DIY small block rebuild?

[JoeliusZ28]

Looking for feedback from anyone that may have done this. Ive seen/heard of people doing basic engine rebuilds at home in their garage and I found that you can get complete rebuild kits including new pistons for under $300 on summit. I'm thinking about trying it on the 305 in my 1984 K10 due it it being such a dismal performer. my thinking is it could be a good learning experience on an engine that isnt particularly valuable so i don't need to be in a panic about screwing it up. if i succeed the truck should be substantially better than it is now.

Any glaring reason i shouldnt it a whirl or specific things I MUST farm out to a machine shop?

[MP81]

The only thing I can think of that you'd need a machine shop for is honing the cylinders. Otherwise, it's pretty easy to do, honestly. The most complicated part is getting the ring gap right.

[JoeliusZ28]

I honestly doubt the cylinders need anything more than what i can do at home with a power drill. It definitely needs rings, pistons, valve seals and SOME kind of improvement to the ultra restrictive heads. I was thinking either replace the heads/intake entirely with aluminum ones or do some DIY porting to the stock heads and have a larger intake valve installed... all depends on what each would cost.

[MP81]

I think the castings themselves, as you've mentioned to me before, are so thick, porting them likely won't help. The Trick Flows I've been looking at (via the Super Chevy article) are made for smaller combustion chambers, and really aren't too expensive, all things considered, for assembled (minus rockers) aluminum heads at around $550 a head.

If the cross hatching is still visible in the bores, then yeah, a drill-hone would probably be fine.

[JoeliusZ28]

I agree. I think the aluminum head due to better cooling and flow would simply make the engine work the way it should have from the beginning. And if i paint them black they'll look OEM.

[MP81]

And they'll provide some pretty hefty power gains, to boot: http://www.superchevy.com/how-to/eng...-add-168-rwhp/

[farmington]

see if you can borrow a dial bore gauge. will tell you if your bores are still good before you buy pistons and rings.

[DynoDave]

Agree with Don. If you have enough wear to need rings and pistons, you probably have some cylinder wear as well. Taper. Wear at the top more than the bottom. Makes it impossible to get your ring gap "right".

[JoeliusZ28]

Thats good to know. Theres nothing indicating that it needs rings/pistons but after all the spark knock problems ive had i would just prefer it had new hardware. The more i consider the individual costs the more i start to lean back towards a crate 350. Hmm.

[MP81]

When you factor in heads and a mild cam, you might get closer to that, yes.

[DynoDave]

OK, I thought YOU were saying it NEEDED new rings and pistons. You might get away without boring it then. You'd just have to open it up and see.

I don't disagree with your thinking though. If my engine had extreme spark knock, I'd feel better with new slugs too.

[JoeliusZ28]

It very well could need a ring job. I dont know. It doesnt blow clouds of smoke everywhere but if you really rev it good and pay attention to the tailpipes it'll make some light haze. Otherwise the only time it visibly burns oil is on a hot start which i know is valve seals.

The bigger reason i was considering it is the dismal performance. I am going to try tuning it better with a wideband soon.

[MP81]

I'll be interested to see how the wideband works out. I had the bung put in my right-hand header as well as the left-hand one for exactly that reason.

They make a module for the cluster that'll interface with different brands of Wideband (I'd likely go with another Innovate, like I have in the Cobalt). I'll be able to get a wideband readout on the screens. Seems like a great way to tweak the carb.

[TSTONE]

While it could be a fun learning experience - I say if you're going to start messing with it just buy a crate and be done.

You could always fog and bag the 305 if some purist REALLY wants a #'s truck. Otherwise from a resale stand point most potential buyers are going to be like "Wow - he sure did a lot of work to that engine - Oh well pull it so we can something else in"

JMO

[farmington]

Have you tried to do a compression test or leak down on it? I would do that before I turned a single wrench. I have a leak down tester and a compression tester if you need one