NavyVet

I toasted my LT4 on 12/1 when the shaft that drives the oil pump went away. As the rebuild approaches, I am wondering if anyone knows of a supplier of a metal housing to retain the oil pump drive shaft in a LT1/LT4 instead of the factory's plastic one? Thanks in advance. Paul


[Modified by NavyVet, 11:58 AM 12/13/2002]

snydcat

I got mine at Autozone for a few $'s.

Rich

NavyVet

Was the housing that retains the oil pump drive shaft with the cam gear made of metal? It's the one with the single bolt retaining it. Thanks, Paul

snydcat

I hope we are talking about the same part, yours might be different than my 85, but yes it's metal. When I got all the parts for mine they asked if I wanted nylon or metal.


Good luck,
Rich

STL94LT1

You guys are talking about differnet parts.

snydcat

I thought so, kinda like my thread on my oil pump adapter gasket :crazy:

superlund

Sorry to hear about a toasted LT4 :sad:
I spotted a billet one recently on the web somewhere; I'll look around & post the link if I can find it. What part of your plastic one broke? Was it the bolt flange? More Performance sells a metal retaining plate that bolts on top of your plastic drive I believe they call it an "Oil Pressure Saver". If the plastic bolt flange breaks the oil pump drive will lift straight up vertically & disengage the oil pump. The metal plate is supposed to keep the drive from lifting vertically & disengaging the pump. I assume the plastic housing would then just spin in the block, but it would keep you from losing oil pressure suddenly. I made my retaining plate from a 3/16" thick piece of stainless steel. http://www.moreperformanceinc.com/

MSR

did you have a shaft failure, or was it actually a problem with the LT-specific drive stump?

NavyVet

The drive gear on the shaft was so far worn away that it evidently became disengaged from the gear on the camshaft. It was worn "funny" too - sort of concex with the top and bottom looking fine and the middle gone :confused:

The plastic retainer did not break. I just looked at the plastic piece and figured when it's being rebuilt, I should find a way to prevent it from braking and having the shaft ride up and disengage the pump. Not quite like locking the barn door after the horses are gone - more like building an even stronger barn door after they're gone!

At least when it's all done (about $10-15k from now), I will have a stonger LT4 :chevy

larryfs

2 questions....
what was the mileage on the LT4 motor when it gave way ...?

why so much money 10k-15k.......
I know there are NO LT4 crate motors, but can't you rebuild it right for less?

just curious.......

NavyVet

Mileage = 79K

Cost includes balancing, replacing the flywheel (it got so hot at the rear main that the rubber in the dual mass started to melt), cam, cam bearings, new rockers, etc. Also includes labor. Also need to add LT headers and random cats when it goes back together.

Started to lose power - checked gauge = Zero! Everything is pretty well heat & oil starvation damaged.

I thought there was supposed to be a fuel cut-off if oil pressure dropped below 10 or something? If so, it didn't work!

MSR

do you have an aftermarket cam? that sounds like damage from a materials mismatch between driven gear and cam.

or, if it had ever been apart, is it possible the gear/drive assembly was not fully seated?

regardless, i've never heard of the actual drive mechanism failing. given the heat versus plastic, you'd do well to replace the whole thing rather than just the gear, but i don't think you need some super duper billet jobbie...

superlund

I looked for awhile earlier & can't seem to find the super duper billet one anyway; I remember running across it somewhere a month or so after I finished my motor. I had been looking for something to replace the plastic one when rebuilding mine also. It had been nc machined by someone as I also remember looking at the scallop heights & faceting in the machine work. The plastic drives do occasionally break, though it is not common. Usually at that bolt down flange... If I run across it I'll post.
:seeya

NavyVet

Cam is stock and motor has never been apart. The plastic piece is fine - just the gears are worn down!

I will try some searches for a billet piece - might as well try to find it before new motor time. The plastic piece looks like the single bolt ear is the weak spot to me too.

Thanks for the replies. Paul

superlund

I still haven't found where I spotted that machined one at? If you are going to trash that one, send it to me and I'll reverse eng & model it up. I can then get a few quotes on having the housings produced/machined out of 6061-T6 Alum.
I though about doing that when I had mine apart, but never found time. I just don't want to pull my intake until I need to for something else.

:seeya

gtsyellow

ARP makes one STRONG pump driveshaft for $15, buy one, you won't break it. melling also makes a nice oil pump for little money or moroso has blueprinted race pumps and could take insane abuse for 3-4x the price.