Be careful, almost any kit you buy is going to have compression-killing big dish pistons in it.

 

here is a few pics of the rods and motor

 

Flat pistons will be ok ???

 

more

 

i would check side clearances those are good pistons you can gain 9.5 with the right machining and gaskets . I would take the engine apart and measure under the ridge and measure the piston skirt and if it's within factory low and high's i would re use those. You also gotta check ad see what kind of shape the skirts are in . Those look like the 7 cc dish pistons. If none of the pistons where hurt from any failure and they are within spec i would re use them .

 

ok i was under the impression i would need to replace the pistons if i was machining and rebuilding ???? im very confused after this post ...

and what does gain 9.5 mean ???

 

9.5 means compression the last two olds engines I have run I have reused pistons. They have to be in good shape but it can be done also you have to see where your bore is as far as after honing etc. You can't run a cast piston very loose .

 

by what i saw they are loose... i was going to go .30 0ver and use alloy flat top pistons...
those should put it at 10.5 compression if my research is correct ..
and those flat tops were used in the w-31 i believe ??????

do these pistons have any value the ones in there currently ???

 

No but they can used on another engine with less wear it all comes down to what you want to do.

 

It is going to be tought to find a 35 year old block that is not worn. The front 2 cylinders are almost always worn too much. IMO, .0035 piston/wall is max for cast. Bore it, new pistons, do it right, do it once.

 

i have a 1972 350 block i just tore down right before login in the skirts have minimal scuffs the rod journals are all within factory limits after polishing will be perfect for a race app. It still has the orginal timing chain and bearings. You can find them it depends who you know and where to look . I like to build my own engines the only thing i farm out is machining and i like to re use as much as i can. If you have the money buy the new pistons if you have a tight budget measure stuff out and see what can be re used.

 

I agree, with the V-notch and the small dish, those should be pistons for a 10.25:1 engine.
Take a close look at the crowns, under the carbon - What are the letters on them (A, B, or C)?

I've got a 350 that I want to build up one day as a cheap driver, kind of like what Copper did, and I could use a set of pistons like that if they're all in one piece.

I'll PM you about it.

And, yes, your understanding is correct, any time you do more than just hone the cylinders, you change their diameter too much, and need larger pistons to fit in the larger holes.

- Eric

 

eric you got the same idea as me i was gonna ask if he wanted to sell those pistons., but i already have a set of slighly used .030 425 pistons waiting for that 350 i just took apart. Im always building budget stuff.

 

With all the fancy-rebuilt engines I've heard of that grenaded after a few hundred miles, I'd rather take that chance with a few hundred dollars into it, rather than a few thousand.
After a certain number of dollars, they stop being toys, and then they're no fun anymore.

- Eric

 

Yep i couldnt agree more with you. People seem to forget this is how hot rodding started mixing parts re using gmc blowers off old trucks etc. Goin fast cheap is fun but if it's not done properly it can also be expensive. That's where careful picking and planing come into play.

 

At the risk of offending some viewers, the first motor I built was a Porsche 911 motor (with used parts, many from a car that had been rotting for over ten years) - compared to that, these are just big lawnmower engines.

That car flew, by the way, and I never had a problem in the ten years I owned it after the rebuild.

- Eric

 

Sorry but I disagree with all that. After owning my car for 30 years I still have fun with it, even tho I can't drive it........I still get to watch it go down the track. Remember......" how fast do you want to go?.......how deep is your pocketbook?" Trust me the cheap junkyard refugee motors won't last very long. You have to remember, you don't beat your motors like I beat mine.

 

i beat thew crap out of mine . I drive them hard and beat on them at the track . IM not saying build a junkyard motor . I build my crap with carefully picked cores and parts. To each their own . The current motor i have would probably run someone 5k. i got 2800 carb to oil pan and it runs like a champ does not smoke like a chimney and no noises.

 

My point exactly.

I have no need to go exceptionally fast. I'm happy within one standard deviation of the mean.
Therefore, I can go as fast as I ever want or need to without spending a lot of money, and still have fun, and if I have a catastrophic failure, it's not a disaster.

There are people who will realize a lot of benefit from spending a lot of money, or for whom it's worth the bread to get the bragging rights to X number of horsepower.
I'm not one of them.

- Eric

 

Yep I don't know how many hp my engine puts out but I know its a lot of fun for not a lot of money and I'm beating all my friends with chevy's and fords. I agree I can't build a 900 hp motor cheap but again I aint looking to go that fast .

 

Yeah, just to elaborate, my idea of old cars is to do some wrenching and have some fun, not to create some pinnacle of mechanical perfection or to try to make a silk purse from a sow's ear by remachining and adding Ferrari-grade parts to a 50 year old cast iron boat anchor.

While I appreciate the challenge of getting maximum power from an engine and far exceeding it's design parameters, I personally prefer the challenge of doing more with less - anyone can solve a problem by throwing enough money at it, but I prefer to try to solve it by scrounging around.

