1991 Engine Question

[along4]

I have a 1991 K5 with a 350 and just pulled the top end off to find what was making all the noise. Much to my surprise it has roller lifters, and not like any after market ones that I have seen. They have long connecting sleaves between each pair, and all of the sleeves are all held in place by one spring plate attached in the bottom of the gallery by 3 bolts. My question is: Is this a factory roller engine that just happened to make into my truck, or did somebody mess with it?
The noise is most likely the bottom end, and I am not going to mess with that, so it is time for a new engine (170-200k mi. on this one). AutoZone has a rebuilder that offers both a flat and roller cam. I would really like to replace this one with one that is just as good, because I have been spoiled by this one's power and smoothness. Hope I can scrape up the $$ before it throws a connecting rod 100 miles from a tow truck. Thanks.

 

[dyeager535]

I was under the impression that trucks that "early" shouldn't have have been roller.

That's beside the point though since you have to replace it. Make sure you get a factory roller block, or one of the truck blocks that could have had a roller cam, but didn't. They will have the "bosses" to bolt that holddown "spider" in place, you just have to tap them.

Should have no problem reusing your cam and lifters, just check the rollers for play and check the cam for wear. As long as it hasn't been abused, they should be fine.

 

[along4]

Thanks for your post, that answers the question as to wheather or not Chevy made a different block for the roller option. Idiots at the parts shop didn't think so.
This engine/truck was seriously abused by the prior owner, and there is quite a bit of scoring on all of the parts that I inspected.

 

[RootBreaker]

ive got a hydraulic roller cam/lifter motor...
1991 caprice police motor option 9C1

does it look like this??? sorry pic is big....
and when it is gone.. my ip address changed again... DAMN COMCAST!!!!

i hear these motors are ok... 260+hp... vortec block but not vortec heads...if you get the other one.... see if it is a vortec block and vortec heads.... if so you can be around 300hp... and do a few mods and get 350hp from that baby..... im plannin on going 383 with mine eventually.... /forums/images/graemlins/truck.gif /forums/images/graemlins/thumb.gif

 

[dyeager535]

Where do you come up with a Vortec block? A 9C1 Caprice wouldn't have a Vortec block either.

1996 is when Vortec V8's came out, period. I seriously doubt there is much different in the Vortec block casting than a 1991 motor anyways. Vortec motors are good because of the injection/heads, nothing else. It's not like its got a different bore/stroke if its a 5.7L motor.

 

[along4]

That engine looks the same as mine, except mine has a larger flat spot on the back side of the gallery that has what I think is a very large oil pressure sender sticking up from it. I am fairly sure it does not have the vortec heads, because the heads look like every other Chevy that I have seen. Maybe I will have this one rebuilt rather than getting a random replacement from a rebuilder. Thanks

 

[RootBreaker]

[ QUOTE ]
Where do you come up with a Vortec block? A 9C1 Caprice wouldn't have a Vortec block either.


[/ QUOTE ]

before i put the motor in the truck i took the casting numbers off... searched the internet... and it came up as a vortec block but not vortec heads..... that is what i read somewhere... I have to pull the motor again.. Dippy (me) didnt know you could put a clutch in backwards... so i will take the numbers down again and give you a link to the site......

 

[Derf00]

Simple solution, if it's a Vortec it isn't a '91.