My Flat Tappet Cam Wiped Out So I Decided To Go Roller

[L31MaxExpress]

Right now I'm running 87 and was hoping I could get by with it, at least during the cooler months

Long ago I figured out I was shooting myself in the foot with 87 even with stockish engines. Once I discovered TBI 305s and 350s making 30-50 ft/lbs more torque with an aggressive timing curve on 91 and the added torque helping fuel mileage enough that it more than offset the cost. A stock L05 I was playing with on 91 made over 300 ft/lbs @ 2,500 at the tires rather than 250-260 ft/lbs at the same engine speed. On 91 I had the full total timing in it at 2,400 rpm without detonation or knock retard.

 

[PlayingWithTBI]

I would try the throttle follower IAC trick before spending money on a larger throttle body.

Well, it might help if the throttle blades opened all the way with the pedal on the floor. It looks like it has another couple degrees of rotation before hitting the WOT stop on the TB. It looks like I have to bend the cable bracket on the pedal down a little - maybe? Or look for some way to adjust it.

IIRC 255 steps is the limit of the code.

Yep, I think I'll start with 220, from the 145 shown on the WUD, for $hits and giggles.

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[L31MaxExpress]

Well, it might help if the throttle blades opened all the way with the pedal on the floor. It looks like it has another couple degrees of rotation before hitting the WOT stop on the TB. It looks like I have to bend the cable bracket on the pedal down a little - maybe? Or look for some way to adjust it.


Yep, I think I'll start with 220, from the 145 shown on the WUD, for $hits and giggles.

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Update the TF, throttle follower max steps too.

 

[PlayingWithTBI]

Update the TF, throttle follower max steps too.

Got it - I think

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[PlayingWithTBI]

We pulled the oil pan, it dropped out without any issues - didn't even have to rotate the crank. After I cleaned the windage tray, David was trimming it, while I cleaned the oil pan

Here's some of what we found. The original 23 year old oil pump showed plenty of wear.

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Some pieces and parts in the oil pan.

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Sludge I washed out of the pan, with brake and parts cleaner.

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1-1/2 hours later, 3 cans of brake cleaner, and a half dozen shop rags, the cleaned oil pan.

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Here's the new pump installed. The bottom end looked nice and clean.

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It took us about 4-1/2 hours to complete the job and take it out for a test drive. If you go by the rule of thumb - 10 PSI/1000 RPM it's good enough. When cold I get >60 PSI at idle but, when heat soaked, it's still ~8. When cruising at ~2000RPM it's ~35. I don't know how accurate my Dakota Digital gauge is but, I'm calling it good enough.

 

[PlayingWithTBI]

Well, I took the truck, picked up my buddy, and drove to a restaurant about 18 miles away for lunch. The engine started making some noise, I couldn't tell if it was an exhaust leak or what. After lunch we headed back home and it started getting louder. By the time we got to his house, it was a constant knock or metal on metal squeal. Maybe the timing gear is rubbing on the button head bolts holding the cam retainer plate? Anyway, I parked it in his driveway and he gave me a ride home. Thursday when we don't have anything going on I'll call AAA and have it towed home.

I'M PISSED!!!

 

[kennythewelder]

Well, I took the truck, picked up my buddy, and drove to a restaurant about 18 miles away for lunch. The engine started making some noise, I couldn't tell if it was an exhaust leak or what. After lunch we headed back home and it started getting louder. By the time we got to his house, it was a constant knock or metal on metal squeal. Maybe the timing gear is rubbing on the button head bolts holding the cam retainer plate? Anyway, I parked it in his driveway and he gave me a ride home. Thursday when we don't have anything going on I'll call AAA and have it towed home.

I'M PISSED!!!

Man, that sucks.

 

[0xDEADBEEF]

Hope it's not a spun bearing. Kinda looks like bearing "foil" in one of your pics. Hope I'm wrong ...

 

[PlayingWithTBI]

Hope it's not a spun bearing. Kinda looks like bearing "foil" in one of your pics. Hope I'm wrong ...

Yeah it does, it's non-ferrous too. IDK, we'll tear into it next week. I may be looking for a 383 short block soon.

Edit: That's why I'm hoping the billet aluminum timing gear is being damaged.

 

[L31MaxExpress]

Yeah it does, it's non-ferrous too. IDK, we'll tear into it next week. I may be looking for a 383 short block soon.

383 would be nice. GM still had the ZZx shortblock for a resonable price last I checked. Compared to having a short block built now it may be a cheaper alternative.

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