How much would the stock motor hold? As the saying goes "turbo's are for people who can't build engines". Not that I can't build one, but it would take some serious coin to do so. Plus I've looked around a little but everyone seems to build these engines correctly.

I've realized through research that the bottom end won't do well over 5500 rpm. Something about weak stock rod ends and compression ring deflection makes it a bad idea. In the past, I've run mine up to the fuel cutoff of 6500 enough times to know that the engine pulls fine, but the risk of desintegration is scary.

So if I were to bolt up a turbo, how much could I safely push the engine to? For example, the stock 60V6 should hold 300ftlbs and 6000rpm before any badness happens (immediatly at least). The good rule of thumb is 6psi, but would it hold more with occasional use?

 

I'm just looking for a number so I don't do anything crazy and I know where my limits are. Plus it will let me know where the weakest link is, weither it be the pistons, heads, connecting rods, or crank.

 

Should be able to do 6psi but let it detonate and you will crack a piston.
The weakest link in the stock parts is the bearings followed by the pistons but they are really only an issue if you let it detonate. Rods and crank are pretty stout. The rods most guys replace with a build because you can get decent aftermarket ones for little more than the stockers cost to rebuild. The crank is actually a pretty nice piece I would reuse it before any aftermarket cast ones.

 

Are u talking about putting boost on it the way it sits? Or are u going to do a stock rebuild and then add boost? If your going to do a stock rebuild then it would be a good idea to at least upgrade the hardware. Like rod bolts and anything like that.

 

I'm just curious what needs to be strengthened and where the weak points are, regardless of what power adder gets added.

Seems like I was on the right track with the pistons. Is it true that the connecting rods are weak too? If I were to throw some parts at the bottom end, is that where I should focus? How do you get stronger bearings?

I want to do something mildly fun with the car, but need to feel confident that the bottom end will hold. I don't want to destroy the block! Thanks for you feedback!

I'm using these two pages as reference for now.
http://www.automotiverebuilder.com/ar/ar99928.htm
http://vette.ohioracing.com/majmods.html

 

Boosting the stock bottom end is a bad idea. The piston ring end gap is too small for boosted applications. The gap "tends" to close, and ringlands tend to break because of it.

Yes, some people seem to have boost for years and nothing bad happens. Most of the time it'll last a month if you're lucky. Good luck.

In my opinion if you're going to run boost, you'll want to upgrade pistons to get a lower CR. Upgraded bolts on stock rods would help, but like previously said RODS are relatively inexpensive for what you get. The stock crank is the strongest part of the stock bottom end, but it's held in by 2 bolt mains. Depending on who you talk to, you may be at risk for the caps walking at relatively low HP levels (it's not super common, but it happens)...leading to failure.

just my $.02.

 

I would replace pistons (forged of course), stouter rings (wider), and get some 4340 scat rods for 200$. With just these mods yucould handle probably double what the stock pistons would.
But as in any PA set-up add detonation to the mix and it all goes down hill from there.

 

Good deal. I'll start looking into pistons, rods, and new bearings. My motor has a few miles on it (around 170k) so I'm just trying to be cautious. Sounds like I could do all of this in my garage huh?

 

Yep, you could do that, just remember cleanliness is next to Godliness when putting a motor together.

 

Word. Since the raceway is open, I'll put my V6 car on the track and let you know how it does. That was my first motor build. I'm hoping for high 14's.

 

Holy crap, I just noticed you live in my area (sort of). You're on the westside of the mtns...I'm on the east.

Either way....probably the closest person to me I've ever seen on this board.

 

Craziness! The main reason I started posting over here was because of the high level of technically compentent posters. I usually post on cascadecrew.org or tgo. There is at least one person from ellensburg on cco, many in the area. They have a few meets throughout the year so you get to meet everyone. Go check it out.

Summit has a bunch of Keith Black forged pistons for a decent price (under 400). Thanks for all the help!