basically it's understood from the camshaft manufactures if you run anything with a flat tappet camshaft, especially something with higher spring pressures, you'll need to keep the ZDDP content at 1200+ parts-per-million or higher to be on the safe side. All the oils I mentioned above are 1400 or higher.

[shok]

Originally Posted by Firebirdjones

BBC's from 73 on didn't really chance much. After 74 you didn't see them in passenger cars anymore and were soley used in trucks and went unchanged for many years. HP numbers may have joggled around slightly from year to year, but they all shared the same compression, cylinder heads, intakes, camshafts, for the most part up until the Gen V next generation came out in 1996 (I think was the first year).

Camshafts going flat really isn't a big block chevy thing, as it has happened just as frequently in the small blocks. There was rumor that in the late 70's GM had a run of soft camshaft material with flat lobe problems, but personally having several vehicles from the 70's (big and small block) I have never experienced that issue.

What is more common now in the last few years with any engine manufacture is the ZDDP being removed in the oil causing flat camshaft lobes. It's been a debate for a few years now among camshaft manufactures that the oil companies started lowering ZDDP in the oils for emissions reasons (clogging cat converters etc... was part of the explanation) but left us classic car guys that don't need to worry about cats with a subpar oil.

There are oils out there now that carry the Zinc/Phosphorous levels needed for flat tappet cams. All your 20W/50 weight oils will have enough as they don't have to comply with the new ZDDP regulations I'm told. To be certain you can also buy oils that advertise more ZDDP from Brad Penn, Amsoil, etc..
Valvoline Racing oils also have higher ZDDP content. Basically it's understood from the camshaft manufactures if you run anything with a flat tappet camshaft, especially something with higher spring pressures, you'll need to keep the ZDDP content at 1200+ parts-per-million or higher to be on the safe side. All the oils I mentioned above are 1400 or higher.

So just a slight topic derailment for my car. I have a 2010 Challenger with the 3.5 V6, and I drive the snot out of it and am about to hit 100k already. It seems you've done some research, any recommendation of where I can do some reading to see if my motor will benefit from more ZDDP since I'm gonna easily cross the 200k barrier with this car before it is retired from daily driver duty? I usually run Mobil Syn which took a Chevy 4.3 past 200k easily (last daily driver).

[INSIDIOUS '86]

My freinds 77 burn big block flat cammed last week and I just pulled a 77 truck 350 apart after it flat cammed a few years ago and a few years back we did the same with my freinds 78 Camaro which flat cammed and we didn't know

So yes I must say these late 70s engines either have dog cams or lifters. I think it may be the lifters cause even on the good lobe parts of the cam the lifters were crushed where ther should be a sleight crown
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[Firebirdjones]

Originally Posted by shok

So just a slight topic derailment for my car. I have a 2010 Challenger with the 3.5 V6, and I drive the snot out of it and am about to hit 100k already. It seems you've done some research, any recommendation of where I can do some reading to see if my motor will benefit from more ZDDP since I'm gonna easily cross the 200k barrier with this car before it is retired from daily driver duty? I usually run Mobil Syn which took a Chevy 4.3 past 200k easily (last daily driver).

Really don't have to worry too much about ZDDP in newer cars because they have all went to roller cams by now. Rollers started showing up in the mid 80's for some, and are now pretty much accross the board.

However more ZDDP is always a good thing as that's what gives oil it's lubricity characteristics, and anything that cuts down on wear and tear is good in my book. Cat Converters may not like it (so they say) but I've never had a car with cats so I can't comment on the longevity affect.

I'd check out some of the oils I mentioned, they have good websites that are informative. Bob the Oil guy has a pretty good website with knowledgable people as well.

[tucsonjwt]

My brother had a 73 caprice 454 with a soft cam - wore flat, bent pushrods, etc. I had a 73 C20 454 - same thing. My current 83 C20 454 is a a GM goodwrench rebuild, so I don't know what happened to the original engine. My guess is that was a early 1970s big block thing. I am pretty sure the truck engine cams are different from the passenger car engine cams, though they might have been made from the same steel back in the 1970s.