None of the foregoing should be construed as being in any way hostile to those who prefer to do things a different way. We're all different, and that's good.
If I had the dough, I'd probably try one if those highfalutin builds one day, just for fun, but I'm not counting on that happening soon.

- Eric

 

All due respect, a dingleberry hone and re-ring is NOT "Building an engine". I have done it both ways and IMO there is a difference in performance between a quality build and a slap-together re-ring. Yes, there is a difference in price, too, but IMO you get what you pay for. I posted this here, my idea of a fair cost of a 350 HP SBO,
https://classicoldsmobile.com/forums...arts-list.html

 

I agree wholeheartedly, you (usually) get what you pay for.

Those extra horses just aren't worth the extra money to me, and when I DO put a lot of money into something, I get afraid to use it. I'm happier going slower and worrying less.

- Eric

 

Going back to post #1--you want to get at least the power the engine made when new, stock. OK, those old worn pistons have worn ring grooves and don't fit the worn bores too well. Poor ring seal leads to lower power. How about the worn crankshaft journals. . .on and on. Each part brings about a decision to go cheaply, or correctly. For decent power and longevity, you will spend money and effort. Bulk rebuilders minimize both, and the results are low quality. On this thread, the advice has been directed toward your stated goal of building the engine for at least as good a result as the stock engine was new. There will be a large number of decision points, and things that should be checked; too many to give all the details here.

 

I actually don't use a ball hone I use and adjustable stone hone and I also cut the ridge with a ridge cutter. I also measure at every step of the honing process to make sure the diamater stays where I want it . I will admit its not the same as a machine shop doing it but it's good enough for me . I also polish my own cranks depending on how they look. I just like doing as much as I can I take my time and do it very carefully. A lot of people will disagree with what I do but my junk is out there running and doing very well for what it is.

 

I agree there is a certain satisfaction going fast for less for sure.

 

My point is that I have alot of fun too, even when I have spent many $$$$$. I love the look on people's faces when they find out it's a small block Olds not a BBC.

 

I put the money in it so I CAN use it.............

 

I put money in I just put alot less and it's still running.

 

I agree with the "rinse and re-use" idea. Im sure lots of companies would have you believe that re-using parts is inferior and illogical and even dangerous, of course, thats how they convince you to buy their product. But i feel like too many people put too much money into their projects these days, why does everything have to be new when you can easily refurbish what you have and it will be just as nice? I mean, no disrespect to anyone who has the money to buy all new parts for their project but for us working folk who can barely afford our necessities let alone our toys, its good to have a little ingenuity Remember, knowledge is power, not money

 

The main issue we are dealing with is cylinder bore wear. I worked at a machine shop for several years, ASE tech for the first part of my adult life. It is rare indeed to find a V-8 engine with close to 100,000 miles on it that has cylinders that will clean up, be round, and still be within spec as far as piston to wall clearance is concerned. Yes, you can re-ring, and even hone correctly and it will run OK. But the pistons will be sloppy, you will have ring seal issues and will be leaving HP and longevity on the table. IMHO.
The same is true of rod and main clearances. How many of you realize that the factory considers .0008 main bearing clearance to be acceptable? I don't. The only way to get the clearances correct is to build it right and have the crank cut to fit. Ring grooves wear on pistons. Skirts wear, decks get warped, and on and on. Do what you want, I will rebuild mine correctly.
This "do it cheap as possible" attitude is more prevalent in the Olds community than most, and IMO opinion is one reason so few aftermarket parts are made. Next time you complain about the lack of piston choice, or connecting rods, come back and look at threads like this.

 

That's factory spec. On my current engine i have .003 for bearing clearances. psiton to wall is a little over .003 the only cylider i screwed up was number one i over honed and that oe does not seal as well. Now this engine does not smoke, oil psi is alittle bouncy but the idle is very choppy and it stay's above 20 psi, The only smoke i see on occasion is on a light heavy load acceleration usually slow from a stop sign ill see a puff just a puff of smoke from the breathers. I checked my deck i have a machinist straight edge. I once read an article on the old 409 impalas they ran the so loose to gain hp they smoked quite abit. My car see's street driving and racing. Like i said my junk is still running and i had no issues last summer. Im not saying this should be done but it is an option but it comes with it's calculated risk's I took mine and so far so good . It's all in what you wanna do. I just like going fast using ingenuity and little money.

 

We re-use aftermarket parts too, its not just boneyard salvaging. Being thorough in a build is very much encouraged but you dont have to go crazy with it, unless youre building monster strip machines these motors are very forgiving. Also proper upkeep goes a long way with any motor. In the end neither way is "better" but if youve got the knowledge, the parts, and all your minus one deep deep wallet, why not?

 

just a few photos

needing a dipstick and dust cover for that 200r4

 

Sounds like a nice build good luck with it.