hey there, I was planning on rebuilding my 305 (yea yea, I know, it's not a 350, i'm getting to that.), mostly as a "get my hands dirty" sorta thing, since it's burning a decent amount of oil, and i'm not sure how many kms are actually on it (speedo broken when I bought it, *** knows...)
anyway, I plan on rebuilding it, and then some generic bolt ons (headers, cam, self port the heads a-la Sitting bull, etc.) then build up a 383 with good stuff in it, after a little experience under my belt, then be able to reuse the bolt ons...
anyway, I want to do as much of this as possible myself, for the learning experience, and spend as little as possible too (since it's just the 305)
If I were to rebuild this in my garage, could I get away with:

- honing the cylinders with a drill mounted ball hone (or stone hone, however that works..)
- new rings (keep stock pistons)
- new bearings
- new cam (part of the reusable parts that would go on next motor)

and as little machine work as I can get away with..
How do I know if my cylinders would REQUIRE boring, rather then just honing? a certain way to check the integrity of the walls?
I'd be trying to avoid bringing this to the machine shop (as I don't really have a truck to do that with...)

Thanks -J

 

The oil it burns, is it just at start up? If so, you don't have to rebuild anything, just replace the valve seals.

As for just honing it...it depends. I know on my old Chrysler motor, when I put a new headgasket on it, you could actually see the cross-hatch pattern from the original honing after 155k miles! That car died shortly after that (was flipped upside down in a "wet ditch" AKA creek )

You can use a micrometer to check the bore at various depths in each cylinder. I don't know what the accepted wear is, but I'm sure someone on here knows. I actually remember reading it in an old shop class engine rebuild book my uncle gave me, so you could probably just read a few books.

 

wow, that was a fast reply, thanks
hmm, well I'm not sure exactly when it burns oil, I know it does at start-up, nice puff of blue, but I've added about 1L of oil in 800kms or so, so I think it's a bit more than just start-up...
well come to think of it, since i've never done a compression test, I guess I might be able to skip that eh?
so if the wear is somewhat bad, bore it, if not, hone it, then new rings, but not new pistons with just honing right?
The valve seals I would be doing during the head porting, so I suppose I'll do that and then check the oil consumption after, and a compression test and maybe skip the whole motor rebuild altogether until the 350 comes along... -J

 

Are you sure your not leaking oil someplace? Do a compression and leakdown tests. But if you want to take it apart and reassemble it for the hell of it go for it.

 

305's are notorious for wearing out the valve guides. Quite possibly the rings are fine and it's just the Valve guides and seals that are shot.

 

as for how to know if it needs bored over size or not, only way to tell is to measure out of round and taper. if it's in spec you can hone it with no problems other wise it'd need over bored to the next size up.

 

I would still rethink some of the logic. Any cam you have in a cheap 305 buildup, probably isnt what you are going to want in a 383 build. Also is this a roller motor?

 

yeah but by reusing the cam you'd see a 100 dollar or more savings.

 

What is a 100 dollars when you are building a 383 though? Especially if this isnt a roller motor. Yes, you can reuse flat tappet cams, either keeping the lifters to the right lobes, or using new ones. I wouldnt do it. To me it wouldnt be worth it. Just like its not worth it to put the wrong cam in an engine just to save 100 bucks.

 

well I could reuse the stock cam until I do the 383 I suppose, I just figured since I may have the engine out, I could drop in a cam then, i'd probably go with a flat tappet, so I would only need the cam itself (right?, no new lifters?) but get a cam that would be most suited for the 383, since that would be the more permanent application... And the 383 cam would work ok (better than stock) in the 305 wouldn't it ? I was thinking of a 2000-5000RPM powerband for both motors...

Measure out of round and taper? is that something I can measure in my garage with a rented/somewhat inexpensive tool, or a machine shop?

well ok then, valve seals/guides with porting will be my first check then...

Would it be ok to use my stock 305 head castings(ported) on the 383? not sure the exact casting # on the heads now, but would they work alright on the 383 or would that be a big bottleneck?

 

If you're just doing a quickie re ring job and you want to measure the bores, get a piston ring and measure the ring gap at the top of the bore with a feeler ga, then you compare that to the ring gap at the bottom of the bore.
But then there's the issue of the ridge at the top of the bore.
But if there's much of a ridge at all, you don't want to use the block without a rebore.
Personally, I've re ringed engines that had some taper, and I had to take down the ridge with a ridge reamer. But that's not very proper.
The engine ended up running better than it did before the okie rering job tho.
It's something you can do if you're desperate.

 

If you use a flat tappet, you will most definately need new lifters. If you take the cam and lifters out and are going to reuse them, make sure to keep the lifters marked for with lobe they go with. Otherwise you will have problems.