rebuilt engine troubles, need advice.

[ciffer]

Here is the background on the story. A friend of mine purchased a small block from a guy on ebay, long story short, it didn't run right for my friend so he sold it to me cheap.

Here is what I have been told about the engine:
350ci .060 over
"RV" roller cam, unsure if hydraulic or solid
fresh rebuild, assembly lube could been seen in many areas of the engine.

Here is what I know about the engine:
It won't idle under 1500rpms
no power at low RPMs
pulls pretty good at higher RPMs
it needs a TBI compatible cam to work in my 88.

Here is where I need the advice. My older suburban which I am currently campaigning on the local mud bog circuit runs good but the motor is showing it's age. The current motor leaks/burns a full quart of SAE 40wt every tank of gas. I want more power and have a spare engine.

I can think a few options for the engine, run a leakdown test to see if the engine is sealing then install a TBI cam and hope for the best. The other option would be to tear down the engine, measure and inspect the bores, hone and ring the engine and hope for the best.

You guy's have have never disappointed me before, lets see what you got.

 

[496truck]

First thing that gets my attention is the cam. Sounds like the cam is not timed right. If you're planning on getting a new cam anyways this is a non issue. Just make sure you get a new timing set and time it properly.

Obviously there are many things that will make an engine run the way you described, I am assuming all outside parts were tuned properly.

What's on there for heads? They could be too big for the application.

 

[K5dreamer]

x2 on valve timing being a likely culprit. just cuz it was rebuilt, dosnt mean the guy who did it has a clue what he was doing.

 

[ciffer]

There were a number of people that worked on the engine, all of them convinced the problem was not the cam because the dots on the timing set lined up. I am not convinced, it sounds retarded to me; no one bothered to actually check the cam timing to TDC on cyl 1.

The heads are either iron or painted aluminum, I'll look for a casting number when I get home.

 

[ciffer]

i see casting numbers under the valve covers, right bank the number is between cyls 1 and 3, it reads "462624" and below that "g78". left bank between 6 and 8 it reads "462624" and below that "f228". both have GM marks.the block number as the rear reads "8970010"can anyone decode these?

 

[ciffer]

i tore into the engine a bit tonight, and found the motor has 1.5:1 roller rockers and solid roller lifters.the block casting is either a 302, 327 or 350 and the heads are a common head used on many 350s. the heads appear to be small vavles and poor for high performance applications but should be fine lugging around 5400lbs that rarely sees half throttle.i'll yank the cam one of these days and see if it has any clues.