Question : Rebuild or not?

[mfuller]

Everyone:

I am looking for some guidance here, and I'd really appreciate any words of wisdom.

My current "fun" car is a 2000 Olds Alero with the 3400 LA1. It's got over 117k miles on the factory bottom-end.
I have a plethora of parts coming from Ben, including a new set of heads and a 1280 cam grind. Yep, gotta pull the motor to replace the cam (which I'm having someone do for me since I don't have the brains/time/patience/space/understanding wife for it). So here's the multi-tiered question:

I was planning on replacing the timing set and all other valvetrain parts and gaskets (natch) for the new stuff anyway. But with the mileage on the bottom end, do I need to worry about failures? I suppose I could just do a compression test to get a bit of information into the condition of the motor, but I don't know how bulletproof it will be.
Or should I just rebuild the whole thing (main and rod bearings, new pistons and rings, etc.)? And who thinks a TCE double-roller is required for the 1280 grind/Comp 28986 springs?
What about getting a lower-mileage donor motor and using it's bottom-end?

I have no engine-building experience but it might be interesting to try.

[IanSzgatti]

I'd say it's strong enough, half way through it's life. These engines run better the harder they're run it seems.

[Wiz85]

Well, your stock bottom end should be fine if you still have good compression. Because if its dropped to a certain percentage or psi, you wouldn't either get the full potential of that aggressive of a cam or that cam might hurt performance than gain. The more aggressive a cam gets, the higher the mininum compression ratio if needed. I would suggest the 1393 cam. But the 1280 might work really well. Just saying.

[Superdave]

I just tuned a LA1 5 speed Sunbird that put down like 225 WHP with a 1617 grind and a ported top end. The bottom end has 90K miles on it.

the TCE double roller would be more ideal for the really agressive cams and high revving engines.. maybe 350+ crank HP, 7k+ RPM or in a boosted application. IMO

[SappySE107]

If you tear apart the bottom end, you should increase the compression. This will improve performance and gas mileage. Otherwise its probably ok to run it as it is. Compression test will help. New oil pump wouldn't hurt at the least (stock, no high output or high pressure).

The double roller is really nice but I don't know if the line is drawn on spring pressure alone, or high compression as well. If it bolted right on, then id say by all means do it, but its not and so I say for a rebuild, do it. With high compression I would highly recommend it for longevity.

Perhaps I should rename the 1280 stage 2.2. Its the high rpm version of the 1393, making it a stage 2 varation. To keep things simple, I made it stage 3 and stage 4 is the high compression cam. The 1280 grind is fine with stock compression. Bumping it up would make it better though

[sprucegagt]

Depends on how much money you want to put into the car. I've heard of some of the things you've bought and put into that car, so this may not be the case. But a short block rebuild will run in the $2,000+ range if you have someone do it for you.

But if your current short block still has good compression and oil pressure, then you don't really need to rebuild it. It just makes it more fun if you do.

[mfuller]

Perhaps I should rename the 1280 stage 2.2. Its the high rpm version of the 1393, making it a stage 2 varation. To keep things simple, I made it stage 3 and stage 4 is the high compression cam. The 1280 grind is fine with stock compression. Bumping it up would make it better though

Well, between milling the heads and the SI valves, I'm expecting somewhere between 10:1 and 10.4:1.