ATK High Performance 350ci TBI engine for 1988-1995 Trucks from Jegs

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Did you call S&J see if they have any recommendations?

I'm kinda in the same boat, i suspect the 95's cam has lost some of it's already low lift.
Back in the day, SBC were know for being tough on cam lobes.
Would like to go roller but the options are expensive .....
I have not, been a long week at work, 12-14 hour days. But I have tomorrow off so I probably will then!

Yeah, they are pricey, and I don’t want to buy one without knowing I have provisions to install it. That’s why the ATK crate engine is so appealing. But I feel there is definitely reasons for it’s low price after hearing some feedback, and they probably aren’t good reasons.
 
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Sure, but today's oil formulations lack the ZDDP that valvetrains depended on in the non-roller days. Can't be contaminating those catalytic converters.

Nobody said roller valvetrains are perfect. They're superior to flat tappet in many ways, but you can still fall victim to defective parts. All of the "big three" are no strangers to valvetrain failures, in big numbers, across a wide variety of modern engines.

Richard

Fortunately the test pipes on my truck aren’t hurt by zddp, and they pass inspection where I live. Seems like no good option, just choose the better of the two- drive the worn out cam or replace it with one that could be defective.
 
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Lack of ZDDP does not seem to bother my Imports. Also most of the TBI trucks had the GM hard faced lifters. I cannot say that I have ever seen a flat tappet lifter or cam failure with those lifters.
So if I replace my cam, should I go with another set of those hard faced lifters instead of something from the aftermarket? Instead of an engine swap, I may just get some Vortec heads and get the whole top end refreshed. I have the cash to get most of that stuff right now, vs an entire engine.
 

Donald Mitchell

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It was a response to the broad-strokes statement of "I'm not looking for an argument, but hydraulic lifters were used successfully for more years than most of you have been around. Oh, and I remember the look on my friends face when one of his rollers ate a cam lobe." He didn't specifically say "flat tappet" but then the opposing argument of a single example of a roller lifter failure seemed to imply it. Either way it was weak bait and I shouldn't have bothered.

Richard
Sorry, Richard. It wasn't meant to be inflammatory. And thanks for your response as I did not know about ZDDP. I went to comp cams website and they said that there is still a small amount of ZDDP in engine oils to help with older vehicles and racing oils have more.

 
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Hipster

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ZDDP is only part of the problem. Harvey Crane, Racer Brown, Cam Dynamics and a few other pushed rate of lift on flat tappets as far as they thought they could go in the 60's. Today we have companies offering flat tappet profiles above and beyond that with the corresponding spring rates that used to be in roller only territory as the best thing since sliced bread. Couple that with the inexperienced that won't prime an engine, unknown/untested induction or thinks the dot to dot is tdc #1 and you crank the cam into disaster before the engine even fires.

never had an issue with mild flat tappets with moderate spring pressures. Rather have an oil that's higher in zddp as part of the package instead of a bottle you pour in that might or might not stay suspended.
 
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Erik the Awful

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Cams are manufactured and sold unhardened. The heat and friction of the break-in process work hardens the cam lobes, and that's why break-in is so critical.

I have an old pre-HEI Cadillac distributor shaft and gear that I ground the teeth off of that I use to pre-lube an engine right before firing. If the weather ever quits feeling like it blew right out of Satan's butthole, I'll get out there and get video of the process of firing up this flat-tappet motor.

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0xDEADBEEF

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Has anyone actually killed a cat from ZDDP? I used to run various racing oils in my C5 and never had a problem with the cats. Eventually it became a track only vehicle and I removed the cats and put on a set of long tubes and offroad x-pipe.
 

PlayingWithTBI

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I have an old pre-HEI Cadillac distributor shaft and gear that I ground the teeth off of that I use to pre-lube an engine right before firing.
I did the same thing with an old TBI distributor. I welded a nut on the top of the shaft so I can prime the engine using a 1/4" air ratchet with the engine in the truck.
 

Knuckle Dragger

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I'm not looking for an argument, but hydraulic lifters were used successfully for more years than most of you have been around. Oh, and I remember the look on my friends face when one of his rollers ate a cam lobe.
The Ls stuff with displacement on demand never met a roller cam it didn't destroy.
Cams are manufactured and sold unhardened. The heat and friction of the break-in process work hardens the cam lobes, and that's why break-in is so critical.

I have an old pre-HEI Cadillac distributor shaft and gear that I ground the teeth off of that I use to pre-lube an engine right before firing. If the weather ever quits feeling like it blew right out of Satan's butthole, I'll get out there and get video of the process of firing up this flat-tappet motor.

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So about October then? :)
 
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